Improvement and Analysis of Piezoresistive Effect Model of Suspended Graphene Pressure Sensor

The proposed piezoresistive effect model of suspended graphene pressure sensor assumes that the reference pressure in the sealed cavity is constant. The influence of gas state variation on the strain of graphene is not considered in the [1] cavity. Therefore, the accuracy of the model is not high, and not conducive to guiding design of high precision suspended graphene pressure sensor. In this paper, the change of the reference pressure caused by gas temperature and volume variation in cavity is considered. The piezoresistive effect model of the suspended graphene pressure sensor is improved using bulge test method and the ideal gas state equation. Model analysis shows that the change of gas state caused by gas temperature and volume variation changes the reference pressure in cavity, and ignoring the change of cavity gas state will reduce the accuracy of the piezoresistive effect model. The model error gets larger with larger temperature deviation from the initial value and smaller cavity volume. The improved piezoresistive effect model reduces the error introduced by the cavity gas state change and can be used to guide the design of the cavity structure and size of suspended graphene pressure sensor.