Challenge of Position Control of Biomedical Microrobot Using Self-Propulsion and Magnetic Steering

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K21943
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 20:Mechanical dynamics, robotics, and related fields
• Research Institution: The University of Tokyo (2020); Nagoya University (2019)
• Principal Investigator: Arai Fumihito 東京大学, 大学院工学系研究科(工学部), 教授 (90221051)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: マイクロ・ナノデバイス / マイクロマシン / 燃料電池 / 機械力学・制御 / バイオ関連機器

Outline of Final Research Achievements

We tried to realize a new self-propelled swimming microrobot and its position control system. The microrobot is integrated with a biofuel cell that uses glucose and oxygen as fuels supplied in the living body, and an electroosmotic propulsion mechanism that uses the electroosmotic flow reaction force generated by the biofuel cell. The control system can steer the microrobot incorporated with magnetic nanoparticles by external magnetic fields. We established a fabricating method for the microrobots made of photocurable composites containing nanoparticles using two-photon absorption three-dimensional lithography. Using about 10 μm microrobots by the fabrication method, we confirmed the self-propulsion velocity of 100 μm/s or more in a glucose solution. Therefore, we demonstrated the smaller and faster feature of that self-propelled mechanism expected theoretically. Furthermore, we developed a Helmholtz coil system for the steering control.

Free Research Field

機械力学、ロボティクスおよびその関連分野

Academic Significance and Societal Importance of the Research Achievements

本方式のマイクロロボットでは，生体で動作する動力源と小型化するほど高速となる自己推進機構を備え，操舵にのみ磁場を用いるため均一磁場生成と方向制御のみの簡略な装置構成となる．従って本方式は従来のマイクロロボット技術に対し，医用マイクロロボットの駆動・制御方式として優位かつ革新的であり，新規医療システムの創出に貢献できる可能性がある．特に従来のロボットでは到達が困難であった数100 μm以下の細く小さい領域での応用に適している．例えば，超極細の柔軟なカテーテルガイドワイヤ先端に配置し牽引・誘導するロボットや，所望の位置に薬剤などを搬送・投与する移動マイクロロボットなどが考えられる．