MEMS Capacitive Force Sensor for Use in Microassembly

This paper presents the design and modeling of a MEMS capacitive sensor for use in microassembly processes. Force monitoring is an important aspect in microassembly processes. It can be used to control the movement of the microgripper to properly engage with and release the micropart without physical damages due to excessive force. In this paper, the proposed sensor structure has an overall dimension of 3600 mum times 840 mum times 10 mum and was fabricated using the Micragem fabrication process. A displacement reduction mechanism is incorporated in this sensor design to increase the sensitivity of the sensor. Experimental results showed that a capacitance change of 112.4 fF would result for a 20-mum input displacement.