Stress, sensitivity and frequency analysis of the corrugated diaphragm for different corrugation structures

Abstract

Corrugated and flat circular diaphragm-based piezoresistive pressure sensors are designed and proposed for different applications. Regarding to different criteria including maximum stress, sensitivity and natural frequency, different diaphragms with semicircular, sinusoidal and trapezoidal corrugation are modeled, simulated and investigated in finite element software. The finite element model is validated by experimental results from the literature and also with theoretical formula to ensure the accuracy of the finite element modeling process. Wavelength and location of the corrugation are optimized to achieve best performing sensor. For the application with large acceptable induced stress, circular flat diaphragm is proposed. To enhance the sensitivity of the sensor as a crucial parameter, semicircular corrugation for circular diaphragm with 360 μmm wavelength and 240 μmm distance from the center is designed and proposed. This configuration shows obvious improvement of the sensitivity with more than 18% enhancement. To extend the working range of the sensor regarding to input frequency, trapezoidal corrugation with 360 μm wavelength and 240 μmm distance from the center is proposed to reach more than 29% enlargement in first natural frequency. Eventually, this paper tries to provide an overview to design the optimal pressure sensor according to desired specifications.