Design and analysis of a MEMS pressure sensor with a bossed membrane and ancillary bi-functional frog arm structure for low pressure measurement

Abstract

This work presents a micro-electromechanical system based novel piezoresistive pressure sensor with frog arm structure for low pressure measurements up to one psi. The structure has been proposed with the objective of alleviating the trade-off between sensitivity and linearity of the sensor output. While a common feature of most of the previous works is deployment of two or more different methods to create sensitivity—linearity balance, the novelty of the proposed membrane lies in the frog arm structure’s dual functionality. The frog arm structure plays a cardinal role in the creation of stress concentrated regions leading to enhanced sensitivity, while the same works in a role ancillary to center mass structure in the proposed membrane to ensure an unprecedented linearity. The analytical design, geometry analysis and comparison of the proposed membrane with conventional membrane structures have been illustrated in detail. The finite element method has been used to analyze the stress distribution on the membrane and its deflection. The proposed structure achieves a high sensitivity of 17 mV/kPa with a minimal nonlinearity of 0.048% Full Scale Span. On the basis of simulation results, the proposed sensor tends to achieve sensor performance which is at par with the traditional membrane structures and various previous works.