A High-Sensitivity MEMS Pressure Sensor with a Narrow Cross-Beam Membrane-Short Beam Structure

To address the difficulty of balancing sensitivity and nonlinearity in MEMS piezoresistive pressure sensors, this study proposes an MEMS piezoresistive pressure sensor with a narrow cross-beam membrane-short beam structure. The structure introduces a tapered design at the ends of a conventional cross beam and incorporates short beams to enhance stress concentration in the sensitive regions, thereby improving output sensitivity while maintaining low nonlinearity. Finite-element analysis was performed to evaluate the stress distribution and deflection characteristics and to compare the proposed structure with conventional cross-beam and other diaphragm structures. Under identical overall dimensions, the proposed structure improves sensitivity by 61% relative to the conventional cross beam. Based on the finite-element results, multivariate fitting models for surface stress and deflection were established, and nonlinear optimization was used to determine the constrained optimal geometrical parameters within the validated design domain. Simulation results indicate that, over a pressure range of 0-1 kPa, the proposed sensor achieves a sensitivity of 12.23 mV/V/kPa and a maximum nonlinearity of 0.196% FSS, demonstrating favorable performance for micropressure detection.