Multiphysics Finite Element Analysis of a U-Shaped Thermal Microactuator for MEMS Applications

Significant attention has been devoted to electrothermal microactuators over last twenty years in the research community due to their low-cost fabrication, material flexibility, and capability for generating large displacements. This study presents a comprehensive Metaphysics finite element analysis of a U-shaped electrothermal microactuator intended for MEMS applications. A coupled-field numerical simulation approach is employed to accurately model the electrical, thermal, and structural domains, ensuring precise prediction of actuator performance. The actuator operates based on differential thermal expansion between a slender hot arm and a cold arm (blade), resulting in directional motion. Such actuators are widely used for actuating micromechanical components, including ratchets and gear trains. Furthermore, actuator arrays can be integrated at their blade tips to amplify output force. In the present analysis, two-dimensional electro- thermal- structural coupling is implemented, where Joule heating is treated as a heat source to evaluate temperature distribution, voltage response, and mechanical displacement across the actuator structure.