An artificial acoustics-actuated microrobot bioinspired by Chlamydomonas

Chlamydomonas, a microorganism with significant potential for various biotechnological and industrial applications. However, bioorganisms are always vulnerable and contingent, while artificial microrobots with robust and stable mechanical properties, making them highly desirable for expanding applications. Herein, we propose an artificial Chlamydomonas-like acoustics-actuated microrobot. Through the numerical simulation, we investigated the impact of tail tip angle and tail spacing on acoustic streaming intensity. Our findings reveal that smaller tip angles and wider tail spacing result in stronger acoustic streaming intensity. Based on optimization, we propose a microrobot structure with a tail tip angle of 5° and a tail spacing of 100 µm. Ultraviolet (UV) polymerization is employed to fabricate the microrobot. The effect of exposure time on manufacturing precision is examined. The acoustic propulsion of the bioinspired microrobot is verified by experiments, and the velocity of the microrobot can reach as fast as approximately 200 µm/s. Meanwhile, the vibration amplitude of the microrobot tail can be easily adjusted by the applied voltage. These findings not only provide important guidelines for the rational design of microrobots, but also offer novel insights into the applications of acoustic-driven techniques.