Low voltage electrothermal vibromotor for silicon optical bench applications

Abstract

The design and the testing results of a low voltage, compact electrothermal vibromotor (ETV motor) intended for silicon optical bench applications are presented. The surface-micromachined ETV motor consists of a guided movable slider and thermal actuator elements. Actuation occurs with the interaction of vibrating thermal actuators with the slider through coupling by way of impact. Two operation modes, causing forward and backward travel, can be controlled by the input voltage level. The ETV motor is operated with an AC signal at, as low as 5.4 V. A slider traveling speed of 10.2 mm/s is achieved with 12 V square-wave signals at 10.5 kHz. The speed is proportional to the input drive signal frequency. The ETV motor has been operated with the thermal actuator elements driven at frequencies up to 19 kHz. Finally, a hinged vertical micromirror and a rotation stage integrated with the ETV motors are used to demonstrate its capability in the silicon optical bench applications.