Papers - Takemura, Kenjiro

A Cross-Modal Tactile Reproduction Utilizing Tactile and Visual Information Generated by Conditional Generative Adversarial Networks

Koki Hatori, Takashi Morikura, Akira Funahashi, Kenjiro Takemura

IEEE Access (IEEE)  13   9223 - 9229 2025.01

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Methods for quantitative evaluation of individual differences in tactile perception - Euclidean distance, cosine similarity, and their hybrid indices -

Kaito Kikuhara, Kenjiro Takemura

International Journal of Affective Engineering 24 ( 1 ) 81 - 90 2024.12

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Detaching Cells in Culture Medium using Forced Vibration for Removing a Centrifugation from Culture Process

Hayato Shimoguchi, Chikahiro Imashiro, Kenjiro Takemura

Frontiers in Acoustics 2   1502136 2024.11

Research paper (scientific journal), Joint Work, Corresponding author, Accepted

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Enhanced Model-Free Dynamic State Estimation for a Soft Robot Finger Using an Embedded Optical Waveguide Sensor

Henrik Krauss, Kenjiro Takemura

IEEE Robotics and Automation Letters (IEEE)  9 ( 7 ) 6123 - 6129 2024.05

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Conditional Generative Adversarial Network-Based Tactile Stimulus Generation for Ultrasonic Tactile Display

Koki Hatori, Kenjiro Takemura

IEEE Access 11   53531 - 53537 2023.05

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Quantifying cell adhesion through forces generated by acoustic streaming

Chikahiro Imashiro, Jiyang Mei, James Friend, Kenjiro Takemura

Ultrasonics - Sonochemistry (Elsevier)  90   106204 2022.10

Research paper (scientific journal), Joint Work, Last author, Accepted

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Nonlinear Tactile Estimation Model based on Perceptibility of Mechanoreceptors improves Quantitative Tactile Sensing

Momoko Sagara, Lisako Nobuyama, Kenjiro Takemura

Sensors 22   6697 2022.09

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Stretchable Optical Waveguide Sensor Capable of Two-Degree-of-Freedom Strain Sensing Mediated by a Semidivided Optical Core

Henrik Krauss, Kenjiro Takemura

IEEE/ASME Transactions on Mechatronics 27 ( 4 ) 2151 - 2157 2022.06

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Switching Control of Latex Balloon Expansion by using Switching Valve mediated with the Coanda Effect

Keita Kaneko, Kenjiro Takemura

ROBOMECH Journal (Springer Nature)  9   14 2022.05

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

Well-free agglomeration and on-demand three-dimensional cell cluster formation using guided surface acoustic waves through a couplant layer

J Mei, A Vasan, U Magaram, K Takemura, SH Chalasani, J Friend

Biomedical Microdevices 24 ( 2 ) 18 2022.05

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1387-2176

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A Model for Estimating Tactile Sensation by Machine Learning Based on Vibration Information Obtained while Touching an Object

Fumiya Ito, Kenjiro Takemura

Sensors 21 ( 23 ) 7772 2021.11

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Propagating acoustic waves on a culture substrate regulate the directional collective cell migration

Imashiro Chikahiro, Kang Byungjun, Lee Yunam, Hwang Youn-Hoo, Im Seonghun, Kim Dae-Eun, Takemura Kenjiro, Lee Hyungsuk

Microsystems & Nanoengineering 7   90 2021.11

Research paper (scientific journal), Joint Work, Accepted

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Development of accurate temperature regulation culture system with metallic culture vessel demonstrates different thermal cytotoxicity in cancer and normal cells

Imashiro Chikahiro, Takeshita Haruka, Morikura Takashi, Miyata Shogo, Takemura Kenjiro, Komotori Jun

Scientific reports 11   21466 2021.11

Research paper (scientific journal), Joint Work, Accepted

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Nonlinear tactile estimation model using vibration information from tactile sensor mediated by mechanoreceptors' perceptibility

Momoko Sagara, Lisako Nobuyama, Kenjiro Takemura

Proceedings of IEEE Sensors (IEEE)  2021-October 2021.10

Research paper (international conference proceedings), Joint Work, Last author, Accepted,  ISSN  19300395

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A Quantitative Study on Cell Adhesion using Surface Acoustic Wave

KURIYAMA Takuma, MEI Jiyang, FRIEND James, TAKEMURA Kenjiro

The Proceedings of the Dynamics & Design Conference (The Japan Society of Mechanical Engineers)  2021   429 2021.09

Research paper (other academic), Joint Work, Last author, Corresponding author

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Acoustic streaming induced by MHz-frequency ultrasound extends the volume limit of cell suspension culture

Taigo Oyama, Chikahiro Imashiro, Takuma Kuriyama, Hidehisa Usui, Keita Ando, Tetsushi Azuma, Akira Morikawa, Kazuhide Kodeki, Osamu Takahara, Kenjiro Takemura

The Journal of the Acoustical Society of America (the Acoustical Society of America )  149 ( 6 ) 4180 - 4189 2021.06

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Travelling ultrasound promotes vasculogenesis of three‐dimensional‐monocultured human umbilical vein endothelial cells

Chikahiro Imashiro, Tetsuya Azuma, Shun Itai, Taiki Kuribara, Kiichiro Totani, Hiroaki Onoe, Kenjiro Takemura

Biotechnology and Bioengineering (Wiley)  118 ( 10 ) 3760 - 3769 2021.06

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Switching Control of Latex Balloons with a Fluidic Switching Valve using Coanda Effect

KANEKO Keita, TAKEMURA Kenjiro

The Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) (The Japan Society of Mechanical Engineers)  2021   2P1-K04 2021.06

Research paper (other academic), Joint Work, Last author, Corresponding author

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Non-linear model of tactile estimation based on the vibration information mediated by mechanoreceptors' perceptibility

SAGARA Momoko, TAKEMURA Kenjiro

The Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) (The Japan Society of Mechanical Engineers)  2021   1P1-M03 2021.06

Research paper (other academic), Joint Work, Last author, Corresponding author

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Focused surface acoustic wave locally removes cells from culture surface

Takumi Inui, Jiyang Mei, Chikahiro Imashiro, Yuta Kurashina, James Friend, Kenjiro Takemura

Lab on a Chip (Royal Society of Chemistry)  21 ( 7 ) 1299 - 1306 2021.03

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Detachment of RAW264.7 macrophages from a culture dish using ultrasound excited by a Langevin transducer

Takuma Kuriyama, Yuki Fukuma, Chikahiro Imashiro, Kazuya Kabayama, Yuta Kurashina, Kenjiro Takemura

Journal of Bioscience and Bioengineering (Elsevier)  131 ( 3 ) 320 - 325 2021.02

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

Suspension culture in a T-flask with acoustic flow induced by ultrasonic irradiation

Genichiro Fujii, Yuta Kurashina, Yusuke Terao, Tetsushi Azuma, Akira Morikawa, Kazuhide Kodeki, Osamu Takahara, Kenjiro Takemura

Ultrasonics Sonochemistry (Elsevier)  73   105488 2021.02

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Containerless Bioorganic Reactions in a Floating Droplet by Levitation Technique Using an Ultrasonic Wave

Teruhiko Matsubara, Kenjiro Takemura

Advanced Science (Wiley)  8 ( 3 ) 2002780 2020.12

Research paper (scientific journal), Joint Work, Last author, Accepted

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Direct Cell Counting Using Macro-Scale Smartphone Images of Cell Aggregates

C Imashiro, Y Tokuoka, K Kikuhara, TG Yamada, K Takemura, ...

IEEE Access (Institute of Electrical and Electronics Engineers (IEEE))  8   170033 - 170043 2020.09

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2169-3536

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超音波細胞学：音響工学と細胞生物学の融合

竹村 研治郎

The Proceedings of Mechanical Engineering Congress, Japan (The Japan Society of Mechanical Engineers)  2020 ( 0 ) K11200 2020.09

Research paper (other academic), Single Work, Lead author, Corresponding author

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Microfluidic channel for measurement of cell adhesion strength using ultrasonic

KURAHINA Yuta, IMASHIRO Chikahiro, TAKEMURA Kenjiro

The Proceedings of the Dynamics & Design Conference (The Japan Society of Mechanical Engineers)  2020 ( 0 ) 411 2020.09

Research paper (other academic), Joint Work, Last author, Corresponding author

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Cell Suspension Culture Method Using Agitation by Ultrasound Irradiation

OYAMA Taigo, IMASHIRO Chikahiro, TAKAHARA Osamu, MORIKAWA Akira, KODEKI Kazuhide, AZUMA Tetsushi, TAKEMURA Kenjiro

The Proceedings of the Dynamics & Design Conference (The Japan Society of Mechanical Engineers)  2020 ( 0 ) 410 2020.09

Research paper (other academic), Joint Work, Last author

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Collective cell migration of fibroblasts is affected by horizontal vibration of the cell culture dish

U Enomoto, C Imashiro, K Takemura

Engineering in Life Sciences (Wiley)  20 ( 9-10 ) 402 - 411 2020.07

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  1618-0240

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Homogenization of initial cell distribution by secondary flow of medium improves cell culture efficiency

Y Fukuma, T Inui, C Imashiro, Y Kurashina, K Takemura

PLoS One (Public Library of Science (PLoS))  15 ( 7 ) e0235827 2020.07

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  1932-6203

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Detachment of cell sheets from clinically ubiquitous cell culture vessels by ultrasonic vibration

C Imashiro, M Hirano, T Morikura, Y Fukuma, K Ohnuma, Y Kurashina, ...

Scientific Reports (Springer Science and Business Media)  10 ( 1 ) 9468 2020.06

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  2045-2322

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超音波技術を基盤とした細胞培養システム

竹村 研治郎

Journal of the Society of Mechanical Engineers (The Japan Society of Mechanical Engineers)  123 ( 1218 ) 22 - 25 2020.05

Research paper (other academic), Single Work, Lead author, Last author, Corresponding author,  ISSN  0021-4728

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Feature extraction from vibration information obtained from a sensor tracing on objects by machine learning

ITO Fumiya, TAKEMURA Kenjiro

The Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) (The Japan Society of Mechanical Engineers)  2020   2A1-P13 2020.05

Research paper (other academic), Joint Work, Last author, Corresponding author

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Grasping Experiments with Dexterous Soft Robot Hand Capable of Flexion and Adduction Motion of Finger

OZAKI Akihiro, TAKEMURA Kenjiro

The Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) (The Japan Society of Mechanical Engineers)  2020   1A1-J05 2020.05

Research paper (other academic), Joint Work, Last author, Corresponding author

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Influence of vibration stimulus on tactile sensation using ultrasonic tactile display

KOBAYSHI Chiyano, TAKEMURA Kenjiro

The Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) (The Japan Society of Mechanical Engineers)  2020   2A2-N04 2020.05

Research paper (other academic), Joint Work, Last author, Corresponding author

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Steerable inchworm soft robot using electro-conjugate fluid

Aoki Yuji, Ozaki Akihiro, Takemura Kenjiro, Edamura Kazuya

The Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) (The Japan Society of Mechanical Engineers)  2020   1A1-J03 2020.05

Research paper (other academic), Joint Work

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Low-frequency mechanical vibration induces apoptosis of A431 epidermoid carcinoma cells

Anggayasti W.L., Imashiro C., Kuribara T., Totani K., Takemura K.

Engineering in Life Sciences (Wiley)  20 ( 7 ) 232 - 238 2020.02

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  16180240

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Effects of acoustic waves on the collective cell migration

B Kang, C Imashiro, K Takemura, H Lee

대한기계학회 춘추학술대회, 25-25  2020

Research paper (other academic), Joint Work

Cell agglomeration using guided surface acoustic waves through a couplant layer

J Mei, K Takemura, J Friend

178th Meeting of the Acoustical Society of America (the Acoustical Society of America)     1aPA4 2019.12

Research paper (international conference proceedings), Joint Work, Accepted

Informotion for Cell Culture Engineering

K TAKEMURA, Y KURASHINA

Journal of the Japan Society of Applied Electromagnetics and Mechanics 27 ( 4 ) 402 - 406 2019.12

Research paper (scientific journal), Joint Work, Lead author, Corresponding author

An effective detachment system for human induced pluripotent stem cells cultured on multilayered cultivation substrates using resonance vibrations

Yusuke Terao, Yuta Kurashina, Shugo Tohyama, Yuki Fukuma, Keiichi Fukuda, Jun Fujita, Kenjiro Takemura

Scientific Reports (Nature Publishing)  9 ( 1 ) 15655 2019.10

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  2045-2322

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Enzyme-free release of adhered cells from standard culture dishes using intermittent ultrasonic traveling waves

Yuta Kurashina, Chikahiro Imashiro, Makoto Hirano, Taiki Kuribara, Kiichiro Totani, Kiyoshi Ohnuma, James Friend, Kenjiro Takemura

Communications Biology (Nature Publishing)  2 ( 1 ) 393 2019.10

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  2399-3642

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Cell detachment is essential in culturing adherent cells. Trypsinization is the most popular detachment technique, even though it reduces viability due to the damage to the membrane and extracellular matrix. Avoiding such damage would improve cell culture efficiency. Here we propose an enzyme-free cell detachment method that employs the acoustic pressure, sloshing in serum-free medium from intermittent traveling wave. This method detaches 96.2% of the cells, and increases its transfer yield to 130% of conventional methods for 48 h, compared to the number of cells detached by trypsinization. We show the elimination of trypsinization reduces cell damage, improving the survival of the detached cells. Acoustic pressure applied to the cells and media sloshing from the intermittent traveling wave were identified as the most important factors leading to cell detachment. This proposed method will improve biopharmaceutical production by expediting the amplification of tissue-cultured cells through a more efficient transfer process.

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Method of localized removal of cells using a bolt‐clamped Langevin transducer with an ultrasonic horn

T Inui, Y Kurashina, C Imashiro, K Takemura

Engineering in Life Sciences (Wiley)  19 ( 8 ) 575 - 583 2019.08

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Mechanism of cellular detachment caused by frequency sweep vibration

KURASHINA Yuta, IMASHIRO Chikahiro, TAKEMURA Kenjiro

The Proceedings of the Dynamics & Design Conference (The Japan Society of Mechanical Engineers)  2019   426 2019.08

Research paper (other academic), Joint Work, Last author

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Nowadays, innovative therapies for tissue engineering and regenerative medicine have been created and a large number of cells with high viability are cultured for these therapies. In the cell detachment method with common protein-degrading enzymes, the cell membranes are damaged at the detachment. On the other hand, the cell detachment method with ultrasonic vibration can detach without damage of cell membranes. For instance, the adherent cells on the culture dish are detached from the bottom of the dish by using sweep vibration without enzymes. The deformation of the culture dish, the acoustic streaming-driven shear flow, the acoustic pressure on a boundary of different materials having different acoustic impedance, and the sloshing of the liquid are candidates for detachment factor. However, details of the dominant conditions for cell detachment are not obvious. Therefore, in this study, we evaluated the effects of each factor on cell detachment from experiments and theory. As results, the deformation of the culture dish or the acoustic streaming-driven shear flow does not have sufficient force to detach the cells, while the pressure between the different acoustic impedance and the sloshing of the liquid are sufficient to detach the cells from reference. That is, these results indicate that the different acoustic impedance and the sloshing of the liquid are dominant factors for cell detachment with ultrasonic vibration.

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Effective and Intact Cell Detachment from a Clinically Ubiquitous Culture Flask by Combining Ultrasonic Wave Exposure and Diluted Trypsin

H Tauchi, C Imashiro, T Kuribara, G Fujii, Y Kurashina, K Totani, ...

Biotechnology and Bioprocess Engineering (Springer)  24 ( 3 ) 536 - 543 2019.06

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  12268372

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シートベルトウェビングの触感の定量化

小山 和人, 小ヶ口 晃, 嶋崎 定幸, 中山 正大, 寺井 宏樹, 竹村 研治郎

第58回日本生体医工学会大会予稿集 (Japanese Society for Medical and Biological Engineering)  57   jsmbe58001-00190 2019.06

Research paper (other academic), Joint Work, Last author, Corresponding author,  ISSN  1347-443X

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シートベルトウェビング（ベルト部分）は乗車に際して必ず触れるものであり，製品開発において触感の向上が重要な課題のひとつである．シートベルトウェビングの触感向上に関する先行研究の多くは触感を説明する要因として物性値を測定しているが，ヒトが触覚受容器の応答によって触感を知覚することに鑑みると，物性値のみでは必ずしもシートベルトウェビングの触感を言い表せるとは言えない．このため，本研究では物性値だけでなくシートベルトウェビングを触察した際の振動情報も用いて触感を定量化した．被験者に7種類のサンプルをSD法により評価させ，その結果から主成分分析を用いてシートベルトウェビングの触感に関する主成分を求めた．この結果，低次触感では「粗滑感」「硬軟感」「湿感」，高次触感では「高級感」の主成分が抽出された．つぎに，サンプルの物性値および触察時の振動情報を測定し，重回帰分析を用いて，物性値および振動情報と触感に関する主成分の関係を定式化した．この結果，物性値および振動情報から触感を予測する線形モデルを構築した．

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内部閉流路の選択的加圧による多自由度ソフトロボットフィンガ

尾﨑 晃洋, 新間 良平, 竹村 研治郎

第58回日本生体医工学会大会 (Japanese Society for Medical and Biological Engineering)  57 ( 0 ) jsmbe58001-00143 2019.06

Research paper (other academic), Joint Work, Last author, Corresponding author,  ISSN  1347-443X

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近年，柔軟軽量なソフトロボットに関する研究が広く行われており，ロボットハンドもその対象として注目されている．ロボットハンドが様々な形状の物体を把持するには多様な把持姿勢の実現が求められる．すなわち，ロボットハンドを構成するロボットフィンガには，屈曲伸展運動に加えて内転外転運動が必要になる．このため，本研究では，屈曲伸展運動および内転外転運動が可能なソフトロボットフィンガを具現化する．開発したソフトロボットフィンガはアラミド繊維で繊維強化されたシリコーンゴム製のチューブで構成される．チューブ内部には半円筒状の閉流路が2本設けられており，それぞれ独立して内部を加圧できる．閉流路を加圧するとチューブは膨張するが，周方向および手掌側に配置された繊維によって，その膨張は一部拘束される．結果，双方の閉流路を加圧するとフィンガは屈曲し，一方の閉流路を加圧するとフィンガは内転する．本フィンガは，直径7.0 mm，全長60 mm，質量0.70 gであり，上記閉流路を最大14 kPaで加圧した際の最大屈曲角度および内転角度はそれぞれ79°および34°であった．

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低濃度のトリプシンと超音波照射による汎用フラスコからの細胞剥離

今城 哉裕, 田内 葉奈子, 栗原 大輝, 倉科 佑太, 戸谷 希一郎, 竹村 研治郎

第58回日本生体医工学会大会 (Japanese Society for Medical and Biological Engineering)  57 ( 0 ) 2-PM-PO-B5 PO-B-110 2019.06

Research paper (other academic), Joint Work, Last author, Corresponding author,  ISSN  1347-443X

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近年，細胞の医療応用に注目が集まっている．これに伴って効率的な細胞培養法が研究されており，とくに細胞剥離に関する研究が盛んである．一般的にはトリプシンに浸漬した細胞に対してピペッティング等の機械刺激を付与することで細胞を剥離する．トリプシンの毒性を鑑みると，低濃度のトリプシンを用いることが望ましいが，細胞の剥離率が低下してしまう．そこで，本研究では，超音波の併用よって低濃度のトリプシンによる細胞剥離を実現した．汎用フラスコに接着した接着細胞の下方から超音波を付与する装置（図）を開発した．さらに，バースト波を用いた超音波照射によって温度上昇を抑制しつつ，高強度の超音波を細胞に付与した．この結果，ピペッティングでは一部の細胞のみが剥離する低濃度トリプシンを用いた際にも，超音波の照射によって全細胞が剥離した．低濃度トリプシンで細胞剥離を実現したことで細胞の増殖性が向上したこと，超音波照射によるタンパク質発現の変化や代謝に異常がないことを確認した．

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Formation of Large Scaffold-Free 3-D Aggregates in a Cell Culture Dish by Ultrasound Standing Wave Trapping

Nakao Misa, Imashiro Chikahiro, Kuribara Taiki, Kurashina Yuta, Totani Kiichiro, Takemura Kenjiro

Ultrasound in medicine and biology (Elsevier)  45 ( 5 ) 1306 - 1315 2019.05

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  0301-5629

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Cellular aggregates that mimic cell–cell interactions in vitro are essential for biological research. This study introduces a method to form large scaffold-free 3-D aggregates in a clinically ubiquitous cell culture dish using kilohertz-order ultrasound standing wave trapping (USWT). We fabricated an aggregate formation system in which a 60-mm dish was set above a Langevin transducer via water. The transducer was excited at 110.8 kHz, and then C2C12 myoblasts were injected into the dish and trapped at the node position of the standing wave. The diameter and thickness of the formed aggregate were 8 and 2.7 mm, respectively, which are larger than those of aggregates formed previously by USWT. Moreover, we confirmed that >94% of cells constituting the aggregates survived 9 h, and the protein expression of cells was not altered significantly. This method can be applied to form aggregates with high functionality, which contributes to the development of biological research methodology.

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Ultrasonic motor with embedded preload mechanism

T Kazumi, Y Kurashina, K Takemura

Sensors and Actuators A: Physical (Elsevier)  289   44 - 49 2019.04

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  09244247

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Growth control of leaf lettuce with exposure to underwater ultrasound and dissolved oxygen supersaturation

Yuta Kurashina, Tatsuya Yamashita, Shuichi Kurabayashi, Kenjiro Takemura, Keita Ando

Ultrasonics - Sonochemistry (ELSEVIER)  51   292 - 297 2019.03

Research paper (scientific journal), Joint Work, Accepted,  ISSN  13504177

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The growth rate of vegetables in plant factories can be regulated by environmental factors including light, temperature, and chemicals, which might give rise to mutation in leaf health. Here, we aim to devise a new way that allows for controlling the growth rate of plants in hydroponics as well as maintaining the product quality; we apply underwater ultrasound and dissolved oxygen supersaturation as external stimuli to plants. As an example, we examine the growth of leaf lettuce in hydroponics with exposure to 28-kHz ultrasound and dissolved oxygen supersaturation up to 36 mg/L at 20 °C. Our results show that exposure to the ultrasound of peak-to-peak pressure at 20 kPa or larger works as the growth inhibitor of the leaves and the roots, while the oxygen supersaturation as the growth promoter, without any degradation of chlorophyll in the leaves. This suggests that these external stimuli can be used in the growth control system of plant factories.

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ECF (electro-conjugate fluid) finger with bidirectional motion and its application to a flexible hand

T Nagaoka, Z Mao, K Takemura, S Yokota, JW Kim

Smart Materials and Structures ( IOP)  28 ( 2 ) 025032 2019.01

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0964-1726

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Cell patterning method on a clinically ubiquitous culture dish using acoustic pressure generated from resonance vibration of a disk-shaped ultrasonic transducer

C Imashiro, Y Kurashina, T Kuribara, M Hirano, K Totani, K Takemura

IEEE Transactions on Biomedical Engineering (IEEE)  66 ( 1 ) 111 - 118 2019.01

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  00189294

　View Summary

Cell patterning methods have been previously reported for cell culture. However, these methods use inclusions or devices that are not used in general cell culture and that might affect cell functionality. Here, we report a cell patterning method that can be conducted on a general cell culture dish without any inclusions by employing a resonance vibration of a disk-shaped ultrasonic transducer located under the dish. A resonance vibration with a single nodal circle patterned C2C12 myoblasts into a circular shape on the dish with 10-min exposure of the vibration with maximum peak-peak amplitude of 10 μm${}-{\text{p-p}}$. Furthermore, the relationship between the amplitude distribution of the transducer and the cell density in the patterned sample could be expressed as a linear function, and there was a clear threshold of amplitude for cell adhesion. To evaluate the cell function of the patterned cells, we conducted proliferation and protein assays at 120-h culture after patterning. Our results showed that the cell proliferation rate did not decrease and the expression of cellular proteins was unchanged. Thus, we conclude, this method can successfully pattern cells

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Difference of Tactile Perception Models by Individuals and Dominant Factor of Fabric Hand for Knitted Fabric for Underwear

Iza Husna MOHAMAD HASHIM, Sumi NANAKAMURA, Kenjiro TAKEMURA

Journal of Textile Engineering (The Textile Machinery Society of Japan)  65 ( 1 ) 1 - 10 2019.01

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  13468235

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In the textile industry, fabric hand is one of the crucial aspects that influence the value of fabric. However, the judgement of fabric hand may vary across subjects. Thus, this study proposes to group the subjects based on their evaluation of fabric hand, and the tactile sensations that are dominantly related to fabric hand are investigated. First, a sensory evaluation of eight knitted fabric samples was carried out using 14 verbal expressions of tactile sensation. These 14 verbal expressions were hierarchically classified into three stages which were called as low-order of tactile sensation, high-order of tactile sensation and lastly, fabric hand. After grouping the subjects by using cluster analysis, a principal component analysis was conducted in each stage of tactile sensation to gather the strong correlations of the verbal expressions. Then, the correlations between principal components of each stage were determined by multiple regression analysis. As a result, the study showed that the subjects could be mainly grouped into two. The former group expressed fabric hand as good when the fabric is soft and moist. On the other hand, the latter group defined good fabric hand when the fabric is silky and smooth.

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Biotechnology and informotion-ultrasonic actuation technology for cell culture process

Y Kurashina, K Takemura

Journal of Japanese Society of Tribologists (Japanese Society of Tribologists)  63 ( 9 ) 599 - 604 2018.09

Research paper (other academic), Joint Work, Last author, Corresponding author,  ISSN  09151168

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Making cell culture process automated and efficient is one of the biggest challenges for cell therapy including regenerative medicine, drug screening and body-on-chip drug development. Cell culture process with cell seeding, culturing, detaching and collecting processes is in general conducted manually by a technician. To establish an efficient and stable mass culture process of cells, "informotion technology" may play an important role. By automating cell culture process with actuator/sensor technology and networking them online, know-hows to deal with living cells can be shared. By doing so, we may efficiently provide large number of cells, ready for accelerating regenerative medicine spread. Ultrasonic actuation technology has proved its potentials to be used for cell culture automation.

A Cell Aggregation Method using Acoustic Radiation Pressure and Ekman Transport:(Manipulation of cells using ultrasound and flow)

FUKUMA Yuki, TERAO Yusuke, KURASHINA Yuta, TAKEMURA Kenjiro

The Proceedings of the Dynamics & Design Conference (The Japan Society of Mechanical Engineers)  2018   538 2018.08

Research paper (other academic), Joint Work, Last author, Corresponding author

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When co-culturing cells outside the body, it is necessary to culture in an environment closer to the living body. In this study, we tried to manufacture a culture vessel and generate three-dimensional tissue of cells by acoustic radiation pressure and Ekman transport. As a result of experiments with particles simulating cells, the particles remained outside the culture surface in the case of only using acoustic radiation pressure. However, by combining Ekman transport and acoustic radiation pressure, particles could be aggregated efficiently. Therefore, three-dimensional tissue of cells can be generated using these techniques.

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Global Regionality of Tactile Perception for Door Armrests

Wada Toshiyuki, Mori Yukio, Mohamad Hashim Iza Husna, Maeno Takashi, Takemua Kenjiro

Transactions of Society of Automotive Engineers of Japan (Society of Automotive Engineers of Japan)  49 ( 4 ) 764 - 771 2018.07

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  0287-8321

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Automobile interior is one of the most crucial factors for evaluating products' value. During the evaluation, tactile cue must play an important role in deducing product's quality, however, the regionality of customer's tactile perception is in most cases neglected in previous studies. This study conducted sensory evaluation tests of door armrests in three countries, Japan, USA and Denmark, which are representatives of East Asia, North America and Europe, respectively. Eight samples of door armrests and 29 words expressing tactile sensations were used in the test. 167 participants in total participated in the evaluation test, 53 from Japan, 64 from USA and 50 from Denmark. As results of factor analysis, cluster analysis and multiple regression analysis, the following conclusion can be derived, i.e., although there is no significant difference in preference perception of door armrests, the tactile perception structures are different among three countries.

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Selective Cell Elimination Mediated by Ultrasonic Irradiation

Takumi Inui, Yuta Kurashina, Chikahiro Imashiro, Kenjiro Takemura

The 40th International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE)   2018.07

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Efficient electrode configuration for electro-conjugate fluid flow generation with dibutyl decanedioate: Experimental and theoretical investigation

Y.Kuroboshi, K.Takemura, K.Edamura

Sensors and Actuators, A: Physical (ELSEVIER)  279   223 - 228 2018.06

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  09244247

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Electro-conjugate fluid (ECF) is a functional fluid that can generate a high-power flow induced by a high direct-current voltage. While ECF has been used in various fields, including mechanical, chemical, and biomedical systems, its underlying principles have not been sufficiently understood to be applicable to ECF system design, and the lack of theoretical models hampers further applications of ECF. This study aims to investigate underlying principles of ECF flow generation with a rectangular-slit electrode pair. By analyzing the effect of electrode configuration on the flow generation, this paper proposes a theoretical model for electrode design for efficient flow generation. The proposed model has been validated by comparing the simulation results with the visualized characteristics from flow experiments. The results show that the flow rate can be controlled by changing the electrode configuration with the maximum flow rate with the rectangular-slit electrode gap of 1.0 mm and the slit electrode gap of 5.0 mm.

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The Influence of Touch Speed on Roughness Perception

Takahiko Nakamura, Masahiro Saito, Kenjiro Takemura

EUROHAPTICS2018  2018.06

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Development of Deep Neural Network Models to Mimic Human-Like Classification of Genuine/synthetic Leathers

Masahiro Saito, Shinsuk Park, Kenjiro Takemura

EUROHAPTICS2018  2018.06

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Tactile Quantification Method for Tissue based on Tactile Perception Characteristics of Human

Masaki Endo, Lisako Nobuyama, Koji Okomori, So Takahashi, Kenjiro Takemura

EUROHAPTICS2018  2018.06

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Tactile estimation of molded plastic plates based on the estimated impulse responses of mechanoreceptive units

Lisako Nobuyama, Yuta Kurashina, Kei Kawauchi, Koji Matsui, Kenjiro Takemura

Sensors (MDPI)  18 ( 5 ) 1588 2018.05

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  14248220

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Application of Ultrasonic Vibration for Cell Culture

Kurashina Yuta, Takemura Kenjiro

Journal of the Robotics Society of Japan (The Robotics Society of Japan)  36 ( 3 ) 203 - 206 2018.04

Research paper (other academic), Joint Work, Last author, Corresponding author,  ISSN  0289-1824

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Understanding of electro-conjugate fluid flow with dibutyl decanedioate using numerical simulation—Calculating ion mobility using molecular dynamics simulation

Y. Kuroboshi, K. Takemura, K. Edamura

Sensors and Actuators, B: Chemical (Elsevier)  255 ( 1 ) 448 - 453 2018.02

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  09254005

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An electro-conjugate fluid (ECF) is a type of dielectric functional fluid, which generates a powerful flow when a high direct-current voltage is applied. To date, ECF flow has been used in mechanical, chemical and biomedical applications because of its outstanding properties as a micro-pressure source for compact fluid-driven systems. However, the mechanism of ECF flow generation is not clarified and a basic understanding of ECF flow is required to progress ECF applications. We have developed the basic understanding of ECF flow generation through mathematical modeling, and have investigated electrical parameters theoretically. We have clarified microscopically the mechanism for ECF flow generation. We have proven the adequacy of the developed basic understanding by comparing visualized and computed flow characteristics. Furthermore, we have clarified the mechanism for ECF flow generation by comparing ionic transfer and ECF flow.

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A method for collecting single cell suspensions using an ultrasonic pump

Misa Nakao, Yuta Kurashina, Chikahiro Imashiro, and Kenjiro Takemura

IEEE Transactions on Biomedical Engineering (IEEE)  65 ( 1 ) 224 - 231 2018.01

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  0018-9294

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Soft Robotics Using Electro-Conjugate Fluid

TAKEMURA Kenjiro

Journal of The Society of Instrument and Control Engineers (The Society of Instrument and Control Engineers)  57 ( 11 ) 775 - 779 2018

Research paper (scientific journal), Single Work, Lead author, Last author, Corresponding author,  ISSN  0453-4662

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Acoustic Cell Trapping to Rapidly Generate Three-dimensional Large Tissues

Misa Nakao, Chikahiro Imashiro, Yuta Kurashina, Kenjiro Takemura

TERMIS-AM2017  2017.12

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Tactile Evaluation Feedback System for Multi-layered Structure Inspired by Human Tactile Perception Mechanism

Iza Husna Mohamad Hashim, Shogo Kumamoto, Kenjiro Takemura, Takashi Maeno, Shin Okuda, Yukio Mori

Sensors (Multidisciplinary Digital Publishing Institute)  17 ( 11 ) 2601 - 2614 2017.11

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  1424-8220

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Tactile sensation is one type of valuable feedback in evaluating a product. Conventionally, sensory evaluation is used to get direct subjective responses from the consumers, in order to improve the product's quality. However, this method is a time-consuming and costly process. Therefore, this paper proposes a novel tactile evaluation system that can give tactile feedback from a sensor's output. The main concept of this system is hierarchically layering the tactile sensation, which is inspired by the flow of human perception. The tactile sensation is classified from low-order of tactile sensation (LTS) to high-order of tactile sensation (HTS), and also to preference. Here, LTS will be correlated with physical measures. Furthermore, the physical measures that are used to correlate with LTS are selected based on four main aspects of haptic information (roughness, compliance, coldness, and slipperiness), which are perceived through human tactile sensors. By using statistical analysis, the correlation between each hierarchy was obtained, and the preference was derived in terms of physical measures. A verification test was conducted by using unknown samples to determine the reliability of the system. The results showed that the system developed was capable of estimating preference with an accuracy of approximately 80%.

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Effect of underwater ultrasound exposure on growth of plant roots and leaves

Yuta Kurashina, Tatsuya Yamashita, Shuichi Kurabayashi, Keita Ando, Kenjiro Takemura

IEEE International Ultrasonics Symposium, IUS (IEEE Computer Society)   2017.10

Research paper (international conference proceedings), Last author, Accepted,  ISSN  1948-5727

　View Summary

Growth control is an important technique in plant markets, for appropriate shipping time of plants (e.g., flowers and fruits) allows for reducing production costs for post harvesting storage and pesticide. It is favorable to control plant growth without any chemicals
physical stresses are attractive candidates for this purpose. Here, we propose an ultrasound-based technique to control plant growth.

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Enzyme-free cell detachment mediated by resonance vibration with temperature modulation

Yuta Kurashina, Makoto Hirano, Chikahiro Imashiro, Kiichiro Totani, Jun Komotori, Kenjiro Takemura

Biotechnology & Bioengineering (John Wiley & Sons, Inc)  114 ( 10 ) 2279 - 2288 2017.10

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0006-3592

　View Summary

Cell detachment is an essential process in adherent cell culture. However, trypsinization, which is the most popular detachment technique used in culture, damages cellular membranes. Reducing cellular membrane damage during detachment should improve the quality of cell culture. In this article, we propose an enzyme-free cell detachment method based on resonance vibration with temperature modulation. We developed a culture device that can excite a resonance vibration and control temperature. We then evaluated the cell detachment ratio and the growth response, observed the morphology, and analyzed the cellular protein of the collected cellsmouse myoblast cell line (C2C12). With the temperature of 10 degrees C and the maximum vibration amplitude of 2m, 77.9% of cells in number were successfully detached compared with traditional trypsinization. The 72-h proliferation ratio of the reseeded cells was similar to that with trypsinization, whereas the proliferation ratio of proposed method was 12.6% greater than that of trypsinization after freezing and thawing. Moreover, the cells can be collected relatively intact and both intracellular and cell surface proteins in the proposed method were less damaged than in trypsinization. These results show that this method has definite advantages over trypsinization, which indicates that it could be applied to subcultures of cells that are more susceptible to trypsin damage for mass culture of sustainable clinical use. Biotechnol. Bioeng. 2017;114: 2279-2288. (c) 2017 Wiley Periodicals, Inc.

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Cover Image, Volume 114, Number 10, October 2017

Yuta Kurashina, Makoto Hirano, Chikahiro Imashiro, Kiichiro Totani, Jun Komotori, Kenjiro Takemura

Biotechnology and Bioengineering (John Wiley & Sons, Inc)  114 ( 10 ) i - i 2017.10

Research paper (scientific journal), Joint Work, Accepted

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Effective Arrangement of Electrodes for Electro-conjugate Fluid Flow Generation

Yuichiro Kuroboshi, Kenjiro Takemura, Kazuya Edamura

JFPS International Symposium on Fluid Power System  2017.10

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Detaching cells from cultivation flask using acoustic radiation pressure induced by Langevin transducer

Hanako Tauchi, Genichiro Fujii, Chikahiro Imashiro, Kenjiro Takemura

Acoustofluidics 2017  2017.08

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Single Cell Sorter Driven by Resonance Vibration of Cell Culture Substrate

Misa Nakao, Yuta Kurashina, Chikahiro Imashiro, Kenjiro Takemura

19th International Conference on Ultrasonics    3143 2017.06

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Acoustic Radiation Pressure Detaches Myoblast from Culture Substrate by Assistance of Serum-free Medium

Yuta Kurashina, Chikahiro Imashiro, Kiyoshi Ohnuma, Kenjiro Takemura

19th International Conference on Ultrasonics    3140 2017.06

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Droplet generating device for Droplet-based μTAS using electro-conjugate fluid

Yoshiki Iijima, Kenjiro Takemura, Kazuya Edamura

Smart Materials and Structures (IOP Publishing)  26 ( 5 ) 054002 2017.04

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0964-1726

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Droplet-based mu TAS, which carries out biochemical inspection and synthesis by handling samples as droplets on a single chip, has been attracting attentions in recent years. Although miniaturization of a chip is progressed, there are some problems in miniaturization of a whole system because of the necessity to connect syringe pumps to the chip. Thus, this study aims to realize a novel droplets generating device for droplet-based mu TAS using electro-conjugate fluid (ECF). The ECF is a dielectric liquid generating a powerful flow when subjected to high DC voltage. The ECF flow generation allows us to realize a tiny hydraulic power source. Using the ECF flow, we can develop a droplet generating device for droplet-based mu TAS by placing minute electrode pairs in flow channels. The device contains two channels filled with the ECF, which are dispersed and continuous phases meeting at a T-junction. When a sample in the dispersed phase is injected by the ECF flow to the continuous phase at T-junction, droplets are generated by shearing force between the two phases. We conducted droplet generating experiment and confirmed that droplets are successfully generated when the flow rate of the continuous phase is between 90 and 360 mm(3) s(-1), and the flow rate of the dispersed phase is between 10 and 40 mm(3) s(-1). We also confirmed that the droplet diameter and the droplet production rate are controllable by tuning the applied voltage to the electrode pairs.

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Ultrasonic Motor with Embedded Preload Mechanism for Miniaturization

Tomoya Kazumi, Yuta Kurashina, Kenjiro Takemura

The 7th International Conference on Manufacturing, Machine Design and Tribology  2017.04

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Tactile Sensor Inspired by Human Mechanoreceptors

Lisako Nobuyama, Iza Husna Mohamad Hashim, Yuta Kurashina, Kei Kawauchi, Koji Matsui, Kenjiro Takemura

The 7th International Conference on Manufacturing, Machine Design and Tribology  2017.04

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Efficient subculture process for adherent cells by selective collection using cultivation substrate vibration

Yuta Kurashina, Kenjiro Takemura, James Friend, Shogo Miyata, Jun Komotori

IEEE Transactions on Biomedical Engineering (IEEE)  64 ( 3 ) 580 - 587 2017.03

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0018-9294

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Cell detachment and reseeding are typical operations in cell culturing, often using trypsin exposure and pipetting, even though this process is known to damage the cells. Reducing the number of detachment and reseeding steps might consequently improve the overall quality of the culture, but to date this has not been an option. This study proposes the use of resonant vibration in the cell cultivation substrate to selectively release adherent calf chondrocyte cells: Some were released from the substrate and collected while others were left upon the substrate to grow to confluence as a subculture-without requiring reseeding. An out-of-plane vibration mode with a single nodal circle was used in the custom culture substrate. At a maximum vibration amplitude of 0.6 mu m, 84.9% of the cells adhering to the substrate were released after 3 min exposure, leaving a sufficient number of cells for passage and long-term cell culture, with the greatest cell concentration along the nodal circle where the vibration was relatively quiescent. The 72 h proliferation of the unreleased cells was 20% greater in number than cells handled using the traditional method of trypsin-EDTA (0.050%) release, pipette collection, and reseeding. Due to the vibration, it was possible to reduce the trypsin-EDTA used for selective release to only 0.025%, and in doing so the cell number after 72 h of proliferation was 42% greater in number than the traditional technique.

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Cell agglomeration in the wells of a 24-well plate using acoustic streaming

Yuta Kurashina, Kenjiro Takemura, James Friend

Lab on a Chip (Royal Society of Chemistry)  17 ( 5 ) 876 - 886 2017.02

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1473-0197

　View Summary

Cell agglomeration is essential both to the success of drug testing and to the development of tissue engineering. Here, a MHz-order acoustic wave is used to generate acoustic streaming in the wells of a 24-well plate to drive particle and cell agglomeration. Acoustic streaming is known to manipulate particles in microfluidic devices, and even provide concentration in sessile droplets, but concentration of particles or cells in individual wells has never been shown, principally due to the drag present along the periphery of the fluid in such a well. The agglomeration time for a range of particle sizes suggests that shear-induced migration plays an important role in the agglomeration process. Particles with a diameter of 45 mu m agglomerated into a suspended pellet under exposure to 2.134 MHz acoustic waves at 1.5 W in 30 s. Additionally, BT-474 cells also agglomerated as adherent masses at the center bottom of the wells of tissue-culture treated 24-well plates. By switching to low cell binding 24-well plates, the BT-474 cells formed suspended agglomerations that appeared to be spheroids, fully fifteen times larger than any cell agglomerates without the acoustic streaming. In either case, the viability and proliferation of the cells were maintained despite acoustic irradiation and streaming. Intermittent excitation was effective in avoiding temperature excursions, consuming only 75 mW per well on average, presenting a convenient means to form fully three-dimensional cellular masses potentially useful for tissue, cancer, and drug research.

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Cell patterning method using resonance vibration of metallic cell cultivation substrate

Chikahiro Imashiro, Yuta Kurashina, Kenjiro Takemura

Advanced Biomedical Engineering 5   142 - 148 2016.12

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Coarse Grained Model for Calculating the Ion Mobility of Hydrocarbon

Yuichiro Kuroboshi,Kenjiro Takemura

AIP Advances (AIP Publishing)  6 ( 12 ) 125307 2016.12

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  2158-3226

　View Summary

Hydrocarbons are widely used as insulating compounds. However, their fundamental characteristics in conduction phenomena are not completely understood. A great deal of effort is required to determine reasonable ionic behavior from experiments because of their complicated procedures and tight controls of the temperature and the purity of the liquids. In order to understand the conduction phenomena, we have theoretically calculated the ion mobilities of hydrocarbons and investigated their characteristics using the coarse grained model in molecular dynamics simulations. We assumed a molecule of hydrocarbons to be a bead and simulated its dependence on the viscosity, electric field, and temperature. Furthermore, we verified the suitability of the conformation, scale size, and long-range interactions for the ion mobility. The results of the simulations show that the ion mobility values agree reasonably well with the values from Walden's rule and depend on the viscosity but not on the electric field. The ion mobility and self-diffusion coefficient exponentially increase with increasing temperature, while the activation energy decreases with increasing molecular size. These values and characteristics of the ion mobility are in reasonable agreement with experimental results. In the future, we can understand not only the ion mobilies of hydrocarbons in conduction, but also we can predict general phenomena in electrochemistry with molecular dynamics simulations. (C) 2016 Author(s).

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Viability of Myoblasts Manipulated by Resonance Vibration of a Disk-shaped Transducer with a Single Nodal Circle

Chikahiro Imashiro, Yuta Kurashina, Misa Nakao, Kenjiro Takemura

EMBS Micro and Nanotechnology in Medicine Conference  2016.12

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

A Method to Generate 3D Cell Tissue using Acoustic Streaming

Yusuke Terao, Chikahiro Imashiro, Yuta Kurashina, Kenjiro Takemura

EMBS Micro and Nanotechnology in Medicine Conference (IEEE)   2016.12

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Selectively Detaching Highly Proliferative Cells using Temperature Modulation and Resonance Vibration of Cultivation Substrate

Yuta Kurashina, Chikahiro Imashiro, Kenjiro Takemura, Jun Komotori

2016 IEEE International Ultrasonic Symposium Proceedings (IEEE)   2016.09

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Manipulation of Myoblasts in Cell Cultivation Dish Using Resonance Vibration of Disk with a Single Nodal Circle

Chikahiro Imashiro, Yuta Kurashina, Kenjiro Takemura

2016 IEEE International Ultrasonic Symposium Proceedings (IEEE)   2016.09

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Droplet Generating Device for Droplet-based μTAS using Electro-conjugate Fluid

Yoshiki Iijima, Kenjiro Taekmura, Kazuya Edamura

Proceedings of The 15th International Conference on Electrorheological Fluids and Magnetorheological Suspensions    A-42 2016.07

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

The Experimental and Theoretical Understandings of Electro-conjugate Fluid Flow Generation

Yuichiro Kuroboshi, Kenjiro Takemura

Proceedings of The 15th International Conference on Electrorheological Fluids and Magnetorheological Suspensions    A-41 2016.07

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Biocompatibility of a droplet-mixing device using an electro-conjugate fluid

Kenjiro Takemura, Kiho Kobayashi, Kazuya Edamura

JSME Mechanical Engineering Journal (Japan Society of Mechanical Engineers)  3 ( 2 ) No.15-00421 2016.02

Research paper (scientific journal), Joint Work, Lead author, Corresponding author, Accepted

Vision Based Detection of Human Behavior Primitives in Assembly Tasks

Asuka Kobari, Philipp Ennen, Daniel Ewert, Kenjiro Takemura

Proceedings of 2016 7th International Conference on Mechanical, Industrial, and Manufacturing Technologies    55 2016.02

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Numerical simulation of electro-conjugate fluid flow considering electric double layer

Yoshiki Iijima, Kyohei Hosoda, Kenjiro Takemura, Koji Fukagata, Kazuya Edamura

JSME Mechanical Engineering Journal (Japan Society of Mechanical Engineers)  2 ( 6 ) No. 15-00341 2015.11

Research paper (scientific journal), Joint Work, Corresponding author, Accepted

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A Novel Cell Collection Method using Natural Vibration and Temperature Modulation of Cultivation Base

Yuta Kurashina, Iza Husna Mohamad Hashim, Kenjiro Takemura, Shogo Miyata, Jun Komotori, Tadayoshi Koyama

Proceedings of ASME 2015 International Mechanical Engineering Congress & Exposition (ASME)   2015.11

Research paper (international conference proceedings), Joint Work, Last author, Accepted

Resonance Vibration and Temperature Modulation Enhances Cell Detachment from Cultivation Substrate

Yuta Kurashina, Iza Husna Mohamad Hashim, Kenjiro Takemura, Shogo Miyata, Jun Komotori, Tadayoshi Koyama

Proceedings of ASME 2015 International Mechanical Engineering Congress & Exposition (ASME)   2015.11

Research paper (international conference proceedings), Joint Work, Corresponding author

Method for Generating Cell Aggregates using Ultrasonic Standing Wave Trapping in a Disposable Capsule

Yuta Kurashina, Kenjiro Takemura, Shogo Miyata, James Friend

2015 IEEE International Ultrasonic Symposium Proceedings (IEEE)     P1B8-4 2015.10

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Cell Manipulation by Nodal Circle Resonance Vibration of a Cell Cultivation Substrate

Chikahiro Imashiro, Yuta Kurashina, Kenjiro Takemura, Shogo Miyata, Jun Komotori

2015 IEEE International Ultrasonic Symposium Proceedings (IEEE)     P1B8-5 2015.10

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted,  ISSN  1948-5719

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Numerical Simulation of Electro-conjugation Fluid Flow Considering Electric Double Layer

Yoshiki Iijima, Kyohei Hosoda, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 6th International Conference on Manufacturing, Machine Design, and Tribology    466 - 467 2015.04

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Development of Tactile Evaluation System based on Hierarchical Tactile Perceptive Process

Shogo Kumamoto, Iza Husna Mohamad Hashim, Kenjiro Takemura, Takashi Maeno, Shin Okuda, Yukio Mori

Proc. The 6th International Conference on Manufacturing, Machine Design, and Tribology    376 - 377 2015.04

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Cytodetachment Technique using Ultrasonic Vibration

K. Kurashina, K. Takemura, S. Miyara, J. Komotori, T. Koyama

Proc. EMBS Micro and Nanotechnology in Medicine Conference    36 2014.12

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Bioluminescence Verification for Droplets Mixing Device using Electro-conjugate Fluid

Kiho Kobayashi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. EMBS Micro and Nanotechnology in Medicine Conference    96 2014.12

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

電界共役流体を用いたDroplet µTASのための液滴混合デバイスの開発

小林紀穂，倉科佑太，竹村研治郎，横田眞一，枝村一弥

日本機械学会論文集 80 ( 819 ) MN0332 2014.11

Research paper (scientific journal), Joint Work, Accepted

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Effective Cell Collection Method using Collagenase and Ultrasonic Vibration

Y. Kurashina, K. Takemura, S. Miyata, J. Komotori, T. Koyama

Biomicrofluidics (AIP Publishing)  8 ( 5 ) 54118 2014.10

Research paper (scientific journal), Joint Work, Corresponding author, Accepted

Effect of Electrode Materials on Electro-conjugate Fluid Flow Generation

Mika Naraki, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 9th International Symposium on Fluid Power    447 - 451 2014.10

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Improvement of Driving Efficiency of Ultrasonic Motor by Improvement of Vibration Configuration

Shogo Kumamoto, Kyohei Hosoda, Kenjiro Takemura

Proc. The 2014 IEEE International Ultrasonics Symposium (IEEE)     2129 - 2132 2014.09

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted,  ISSN  1948-5719

　View Summary

An ultrasonic motor is generally composed of a vibrator and a rotor, and is driven by the frictional force between the vibrator/rotor. Since the contact points on the vibrator draw elliptic trajectory, relative speed of the point against the rotor varies even when the rotor rotates with a constant speed. This may cause abrasion between the vibrator/rotor and decrease in driving efficiency. This research proposes a novel method to reduce the relative speed to improve the driving efficiency of ultrasonic motors by superimposing harmonic vibrations with driving vibration. Results of numerical calculation show that driving efficiency may be improved by 27% by the proposed method.

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Development of Robot Finger using Ultrasonic Motors Driven by Superimposed Signal Input

Shosho Oh, Kenjiro Takemura

Proc. The 2014 IEEE International Ultrasonics Symposium (IEEE)     2490 - 2493 2014.09

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted,  ISSN  1948-5719

　View Summary

When developing a multi-fingered robot hand driven by ultrasonic motors (USM), complicated wiring may become one of the essential problems. This study introduces a novel driving method for multiple USMs using superimposed signal input to overcome this problem. First, we designed a robot finger driven by built-in USMs. The robot finger has four joints with three-degree-of-freedom, i.e., DIP joint is dependent to PIP joint. Second, we developed USMs which are suitable for the robot finger actuation. Finally, we developed and characterized the robot finger with the superimposed signal input.

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Tactile Sensor for Robotic System using Cosmetic Powder Brush

Iza Husna Binti Mohamad Hashim, Takashi Maeno, Kenjiro Takemura, Sumi Nakamura, Narumi Saegusa

Proc. World Automation Congress 2014    1569892519 2014.08

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted,  ISSN  2154-4824

　View Summary

Introducing tactile sensation to robotic system is one of the biggest challenges for robotic researchers. Since several sensations such as audio, visual, force and kinetic sensation have already been installed in robotic systems, tactile sensation may bring a next breakthrough for intelligent systems. Hence, this study proposes a new idea of tactile sensor for robotic systems using a cosmetic powder brush. That is, the brush is used in our system as a tracing element against an object. The vibration during the brush traces an object is measured using a piezoelectric vibration sensor which is attached to the base of brush's bristles. Tracing experiments are conducted with 9 samples of underclothes' fabrics and a paper. Vibration data obtained shows distinct differences between the samples. This may suggest that the cosmetic powder brush could be used as a tracing element of tactile sensor because it can distinguishes a slight difference of texture of objects.

Micro Inchworm Robot using Electro-conjugate Fluid

Shohei Ueno, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Sensors & Actuators A (Elsevier)  216   36 - 42 2014.05

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0924-4247

　View Summary

An electro-conjugate fluid (ECF) is a kind of functional fluid, which produces a flow (ECF flow) when high DC voltage is subjected. Since it only requires a tiny electrode pair in micrometer-scale size in order to generate ECF flow, ECF is a promising micro fluid pressure source. Hence, by using ECF as the power source, we realize a micro inchworm robot. In this study, first, we have proposed the concept of a novel micro inchworm robot driven by the ECF. Second, we have designed, fabricated and characterized each component of the micro robot. Third, we have developed the micro inchworm robot by using each component. The length, width and mass of the micro robot are approximately 23 mm, 8.5 mm and 1.9 g, respectively. Finally, we observed the characteristics of micro robot with conducting an experiment. Experimental results proved that the micro robot could move on a horizontal acrylic surface with maximum speed of 5.2 mm/s. The micro robot has superior ability in migration speed, compared with previously developed micro inchworm robots. (C) 2014 Elsevier BM. All rights reserved.

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Tactile Evaluation based on Human Tactile Perception Mechanism

Emi Asaga, Kenjiro Takemura, Takashi Maeno, Akane Ban, Masayoshi Toriumi

Sensors & Actuators A (Elsevier)  203   69 - 75 2013.12

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0924-4247

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This paper presents a novel tactile evaluation method. Although tactile sense is important information for end users to evaluate products, it has not been characterized quantitatively. In order to achieve quantitative characterization of tactile sense, this paper develops a novel tactile evaluation system based on human tactile perception mechanism. In the system, an object, which will be evaluated, is fixed on a sample table rotated with constant speed, and a piezoelectric element is placed in contact with the object surface with constant normal force. Then the piezoelectric element measures the vibration information during experiment. Comparing the vibration information with tactile receptors properties, we could estimate information we are getting during actively touching the object. Comparing the sensory evaluation results with the estimated information, the paper defines three tactile evaluation indexes relating to softness, roughness and preference of the target object. (C) 2013 Elsevier By. All rights reserved.

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Micro Flexible Robot Hand using Electro-conjugate Fluid

Shohei Ueno, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. SPIE, Micro/Nano Materials, Devices, and Systems (SPIE)  8923   8923U-1 2013.12

Research paper (international conference proceedings), Joint Work, Accepted

Governing Equations for Electro-conjugate Fluid Flow

Kyohei Hosoda, Kenjiro Takemura, Koji Fukagata, Shinichi Yokota, Kazuya Edamura

Proc. SPIE, Micro/Nano Materials, Devices, and Systems (SPIE)  8923   8923Z 2013.12

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted,  ISSN  0277-786X

　View Summary

An electro-conjugation fluid (ECF) is a kind of dielectric liquid, which generates a powerful flow when high DC voltage is applied with tiny electrodes. This study deals with the derivation of the governing equations for electro-conjugate fluid flow based on the Korteweg-Helmholtz (KH) equation which represents the force in dielectric liquid subjected to high DC voltage. The governing equations consist of the Gauss's law, charge conservation with charge recombination, the KH equation, the continuity equation and the incompressible Navier-Stokes equations. The KH equation consists of coulomb force, dielectric constant gradient force and electrostriction force. The governing equation gives the distribution of electric field, charge density and flow velocity. In this study, direct numerical simulation (DNS) is used in order to get these distribution at arbitrary time. Successive over-relaxation (SOR) method is used in analyzing Gauss's law and constrained interpolation pseudo-particle (CIP) method is used in analyzing charge conservation with charge recombination. The third order Runge-Kutta method and conservative second-order-accurate finite difference method is used in analyzing the Navier-Stokes equations with the KH equation. This study also deals with the measurement of ECF flow generated with a symmetrical pole electrodes pair which are made of 0.3 mm diameter piano wire. Working fluid is FF-1EHA2 which is an ECF family. The flow is observed from the both electrodes, i.e., the flow collides in between the electrodes. The governing equation successfully calculates mean flow velocity in between the collector pole electrode and the colliding region by the numerical simulation.

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Tactile Bump Dusplay using Electro-rheological Fluid

Masataka Goto, Kenjiro Takemura

Proc. 2013 IEEE/RSJ International Conference on Intelligent Robots and Systems    4478 - 4483 2013.11

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Understanding of electro-conjugate Fluid Flow through Flow Visualization Experiments

K. Nakagawa, T. Okada, K. Takemura, S. Yokota, K. Edamura

Proc. The12th International Symposium on Fluid Control, Measurement and Visualization    OS5-02-1 2013.11

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

An Inchworm Robot using Electro-conjugate Fluid

S. Ueno, K. Takemura, S. Yokota, K. Edamura

Proc. The12th International Symposium on Fluid Control, Measurement and Visualization    OS5-02-3 2013.11

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

3-joint Robot Finger using Electro-conjugate Fuid

Kiho Kobayashi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. 22nd International Conference on Hydraulics and Pneumatics    41 - 47 2013.10

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Droplet μTAS using Electro-conjugate Fluid - Feedback position control of multiple droplets in flow channel matrix

Yoko Abe, Kenjiro Takemura, Katsunari Sato, Shinichi Yokota, Kazuya Edamura

Sensors & Actuators A (Elsevier)  198   1 - 7 2013.08

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0924-4247

　View Summary

This paper proposes a novel droplet transportation method for micro total analysis system (mu TAS), which we called as an active flow channel matrix, using an electro-conjugate fluid (ECF). The ECF is a kind of functional fluid, which generates a powerful flow when applying a high voltage across the electrodes. A droplet that is placed into the channel may move in any direction according to the channel flow generated by the ECF. Therefore, in order for the multiple droplets from different channels to be merged, they are moved to reach the desired intersection. According to this concept, we developed a prototype of the active flow channel matrix. Then, we measured two droplets' position and controlled the position of them by using image processing technique. The experimental results demonstrated the possibility of our concept for mu TAS. (C) 2013 Published by Elsevier B.V.

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A Bio-inspired Robot Using Electro-conjugate Fluid

Kenichiro Tokida, Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Journal of Robotics and Mechatronics 25 ( 1 ) 16 - 24 2013.02

Research paper (scientific journal), Joint Work, Corresponding author, Accepted

An Inchworm Robot using Electro-conjugate Fluid

Sohei Ueno, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. 2012 IEEE International Conference on Robotics and Biomimetics    1017 - 1022 2012.12

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Active Flow Channel Matrix for Droplet mTAS using Electro-conjugate Fluid

Yoko Abe, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. IEEE EMBS Micro and Nanotechnology in Medicine Conference    16 2012.12

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Active Flow Channel Matrix using Electro-conjugate Fluid for μTAS Application

Yoko Abe, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

International Journal of Fluid Power System 5 ( 1 ) 11 - 15 2012.11

Research paper (scientific journal), Joint Work, Corresponding author, Accepted

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Effective Learning Environments in Higher Education: Case Studies of Albanian, Austrian, Japanese and Croatian Universities

Violeta Vidacek-Hains, Jozef Bushaty, Victoria Appatova, Harry Prats, Katarina Pazur, Norbert Berger, Kenjiro Takemura

Proceedings of International Conference on Towards Future Sustainable Development  2012.11

Research paper (international conference proceedings), Joint Work, Last author, Accepted

A Robot Hand using Electro-conjugate Fluid: Grasping experimrnt with balloon actuators inducing a palm motion

Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 2nd IFToMM Asian Conference on Mechanism and Machine Science    ID97 2012.11

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Tactile Sense Measurement based on Vibration Information obtained during Active Touch

Emi Asaga, Kenjiro Takemura, Takashi Maeno

IEEE Sensors 2012 (IEEE)   2012.10

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Control of a Novel Flexible Finger using Electro-conjugate Fluid with Built-in Angle Sensor

Kento Mori, Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Sensors & Actuators A (ELSEVIER SCIENCE SA)  183   75 - 83 2012.08

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0924-4247

　View Summary

An electro-conjugate fluid (ECF) is a kind of functional fluid, which produces a powerful flow when subjected to high DC voltage. It is known that a strong ECF flow is generated under non-uniform electric field, for example, the field with a pair of needle and ring electrodes. The ECF flow could be used as a micro fluid pressure source (an ECF pump) for actuators including an artificial muscle and a flexible finger. However, previous studies on ECF soft actuators only focused on confirmation of the driving principle. This means, an improvement of performance of ECF pumps and a control scheme for ECF soft actuators have yet to be studied in detail. Hence, this study improves the performance of the ECF pump, and proposes a novel control system for an ECF flexible finger. The ECF pump developed in this study, 200.3 mm(3), generates maximum pressure of 92.6 kPa and maximum flow rate of 103.0 ml/min. The flexible finger (empty set 5 mm x 30 mm), driven by the ECF pump, bends 150 degrees with a rise time of 1 s. In addition, we construct a master-slave system using the ECF flexible finger and confirm its performance. (C) 2012 Elsevier By. All rights reserved.

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An Ungrounded Pulling Force Feedback Device Using Periodical Vibration-Impact

Takuya Shima, Kenjiro Takemura

Proc. EuroHaptics 2012 7282 ( 1 ) 481 - 492 2012.06

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted,  ISSN  0302-9743

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This paper presents a novel ungrounded force feedback device which is capable of making the user confuse as if a pulling force is displayed by utilizing non-linear characteristics of human perception. The force feedback device is mainly composed of a spring-mass system and a voice coil motor. By hitting a weight against a wall periodically, the device generates a vibration impact to the user. The device is 140 x 41.5 x 41.5 mm3 with total mass of 230 g. A sensitivity of the pulling force perception are evaluated and presented in this paper. © 2012 Springer-Verlag.

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Direct Touch Haptic Display Using Immersive Illusion with Interactive Virtual Finger

Maisarah Binti Ridzuan, Yasutoshi Makino, Kenjiro Takemura

Proc. EuroHaptics 2012 7282 ( 1 ) 432 - 444 2012.06

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted,  ISSN  0302-9743

　View Summary

In attempt to improve haptic interaction and manipulation technique in surface computers, we propose an interactive haptic feedback display that utilizes 'direct touch' on a surface computer without using a mediation device. The proposed haptic display lets users interact with the virtual objects inside a pressure-sensitive screen directly using a virtual finger as if the user's finger can penetrate through the screen surface and sink in to the digital world inside the screen, as well as receive haptic feedback direct to their fingers from the display. Using the proposed display, users were able to perceive touch sensation with haptic feedback when they come in contact with virtual object surfaces and discriminate different stiffness using vibratory and pseudo-haptic feedback respectively. This innovation creates a new breakthrough in virtual interaction with more accessible and realistic haptic interaction approach for surface computing. © 2012 Springer-Verlag.

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Active Flow Channel Matrix using Electro-conjugate Fluid for μTAS Application

Yoko Abe, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 2nd Japan-China Joint Workshop on Fluid Power    45 - 49 2012.05

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Emergent Design of Dynamical Behavior

Toru Nagata, Kenjiro Takemura, Koichiro Sato, Yoshiyuki Matsuoka

Journal of Advanced Mechanical Design, Systems, and Manufacturing 6 ( 2 ) 274 - 286 2012.03

Research paper (scientific journal), Joint Work, Corresponding author, Accepted

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A Robot Hand Using Electro-conjugate Fluid: Grasping experiment with balloon actuators inducing a palm motion of robot hand

Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Sensors & Actuators A (ELSEVIER SCIENCE SA)  174   181 - 188 2012.02

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0924-4247

　View Summary

An electro-conjugate fluid (ECF) is a kind of functional fluid, which produces a jet flow (ECF jet) when subjected to high DC voltage. It is known that a strong ECF jet is generated under nonuniform electric field, for example, the field with a pair of needle and ring electrodes. We developed in our previous study a novel five-fingered flexible robot hand using the ECF. In this study, in order to improve the ECF hand we pay our attention to the flexion of palm because human often grasp an object with the flexion of palm. First, we propose a concept of five fingered robot hand which has balloon actuators driven by the ECF jet to produce the flexion of palm. The actuator is mainly composed of silicone rubber membrane and a rubber base with a slit, so that when the actuator is pressurized, the slit is opened, resulting in making the palm of the robot hand actuate. Finally we conduct grasping experiments based on Cutkosky's taxonomy of human grasping, and demonstrate the robot hand can grasp some objects with various shapes without any complex controller. The height, the width and the mass of the robot hand are approximately 70 mm, 40 mm and 40 g, respectively. (C) 2011 Elsevier B.V. All rights reserved.

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Impingement Type Micro Fluidic Device using Electro-Conjugate Fluid

Kei Nakagawa, Kento Mori, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

2012 INTERNATIONAL SYMPOSIUM ON MICRO-NANOMECHATRONICS AND HUMAN SCIENCE (MHS) (IEEE)     41 - 45 2012

Research paper (other academic), Corresponding author, Accepted,  ISSN  2474-378X

　View Summary

An electro-conjugate fluid (ECF) is a kind of dielectric fluid which produces a strong jet flow (ECF jet) when subjected to high DC voltage. Namely, a pair of electrodes generates nonuniform electric field, which induces the ECF jet. It is known that some kinds of ECF may possibly produce an impingement jet which occurs between electrodes. This study proposes an impingement type micro fluidic device whose power source is integrated by using the ECF. We developed a prototype and confirmed our concept.

Control of a Flexible Finger using Electro-conjugate Fluid

Kento Mori, Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. 2011 IEEE International Conference on Robotics and Biomimetics    709 - 714 2011.12

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

　View Summary

An electro-conjugate fluid (ECF) is a kind of functional fluid, which produces a powerful flow when subjected to high DC voltage. It is known that a strong ECF flow is generated under non-uniform electric field, for example, the field with a pair of needle and ring electrodes. The ECF flow could be used as a micro fluid pressure source (an ECF pump) for actuators including an artificial muscle and a flexible finger etc. However, previous studies on ECF soft actuators only focused on confirmation of the driving principle. This means, an improvement of performance of ECF pumps and a control scheme for ECF soft actuators have yet to be studied in detail. Hence, this study improves the performance of the ECF pump, and proposes a novel control system for an ECF flexible finger. The ECF pump developed in this study generates maximum pressure of 92.6 kPa and maximum flow rate of 103.0 ml/min with 200.3 mm 3. The flexible finger (φ5 mm x 30 mm), driven by the ECF pump, bends 150 deg with a rise time of 1000 ms. In addition, we construct a master-slave system using the ECF flexible finger and confirm its performance. © 2011 IEEE.

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A Robot Hand Using Electro-conjugate Fluid: Imitating a palm motion of human hand using soft balloon actuator

Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. 2011 IEEE International Conference on Robotics and Biomimetics    1807 - 1812 2011.12

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

　View Summary

An electro-conjugate fluid (ECF) is a kind of functional fluid, which produces a jet flow (ECF jet) when subjected to high DC voltage. It is known that a strong ECF jet is generated under nonuniform electric field, for example, the field with a pair of needle and ring electrodes. We developed in our previous study a novel five-fingered flexible robot hand using the ECF. In this study, in order to improve the ECF hand we pay our attention to the flexion of palm because human hand can grasp an object with the flexion of palm. First, we propose a concept of five fingered robot hand which has balloon actuators driven by ECF jet to produce the flexion of palm. The actuator is mainly composed of silicone rubber membrane and a rubber base with a slit, so that when the actuator is pressurized the slit is opened, resulting in making the palm of the robot hand actuate. When the actuator is pressurized with 20 kPa the rubber slit is opened with approximately 60 deg. Finally we investigate the characteristics of the actuator and introduce it into the ECF robot hand. © 2011 IEEE.

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A Flexible Pump Using Electro-Conjugate Fluid for Liquid Cooling of Electronic Chips

Atsushi Yashiki, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 15th International Conference on Mechatronics Technology    174 - 179 2011.11

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

A Robot Hand Using Electro-conjugate Fluid

Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Sensors & Actuators A 170 ( 1-2 ) 139 - 146 2011.11

Research paper (scientific journal), Joint Work, Corresponding author, Accepted

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A Bio-inspired Robot Using Electro-conjugate Fluid

Kenichiro Tokida, Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 15th International Conference on Mechatronics Technology    85 - 90 2011.11

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

An In-pipe Mobile Robot Using Electro-conjugate Fluid

Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Journal of Advanced Mechanical Design, Systems, and Manufacturing 5 ( 3 ) 214 - 226 2011.10

Research paper (scientific journal), Joint Work, Corresponding author, Accepted

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Control of Bellows Actuator using Electro-conjugate Fluid

Kento Mori, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 8th JFPS International Symposium on Fluid Power    488 - 494 2011.10

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

An In-Pipe Mobile Robot Using Electro-conjugate Fluid

Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 8th JFPS International Symposium on Fluid Power    456 - 463 2011.10

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

A Robot Finger Using Electro-conjugate Fluid

A. Yamaguchi, K. Takemura, S. Yokota, K. Edamura

Advanced Robotics (TAYLOR & FRANCIS LTD)  26 ( 8-9 ) 861 - 876 2011.07

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0169-1864

　View Summary

An electro-conjugate fluid (ECF) is a kind of functional fluid, which produces a jet flow (ECF jet) when subjected to high DC voltage. It is known that a strong ECF jet is generated under a non-uniform electric field (e.g., a field with a pair of needle and ring electrodes (a needle-ring electrode pair)). This study introduces the ECF jet to develop a novel flexible robot finger. First, we propose a concept for a novel robot finger. The robot finger mainly consists of a bending actuator, an ECF tank and ECF jet generators, which could be a micro fluid pressure source of the robot finger. Second, we characterize each component of the robot finger (i.e., the bending actuator and the ECF jet generator). We investigate the influences of electrode parameters on ECF jet generator performance in order to design the finger prototype. Finally we clarify the characteristics of the robot finger. The length, the diameter and the mass of the robot finger are 34.2 mm, 12 mm and 3.8 g, respectively. The robot finger can generate a force of 0.28 N and bend approximately 70 degrees. (C) Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2012

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Dominant Factors Inducing Electro-conjugate Fluid Flow

K. Mori, H. Yamamoto, K. Takemura, S. Yokota, K. Edamura

Sensors & Actuators A (ELSEVIER SCIENCE SA)  167 ( 1 ) 84 - 90 2011.05

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0924-4247

　View Summary

An electro-conjugate fluid (ECF) is a kind of dielectric fluid which produces a powerful flow (ECF jet) when subjected to high DC voltage. The ECF jet is a promising micro fluid power source for actuators and sensors including micro motors, liquid rate gyroscope, etc., however, these applications are developed upon trials and errors because the theory of the ECF flow has yet to be fully established. In this study we introduce the Korteweg-Helmholtz equation to develop an ECF flow model. Then we hypothesize that the Coulomb force is the dominant factor of the flow, and is occurred by two causes: an inherent dominant charge of fluid and a charge injected from a sharp electrode edge. The hypotheses are proved by the experimental results in this study. (C) 2011 Elsevier B.V. All rights reserved.

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A Robot Hand Using Electro-conjugate Fluid

Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. IEEE International Conference on Robotics and Automation    5923 - 5928 2011.05

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Wearable Tactile Display using Ultrasonic Vibration

Shunsuke Ninomiya, Kenjiro Takemura

Proc. The 4th International Conference on Manufacturing, Machine Design and Tribology (JSME, KSME)     167 - 168 2011.04

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Generation of Diverse Dynamic Behaviors Using the Emergent Design System

Koichiro Sato, Kenjiro Takemura, Yoshiyuki Matsuoka

Proc. International Conference on Research into Design 2011    571 - 580 2011.01

Research paper (international conference proceedings), Joint Work, Accepted

電界共役流体を用いた2軸液体マイクロレートジャイロの開発

尾川宜嗣，横田眞一，枝村一弥，竹村研治郎

日本機械学会論文集（C編） 77 ( 773 ) 204 - 211 2011.01

Research paper (scientific journal), Joint Work, Accepted

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A robot finger with integrated pump/tank using electro-conjugate fluid

Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C (Japan Society of Mechanical Engineers)  76 ( 772 ) 507 - 513 2010.12

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0387-5024

　View Summary

Electro-conjugate fluid (ECF) is a kind of functional fluid, which produces a jet flow (ECF jet) when subjected to high DC voltage. It is known that a strong ECF jet is generated under nonuniform electric field, for example, the field with a pair of needle and ring electrode. This study introduces the ECF jet to develop a novel robot finger. First, we propose a concept of the robot finger which mainly consists of an ECF jet generator, a bending actuator and an ECF tank. The robot finger is driven by ECF jet, and integrated with a pump and a tank. Next, we characterize the ECF jet generator and confirm the effect of the variation of electrode gap and number of electrode pair on its performance. Finally, we investigate the characteristics of the robot finger. The length, the diameter, and the mass of the robot finger are 25 mm, 5 mm, and 3.8 g, respectively. The robot finger can move 27.8 mm in x direction and 26.7 mm in y direction at 3.1 s when ECF jet generator is applied at 6.0 kV.

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Environmental Adaptability of Emergent Dynamical Behavior Design

Toru Nagata, Kenjiro Takemura, Koichiro Sato, Yoshiyuki Matsuoka

Proc. The 14th International Conference on Mechatronics Technology    185 - 190 2010.11

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Robotic Earthworm using Electro-conjugate Fluid

Kenichiro Tokida, Kenjiro Takemura, Shinichi Yokota, Kauya Edamura

International Journal of Applied Electromagnetics and Mechanics 33 ( 3-4 ) 1643 - 1651 2010.11

Research paper (scientific journal), Joint Work, Corresponding author, Accepted

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直流高電圧の印加によって活発なジェット流を発生する機能性流体である電界共役流体をマイクロ液圧源として内蔵し，柔軟なゴムチューブにぜん動運動を発生させるミミズ型ロボットを開発した．また，有限要素法を用いてゴムチューブの構造を改善した．

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多空間デザインモデルに基づくロボットの親近感生起動作生成法

氏家良樹，奈良原久之，前野隆司，竹村研治郎，松岡由幸

デザイン学研究 57 ( 3 ) 35-42 2010.11

Research paper (scientific journal), Joint Work, Accepted

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An Ungrounded Force Feedback Device Using Gyroscopic Torque

Yuri Yamamoto, Kenjiro Takemura

Proc. The 8th France-Japan and 6th Europe-Asia Congress on Mechatronics    453 - 457 2010.11

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

Micro screw pump using electrostatic force

Hideki Kadonami, Kenjiro Takemura, Akio Yamamoto

Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C (Japan Society of Mechanical Engineers)  76 ( 770 ) 2604 - 2610 2010.10

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0387-5024

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A micro pump is one of the most essential components in μTAS. However, conventional pumping systems have some difficulties to be miniaturized because it requires a power source. In this paper, we propose a novel micro screw pump driven by electrostatic force. Since the electrostatic force becomes dominant in micro region, it may be an effective driving source for micro pump. We propose an electrostatic drive principle of a screw pump using three-phase AC input. The micro screw pump is composed of a stator having flexible printed dircuits and a screw covered with a PET sheet. The drive experiments confirmed the effectiveness of the proposed driving principle and successful pumping with the developed micro screw pump at a flow rate of 111.4 μl/s.

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Electro-conjugate fluid Jet-Driven Micro Artificial Antagonistic Muscle Actuators and their Integration

Shinichi Yokota, Fumiya Yajima, Kenjiro Takemura, Kazuya Edamura

Advanced Robotics 24 ( 14 ) 1929-1934 - 1943 2010.10

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0169-1864

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An electro-conjugate fluid (ECF) is a type of dielectric and functional fluid that generates a powerful jet flow when subjected to high DC voltage. Although a high voltage is needed to generate the jet flow, the current is quite low at several microamperes, resulting in a total power consumption of several milliwatts. Using this smart fluid, we can develop micro fluid-driven mechanical components without any bulky pumps. Also, it is clarified that the power density of the ECF jet is higher when the electrode pair is miniaturized; therefore, it is suitable for micro actuators. Here, we propose and fabricate three types of soft actuators with an antagonistic configuration: (i) micro artificial muscle cells, (ii) a McKibben-type micro artificial muscle actuator using the ECF effect and (iii) a micro finger actuator with two chambers to bend. The actuators basically consist of a silicone rubber tube covered with a fiber sleeve and a micro pressure source using the ECF effect. Next, we apply and integrate these actuators into a micro robot hand, driven with ECF jets. The driving characteristics of the micro artificial muscle actuator and the integrated micro ECF hand with ECF fingers were fabricated and experimentally investigated. The experimental results show that this ECF jet actuation is effective for driving soft micro hands. (C) Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2010

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Implementation of information and communication technology in higher education: Comparative research in Asian, American and European universities

Vidaček-Hainš, V., Appatova, V., Prats, H., Takemura, K., An, L., Bushaty, J., Berger, N., Pazur, K.

Proc. the 21st Central European Conference on Information and Intelligent Systems    149 - 155 2010.09

Research paper (international conference proceedings), Joint Work, Accepted

Theoretical Modeling and Corroborative Experiments for Electro-conjugate Fluid Flow

Kento Mori, Hideki Yamamoto, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. International Conference on Electrical Machines    RF-002283 2010.09

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

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An electro-conjugate fluid (ECF) is a kind of dielectric fluid which produces a powerful flow (ECF jet) when subjected to high DC voltage. The ECF jet is a promising micro fluid power source for actuators and sensors including micro motors [4] [5], liquid rate gyroscope [8] [9] etc. However, these applications are developed upon trials and errors because the theory of the ECF flow has yet to be fully established. In this study we introduce the Coulomb force to develop an ECF flow model. Then we hypothesize that the Coulomb force is occurred by two causes
an inherent dominant charge depending on each fluid and a charge injected from a sharp electrode. The hypotheses are proved by the experimental results in this study. ©2010 IEEE.

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A Robot Finger using Electro-conjugate Fluid

Akihiro Yamaguchi, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. International Conference on Electrical Machines    RF-002852 2010.09

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Driving Method of Multiple Ultrasonic Motors using a Common Line Signal Input

Kohei Matsuzawa, Kenjiro Takemura

Sensors & Actuators A (ELSEVIER)  161 ( 1-2 ) 210 - 216 2010.07

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  0924-4247

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As the demand for multi degrees of freedom (DOF) system increases, it becomes more important for engineers to select an appropriate actuator. An ultrasonic motor is one of the promising actuators for multi-DOF system because of its advantages as direct drivability, high stationary holding torque, noiseless and quick response against input signal, however, the complexity of input wiring could be one of the problems for practical use. So this study proposes a novel driving method for multiple ultrasonic motors using a common line signal input. The method uses a superimposed signal, which has frequency components corresponding to the driving frequency of each ultrasonic motor. Because ultrasonic motors are driven by the natural vibration of stators, each motor only drives according to the corresponding frequency component of the common superimposed signal input. First we confirm the influence of the proposed method on the rotational speed of each ultrasonic motor. Then we controlled the rotational speed of each motor using the proportional controller, which operates the superimposed signal commonly inputted to each motor. (C) 2010 Elsevier B.V. All rights reserved.

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Numerical Modeling of Electro-Conjugate Fluid Flows

Hideki Yamamoto, Kento Mori, Kenjiro Takemura, Leslie Yeo, James Friend, Shinichi Yokota, Kazuya Edamura

Sensors & Actuators A (ELSEVIER)  161 ( 1-2 ) 152 - 157 2010.07

Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  0924-4247

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An electro-conjugate fluid (ECF) is a kind of low conductivity dielectric fluid, which produces a strong flow when subjected to high DC voltage. ECFs are potentially useful in a variety of applications, including microactuators, microgyroscopes, and CPU liquid cooling systems. However, the biggest hindrance to the commercial development of applications involving ECFs is the lack of theoretical understanding of the fluid flow mechanisms associated with ECFs. This study presents a numerical simulation based on a physical model for the flow of ECFs that arises due to the generation of electric (Maxwell) stress gradients. Validation of the results from the numerical simulation against experimental data obtained using particle image velocimetry (PIV) provides confidence that the model is capable of quantitatively reproducing the flow of these ECFs. (C) 2010 Elsevier B.V. All rights reserved.

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Emergent Design of Dynamical Behavior

Toru Nagata, Kenjiro Takemura, Koichiro Sato, Yoshiyuki Matsuoka

Proc. 2010 IEEE/ASME International Conference on Advanced Intelligent Mechatronics    373 - 378 2010.07

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

超音波振動を利用したマルチパーパス微小流体駆動デバイス（第１報，概念の提案とマイクロミキサとしての評価）

五味淳，竹村研治郎

日本フルードパワーシステム学会論文集 41 ( 1 ) 8-13 2010.01

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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チップ上での化学分析や医療診断を目指したμTAS（Micro Total Analysis System）の研究において，流体の駆動や撹拌に必要なマイクロポンプやマイクロミキサの小型化が急がれている．このため，流路の一部を振動子とし，適切な固有振動を励振することによってポンプ／ミキサの機能を選択的実現する微小流体デバイスを提案，開発した．また，実験によって提案手法の有効性を明らかにした．

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A dual-axis liquid rate micro gyroscope using Electro-Conjugate Fluid

Shinichi Yokota, Yoshitsugu Ogawa, Kenjiro Takemura, Kazuya Edamura

Journal of Advanced Computational Intelligence and Intelligent Informatics 14 ( 7 ) 751-755 2010

Research paper (scientific journal), Joint Work, Accepted

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超音波振動を利用したマルチパーパス微小流体駆動デバイス（第2報，ミキシングおよびポンピング性能の定量的評価）

五味淳，竹村研治郎

日本フルードパワーシステム学会論文集 41 ( 6 ) 9 - 15 2010

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

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Experimental Study on ECF-jet for ECF driven Micro Fingers

J. Inoue, S. Yokota, K. Takemura, K. Edamura

Proc. The 13th International Conference on Mechatronics Technology    CD-ROM 2009.10

Research paper (international conference proceedings), Joint Work, Accepted

Theorerical Modeling of Electro-conjugate Fluid Flow

Hideki Yamamoto, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura, James R. Friend, Leslie Y. Yeo

Proc. The 13th International Conference on Mechatronics Technology    CD-ROM 2009.10

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

Robotic Earthworm using Electro-conjugate Fluid - Confirmation of fundamental principle -

Kenichiro Tokida, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 13th International Conference on Mechatronics Technology    CD-ROM 2009.10

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

A multi-purpose Micro Fluid Power Component using Ultrasonic Vibration

Jun Gomi, Kenjiro Takemura

Proc. The 13th International Conference on Mechatronics Technology    CD-ROM 2009.10

Research paper (international conference proceedings), Joint Work, Last author, Corresponding author, Accepted

A Dual-Axis Liquid Rate Micro Gyroscope using Electro-conjugate Fluid

Yoshitsugu Ogawa, Shinichi Yokota, Kazuya Edamura, Kenjiro Takemura

Proc. The 13th International Conference on Mechatronics Technology    CD-ROM 2009.10

Research paper (international conference proceedings), Joint Work, Accepted

Robotic Earthworm using Electro-conjugate Fluid

Kenichiro Tokida, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 14th International Symposium on Applied Electromagnetics and Mechanics    633 - 634 2009.09

Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

ECF Liquid Rate Gyroscope

Shinichi Yokota, Mitsutoshi Hongo, Kenjiro Takemura, Kazuya Edamura, Tsunehiko Imamura, Hideo Kumagai

Proc. The 14th International Symposium on Applied Electromagnetics and Mechanics 13   625 - 626 2009.09

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1343-2869

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An electro-conjugate fluid (ECF) is a kind of functional fluid, which generates a powerful jet flow (ECF jet) when subjected to a high DC voltage. This study applies the ECF on a novel liquid rate gyroscope. The gyroscope has a liquid flow inside generated by the ECF jet When a rate is applied to the gyroscope, the flow drifts due to the Coliolis force. The gyroscope senses this drift by using hotwires to detect the applied rate. A prototype could successfully detect the applied rate with appropriate response.

Electrokinetic Actuation of Low Conductivity Dielectric Liquids

R.V. Raghavan, J. Qin, L.Y. Yeo, J.R. Friend, K. Takemura, S. Yokota, K. Edamura

Sensors & Actuators B (ELSEVIER)  140 ( 1 ) 287 - 294 2009.06

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0925-4005

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There has been some amount of confusion over the origin of electrohydrodynamic phenomena responsible for the actuation of dielectric fluids in the presence of an electric field. Previous studies have accounted for the possibility of conduction pumping, ion drag pumping and induction pumping as driving mechanisms but have ignored the possibility of Maxwell (electric) pressure driven flow. Until recently, this mechanism has been poorly understood and as a result has often been overlooked. This paper demonstrates how a Maxwell pressure gradient can induce flow in dielectric liquids in the presence of a non-uniform field. We derive, from first principles using lubrication theory, an expression for the flow velocity which exhibits a quadratic dependence on the applied voltage and also proportionality to the ratio of the permittivity and viscosity. The theoretical predictions are supported by experimental results. Although we have examined the phenomenon for a particular class of dielectric liquids, it is believed that this mechanism could well be responsible for the actuation of other low conductivity dielectric fluids previously attributed to conduction or ion drag pumping. In any case, we discuss ways to identify the dominant mechanism by comparing the salient features for a given type of flow.

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A micro liquid rate gyroscope using an electro-conjugated fluid

Shinichi Yokota, Tsunehiko Imamura, Mamoru Suzuki, Kenjiro Takemura, Kazuya Edamura, Hideo Kumagai

Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C (Japan Society of Mechanical Engineers)  75 ( 750 ) 496 - 502 2009.02

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0387-5024

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We propose in this study a novel concept of a liquid rate gyroscope using electro-conjugate fluid. The electro-conjugate fluid (ECF) is a dielectric fluid which works here as a functional/smart fluid generating a powerful jet flow (ECF jet) under a high DC electric field. The ECF liquid rate gyroscope proposed senses the drift of the liquid flow due to Coriolis force when an angular rate is applied. The contribution of the proposed concept on gyroscope technology is to provide a possibility for a low cost micro gyroscope with impact resistance. This paper describes a design of ECF micro liquid rate gyroscope and performance evaluations. The results of experiments show the ECF micro liquid rate gyroscope could possibly be a next generation standard of micro gyroscope for consumer products.

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A Liquid Rate Gyroscope using Electro-conjugate Fluid

Kenjiro Takemura, Shinichi Yokota, Mamoru Suzuki, Kazuya Edamura, Hideo Kumagai, Tsunehiko Imamura

Sensors & Actuators A 149 ( 2 ) 173 - 179 2009.02

Research paper (scientific journal), Joint Work, Lead author, Corresponding author, Accepted

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電界共役流体に発生するジェット流に角速度が加わるとコリオリ力により偏流する．この偏流量をホットワイヤの抵抗値の変化として検出する液体レートジャイロを開発した．

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ECF-jet Driven Micro Artificial Muscle Actuators and its Application to an ECF Micro Hand

Shinichi Yokota, Fumiya Yajima, Kenjiro Takemura, Kazuya Edamura

Proc. The Seventh International Conference on Fluid Power Transmission and Control (WORLD PUBLISHING CORPORATION)     33 - 37 2009

Research paper (international conference proceedings), Joint Work

　View Summary

We proposed a novel micro hand in which three kinds of soft actuators driven by ECF jet. The electro-conjugate fluid (ECF) Is, a dielectric fluid that works as a functional fluid, generating a powerful jet flow (ECF jet) when Subjected to high DC voltage. First, we have proposed an ECF micro artificial muscle Cell using ECF and integrated the cells. Second, we newly proposed and fabricated an ECF micro artificial antagonistic muscle, which consist of a pair of sleeve-type artificial muscles like. a McKibben type and a common tube. Finally, we proposed an ECF micro finger which is composed of two Fiber-reinforced soft tubes. The main advantage of the ECF soft actuator is tank and power source built-in.

Practical Design of a Liquid Rate Gyroscope using Electro-conjugate Fluid

Kenjiro Takemura, Shinichi Yokota, Tsunehiko Imamura, Kazuya Edamura, Hideo Kumagai

Journal of Systems and Control Engineering, Proceedings of the Institution of Mechanical Engineers, Part I (PROFESSIONAL ENGINEERING PUBLISHING LTD)  223 ( 6 ) 727 - 736 2009

Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  0959-6518

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An electro-conjugate fluid (ECF) is a kind of dielectric fluid that works as a functional/smart fluid generating a powerful jet flow (ECF jet) when subjected to a high d.c. voltage. The authors previously proposed the first liquid rate gyroscope in the world using ECF. The ECF liquid rate gyroscope proposed uses the drift of the ECF jet due to the Coriolis force when an angular motion is applied. The contribution of the proposed concept to gyroscope technology is that it provides the possibility of a low-cost micro gyroscope with inherent robustness to external impact. To move beyond a mere laboratory curiosity, the present paper describes the practical design of an ECF liquid rate gyroscope and characterizes the prototype. The ECF liquid rate gyroscope developed in this study has a scale factor, range of detection, resolution, and linearity of 32 mV/(degrees/s), +/-400 degrees/s, 0.04 degrees/s, and 2 per cent of full scale (with a range of +/-60 degrees/s), respectively. These results show that the ECF liquid rate gyroscope could possibly become the next generation standard of micro gyroscopes.

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A Liquid Rate Gyroscope using Electro-conjugate Fluid

Shinichi Yokota, Tsunehiko Imamura, Kenjiro Takemura, Kazuya Edamura, Hideo Kumagai

Proc. The Fourth International Conference on Intelligent Sensors, Sensor Networks and Information Processing    CD-ROM 2008.12

Research paper (international conference proceedings), Joint Work, Accepted

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電界共役流体を流動の圧力源として，ノズルにより生成されるジェット流に角速度が加わった際に生じる偏流を検出するレートジャイロを開発し，実験的に特性を明らかにした．また，アラン分散解析によってジャイロのドリフト特性を明らかにし，次世代マイクロジャイロのスタンダードとしての可能性を示した．

A Cell-integrated ECF-jet driven Artificial Muscle Actuator

Fumiya Yajima, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 12th International Conference on Mechatronics Technology    CD-ROM 2008.10

Research paper (international conference proceedings), Joint Work, Accepted

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電界共役流体を利用して，液圧駆動でありながらポンプ，アクチュエータ部，タンクを一体化した人工筋を開発し，これを複数個集積化した際の駆動とくしを明らかにした．

A Liquid Rate Gyroscope using Electro-conjugate Fluid - Practical Design and Characterization -

Shinichi Yokota, Kenjiro Takemura, Mamoru Suzuki, Kazuya Edamura, Hideo Kumagai and Tsunehiko Imamuras

Proc. IEEE/RSJ 2008 International Conference on Intelligent Robots and Systems    CD-ROM 2008.09

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

電界共役流体を流動の圧力源として，ノズルにより生成されるジェット流に角速度が加わった際に生じる偏流を検出するレートジャイロを開発し，実験的に特性を明らかにした．

Earthworm type Robot driven by Electro-conjugate Fluid

Kenjiro Takemura, Young-Pyo Hong, Kazuya Edamura, Shinichi Yokota

Proc. 17th CISM-IFToMM Symposium on Robot Design, Dynamics, and Control    85 - 92 2008.07

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

電界共役流体を用いてミミズの運動パターンおよび構造的柔軟性を模倣した新たな移動ロボットを開発し，駆動特性を実験的に明らかにした．

Integration of Micro Artificial Muscle Cells using Electro-conjugate Fluid

Kenjiro Takemura, Fumiya Yajima, Shinichi Yokota, Kazuya Edamura

Sensors & Actuators A (ELSEVIER SCIENCE SA)  144 ( 2 ) 348 - 352 2008.06

Research paper (scientific journal), Joint Work, Lead author, Corresponding author, Accepted,  ISSN  0924-4247

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An artificial muscle is one of the key technologies for soft robots. This paper describes design, fabrication, and characterization of an artificial muscle cell using an electro-conjugate fluid (ECF) and integration of the cells. The ECF is a kind of dielectric and functional fluid, which generates a powerful jet flow or ECF jet under an electrostatic field applied with an electrode pair. It is experimentally clarified that the smaller electrodes generate a more powerful ECF jet with constant voltage applied. The authors propose in this study a new type of micro artificial muscle cell using electro-conjugate fluid (ECF micro artificial muscle cell). This soft actuator having a power source inside is compact enough for integration. By integrating a large number of cells, we can realize a macro-sized artificial muscle. In this paper, we fabricate a prototype of ECF micro artificial muscle cell (emptyset 12.5 mm x 13 mm), and integrate four cells into a 2 x 2 ECF artificial muscle actuator showing larger stroke and force. The maximum stroke and force are 1.56 mm and 320.5 mN with a single cell, and they are increased to be 2.8 mm and 504.1 mN with the 2 x 2 ECF artificial muscle actuator. (C) 2008 Elsevier B.V. All rights reserved.

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Electrokinetic Actuation of Low Conductivity Dielectric Fluids

Rohan Raghavan, Jason Qin, Leslie Y. Yeo, James R. Friend, Kenjiro Takemura, Kazuya Edamura, Shinichi Yokota

Proc. ASME the Sixth International Conference of Nanochannels, Microchannels and Minichannels    CD-ROM(ICNMM2008-62239) 2008.06

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

電界共役流体に発生する流動は工学的に有効なパワー源と成りうるもののその流動メカニズムは不明であった．本研究ではマクスウェル応力を流体の基礎式に導入し，電界共役流体の流動モデルを提案し，実験と比較した．

Concept of a Liquid Rate Gyroscope using an Electro-conjugate Fluid

Shinichi Yokota, Mamoru Suzuki, Kenjiro Takemura, Kazuya Edamura, Hideo Kumagai, and Tunehiko Imamura

Proc. IEEE International Conference on Robotics and Automation (IEEE)     317 - 322 2008.05

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1050-4729

　View Summary

We propose a novel liquid rate gyroscope using an electro-conjugate fluid in this study. The electro-conjugate fluid (ECF) is a dielectric fluid that works here as a functional/smart fluid generating a powerful jet flow (ECF jet) when subjected to high DC voltage. Using the ECF jet, we developed a liquid rate gyroscope based on the principle of a conventional gas rate sensor operated by Coriolis force. Because the ECF jet is generated only with a tiny electrode pair, the pumping part of proposed ECF gyroscope needs no mechanically moving parts, resulting in making the ECF gyroscope suitable for micro sensor compared to the gas rate sensor having a pumping mechanism inside. We fabricated a prototype of liquid rate gyroscope (40mm x 60mm x t7mm) and confirmed its characteristics by experiment. The experimental results confirm the effectiveness of the proposed liquid rate gyroscope. The scale factor of -29 mV/(degrees/s) is obtained with applied voltage of 4.5 kV.

Control of multi-dof ultrasonic actuator for dexterous surgical instrument

Kenjiro Takemura, Shinsuk Park, Takashi Maeno

Journal of Sound and Vibration (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD)  311 ( 3-5 ) 652 - 666 2008.04

Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  0022-460X

　View Summary

For surgical devices used in minimally invasive surgery, compact multi-degree-of-freedom (multi-dof) actuators are required due to a small work space in the patient body. With conventional single-dof actuators such as electromagnetic motors, a multiple number of actuators are required to generate multi-dof motion. Moreover, additional transmission mechanisms make the total system even larger and heavier. In contrast, a single unit of multi-dof ultrasonic actuator can generate multi-dof rotation of a spherical rotor by utilizing three natural vibration modes of a bar-shaped stator. In our previous work we designed and built a surgical forceps with a wrist capable of two-dof motion, using a single multi-dof ultrasonic motor. The present study proposes a novel control scheme to generate three-dof motion of the surgical instrument for minimally invasive surgical procedures. Through experiments we have confirmed the system performance of the developed device. (c) 2007 Elsevier Ltd. All rights reserved.

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Integration of ECF Micro Artificial Muscle Cells

Funiya Yajima, Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 11th International Conference on Mechatronics Technology    434 - 439 2007.11

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

電界共役流体を用いると，簡便な構造でマイクロ人工筋を構成できる．本研究では，タンク，ポンプ，アクチュエータを一体化したマイクロ人工筋セルを提案した．繊維強化チューブとタンク膜を二重円筒構造とすることによって外部に大規模なタンクやポンプを必要としない直径10 mmのセル構造を実現した．

A Micromotor using Electro-conjugate Fluid - Improvement of motor performance by using saw-toothed electrode series -

Kenjiro Takemura, Hiroto Kozuki, Kazuya Edamura, Shinichi Yokota

Sensors & Actuators A (ELSEVIER)  140 ( 1 ) 131 - 137 2007.10

Research paper (scientific journal), Joint Work, Lead author, Corresponding author, Accepted,  ISSN  0924-4247

　View Summary

An electro-conjugate fluid (ECF) is a kind of dielectric fluid, which works as a smart fluid. The fluid generates a powerful jet flow, which we call an ECF jet, when subjected to high DC voltage with a highly non-uniform electric field. This means the ECF works as a fluid power source for mechanical components without any bulky pumps. This paper develops a high-performance ECF micromotor having novel saw-toothed electrode series. The motor has four disk plates with the electrode series as a rotor. The inner diameter and length of the motor are 9 and 10.6 mm, respectively. Experimental results confirm that the output power and torque of the motor are 21 times and 7.5 times larger than those of a previous ECF micromotor having bar-shaped electrode pairs. (C) 2007 Elsevier B.V. All rights reserved.

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ECF Micro Artificial Muscle Actuator and its Application to Micro Robot Arm

Kenjiro Takemura, Shinichi Yokota and Kazuya Edamura

Proc. The 6th International Symposium on Linear Drives for Industry Applications    CD-ROM 2007.09

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

本研究では，繊維強化ゴムチューブの内圧制御に電界共役流体を用いた新たな人工筋アクチュエータを提案した．本流体のポンピングには数100 μmオーダーの微小電極対のみ必要であるため，直径3 mmのマイクロ人工筋アクチュエータを実現した．また，これを2つ並列に配置し片端を弾性ヒンジで連結することによって，マイクロアームを実現した．

ECFジェット駆動マイクロフィンガの提案とラージモデルの特性評価

横田眞一，阿部竜太郎，竹村研治郎，枝村一弥

日本フルードパワーシステム学会論文集 38 ( 5 ) 65 - 70 2007.09

Research paper (scientific journal), Joint Work, Accepted

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先端が閉じ，断面に120度ごとの扇形チャンバを有するチューブにおいて，各チャンバの内圧を変化させるとチューブ先端に多自由度運動を生成できる．本研究では，電界共役流体に発生するジェット流によってこの内圧を制御した．特に，提案した構造では各チャンバ間においてジェット発生用電極対を介して電界共役流体を移動できるため，タンクとアクチュエータ部を共用化でき，またチャンバ間の差圧を利用できる．実験によってフィンガ先端の多自由度駆動を確認するとともに，先端部での発生力を明らかにした．

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電界共役流体により駆動されるミミズ型ぜん動駆動マイクロマシン

横田眞一，洪榮杓，竹村研治郎，枝村一弥

日本ロボット学会誌 25 ( 6 ) 140 - 145 2007.09

Research paper (scientific journal), Joint Work, Accepted

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ミミズは収縮する体節が直列につながった構造であり，各体節は従走筋と環状筋の働きによって軸方向へ収縮し，径方向には膨張する．本研究では，繊維強化チューブの内圧を電界共役流体に発生するジェット流を用いて変化させ，上記ミミズの体節のような変形を実現する液圧駆動セルを提案し，これを直列に配置したぜん動駆動型マイクロマシンを実現した．

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Concept of a Micro Finger using Electro-conjugate Fluid and Fabrication of a Large Mode Prototype

Ryutaro Abe, Kenjiro Takemura, Kazuya Edamura and Shinichi Yokota

Sensors & Actuators A (ELSEVIER SCIENCE SA)  136 ( 2 ) 629 - 637 2007.05

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0924-4247

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Electro-conjugate fluid (ECF) is a kind of functional fluid, which produces jet flow (ECF jet) when subjected to high DC voltage. It is ascertained that a strong ECF jet is generated under nonuniform electric field, for example, around a pair of a needle-electrode and a ring-electrode (a needle-ring electrode pair). This study proposes and develops a novel micro finger with two-DOF motion using ECF jet. First, we propose a concept of novel micro finger driven by ECF jet (ECF micro finger). The ECF micro finger consists of a finger tube with three chambers along its axis and an ECF jet generator with three needle-electrodes and a plate-electrode with three holes. When the ECF jet generated at the ECF jet generator is applied to the chambers of the finger tube, the pressurized chambers expand and the other chambers shrink resulting in the finger tube bending. Next, a large model of the proposed ECF micro finger, with finger tube diameter of 4.5 mm, is fabricated in order to confirm our concept. Finally, we investigate the static characteristics of the large model by experiments. (C) 2006 Elsevier B.V. All rights reserved.

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DP-RE type Micromotors using Electro-conjugate Fluid

Shinichi Yokota, Hiroto Kozuki, Kenjiro Takemura, Kazuya Edamura

Proc. IEEE International Conference on Robotics and Automation (IEEE)     1566 - 1571 2007.04

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1050-4729

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This paper presents a new type of micromotor using electro-conjugate fluid (ECF). An electro-conjugate fluid is a kind of dielectric fluid, which works as a smart fluid. The fluid generates a powerful jet flow, which we call an ECF jet, when subjected to high DC voltage with highly non-uniform electric field, which means, it works as a fluid power source for mechanical components without bulky pumps. We introduce this attractive smart fluid to micromotors in this paper. Inside the motor is filled with the electro-conjugate fluid and a rotor has electrode pairs on the surface. By applying high DC voltage to the electrode pairs, the rotor rotates due to the ECF jet. In this paper, we design several types of electrode pairs and examine each influence on motor performances.

Development of an Ultrasonic Brake

Tatsuya Koyama, Kenjiro Takemura and Takashi Maeno

Journal of Advanced Mechanical Design, Systems, and Manufacturing (JAPAN SOC MECHANICAL ENGINEERS)  1 ( 1 ) 122 - 129 2007.03

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1881-3054

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In the present paper, a newly developed ultrasonic brake is proposed. The ultrasonic brake can solve problems of conventional passive elements, such as time delay, instability, and large size, by using unique characteristics of ultrasonic motor, as fast response, silent motion, and non-magnetic feature. It can also be designed to be smaller than conventional elements due to its simple structure. The brake locks or releases the rotor by use of ultrasonic levitation phenomenon. First, we have designed the structure of the ultrasonic brake using an equation of ultrasonic levitation phenomenon, results from structural analysis and finite element (FE) analysis of piezoelectric material of the vibrator. Then we have manufactured the ultrasonic brake and have conducted a driving experiment. Finally, we have demonstrated that the maximum levitation force is around 40 N and the friction torque of the ultrasonic brake is up to 0.38 Nm. Moreover, we have confirmed that both response time and torque/inertia ratio of the ultrasonic brake are much more superior to the conventional ones.

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単相駆動型多自由度超音波モータ

音川佳代，竹村研治郎，前野隆司

日本機械学会論文集（C編） 73 ( 726 ) 577 - 582 2007.02

Research paper (scientific journal), Joint Work, Accepted

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多自由度超音波モータの多くは，複数の固有振動モードの固有振動数を縮退させ，これらの組み合わせによって回転子の多自由度運動を実現していた．この場合，振動設計が複雑となるため，実用上問題が多かった．本研究では，複数の振動子をマトリクス状に配置し，固有振動数が異なる複数の固有振動モードを選択的に組み合わせることによって振動子マトリクス上に置かれた移動子に多自由度運動を生成する新たな多自由度超音波モータを開発した．

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Development and Control of a Micro Artificial Muscle Cell using Electro-conjugate Fluid

Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Sensors & Actuators A (ELSEVIER)  133 ( 2 ) 493 - 499 2007.02

Research paper (scientific journal), Joint Work, Lead author, Corresponding author, Accepted,  ISSN  0924-4247

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As a man-machine interaction increases its importance in the robotic and mechatronic fields, a soft robot, which is inspired from natural systems, becomes one of the most important research trends. There are several research topics related to soft robots such as soft structures or artificial skins, compliance control, soft actuators or artificial muscles, and so on. For the natural muscle potentially has great flexibility, the authors believe that the artificial muscle actuator must be a promising technology for soft robots. Hence in this study, we develop a new type of micro artificial muscle cell, which is an element of an integrated artificial muscle, using electro-conjugate fluid (ECF) and measure its driving performances. In addition, position control characteristics are also clarified by experiments. Experimental results show the micro artificial muscle cell using electro-conjugate fluid has a quite good control performance. (c) 2006 Elsevier B.V. All rights reserved.

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Improving Output Power of ECF Micromotors with triangle electrodes

K. Takemura, H. Kozuki, H. Hayashi, S. Yokota, K. Edamura

Proc. The 10th International Conference on Mechatronics Technology    CD-ROM 2006.11

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

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直流高電圧の印加によって活発なジェット流を発生する電界共役流体を用いると，単純構造で小型軽量なマイクロモータを比較的容易に構成できる．本研究では，上記マイクロモータの出力パワーの向上を目指して，ジェット発生のための電極形状を改良した．すなわち，従来の棒状電極対に代わって三角形電極を直列に配置し，より不均一な電界の形成および電極密度の向上を試みた．この結果，従来モータに比べて出力パワー密度が約3倍に向上した．

A Micro Finger using Electro-conjugate Fluid - Concept and Performance of Large Model -

S. Yokota, R. Abe, K. Takemura and K. Edamura

Proc. The 10th International Conference on Mechatronics Technology    CD-ROM 2006.11

Research paper (international conference proceedings), Joint Work, Accepted

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電界共役流体は直流高電圧の印加によって活発なジェット流を発生する機能性流体である．本研究では，断面に中心角120度の扇形チャンバ3つを有する直径4 mmのマイクロフィンガを試作し，各チャンバの内圧を上記ジェット流を用いて制御することによって先端に多自由度運動を実現するマイクロフィンガを開発した．特に，各チャンバ間の配管にバッファを設けることによって電界共役流体に発生するジェット圧力を効率的にフィンガの変形へと変換できることを明らかにした．

ECFジェットによる発生圧力を応用したチューブ形ECFマイクロアクチュエータ

阿部竜太郎，横田眞一，竹村研治郎，枝村一弥

日本フルードパワーシステム学会論文集 37 ( 5 ) 55 - 60 2006.09

Research paper (scientific journal), Joint Work, Accepted

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機能性流体の一つである電界共役流体（ECF）に生じるジェット流の圧力により駆動される新たな駆動原理のマイクロアクチュエータを提案，試作し，この駆動特性を実験的に検討した．ブルドン管と同様の原理により駆動される本アクチュエータは，6 kV印加時に設計仕様1.8 mmの178 %の出力変位および2 mNの発生力を得た．このマイクロアクチュエータは，発生力は微小であるが，印加電圧により出力変位を制御できることから，マイクロミラーの微小位置決めなどへの応用が期待できる．

A Micro Gyroscope using Electro-conjugate Fluid

Shinichi Yokota, Ryuta Nishizawa, Kenjiro Takemura, Kazuya Edamura

Proc. IEEE International Conference on Robotics and Automation    4321 - 4323 2006.05

Research paper (international conference proceedings), Joint Work, Accepted

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電界共役流体は直流高電圧の印加によって活発なジェット流を発生する．本流体を用いると，複数の微小な電極対を円筒チャンバ内に配置するだけで回転流を発生できる．本研究では，これに円盤を封入すると回転流によって浮揚，回転することを利用して，円盤とチャンバの相対角度から角速度を検出する新たなジャイロスコープを提案した．また，上記ジャイロスコープのプロトタイプを試作し，基礎的特性を明らかにした．

Driving Performance and Control of a Micro Artificial Muscle Cell using Electro-conjugate Fluid

Kenjiro Takemura, Shinichi Yokota, and Kazuya Edamura

Proc. IEEE International Conference on Robotics and Automation (IEEE)     1018 - 1023 2006.05

Research paper (international conference proceedings), Joint Work, Lead author, Accepted,  ISSN  1050-4729

　View Summary

As a man-machine interaction increases its importance in robotics and mechatronics fields, a soft robot inspired from natural systems becomes one of the research trends. There are several research topics related to soft robots such as soft structures or artificial skins, compliance control, soft actuators or artificial muscles, and so on. For the natural muscle potentially has great flexibility, the authors believe the artificial muscle actuator must have a great potential in soft robots. Hence in this study we develop a new type of micro artificial muscle cell, which is an element of an integrated artificial muscle, using electro-conjugate fluid and measure its driving performances. In addition, position control characteristics are also clarified by experiments. As a result, the micro artificial muscle cell using electro-conjugate fluid shows quite good control performances.

New microactuators using functional fluids, MEXT Grant-in-Aid for Scientific Research on Priority Areas

Shinichi Yokota, Kazuhiro Yoshida, Kenjiro Takemura, Joon-wan Kim

Proc. The 1st International Symposium on Next-Generation Actuators Leading Breakthroughs    35 - 38 2006.04

Research paper (international conference proceedings), Joint Work

電界共役流体（ECF）を用いたマイクロモータの高出力化

横田眞一，河村清美，竹村研治郎，枝村一弥

電気学会論文誌E 126 ( 4 ) 137 - 143 2006.04

Research paper (scientific journal), Joint Work, Accepted

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本研究では微小電極対によって高電圧を印加すると活発なジェット流を発生する電界共役流体（ECF）を利用したマイクロモータの微小化および作動流体の相違に伴う性能向上について検討した．すなわち，表面に放射状電極対を持つディスクプレート(DP)ロータを積層した内径5mmのDP形ECFマイクロモータを設計，試作し，駆動特性を実験により明らかにした．この結果，小型化により出力パワー密度が向上し，作動流体の違いにより出力パワー密度が約4.5倍に向上することが確認された．

Concept of a Micro Gyroscope using Electro-conjugate Fluid (ECF) and Development of an ECF Micro Gyro-motor

Shinichi Yokota, Ryuta Nishizawa, Kenjiro Takemura, and Kazuya Edamura

Journal of Robotics and Mechatronics 18 ( 2 ) 114 - 120 2006.04

Research paper (scientific journal), Joint Work, Accepted

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本研究は，高電圧の印加によって活発なジェット流が生じる電界共役流体（ECF）を利用したECFマイクロジャイロスコープの実現を目的とした．はじめに，液体中の円盤を回転軸なしで浮揚，回転できるロータ径3mmおよび1.5mmのマイクロモータを実現し，回転特性を実験的に明らかにした．つぎに，上記のモータ全体に角速度が加わると浮揚円盤が傾くことを利用した新たなジャイロスコープを提案，試作した．

ECF Micro Finger Driven by ECF-jet and Characteristics Evaluation of a Large Model

R. Abe, S. Yokota, K. Takemura and K. Edamura

Proc. The 9th International Conference on Mechatronics Technology    CD-ROM 2005.12

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

電界共役流体は直流高電圧の印加によって活発なジェット流を発生する機能性流体である．本研究では，断面に中心角120度の扇形チャンバ3つを有する直径4 mmのマイクロフィンガを試作し，各チャンバの内圧を上記ジェット流を用いて制御することによって先端に多自由度運動を実現するマイクロフィンガを実現した．本フィンガは液圧駆動であるものの，電界共役流体を用いたことにより外部に大規模なタンクやポンプを必要としない．

Development of a Micro Gyroscope using Electro-conjugate Fluid

S. Yokota, R. Nishizawa, K. Takemura and K. Edamura

Proc. The 9th International Conference on Mechatronics Technology    CD-ROM 2005.12

Research paper (international conference proceedings), Joint Work, Accepted

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直流高電圧の印加によって活発なジェット流を発生する電界共役流体を用いると，円筒チャンバ内に容易に回転流を発生できる．この中に円盤を封入すると，回転流によって浮揚，回転する．本研究では，この出力軸を持たないモータに角速度が加わった際に円盤とチャンバの相対角度が変化することに着目し，新たなジャイロスコープを提案した．また，実際に上記モータを試作し，寸法パラメータの微小化によって回転数が著しく上昇することを明らかにし，新たなマイクロジャイロの可能性を示した．

Driving Characteristics of a Micro Artificial Muscle Actuator using Electro-conjugate Fluid

K. Takemura, S. Yokota, and K. Edamura

Proc. The 6th JFPS International Symposium on Fluid Power    564 - 568 2005.11

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

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電界共役流体に発生するジェット流の圧力を利用して繊維強化シリコーンゴムチューブの内圧を変化させ，軸方向の収縮変位を得るマイクロ人工筋アクチュエータの駆動特性を明らかにし，先端変位を制御した．直径5 mm，長さ約10 mmのマイクロ人工筋アクチュエータにおいて先端変位は約2 mm，発生力は約0.2 Nであり，PID制御による先端変位の制御を行った結果，少なくとも分解能0.3 mmで位置決めできることを明らかにした．

Development of an Arrayed Multi-Degree-of-Freedom Ultrasonic Motor

K. Otokawa, K. Takemura and T. Maeno

Proc. The 5th International Symposium on Linear Drives for Industry Applications    258 - 261 2005.09

Research paper (international conference proceedings), Joint Work, Accepted

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複数の固有振動モードを選択的に励振し，移動子を多自由度並進運動させる振動子を設計し，これを複数個アレイ状に配置することによってこの上部におかれた移動子に並進2自由度および回転1自由度の運動を実現する多自由度超音波モータを開発した．本モータでは個々の振動子は各瞬間においてある1つの固有振動モードのみ励振されるため，複数の固有振動モードを縮退させる必要がなく，振動設計が容易となった．

A Micro Artificial Muscle Actuator using Electro-conjugate Fluid

Kenjiro Takemura, Shinichi Yokota and Kazuya Edamura

Proc. Bath Workshop on Power Transmission & Motion Control    269 - 276 2005.09

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

直流高電圧の印加によって活発なジェット流を発生する電界共役流体は，微小な電極対のみによってポンピングできるため，マイクロアクチュエータの駆動源として期待できる．本研究では，上記ジェット流により駆動される液圧駆動型マイクロ人工筋アクチュエータを開発し，駆動特性を明らかにした．実験の結果，直径5 mm，長さ10 mmの人工筋アクチュエータにおいて，収縮率約20 %，発生力約0.2 Nを得た．

電界共役流体に発生するジェット流を用いたマイクロ人工筋アクチュエータ

竹村研治郎，横田眞一，枝村一弥

日本機械学会論文集（C編） 71 ( 708 ) 141 - 147 2005.08

Research paper (scientific journal), Joint Work, Lead author, Accepted

　View Summary

電界共役流体は直流高電圧の印加によって活発なジェット流を発生する機能性流体である．すなわち，簡便な電極対のみによって液圧制御が可能であるため，マイクロソフトアクチュエータの駆動源として利用できる．本研究では，軸方向に繊維強化した直径5mmのシリコーンゴムチューブの内圧を上記ジェット流を用いて制御し，軸方向変位を得るマイクロ人工筋アクチュエータを提案し，性能を実験的に確認した．この結果，収縮率は約20%，発生力は0.2N程度であった．

A multi-degree-of-freedom ultrasonic motor using single-phase-driven vibrators

K Otokawa, K Takemura, T Maeno

2005 IEEE/RSJ International Conference on Intelligent Robots and Systems, Vols 1-4 (IEEE)     2259 - 2264 2005.08

Research paper (international conference proceedings), Accepted

　View Summary

This paper presents a novel type of multi degree-of-freedom ultrasonic motors. Today, in various fields, actuators having multi degrees-of-freedom is needed. In the past, many multi-degree-of-freedom actuators have been developed. However, they are all still large and heavy. Thus, we propose a miniature multi-degree-of-freedom actuator using plural single-phase-driven ultrasonic vibrators. A single-phase-driven ultrasonic motor is known for its miniaturizing facility. On the other hand, it is also known for its lack of output force. Therefore, we proposed to use plural single-phase-driven vibrators and also tried to make one vibrator generate great force. This motor has many small vibrators; each one having four patterns in the thrust direction. By controlling the frequency of each vibrator, we can obtain multiple movements of a movable object. First, we proposed the principles of this motor. Next, we selected vibration modes and designed the size of a vibrator to be 10 x 7.5 x 0.9 mm(3) using finite element analysis. Finally, we measured frequency, vibration, and driving characteristics of the vibrators. The maximum thrust was about 3.14 N and the maximum torque was about 6 mN-m.

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A Microactuator Driven by Pressure due to ECF-jet

R.Abe, S.Yokota, K. Takemura, K.Edamura

Proc. The First Joint International Conference on Manufacturing, Machine Design and Tribology    MAA-401 2005.06

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

ブルドン管のように先端が閉じ、かつ湾曲したチューブの内圧を変化させるとチューブ全体が直線形状へと変形し，アクチュエータを構成できる．本研究では，このような原理を用いて直径1 mmの湾曲したシリコーンゴムチューブの内圧を電界共役流体に発生するジェット流により変化させる新たなマイクロアクチュエータを提案し，プロトタイプを開発した．また，実験により先端変位1 mm以上を発生できることを確認した．

A Micro Artificial Muscle Actuator using Electro-conjugate Fluid

Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. IEEE International Conference on Robotics and Automation    534 - 539 2005.04

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

電界共役流体は直流高電圧の印加によって活発なジェット流を発生する機能性流体である．本研究では，上記ジェット流によって軸方向に繊維強化されたシリコーンゴムチューブの内圧を変化させ，軸方向の収縮と径方向の膨張を得る直径5 mmのECFマイクロ人工筋アクチュエータを開発した．本アクチュエータは液圧駆動アクチュエータであるものの，電界共役流体を用いることにより， 外部に大規模なタンクや液圧源を必要としない．

High-integration Micromotor using Electro-conjugate Fluid (ECF)

Shinichi Yokota, Kiyomi Kawamura, Kenjiro Takemura, and Kazuya Edamura

Journal of Robotics and Mechatronics 17 ( 2 ) 142 - 148 2005.04

Research paper (scientific journal), Joint Work, Accepted

　View Summary

高電圧印加時に電界共役流体に発生する活発なジェット流を回転運動に変換するマイクロモータのうち，円盤形ロータ上に電極対を配置したDP-RE形ECFマイクロモータの高集積化について検討した．モータ直径の微小化および円盤形ロータの積層数増加によって，出力パワー密度が著しく向上することを実験的に確認した。すなわち，内径9 mmと5 mmのモータを比較すると出力パワー密度が約2.3倍に，積層数4層と8層のモータを比較すると出力パワー密度が約13.4倍に向上することを明らかにした．

超音波ブレーキの開発

小山辰也，竹村研治郎，前野隆司

日本機械学会論文集（C編） 71 ( 703 ) 111 - 116 2005.03

Research paper (scientific journal), Joint Work, Accepted

　View Summary

本研究では，超音波モータの高応答性，静粛性，単純構造，電磁ノイズレスなどの優れた特徴を有する新たなブレーキシステムを提案した．本ブレーキは超音波浮揚現象を利用してロータのロックと解放を切り替えるものである．はじめに，有限要素法を用いた振動子の振動設計および超音波浮揚理論による保持トルクの計算を行った．つぎに，プロトタイプを試作し，実験によって40Nの浮揚力と0.38Nmの保持トルクが実現可能であることを示した．

Development of a Micro Artificial Muscle Actuator using Electro-conjugate Fluid (ECF)

Kenjiro Takemura, Shinichi Yokota, Kazuya Edamura

Proc. The 8th International Conference on Mechatronics Technology    221 - 226 2004.11

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

電界共役流体は直流高電圧の印加によって活発なジェット流を発生する機能性流体である．すなわち，簡便な電極対のみによって液圧制御が可能であるため，マイクロソフトアクチュエータの駆動源として利用できる．本論文では，軸方向に繊維強化した直径5mmのシリコーンゴムチューブの内圧を上記ジェット流を用いて制御し，軸方向変位を得るマイクロ人工筋アクチュエータを提案し，性能を実験的に確認した．この結果，収縮率は約20%，発生力は0.2N程度であった．

Design of a Plate Type Multi-DOF Ultrasonic Motor and its Self-Oscillation Driving Circuit

K. Takemura, Y. Ohno, and T. Maeno

IEEE/ASME Transactions on Mechatronics (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC)  9 ( 3 ) 474 - 480 2004.09

Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  1083-4435

　View Summary

Multi-degrees-of-freedom (DOF) actuators have become more useful in the field of robotics, as a result of the increasing number of DOFs of systems. The general features of ultrasonic motors are suitable for constructing a direct-drive multi-DOF actuator. However, previously developed ultrasonic motors do not have advantages in volume and weight in contrast to multi-DOF motion units composed of plural electromagnetic motors. In the present study, authors developed a novel multi-DOF ultrasonic motor with a compact plate stator and spherical rotor. First, a new driving principle of the motor is proposed. Next, the stator geometry is designed in detail using the finite element method, and a prototype of the multi-DOF ultrasonic motor is produced. Then, vibration characteristics of the stator and driving characteristics of the motor have been measured, respectively. The results confirm that the motor successfully provides the desired multi-DOF motion of the rotor around orthogonal axes driven by a single plate stator. Finally, a novel self-oscillation driving circuit for the motor is proposed and driving tests using the circuit are conducted.

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Study on Multi-DOF Ultrasonic Actuator for Laparoscopic Instrument

Shinsuk Park, Kenjiro Takemura and Takashi Maeno

JSME International Journal Series C 47 ( 2 ) 574 - 581 2004.07

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1344-7653

　View Summary

In surgical robots, compact manipulators with multi-degree-of-freedom (DOF) are essential owing to a small work volume in the patient body. Conventional single-DOF actuators such as electromagnetic motors require a multiple number of actuators to generate multi-DOF motion, which in turn results in bulky mechanism combined with transmission device. Our previous work has developed a compact ultrasonic motor capable of generating a multi-DOF rotation of a spherical rotor utilizing three natural vibration modes of a bar-shaped stator. The present study designs and builds a novel multi-DOF master-slave system for laparoscopic surgical procedures, using a single ultrasonic actuator. The system consists of surgical forceps on multi-DOF wrist with joystick controller. Experimental results have confirmed high responsiveness and precise position control of the master-slave system.

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Development of a Multi-Degree-of Freedom USM Using Single Mode of Vibrations

Kayo Otokawa, Takashi Maeno, Kenjiro Takemura

Proc. International Conference on Acoustics 2004 IV   3231 - 3234 2004.04

Research paper (international conference proceedings), Joint Work, Last author, Accepted

　View Summary

従来の多自由度超音波モータの多くは，複数の固有振動モードの固有振動数を縮退させ，これらの組み合わせによって回転子の多自由度運動を実現していた．しかし，振動設計が複雑となるため，実用上問題が多かった．本研究では，複数の振動子をマトリクス状に配置し，固有振動数が異なる複数の固有振動モードを選択的に組み合わせることによって振動子マトリクス上に置かれた移動子に多自由度運動を生成する新たな多自由度超音波モータを開発した．

A Wire-Driven Miniature Five Fingered Robot Hand using Elastic Elements as Joint

Yoichi Ogahara, Yusuke Kawato, Kenjiro Takemura, Takashi Maeno

Proc. The 2003 IEEE/RSJ International Conference on Intelligent Robotics and Systems    2672 - 2677 2003.10

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

マイクロロボットハンドなどの微小な機械システムでは，スケール効果によって摺動部などでの損失の影響が増大するため，一般的な機能要素を用いた設計には限界がある．このため，本研究では関節に弾性ヒンジを用いた5指マイクロロボットハンドを開発した．本ハンドはワイヤ駆動によってヒト指と同様にMP，PIP，DIP関節を駆動する構成である．弾性ヒンジの利用によって，摺動損失の低減およびスペース効率の向上を実現した．

Development of an Ultrasonic Clutch

T. Koyama, K. Takemura, and T. Maeno

Proc. 2003 IEEE International Ultrasonic Symposium (IEEE)     1141 - 1144 2003.10

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1051-0117

　View Summary

In the present paper, a newly developed ultrasonic clutch is proposed. The ultrasonic clutch can solve problems of conventional passive elements, such as time delay, instability, and large size, by using unique characteristics of ultrasonic motor, as fast response, silent motion, and non-magnetic feature. It can also be designed to be smaller than conventional elements due to its simple structure. The clutch locks or releases the rotor by use of ultrasonic levitation phenomenon. First, we have designed the structure of the ultrasonic clutch using an equation of ultrasonic levitation phenomenon, results from structural analysis and finite element (FE) analysis of piezoelectric material of the vibrator. Then we have manufactured the ultrasonic clutch and have conducted a driving experiment. Finally, we have demonstrated that the maximum levitation force is around 20 N and the static friction torque of the ultrasonic clutch is up to 0.14 Nm.

The Frictional Characteristics of Single-Phase Drive-Type USM

Y. Nakagawa, K. Takemura, and T. Maeno

Proc. 2003 IEEE International Ultrasonic Symposium (IEEE)     1762 - 1765 2003.10

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1051-0117

　View Summary

In this paper we analyze the mechanical characteristics of the single-phase-drive type ultrasonic motors. Though single-phase-drive type ultrasonic motors (USMs) has many merits against the multi-phase-drive type USMs, the research of them are not popular and the design method is not established yet. We simulated the static driving characteristics of the single-phase-drive type USM and cleared up the relationship between design parameters and T-N curve, output power and frictional efficiency. Finally we will show the adequacy of the simulations by conducting the driving tests.

Development of an Ultrasonic Clutch for Multi-Fingered Exoskeleton Haptic Device using Passive Force Feedback for Dexterous Teleoperation

Tatsuya Koyama, Kenjiro Takemura, Takashi Maeno

Proc. The 2003 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IEEE)     2229 - 2234 2003.10

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

A novel multi-fingered exoskeleton haptic device using passive force feedback has been proposed by the authors. The haptic device solves the conventional problems of previously developed master-slave systems with force feedback, such as oscillations, complex structures and complicated control algorithm. However some problems still remain in the conventional passive elements. In the present paper an ultrasonic clutch for multi-fingered exoskeleton haptic device with passive force feedback function is developed. The ultrasonic clutch can solve problems of conventional passive elements, such as time delay, instability, and large size, by using unique characteristics of ultrasonic motor as fast response, silent motion, and non-magnetic feature. It can also be designed to be smaller than conventional elements due to its simple structure. The clutch locks or releases the rotor by use of ultrasonic levitation phenomenon. First, we have designed the structure of the ultrasonic clutch using an equation of ultrasonic levitation phenomenon, results from structural analysis and finite element (FE) analysis of piezoelectric material of the vibrator Then we have manufactured the ultrasonic clutch and have conducted a driving experiment. Finally, we have demonstrated that the maximum levitation force is around 20 N and the static friction torque of the ultrasonic clutch is up to 0.14 Nm.

Development of a Robot Finger for Five-fingered Hand using Ultrasonic Motors

Ikuo Yamano, Kenjiro Takemura and Takashi Maeno

Proc. The 2003 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IEEE)     2648 - 2653 2003.10

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

A robot finger is developed for five-fingered robot hand having equal number of DOF to human hand. The robot hand is driven by a new method proposed by authors using ultrasonic motors and elastic elements. The method utilizes restoring force of elastic element as driving power for grasping an object, so that the hand can perform the soft and stable grasping motion with no power supply. In addition, all the components are placed inside the hand thanks to the ultrasonic motors with compact size and high torque at low speed. Applying the driving method to multi-DOF mechanism, a robot index finger is designed and implemented It has equal number of joints and DOF to human index finger, and it is also equal in size to the finger of average adult male. The performance of the robot finger is confirmed by fundamental driving test.

Development of Multi-DOF Actuators for Surgical Tools

Shinsuk Park, Kenjiro Takemura and Takashi Maeno

Proc. The 32nd International Congress and Exposition on Noise Control Engineering    3039 - 3046 2003.08

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

腹腔鏡下手術は腹部にあけた直径10mm以下の穴を介して鉗子および腹腔鏡を体内に挿入し腹腔鏡画像下で手術する低侵襲手術である．患者への負担が少ない代わりに術者には高いスキルが要求される．本研究では，球状回転子に直交3軸回りの多自由度回転を生成し得る多自由度超音波モータを用いて，鉗子先端に手首のような多自由度運動を実現する多自由度鉗子のプロトタイプを実現した．

Design of a Plate Type Multi-DOF Ultrasonic Motor and its Driving Characteristics

Kenjiro Takemura, Yuji Ohno and Takashi Maeno

Proc. IEEE/ASME International Conference on Advanced Intelligent Mechatronics (IEEE)     1309 - 1314 2003.07

Research paper (international conference proceedings), Joint Work, Lead author, Accepted,  ISSN  2159-6255

　View Summary

Multi-DOF actuators have become more useful in the field of robotics, thanks to the increasing number of DOFs of systems. General features of ultrasonic motor are suitable for constructing a direct-drive multi-DOF actuator. However, those previously developed do not have advantages in volume and weight against the multi-DOF motion unit composed of several electromagnetic motors. In the present study authors develop a novel multi-DOF ultrasonic motor with a plate stator and a spherical rotor. First, a new driving principle of the motor is proposed. Next, the stator geometry is designed in detail using finite element method, and the prototype of the multi-DOF ultrasonic motor with plate stator is produced. The stator is relatively compact against the rotor. Then, vibration characteristics of the stator and driving characteristics of the motor have been measured respectively. The result confirms that the motor successfully provides the multi-DOF motion of rotor around orthogonal axes by single plate stator. Finally, self-oscillation driving circuit for the motor is proposed.

Method for Controlling Multi-DOF Ultrasonic Motor using Neural Network

Kenjiro Takemura and Takashi Maeno

Journal of Robotics and Mechatronics 15 ( 2 ) 114 - 120 2003.04

Research paper (scientific journal), Joint Work, Lead author, Accepted

　View Summary

多自由度超音波モータは振動方向が互いに直交する3つの固有振動モードを組み合わせて球状回転子に任意軸回りの回転運動を生成する．すなわち，入力パラメータ7つに対して出力3つとなる冗長非線形性を有している．したがって，所望の駆動状態を実現するための入力の組み合わせは複数存在するため，超音波モータに対する経験的所見とニューラルネットワークによる非線形写像を組み合わせて，所望の駆動状態に対して唯一の入力を決定する逆モデルを提案し，これを用いて多自由度超音波モータの駆動制御を実現した．

パッシブフォースフィードバックを用いた多指エクゾスケルトン型ハプティックデバイスの開発

小山辰也，山野郁男，竹村研治郎，前野隆司

日本バーチャルリアリティー学会論文誌 7 ( 4 ) 565 - 574 2002.12

Research paper (scientific journal), Joint Work, Accepted

　View Summary

本研究では，物体との接触／非接触によって力／位置のフィードバックが切り替えられるパッシブフォースフィードバック制御法を提案した．また，本制御法を用いて複雑な手指動作のテレオペレーションを実現する多指エクゾスケルトン型ハプティックデバイスを開発した．本デバイスは，操作者の指先端に接続したリンクとリンク根元部に配置されたクラッチから構成される．操作者に反力を提示する際にはクラッチによるリンク全体の固定とデバイス内の弾性要素の変形を利用する．

Multi-Fingered Exoskeleton Haptic Device using Passive Force Feedback for Dexterous Teleoperation

Tatsuya Koyama, Ikuo Yamano, Kenjiro Takemura and Takashi Maeno

Proc. 2002 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IEEE)     2905 - 2910 2002.09

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

A novel control, methodology for master-slave systems using passive force feedback has been proposed by the authors. The methodology solves the conventional problems of previously developed master-slave systems with force feedback, such as oscillations, complex structures and complicated control algorithm. In the present paper a multi-fingered exoskeleton haptic device (master hand) with passive force feedback function is developed. First, the exoskeleton master hand with three fingers (12 degrees of freedom) is designed and implemented. Each finger of the master hand consists of a link mechanism with elastic-shaft joints and clutches. Using link mechanisms, the master hand measures fingertip positions and angles of index finger middle finger and thumb. Furthermore, it also enables passive force feedback to an operator by the same link mechanism used for the geometric measurements. Then, a virtual reality system of human hand is constructed using the master hand and the control methodology. Using the system, sensory evaluations are conducted on human subjects to confirm the usability of the developed master hand and the possibility of the control methodology in the virtual reality system. As a result, the subjects possibly recognize the stiffness of the objects in the virtual environment.

Control of Multi-DOF Ultrasonic Motor using Neural Network based Inverse Model

Kenjiro Takemura and Takashi Maeno

Proc. 2002 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IEEE)     2187 - 2192 2002.09

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

dA multi-DOF ultrasonic motor developed by the authors is capable of generating multi-DOF rotation of a spherical rotor using three orthogonal natural vibrations of a bar-shaped stator. The ultrasonic motor is suitable for making small, light weight and simple multi-DOF motion unit. In the present paper, a control methodology for the multi-DOF ultrasonic motor is proposed and a motion control test using the method is conducted. First, an inverse model of the multi-DOF ultrasonic motor is developed using our prior knowledge in ultrasonic motors and neural network technique in order to deal with the redundancy and non-linearity of driving characteristics. Second, a novel control method using the inverse model is proposed. Then, motion control tests are conducted to confirm the ability of the proposed control method. The results confirm that the rotor can be rotated around arbitrary rotational axis using the inverse model, and that the proposed control method does work successfully.

Method for Controlling Master-Slave Robots using Switching and Elastic Elements

Ikuo Yamano, Kenjiro Takemura, Ken Endo and Takashi Maeno

Proc. IEEE International Conference on Robotics and Automation (IEEE)     1717 - 1722 2002.05

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

A new type of master-slave control methodology, which has the merits of both unilateral and bilateral ones, is proposed. The methodology is built on switching the unilateral feedback controls of position and force as required using switching and elastic elements. Proposed methodology not only eliminates the demerits of bilateral control, but also supplies the mechanical force feedback to the operator. It utilizes a feature of human factor that direct displacement feedback is not as important as visual and force feedback. Effectiveness of the proposed method is confirmed by experiments using a developed simple single axis master-slave arm system. Driving test of the experimental devices and sensory evaluations are conducted. As a result, it is confirmed that the methodology successfully provides the sense of touch to the operator of the system.

Numerical Analyses on Multi-DOF Ultrasonic Motor - Development of Analysis Method and Results -

Kenjiro Takemura and Takashi Maeno

Proc. IEEE International Conference on Robotics and Automation (IEEE)     2387 - 2392 2002.05

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

A multi-DOF ultrasonic motor developed in our previous study has significant potentials for dexterous actuation. The ultrasonic motor provides multi-DOF rotation of a spherical rotor using three natural vibrations of a bar-shaped stator. In this paper, numerical analyses on the multi-DOF ultrasonic motor are conducted. First, a forward model of multi-DOF ultrasonic motor is developed considering the frictional condition between the rotor/stator. Using the forward model, driving state of the multi-DOF ultrasonic motor under arbitrary combination of vibrations is clarified. Second, an inverse model of the multi-DOF ultrasonic motor is also developed. The inverse model is constructed using experienced knowledge about ultrasonic motor and neural network technique. An appropriate input for the multi-DOF ultrasonic motor with regard to arbitrary rotational axis is estimated using the inverse model. The proposed models are available not only for our motor but for all multi-DOF ultrasonic motors.

Development of a Master-Slave System for Active Endoscope Using a Multi-DOF Ultrasonic Motor

Kenjiro Takemura, Dai Harada, Takashi Maeno

Transactions on Control, Automation and Systems Engineering 4 ( 1 ) 17 - 22 2002.03

Research paper (scientific journal), Joint Work, Lead author, Accepted

　View Summary

多自由度超音波モータを利用した能動内視鏡のためのマスタースレーブシステムを改廃した．ケース，小型位置検出機構を開発するとともに，1つのモータによって多自由度駆動制御を実現した．

Design and Control of an Ultrasonic Motor Capable of Generating Multi-DOF Motion

Kenjiro Takemura, Takashi Maeno

IEEE/ASME Trans. Mechatronics (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC)  6 ( 4 ) 499 - 506 2001.12

Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  1083-4435

　View Summary

A multi-degree-of-freedom (DOF) ultrasonic motor consisting of a bar-shaped stator and a spherical rotor was developed. It can generate 3-DOF rotation of the rotor around perpendicular axes using bending vibrations and a longitudinal vibration of the stator, which was designed using finite element analysis. From the simulated driving characteristics, a control method for the ultrasonic motor was proposed. Following this, the driving characteristics of the motor under open-loop control and closed-loop control were measured experimentally. Mufti-DOF position control of the rotor was achieved successfully using the proposed control method.

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A Master-Slave System using a Multi-DOF Ultrasonic Motor and its Controller designed considering Measured and Simulated Driving Characteristics

Kenjiro Takemura, Dai Harada, and Takashi Maeno

Proc. 2001 IEEE/RSJ International Conference on Intelligent Robots and Systems (IEEE)     1977 - 1982 2001.10

Research paper (international conference proceedings), Joint Work, Accepted

　View Summary

Master-slave active robot hands and endoscopes, which provide dexterous manipulations and wide views like human hands and eyes, are required to be constructed. We have previously developed a multi-DOF ultrasonic motor consisting of a spherical rotor and a bar-shaped stator. The rotor rotates around three perpendicular axes using three natural vibration modes of the stator. In this study, a multi-DOF unilateral master-slave system using the multi-DOF ultrasonic motor is developed. Master and slave arms for the system have similar configurations, so that an operator can easily handle the master-slave system. First, driving characteristics of the multi-DOF ultrasonic motor are clarified experimentally and analytically in order to design the slave arm and its controller. Next, the master-slave arms and the unilateral feedback controller for the master-slave system are developed. Finally, the motion control tests of the system are performed to show the applicability of the master-slave system.

多自由度超音波モータの駆動状態推定法

竹村研治郎，前野隆司

日本音響学会誌 (日本音響学会)  57 ( 7 ) 445 - 452 2001.07

Research paper (scientific journal), Joint Work, Lead author, Accepted

　View Summary

多自由度超音波モータは，振動子の互いに直交する固有振動モードを適当な位相差をもって励振し，回転子に多自由度回転運動を実現するものである．しかし，各振動モードの振幅および位相が任意の値となるときの回転子の回転軸は容易に予想できない．このため，本研究では各固有振動モードが任意の振幅および位相で励振された際に回転子におよぼす駆動力を摩擦モデルにより算出し，このときの回転軸，トルクおよび回転速度を推定する手法を提案した．

Development of a Master-Slave System for Active Endoscope using a Multi-DOF Ultrasonic Motor

Kenjiro Takemura, Dai Harada, and Takashi Maeno

Proc. The 32nd International Symposium on Robotics    254 - 259 2001.04

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

多自由度超音波モータは円柱状振動子の縦振動と曲げ振動を適当に組み合わせることによって振動子先端に加圧接触された球状回転子に直交3軸回りの多自由度回転運動を生成するモータである．このため，上記モータを能動内視鏡の駆動に応用することを提案した．本研究では能動内視鏡のプロトタイプを開発するとともに，マスタ・スレーブシステムとして駆動制御を実現した．

Method for Controlling a Multi-DOF Ultrasonic Motor using a Sigmoid Function

Kenjiro Takemura, T. Maeno

Proc. The 5th International Conference on Motion and Vibration Control    427 - 432 2000.12

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

本研究では，円柱状振動子の縦振動と曲げ振動を用いた多自由度超音波モータの設計および駆動制御を行った．多自由度超音波モータは励振する縦振動および曲げ振動の位相差を-90度から90度まで連続に変化させることによって回転速度をCWからCCWまで連続に変化させることができる．このため，上記の位相差を操作パラメータとしてシグモイド関数を用いて-90度から90度まで所望の回転数に応じて変化させる多自由度超音波モータの速度制御法を提案した．

Characteristics of an Ultrasonic motor Capable of Generating a Multi-Degrees of Freedom Motion

Kenjiro Takemura, Takashi Maeno

Proc. IEEE International Coference on Robotics and Automation    3660 - 3665 2000.04

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

円柱状振動子の固有振動モードのうち，縦振動1次モードと曲げ振動2次モードを縮退させ，これらを適当な位相差をもって励振することによって，振動子先端に接触した球場回転子に多自由度運動を生成する多自由度超音波モータを開発した．本研究では，本モータを直交3軸回りに駆動させた際の無負荷回転特性および速度-負荷特性を実験によって明らかにした．

縦振動と横振動の縮退に基づく多自由度超音波モータの開発

前野隆司，竹村研治郎，小島信行

日本ロボット学会誌 (日本ロボット学会)  16 ( 8 ) 1115 - 1122 1998.11

Research paper (scientific journal), Joint Work, Accepted

　View Summary

円柱状振動子の縦振動と横振動を用いた多自由度超音波モータを実現した．すなわち，円柱の固有振動モードのうち振動方向が互いに直交し，縮退する縦振動と2つの横振動を適当な位相差をもって励振し，振動子先端に直交3軸回りの楕円運動を生成すると，振動子先端に接触した球状回転子は上記軸回りに多自由度回転される．本研究では，駆動原理の提案，有限要素法を用いた振動設計およびプロトタイプによる駆動確認を行った．

Development of a Bar-Shaped Ultrasonic Motor for Three-Degrees of Freedom Motion

K. Takemura, N. Kojima, and T. Maeno

Proc. The 4th International Conference on Motion and Vibration Control    195 - 200 1998.08

Research paper (international conference proceedings), Joint Work, Lead author, Accepted

　View Summary

円柱状振動子の縦振動と曲げ振動を用いた多自由度超音波モータを実現した．すなわち，円柱の固有振動モードのうち振動方向が互いに直交し，縮退する縦振動と2つの曲げ振動を適当な位相差をもって励振し，振動子先端に直交3軸回りの楕円運動を生成すると，振動子先端に接触した球状回転子は上記軸回りに多自由度回転される．本研究では，駆動原理を提案し，プロトタイプによって原理を確認した．