Numerical Simulation of a Striated Piezoresistive MEMS Pressure Sensor on Circular Silicon Diaphragm: A Finite Element Method-Based Study

Abstract

Micro-Electro-Mechanical Systems (MEMS) technology has been heavily incorporated into fabrication of sensors due to its undoubtful advantages such as efficient form-factor, low-power consumption and less bulk manufacturing cost. One of the first sensors to undergo transformation in the micro-scale has been the pressure sensor. Pressure sensors are used excessively in various fields such as automobile, aerospace, aviation, biomedical, consumer electronics, etc. Various researches are being conducted to optimize the design of MEMS-based pressure sensors to meet the specific requirements of different fields. This work presents a piezoresistive pressure sensor design with striated-shaped piezoresistors instead of the conventional bar-shaped piezoresistors. Such a configuration allows positioning the short arms of the striated design effectively on the narrow high stress regions. The piezoresistors are embedded on a circular diaphragm. The performance advantage of such a design is validated through analytical models and numerical simulations. Finite Element Analysis (FEA) is deployed using COMSOL Multiphysics software to achieve precise simulation results. The results are then compared to the existing literature. The proposed design achieves a sensitivity of 40.365 mV/V/MPa under a pressure range of 0–1 MPa. The proposed design performs better than existing literature and can be used in applications that require high sensitivity over a long pressure range, for example, in barometric altimeters.