Papers - Takemura, Kenjiro

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

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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

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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

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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

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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

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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

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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