Functionalization and control of grouping motion of artificial microobjects

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K18968
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 27:Chemical engineering and related fields
• Research Institution: University of Tsukuba
• Principal Investigator: Suzuki Hiroaki 筑波大学, 数理物質系, 教授 (20282337)
• Project Period (FY): 2018-06-29 – 2020-03-31
• Keywords: マイクロモータ / 微小電極 / 電極反応 / 濃度勾配 / 局所電場 / 集団運動

Outline of Final Research Achievements

We have fabricated micromotors that behave like bacteria. As a next step, grouping motion was realized by chemical stimuli. Positively and negatively charged polystyrene beads were prepared. A cell to observe the movement of microbeads was made with a glass substrate with gold microelectrodes and a transparent ITO electrode plate along with a poly(dimethyilsiloxane) container. When the pH around the microelectrodes was changed by the electrolysis of water using the microelectrode, the microbeads approached to and moved away from the microelectrode depending on the polarity of the potential applied to the microelectrode. The same experiment was conducted by reducing and oxidizing hydrogen peroxide. In this case, the same grouping behavior was observed with lower applied potentials, suggesting that the movement of the microbeads was caused by local electric field gradient formed around the microelectrode.

Free Research Field

センサ・マイクロマシン

Academic Significance and Societal Importance of the Research Achievements

近年、様々なスケールで生命体を模倣しようとする試みが進められているが、今回の研究で目指したのは、マイクロメートルオーダーの物体に生命的な挙動をさせるものである。実際に化学物質の局所的な濃度変化により、マイクロビーズを集合・離散させることができた。本研究は人口構造体により、走化性という微生物的挙動をもとにした集合・離散運動を実現するという学術的な興味からスタートしたが、将来的には、多様な分野への応用を目指した高感度バイオセンシングへの応用も可能と思われる。