Design of a four-arm structure MEMS gripper integrated with sidewall force sensor

This work is focused on design and fabrication of a four arms structure MEMS gripper integrated sidewall piezoresistive force sensor. Surface and bulk micromachining technology is employed to fabricate the microgripper from single crystal silicon wafer (i.e., no silicon on insulator wafer is used). Vertical sidewall surface piezoresistor etching technique is used to form the side direction force sensors. The end-effector of this gripper is a four arms structure: two fixed cantilever arms integrated with piezoresistive sensor are designed to sensing the gripping force. The resolution of the force sensor is in the micronewton range and, therefore, provides feedback of the forces that dominate the micromanipulation processes. An electrostatically driven microactuator is designed to provide the force to operate the other two movable arms. This sensorized microgripper can be successfully used in microassembly system for force-controlled micro gripping.