Actuators for micro robots

The problem of scaling robot actuators down to microscopic scale is examined in a review. It is shown that several forces scale well into the micro domain. These include electrostatics, hydraulics, pneumatics, and biological forces. Electromagnetic forces have a less favorable scaling. The scaling of electrostatics and electromagnetics is explained, and two electrostatic actuators are presented. The first actuator is a harmonic electrostatic motor. This motor uses rolling surfaces that reduce friction, and has an integral gear reduction that increases the torque output of the motor. The second actuator is designed to move fibers into alignment with other fibers