講演情報
[10a-PA1-26]Role of AuNPs in Bubble-Assisted Propulsion of Glass Microspheres
〇(M2)Lan Chen1,2, Pengnian Zhao1,2, Sosuke Omata2, Hiroto Yamada2, Yuta Futamata2, Satoshi Honma2, Tian-Song Deng1, Hironori Ito2 (1.Hangzhou Dianzi University, 2.University of Yamanashi)
キーワード：
Laser-Driven Actuation、Plasmonic Photothermal Heating、Optical Manipulation
Bubble-assisted Marangoni propulsion has attracted considerable attention as a method for converting optical energy into mechanical motion in microscale systems. Gold nanoparticles (AuNPs) are widely used as photothermal materials because of their strong light absorption and efficient heat generation under laser irradiation. In this study, bare glass microspheres and AuNP-coated glass microspheres were compared to investigate the role of AuNPs in bubble-assisted propulsion. A 532 nm continuous-wave laser (0.35 W) was focused onto the microsphere surface in acetylacetone, and the resulting bubble formation and propulsion behavior were observed using a high-speed camera. While the bare glass microsphere exhibited bubble formation without measurable displacement after 7.26 s of irradiation, the AuNP-coated microsphere showed stable propulsion and traveled approximately 1.1 mm within 0.176 s. Furthermore, bubble generation without noticeable motion was observed when the laser was focused on AuNP-uncoated regions, whereas stable propulsion occurred only on AuNP-coated regions. These results indicate that bubble formation alone is insufficient to induce propulsion and that AuNP-mediated photothermal heating plays a crucial role in generating the driving force required for stable bubble-assisted motion. The findings provide direct evidence of the importance of AuNP distribution in laser-driven propulsion and offer useful insights for the design of efficient microrobotic systems.