A new MEMS based capacitive differential pressure sensor with acceptable sensitivity and improved linear region

摘要

A new Microelectromechanical systems (MEMS) based capacitive differential pressure sensor is introduced. The capacitive differential pressure sensors have good sensitivity and robust structure while are not so much sensitive to the stress and other ambient conditions and typically have no temperature drift. Meanwhile, they respond nonlinearly to the input pressure variations and their sensitivity near to the linear region is not enough to neglect the parasitic effects. A specific method is proposed to increase the linearity. The diaphragm thickness is considered to be non-uniform. Also the distance between electrodes is considered non-uniform to improve the sensitivity. With these changes, the sensor works in linearity whilst the capacitive sensitivity is improved. The diaphragm can be made by body forming technique.