Understanding Influence of Substrate Floor Concavity on Sensitivity and Linearity Through a Parabolic Model: Theoretical Modeling and Analysis of Performance

Abstract

These microelectromechanical system (MEMS)-based touch mode capacitive pressure sensors (TMCPSs) are popular because of their linear sensor output and mechanical robustness. In this work, we propose a parabolic well substrate TMCPS with a circular diaphragm. The proposed design is modeled mathematically, analyzed, and simulated using MATLAB. The diaphragm of the sensor is modeled using a small deflection model. The sensor is intended to operate until a pressure of 2 MPa. The analysis and simulations indicate an improvement in linearity and sensitivity of the sensor output in the touch mode of operation. The analysis and modeling of the proposed design will be useful for designing TMCPS for performance improvement and understanding its behavior. An analysis of the influence of the sensor substrate’s concavity on the sensitivity and linearity of the sensor’s output is discussed in this work.