A complete analytical model for clamped edge circular diaphragm non-touch and touch mode capacitive pressure sensor

Abstract

Capacitive pressure sensor have become good substitute for piezoresistive pressure sensor because of low power consumption. In order to evaluate the characteristic profile for touch mode micro pressure sensor an accurate and simple model needs to be designed. Hence preferable analytical model is necessary to design and characterize the device. Lot of study has been done on touch mode capacitive sensing but no elaborate work has been presented to clearly understand the underlying expressions and the role of key performance parameters. With this step by step theoretical evaluation model the key performance parameter such as deflection, capacitance and sensitivity can be easily studied for both non-touch and touch mode capacitive pressure sensor. The next aspect has been to simulate the findings in order to validate the results and hence MATLAB has been introduced. It also eliminates the need for design using FEM and hence the study becomes lot easier.