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MEMS piezoresistive pressure sensors are most widely explored for various applications such as industrial, automotive and medical field. Each application covers a wide operating range from very low pressure to the higher pressure. In this paper a novel structure is designed by introducing the local stiffness in the diaphragm membrane for low pressure measurement. Rod beams at the diaphragm with combination of graphene piezoresistors, improves overall performance of the pressure sensor in terms of sensitivity. At higher temperature and higher pressure, a noticeable sensitivity is achieved which is compared to the previous design of graphene pressure sensor without rod beam structure. At room temperature (25 °C), sensitivity of pressure sensor with rod beam structure is 6.28 mV/psi. At 30 °C, the sensitivity is 58% higher than sensitivity of pressure sensor without rod beam structure for low-pressure specific range.

MEMS pressure sensor has shown a remarkable change in revenue collection during the year 2018. Due to recent growth in smart microsystem technology for automation systems, demand has grown substantially for sensors. High sensitivity, flexibility, miniaturization and bulk production are some of the key factors of a pressure sensor in achieving new heights in the MEMS market. In this paper, Graphene piezo resistive material has been analysed for pressure sensing elements and compared with Polysilicon in terms of sensitivity and sensor performance degradation at different temperature. MEMS pressure sensors using Polysilicon and Graphene piezo resistive materials were simulated on silicon (100) substrate by COMSOL Multiphysics 5.3a version. The simulation result shows that at room temperature polysilicon pressure sensor performs well with pressure sensitivity of 3.81 mV/psi as well as it is found that graphene pressure sensor also shows better results at room temperature showing a pressure sensitivity of 3.98 mV/psi. As on frequently increasing the temperature it is noticed that polysilicon pressure sensitivity degrades with a factor of 0.64 mV/psi. However, graphene pressure sensor shows very less variation in sensitivity at higher temperature. Although it shows a small increment of 0.02 mV/psi in the pressure sensitivity. This analysis opens the path to utilise the graphene pressure sensor at high temperature.