Characterization of a micromachined inchworm motor with thermoelastic linkage actuators

A new micromachined inchworm motor has been designed and fabricated for micro assembly applications. In order to implement inchworm motions, two thermoelastic actuators are contrived to have five-linkage mechanism with 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 inchworm operation. The thermal expansion of the active bars generates 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 progressed by the designed steps of 5 /spl mu/m and latched up by the teeth. The estimated driving force was 50 /spl mu/N with less than 0.2 /spl mu/m tolerance.