Verification of the capacitive pressure sensor with additional air chamber

This study presents the effect of the additional air chamber on the sensitivity of an air-sealed capacitive pressure sensor having a flexible diaphragm investigated theoretical analysis, FEA, and experimental validation. First, the sensitivity variation of the capacitive pressure sensor having a various volume of the air chamber has been verified by analytical method as theoretical approach and FEM simulation. The results show that the sensitivity of an air-sealed capacitive pressure sensor having a flexible diaphragm can be enhanced by adopting additional air chamber. Experimental validation is conducted by fabricating sensor to consider the previous result. Finally, the air-sealed capacitive pressure sensor having a natural rubber latex (NRL) diaphragm shows the sensitivity enhanced more than is times by adopting additional air chamber compared to the NRL sensor without air chamber. Consequently, the NRL sensor with additional air chamber measured a pressure sensitivity of 8986 ppm/kPa and a pressure responsivity of 1.391 MHz/kPa in the applied pressure range of 1-10kPa.