Polysilicon vertical actuator powered with waste heat

This paper presents a new micro thermal actuator with bi-directional vertical motion. Traditional thermal actuators require an electric current to generate heat by Joule effect and obtain motion via thermal expansion. This work offers a simplified polysilicon thermal actuator designed to operate with an external heat source and, for example, scavenge heat from the surrounding medium. The actuator was fabricated using a standard surface micromachining process (PolyMUMPs). The thermal actuation characteristics, analysis, and experimental results for this novel micro-mechanical device are provided to illustrate performance and potential applications.