Design and finite element analysis of a MEMS based capacitive pressure sensor using CNT/PDMS nanocomposite electrodes

In this paper, a new design for MEMS capacitive pressure sensor is presented. In this study, we have examined a new electrode configuration in the capacitive sensing pressure sensor where the membrane deformation affects electrodes overlapping area rather than their separation in the commercial sensors. We showed this modification improves sensitivity with a linear operation. Here, we proposed a new technique based on electrode area change to achieve linear operation as well as a highly sensitive pressure sensor. The proposed device is based on changes in electrodes overlapping area, rather than their separation. To assess the design, COMSOL multiphysics software is employed as a modeling and simulating tool. The results show that the novel pressure sensor with a square membrane (2.5 mm × 2.5 mm) can provide a total capacitance change of 0.365 pF for an applied pressure in the range of 0-100 KPa.