A novel single-layer bi-directional out-of-plane electrothermal microactuator

In this study, a novel bi-directional out-of-plane electrothermal actuator is designed and fabricated. Unlike the bi-metal and hot-cold arm thermal actuator, this actuator can move in two directions. Since the actuator consists of only a single layer thin film material, it can prevent delamination. According to the static load-deflection test, this actuator can achieve bi-directional actuation with amplitude near several microns when driven at 5 V. According to the vibration test, the dynamics of the actuator are influenced not only by the thermal characteristics but also by the vibration modes. Consequently, the thermal actuator still has a significant output when driven near 40 kHz. The actuator was subjected to a fatigue test which shows that its resonant frequency remains unchanged after 10/sup 9/ cycles of continuous operation with driving voltage at 2.25 V/sub pp/.