Validation of an analytical model for contact mode plate deflection of touch mode capacitive pressure sensors

Abstract

Design and fabrication of touch mode micro pressure sensors rely on accurate and simple models in order to evaluate the plate deflection profile. This can be used to calculate the capacitance, sensitivity and touch point pressure which are among the key performance parameters of this class of devices. Here we validate a simple analytical model by means of finite element analysis (FEA). An excellent match is shown between the resulting deflection profile and capacitance found by the finite-element and analytical model in both normal mode and touch mode.