Bidirectional Electrothermal Actuator With Z-Shaped Beams

A bidirectional micro-actuator powered by electrothermal force is successfully demonstrated under both dc and ac operations, without the assistance of magnetic field, using MetalMUMPs process. To achieve small stiffness without buckling, which tends to occur in V-shaped actuators, a new Z-shaped electrothermal actuator is designed. With the actuation current from -13 mA to +13 mA, the electrothermal actuator can achieve a bidirectional motion in a dynamic range from -11.6 μm to +12.8 μm. Experimentally obtained frequency response of the actuator indicates that it has a bandwidth of 49 Hz.