Effect of stress concentration regions on the performance of piezoresistive silicon beams

Piezoresistance, which is the change in resistance due to the applied stress, is a phenomenon that has been recognized in silicon. This study analyzes a micro-electro-mechanical-system (MEMS)-based force sensor that is both flexible and highly sensitive, utilizing a piezoresistive sensing mechanism. The design analysis focuses on enhancing the sensitivity of the microcantilever or beams by integrating various combinations of the stress concentration regions (SCRs). For simulation, four-point bending setup is used specifically for analyzing the piezoresistance effect in p-type silicon. The stress distribution in this setup is niform and aligned with the <۱۱۰> crystal axis. The primary objective of this study is to investigate the impact of different shapes, distances, rotations, and the number of SCRs on the performance of piezoresistive beam. A finite element approach is employed to analyze different designs for obtaining relative resistance changes. The simulation results are compared with experimental data, demonstrating a good accuracy and it is also identified the appropriate element size for converging answers. As a result, a force sensor has been designed with high sensitivity and flexibility.

کلیدواژه ها:

Piezoresistance ، Stress concentration region ، Silicon beam ، Finite Element Method ، Micro-electro-mechanical-system