Transportation of Nano/Microparticles via Photoinduced Crawling of Azobenzene Crystals

Abstract The stimulus‐driven motion of microscale objects on solid surfaces is a promising process to realize the manipulation of microdroplets, which has applications in fields areas such as material accumulation and sensing at a micro level. Light is an effective external stimulus for object manipulation because it can provide contactless spatial and temporal control. In this study, a new method is devised to transport nano/micromaterials on a glass surface by exploiting the photoinduced crawling motion of crystals. 4‐(methylamino)azobenzene (4‐MAAB) crystals are used to transport nano/micromaterials via photoirradiation from a single visible‐light source without using expensive equipment such as lasers and positioning devices. Nano/micromaterials mixed with the 4‐MAAB crystals are successfully transported with the crawling 4‐MAAB crystals. The nano/micromaterial transport is tracked using the fluorescence from the nano/micromaterials embedded into the 4‐MAAB crystals. In situ time‐resolved X‐ray diffraction measurements are also conducted for mechanistic analysis. This study offers new development paths in fields such as microfluidics and microrobotics.