Terakawa, Mitsuhiro

写真a

Affiliation

Faculty of Science and Technology, Department of Electronics and Electrical Engineering （Yagami）

Position

Professor

Related Websites
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Career 【 Display / hide 】

  • 2005
    -
    2007

    Japan Society for the Promotion of Science, Doctoral Course Students (DC)

  • 2007
    -
    2008

    Massachusetts General Hospital, Wellman Center for Photomedicine, Research Fellow

  • 2007
    -
    2008

    Japan Society for the Promotion of Science, Postdoctoral Fellow

  • 2009
    -
    2010

    Keio University, Research Associate

  • 2010.04
    -
    2013.03

    Keio University, Department of Electronics and Electrical Engineering, Assistant Professor

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Academic Background 【 Display / hide 】

  • 2003.03

    Keio University, Science and Technology, Department of Electronics and Electrical Engineering

    University, Graduated

  • 2005.03

    Keio University, Science and Technology, Integrated Design Engineering

    Graduate School, Completed, Master's course

  • 2007.09

    Keio University, Science and Technology, Integrated Design Engineering

    Graduate School, Completed, Doctoral course

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Academic Degrees 【 Display / hide 】

  • 博士（工学）, 慶應義塾大学, 2007.09

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Matters concerning Career Achievements 【 Display / hide 】

  • 2013.04
    -
    2014.03

    電子工学科２年生担任

  • 2014.04
    -
    2015.03

    大学院総合デザイン工学専攻　専攻幹事

  • 2014.04
    -
    2015.03

    電子工学科３年生担任

  • 2015.04
    -
    2018.03

    大学院　研究科委員

  • 2016.04
    -
    2018.03

    大学院総合デザイン工学専攻　専攻幹事

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Research Areas 【 Display / hide 】

  • Nanotechnology/Materials / Optical engineering and photon science (laser processing, multi-photon manufacturing, softmaterials and biomaterials)

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Research Keywords 【 Display / hide 】

  • Laser processing

  • Soft materials

  • Biomaterials

  • Laser-induced carbonization and graphitization

  • Laser-based precise processing

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Books 【 Display / hide 】

  • Laser-Induced Carbonization and Graphitization. (in Handbook of Laser Micro- and Nano-Engineering)

    Mitsuhiro Terakawa, Springer Nature Switzerland AG, 2021.05

  • Laser-Induced Carbonization and Graphitization

    Terakawa M., Handbook of Laser Micro-and Nano-Engineering, 2021.01

    　View Summary

    This chapter presents the carbonization and graphitization of polymer materials through laser-based degradation to fabricate conductive structures. The fundamentals of degradation are first explained based on the thermal degradation and photodegradation of polymers to alter the chemical structures to form carbon-rich products. This process yields electrically conductive graphitic carbon under certain conditions. By using a laser as an energy source for the degradation, spatially targeted areas on bendable and stretchable elastomers can be altered to conductive structures that can be used in flexible electronics. Although laser-induced carbonization and graphitization can be traced back to the 1980s, research in this field was revived in the mid-2010s, and increased attention has been paid since then. Fundamental studies along with material analyses and applications of the formed conductive structures in various devices, such as supercapacitors, strain sensors, and bioelectronic devices, are also reviewed in this chapter. In addition, laser degradation of poly-dimethylsiloxane, which is a versatile polymer for flexible devices, and natural materials, such as cellulose, are highlighted as emerging precursors of laser-induced conductive structures.

  • Micro and Nano Fabrication Technology

    Mitsuhiro Terakawa, Springer, 2018

    Scope: Chapter "Femtosecond Laser Direct Writing"

  • Ultrafast Laser Processing: From Micro- to Nanoscale

    Mitsuhiro Terakawa, Minoru Obara, Pan Stanford Publishing, 2013

    Scope: Chapter 7 Nanoablation Using Nanosphere and Nanotip

  • Gold Nanoparticles: Properties, Characterization, and Fabrication

    Y. Tanaka, M. Terakawa, M. Obara, N. Nedyalkov, P. Atanasov, Nova Science Publishers, 2009

    Scope: Chapter 6 Plasmonic Nanopatterning of the Material Surface Mediated with Gold Nanoparticles Excited by a Femtosecond Laser Pulse

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Papers 【 Display / hide 】

  • Light-triggered transmittance control in thermoresponsive hydrogels by femtosecond laser direct writing

    K. Kashikawa, H. Tomikawa, H. Onoe, M. Terakawa

    ACS Applied Optical Materials （ACS)  2 （ 4 ） 565 - 573 2024.03

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

    　View Summary

    Thermoresponsive hydrogels, which exhibit changes in their optical properties and volume due to temperature variations, are promising candidates for applications in soft devices. In this study, we demonstrate the modulation of transmittance in a thermoresponsive hydrogel through light stimulation employing gold microstructures fabricated via multiphoton photoreduction. The spatial integration of photoresponsiveness, attributed to high-density gold nanoparticles within the thermoresponsive hydrogel, was accomplished through the high-speed laser scanning of femtosecond laser pulses. The temperature measurement during the fabrication of the gold microstructure revealed that the high-speed and multiple scanning over the same path effectively reduced the temperature in the irradiated area of femtosecond laser pulses. The present approach enabled the mitigation of thermal effects during the fabrication, resulting in minimizing distortion in the fine lines of the structures. Upon exposure to stimulus light, a rapid change in the transmittance of the region where the structures were fabricated was prominently observed. The present method unveils a promising avenue for the advancement of light-responsive soft devices.

  • Temperature measurement and morphological/crystalline differences in the laser-induced carbonization of polydimethylsiloxane

    M. Kai, S. Hayashi, K. Kashikawa, M. Terakawa

    Optical Materials Express （OPTICA)  14 （ 4 ） 955 - 964 2024.03

    Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted,  ISSN  20102690

    　View Summary

    Laser-induced carbonization, which allows for the facile generation of graphitic carbon, is considered a promising technique for fabricating arbitrary conductive microstructures. The morphology and crystallinity of the resulting product are acknowledged to be significantly influenced by laser irradiation conditions. However, unlike discussions pertaining to furnaces where detailed considerations of applied temperature and resulting products are common, discussions on the process of laser-induced carbonization are limited. In recent years, reports have shown that using polydimethylsiloxane (PDMS) as a precursor material not only produces graphitic carbon but also results in the formation of silicon carbide. In this study, we utilized a thermographic camera to measure temperature changes during laser-induced carbonization, aiming to elucidate the correlation between PDMS temperature fluctuations and the morphology and crystallinity of the resulting graphitic carbon. The results demonstrate that the morphology and crystallinity of the graphitic carbon formed through laser-induced carbonization are not solely determined by the maximum temperature in the laser-irradiated area. The temperature changes during laser irradiation play a crucial role in the selective generation of these materials.

  • Defect-initiated formation mechanism of 3D carbon tracks on flexible transparent substrates by laser irradiation

    S. Hayashi, X. Du, M. Rupp, K. A. Filsinger, M. Terakawa, C. B. Arnold

    Optics and Laser Technology （ELSEVIER)  174   110686 2024.02

    Joint Work, Accepted,  ISSN  00303992

    　View Summary

    Laser direct writing of 3D carbon structures onto flexible polymer substrates offers potential of rapid roll-to-roll manufacturing for a variety of key applications, including large area sensors, flexible electronics, robotics, energy storage/conversion, and other consumer applications. The specific formation mechanism of the carbon structures has been an issue of debate for many years with the prevailing notion of a simple photothermal conversion reaction that mainly depends on the total energy input. However, this view has been shown to be inconsistent with experimental observations of nonlinear changes in the resulting structures when multiple processing parameters are simultaneously changed. In this study, we propose a formation mechanism based on the nucleation and growth of laser-induced defects, which is experimentally validated by irradiating a continuous wave laser beam onto polydimethylsiloxane. The model is further validated by intentionally introducing controlled defects by femtosecond laser irradiation, and indicate the implications of a two-laser laser direct writing technique to go beyond the current processing limits. These results clarify the previously ambiguous mechanisms by which carbon structures form under laser irradiation and provide a deeper understanding of how to control photothermal processes for advanced material processing.

  • Spatially-selective enhancement of mechanical strength through localized cross-linking of double network hydrogels

    Kaneto Tsunemitsu, Akira Watanabe, Hiroaki Onoe, Mitsuhiro Terakawa

    Optical Materials Express （OPTICA)  13 （ 10 ） 2914 - 2924 2023.09

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

    　View Summary

    To advance the development of flexible materials for soft robotics applications, it is crucial to enhance the elastic modulus and breaking the stress of soft materials, such as hydrogels. Double network hydrogels (DN gels) have displayed remarkable mechanical strength owing to their unique network structure composed of two types of polymer networks. However, current fabrication methods for DN gels entail cross-linking two distinct hydrogel polymers throughout the entire hydrogel matrix. In this study, we focused on employing multi-photon polymerization (MPP) with femtosecond laser pulses as a cross-linking method for hydrogels to achieve spatially selective formation of DN gel structures at the micrometer scale, along with the consequent improvement in local mechanical strength. We assessed the mechanical properties of the fabricated structures and confirmed that the mechanical strength varied within the regions where DN gel was locally formed.

  • Laser-induced dielectric to conductor transformation on the surface of aluminium nitride ceramic

    Nedyalkov N., Dikovska A., Nikov R., Koleva M., Grochowska K., Jendrzejewski R., Terakawa M.

    Optics and Laser Technology （Optics and Laser Technology)  163 2023.08

    ISSN  00303992

    　View Summary

    In this work formation of conductive lines on the surface of AlN ceramic induced by laser radiation is presented. The transformation to conductive state is done be ablation of the ceramic surface using nanosecond Nd:YAG laser. The dependences of the processing conditions as applied laser fluence and the pulse overlapping on the resistance value are obtained for different surface modifications including straight lines, ∟, and ┼ shapes. The formation of conductive structures is also studied for application of laser irradiation at the second (532 nm), third (355 nm) and fourth (266 nm) harmonics of the laser system. It is found that the resistance strongly depends on the processing conditions, as at appropriate choice it can be varied in a range of order of magnitude. Processing parameters windows are defined where the structure resistance has a minimal value. The performed analyses based on TEM, SEM, EDX, and Raman spectroscopy indicate that formation of aluminium layer, its oxidation and morphology define the processed areas conductivity. The role of oxidation is also confirmed by analyses of structures fabricated in vacuum, where significant reduction of the resistance is observed. It is found however, that a decrease of the ambient air pressure to 10 Torr is sufficient to obtain structures resistance of the same order as for processing in vacuum. Calculated data about the thickness of the conductive layer is also presented. The obtained results could be used in the design of microelectronic components, resistive elements, and novel optical materials.

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Papers, etc., Registered in KOARA 【 Display / hide 】

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Reviews, Commentaries, etc. 【 Display / hide 】

  • Laser-based molecular delivery and its applications in plant science

    D. Heinemann, M. Zabic, M. Terakawa, J. Boch

    Plant Methods (Springer Nature)  18 ( 82 ) 1 - 14 2022.06

    Joint Work

  • レーザー炭化によるグラフェン生成とその新展開

    寺川光洋

    OPTORONICS 41 ( 484 ) 153 - 158 2022.04

    Article, review, commentary, editorial, etc. (other), Single Work, Lead author, Last author, Corresponding author

  • フェムト秒レーザー改質による高分子材料への導電性付与

    林秀一郎, 寺川光洋

    表面技術 71 ( 11 ) 684 - 688 2020.11

  • 超短パルスレーザーによる多光子還元

    寺川光洋

    光アライアンス 30 ( 8 ) 55 - 58 2019.08

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

  • Femtosecond Laser Processing of Biodegradable Polymers

    Mitsuhiro Terakawa

    Applied Sciences 8 ( 7 ) 1123 2018.07

    Article, review, commentary, editorial, etc. (scientific journal), Single Work

    　View Summary

    © 2018 by the authors. Biodegradable polymers have attracted increasing attention in tissue engineering and drug delivery systems owing to their high biocompatibility and biodegradability. Among the various methods for shape forming and modification of biodegradable polymers, laser processing has advantages in a dry processing approach that can process complex-shaped surfaces without using toxic chemical components. This review provides an overview of femtosecond laser processing of biodegradable polymers, especially in the last decade. The interaction mechanism of femtosecond laser pulse and biodegradable polymers, e.g., bond dissociation after laser irradiation, affects the degradable property of biodegradable polymers, which has the potential to control the degradation and sustainability of a structure. Applied studies on controlling cell behavior, tissue scaffolding, and drug release are also described.

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Presentations 【 Display / hide 】

  • (Invited) Laser-driven conversion of sustainable materials for electrical applications

    M. Terakawa

    SPIE Photonics Europe 2024, 

    2024.04
    , 

    Oral presentation (invited, special)

  • Formation of laser-induced porous graphitic carbon structures for high capacitance supercapacitors

    M. Kato, Y. Kondo, Y. Hattori, R. Funayama, S. Hayashi, M. Terakawa

    SPIE Photonics Europe 2024, 

    2024.04
    , 

    Oral presentation (general)

  • Biocompatible hydrogel-based plasmonic sensor for glucose sensing

    A. Ahmed, T. Amend, C. Wenck, M. Terakawa, M. L. Torres-Mapa, A. Heisterkamp

    SPIE Photonics Europe 2024 , 

    2024.04
    , 

    Oral presentation (general)

  • （招待講演）レーザ誘起グラフェンの基礎から応用まで

    寺川光洋

    第71回応用物理学会春季学術講演会 ー シンポジウムT4 レーザー改質プロセスの基礎と先端技術, 

    2024.03
    , 

    Oral presentation (invited, special)

  • Controlling Optical Response of Hydrogel using Metallic Microstructures Fabricated with High-Speed Scanning of Femtosecond Laser Pulses

    K. Kashikawa, H. Tomikawa, H. Onoe, M. Terakawa

    2023 MRS Fall Meetting & Exhibit, 

    2023.11
    -
    2023.12
    , 

    Poster presentation

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

  • スマートマテリアルに駆動力と機能を付与するレーザープロセシング技術の確立

    2022.04
    -
    2026.03

    文部科学省・日本学術振興会, 科学研究費補助金 基盤研究(B), No Setting

  • レーザプロセシングにより実現するエネルギー・ハーベスティング・デバイス

    2022.04
    -
    2024.03

    東電記念財団, 研究助成（基礎研究）, No Setting

  • 高繰り返しフェムト秒レーザパルス照射による高結晶性かつ高導電性微細構造の直接描画

    2021.09
    -
    2024.03

    天田財団, 重点研究開発助成　課題研究, No Setting

  • 回折限界を超える極微細金属構造のレーザーファブリケーション

    2018.07
    -
    2021.03

    文部科学省・日本学術振興会, 科学研究費補助金　挑戦的研究（萌芽）, Research grant, Principal investigator

  • 三次元多光子レーザープロセシングによる機能因子放出スキャフォールドの実現

    2018.04
    -
    2022.03

    文部科学省・日本学術振興会, 科学研究費補助金　基盤研究(B), Research grant, Principal investigator

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Intellectual Property Rights, etc. 【 Display / hide 】

  • レーザーを用いた薬剤放出方法

    Date applied： 2013-046732  2013.03 

    Patent

  • 移植組織または臓器への薬剤導入方法ならびに薬剤導入装置

    Date applied： 特願2007-196580  2007.07 

    Date announced： 特開2008-49150   

    Patent

  • Method and apparatus for drug delivery to tissue or organ for transplant

    Date applied：   2007 

    Date announced： US 2009/0233987 A1  2009 

    Patent

  • 細胞への薬剤導入方法および細胞への薬剤導入装置

    Date applied： 特願2006-113384  2006.04 

    Date announced： 特開2007-284379   

    Patent

  • 薬剤導入方法及び薬剤導入装置

    Date applied： 特願2004-147971  2004.05 

    Date announced： 特開2005-330194   

    Patent

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Awards 【 Display / hide 】

  • SPIE Fellow

    2023.01, SPIE (International Society for Optics and Photonics)

    Type of Award： Other

  • 電子・情報・システム部門研究会 優秀論文発表賞

    2014.09, 電気学会

  • 応用物理学会　講演奨励賞

    TERAKAWA Mitsuhiro, 2012.03, 応用物理学会, フェムト秒レーザの多微粒子レンズ集光場による細胞膜の単一パルスプロセッシング

    Type of Award： Award from Japanese society, conference, symposium, etc.

  • 慶應義塾大学 総合デザイン工学専攻 優秀研究活動賞 (博士)

    TERAKAWA Mitsuhiro, 2008.03

    Type of Award： Keio commendation etc.

  • 慶應義塾大学 藤原賞

    TERAKAWA Mitsuhiro, 2007.03

    Type of Award： Keio commendation etc.

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Other 【 Display / hide 】

  • 2017年11月

    　View Details

    The Optical Society (OSA) News Release: Metal-Silicone Microstructures Could Enable New Types of Flexible Optical and Electrical Devices

  • 2014年03月

    　View Details

    SPIE Newsroom: Femtosecond laser pulses for smart drug delivery

  • 2012年04月

    　View Details

    SPIE Newsroom: Ultrafast near- and far-field nanoablation patterning

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Courses Taught 【 Display / hide 】

  • SEMINOR IN ELECTRONICS AND INFOTMATION ENGINEERING(2)

    2024

  • RECITATION IN ELECTRONICS AND INFORMATION ENGINEERING

    2024

  • PHYSICS D

    2024

  • PHYSICS C

    2024

  • OPTICS AND QUANTUM ELECTRONICS

    2024

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Memberships in Academic Societies 【 Display / hide 】

  • Fellow of SPIE, 

    2023.01
    -
    Present

  • SPIE, Senior Member, 

    2019.06
    -
    Present

  • OSA, Senior Member, 

    2019.06
    -
    Present

  • Japan Laser Processing Society, 

    2013.04
    -
    Present

  • Japan Society for Laser Surgery and Medicine, 

    2012.11
    -
    2020.09

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Committee Experiences 【 Display / hide 】

  • 2024.04
    -
    Present

    副代表幹事, 光産業技術振興協会　多元技術融合光プロセス研究会

  • 2023.12
    -
    2025.11

    次世代レーザプロセシング技術と応用調査専門委員会 委員, 電気学会

  • 2023.08
    -
    2025.09

    Co-Chair and Program Committee Chair, The 9th International Congress on Laser Advanced Materials Processing

  • 2023.07
    -
    2024.06

    Co-Chair and LPM2025 Program Chair, The 25th International Symposium on Laser Precision Microfabrication

  • 2023.07
    -
    Present

    理事, 一般社団法人レーザ加工学会

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