Swarms of Optically Controllable Electrokinetic Microrobots*

Electrochemical propulsion is a high speed, low energy method of locomotion for microscopic robots. While current devices that operate using this mechanism boast high speed and chemical control, they lack compatibility with standard silicon microelectronics. This limitation makes it difficult to perform tasks like sensing and swarming as devices can’t easily collect and store information or be reprogrammed to change behaviors. Here we show a new class of photovoltaic-powered, electrochemically propelled microrobots that are compatible with CMOS electronics and are fabricated in parallel using standard lithography techniques. The microrobots receive and process basic commands, can be selectively controlled, and locomote at speeds over 300 microns/s when illuminated by light. These results represent an alternative, low power locomotion mechanism for microscopic robots and help pave the way for future studies towards emergent behaviors in swarms of microrobots.