A Highly Sensitive MEMS Three-Dimensional Force Sensor based on Piezoresistive Cantilever with Stress Concentration

Abstract This study presents a highly sensitive 3D force sensor based on a piezoresistive cantilever with stress concentration. The sensor achieves precise 3D force detection by integrating a polydimethylsiloxane (PDMS) cap with pyramid microstructures and silicon chip containing four piezoresistive cantilevers with a micro-hole at their root. Finite element simulation validates the superior performance of the micro-hole in enhancing the sensitivity of the force sensor. Compared to a traditional sensor based on a piezoresistive cantilever, the microhole design increases strain in the piezoresistive region of the cantilever by 2 times and the stress by 2.72 times. The proposed sensor exhibits promising potential for applications in various fields, including medical devices, robotics, industrial automation, and others.