Electrochemical Actuators for Microrobots

We show progress towards the design and fabrication of microrobots with electrochemical actuators. The proof-of-concept robot consists of a simple photovoltaic connected to two electrodes, allowing it to use optical power to drive electrochemical reactions. We show that the robots exhibit a variety of behaviors, including electrokinetic propulsion, electroplating, and active assembly. In hydrogen peroxide, the robots can propel at speeds over 300 microns/s and navigate microfluidic structures. In nickel electrolyte, swarms of robots can form metallic bonds between each other, assembling into macroscopic metallic structures with adaptable strength and conductivity. Notably, these behaviors can be powered and controlled with patterned laser light or onboard CMOS electronics, clearing a path towards a new class of controllable and programmable active microscopic matter.