First steps of a millimeter-scale walking silicon robot

This work presents the locomotion of a ground-based single-legged silicon robot. The robot measures 5mm × 6mm × 0.5mm and weighs 18mg. Fabricated in a silicon-on-insulator (SOI) process, the robot is based on electrostatic inchworm motors that drive a 2 degree-of-freedom (DOF) planar silicon linkage that acts as the leg. The leg sweeps out an area of approximately 500μm × 500μm off the edge of the chip. The chip is connected to power and control by long flexible wires which also act to support the robot upright. The robot exerts over 1.5× its weight in the vertical axis, enough to lift its body and push itself forward.