Abstract
Out-of-plane electrothermal actuators have been applied to a variety of fields. Among them, the actuators whose driving method is bi-metal effect have the advantage of simple fabrication process and are thus most commonly used. However, such an actuator experiences a shear force at the interface of different materials, while actuated. Delamination con-sequently takes place and therefore decreases its life time. In attempt to overcome the drawback inherent in a bi-metal actuator, a novel bi-directional out-of-plane electrothermal actuator of single material is presented. The presented actuator comprises three beams of two different cross-sectional areas. While a current is applied, different beams would have different deflection, which results in the out-of-plane motion. Additionally, by different methods of applying current, bi-directional actuation would be carried out. The feasibility of the presented design was demonstrated in light of finite element analysis and experimental results. The potential application lies in microrelays, variable capacitors, and optical scanning system.