Characteristic analysis of a line-touch mode capacitive pressure-sensitive structure

Capacitive pressure sensors have the advantages of high accuracy and sensitivity compared to piezoresistive pressure sensors, but have serious nonlinearity problems. Although the touch mode capacitive pressure-sensitive structure has improved this issue, it has introduced a large hysteresis. To restrain this effect, a line-touch mode capacitive MEMS pressure-sensitive structure is proposed. A recess on the lower electrode plate of this structure makes the contact between the upper and lower electrode plates appears as the line-touch, and the touched area is almost zero, which can greatly minimize the hysteresis caused by the electrode plate contact. Analysis shows that the linear response range of this pressure-sensitive structure can be expanded several times more than that of the touch mode capacitive pressure-sensitive structure, while the nonlinearity is significantly reduced.