Solar powered 10 mg silicon robot

We have demonstrated an autonomous two-legged microrobot which has taken its first steps. The body of the robot is fabricated in a planarized silicon-on-insulator (SOI), two-layer polysilicon process and is 8.5 mm /spl times/ 4 mm /spl times/ 0.5 mm in size. We previously reported initial leg motion from an off-board controller but have now incorporated control and power supplies onto the robot, resulting in autonomous operation for the first time. This solar-powered microrobot has two, one degree-of-freedom (DOF) legs and drags its tail end. Leg motion is generated via electrostatic inchworm motors on the robot body. The robot is a three chip hybrid assembled from one chip which contains the robot's motors and legs, a second chip which integrates both solar cells and high voltage buffers, and a third chip which incorporates CMOS circuitry for sequencing the legs. The robot has demonstrated 3 mm of motion shuffling sideways and has lifted its front end more than 300 /spl mu/m above the surface. The total weight of the three-chip robot is only 10.2 mg.