Design and characterization of a micromachined inchworm motor with thermoelastic linkage actuators

Abstract

A new micromachined inchworm motor has been designed, fabricated and characterized for microassembly applications. In order to implement inchworm motions, a pair of thermoelastic actuator is devised to have five-linkage mechanism for two-dimensional motions in tangential and normal directions. The thermoelastic actuators consist of two amplification bars and two coupling bars with four hinge springs. A forked tip located on the apex of the linkage is used to fit the teeth of shuttle mass for its tangential translation. The thermal expansions of the active bars generate the displacement of the actuator, which is then transformed into a bending of the active hinges to be finally amplified by the amplification bar. The inchworm actuator performed the operation at a step movement of 50 μm with a latch-up by the teeth fitting and a driving force of 50 μN for 0.2 μm tolerance.