Modeling and simulation of the capacitive NEMS pressure sensor based on suspended graphene membranes

Nanoelectromechanical systems (NEMS) employing graphene have garnered significant attention for their potential applications in pressure sensors. Compared to other electrical readout mechanisms, capacitive sensing is a promising alternative one due to its less dependence on material properties and environmental factors. Graphene, with its unique properties, is an excellent candidate for high-performance NEMS pressure sensors. However, there are few studies on theoretical modeling of capacitive NEMS pressure sensors based on suspended graphene membrane. This paper presents the design, modeling and simulation of capacitive NEMS pressure sensors based on circular suspended graphene membrane. The impact of parameters of graphene membrane on the sensor performance is studied through COMSOL finite element analysis software. The results show that the sensitivity increased with the increase of the radius of graphene membrane but decreased with the increase of the thickness of graphene membrane, and the polar plate spacing determines the trade-off between the sensitivity and the measurement range. Further, decreasing the polar plate spacing increases the sensitivity but changes the capacitance-pressure relationship from linear to nonlinear.