Method for Sensitivity Improvement of MEMS Pressure Sensor: Structural Design and Optimization of Concave Resonant Pressure Sensor

A single silicon island concave silicon microresonant pressure sensor based on frequency difference is proposed in this article. The resonator is designed for electrostatic drive and electrostatic detection, and the lateral synovial motion is taken as the working mode so that the structure has the characteristics of structural stability and small coupling, and the force mode is torque transmission. The structure was simulated by a finite element analysis, and the structure size was determined. The working range of the overall structure was $0\sim 300$ kPa, and the simulation verified that the working mode order in the range did not change with the increase of pressure, ensuring the linearity of the output. The operating resonant frequencies of the resonator are 53324.15 and 54721.82 Hz. The effect of the small deflection deformation of the sensitive film and the inclination angle of the silicon island on the sensitivity of the resonator is analyzed by simulation, and the location of the silicon island is determined. The feasibility of resonator structure is confirmed by a frequency-domain response analysis, and the sensitivity of resonator can reach 50.48 Hz/kPa.