Built upon significant research into ultra-low power CMOS designs, complete sub-mm 3 -wireless sensor systems have been introduced [1]–[7] that include energy harvesting, sensing, processing, and communication. However, a key missing component in such systems is actuation, which could enable a host of new applications. Recently, a new class of electrochemical actuators that operate at low voltage and low power were developed [8]. The lithographic fabrication of these actuators is CMOS compatible, offering an unprecedented opportunity to create micron-scale, monolithic micro-robots. From a circuit point of view, such micro-robots face three design challenges: 1) energy harvesting and voltage generation in ultra-small form factor; 2) a customized processor for compute efficiency with stringent area budget; 3) an energy and area-efficient communication link.