A micromachined thermally-driven gripper: a numerical and experimental study

This paper presents the development of a microgripper for micro-assembly and micro-operation applications. Two design configurations for a silicon-based microgripper with integrated thermal expansion actuator and microsensor were proposed and studied in this work. The opening distance of the microgripper is up to 120 mu m. The microgripper is designed to operate through an integrated thermal or piezoelectric element that is controlled by an electricity supply. Piezoresistive sensors are integrated on the micromachined gripper to detect and feedback the gripping force applied on gripped objects. The two proposed configurations for the microgripper were simulated numerically and compared with one another. The thermal dynamic response of the thermal expansion element was, in particular, studied through finite-element modelling. Finally, a stainless steel prototype of the designed microgripper was fabricated and tested.