Femtosecond Laser Fabrication of Three-Dimensional Bubble-Propelled Microrotors for Multicomponent Mechanical
Dawei Wang1, Chen Xin1,2, Liang Yang3
1CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China.
Abstract:
Inspired by the reverse thrust generated by fuel injection, micromachines that are self-propelled by bubble ejection are developed, such as microrods, microtubes, and microspheres. However, controlling bubble ejection sites to build micromachines with programmable actuation and further enabling mechanical transmission remain challenging. Here, bubble-propelled mechanical microsystems are constructed by proposing a multimaterial femtosecond laser processing method, consisting of direct laser writing and selective laser metal reduction. The polymer frame of the microsystems is first printed, followed by the deposition of catalytic platinum into the desired local site of the microsystems by laser reduction. With this method, a variety of designable microrotors with selective bubble ejection sites are realized, which enable excellent mechanical transmission systems composed of single and multiple mechanical components, including a coupler, a crank slider, and a crank rocker system. We believe the presented bubble-propelled mechanical microsystems could be extended to applications in microrobotics, microfluidics, and microsensors.
