Highly Sensitive Graphene MEMS Pressure Sensor with Integrated Membrane and Cross-Beam with Cavity for Extended Pressure Range Testing

Graphene piezoresistive pressure sensors are expected to be widely used in aerospace, industrial automation and other fields due to their unique advantages. However, the challenge in achieving both high sensitivity and high natural frequency over a broad range causes a gap between research progress and the escalating measurement demands. Here, we present a wide range graphene piezoresistive pressure sensor that employs a membrane and cross-beam with cavity (MCBC) composite structure to balance the trade-off between sensitivity and natural frequency. The different cavities such as circular, square and other are considered, the square cavity has the best effect on strain improvement which is 36.7% higher than that of the noncavity design. For the square cavity, we further discuss the overall stress, deflection, natural frequency and local strain of MCBC structure under different cavity depth, size and position. With the optimal parameters applied, the sensor with MCBC structure demonstrates a high natural frequency of 0.74 MHz within the pressure range of 0 to 25 MPa, and the local strain of the graphene sensitive resistor reaches as high as 0.68%. The sensor with MCBC composite structure has broad application prospects in the field of dynamic pressure measurement with wide range and high sensitivity.