Analysis of Geometry Influence on Performances of Capacitive Pressure Sensor

In this work analysis of performances of a capacitive pressure sensor is performed, using COMSOL software tool. The basic sensor structure is composed of two cavities separated with a thin membrane. One cavity contains reference pressure (vacuum) and the other is connected with the measured pressure. When this pressure is changed, membrane is deformed depending on several factors such as applied pressure, used materials mechanical properties and geometry of the sensor structure. Influence of these parameters on sensor characteristics is analyzed and capacitance as a function of applied pressure plots is presented. It is demonstrated that COMSOL is a powerful software tool for successful prediction of performances of capacitive pressure sensors with different geometries, even in the cases with dynamics such as when sensor membrane is deformed.