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Modeling of an air-backed diaphragm in dynamic pressure sensors: effects of the air cavity



Haijun H. Liu, Douglas A. Olson, Miao Yu


As the key structure of most dynamic pressure sensors, a diaphragm backed by an air cavity plays a critical role in the determination of sensor performance. In this paper, a continuum mechanics model is developed to fully capture the structural-acoustic coupling of the diaphragm and air cavity. Through modal analysis, simulation results show that the air cavity can change both the effective mass and the effective stiffness of the diaphragm, and thus affect the sensitivity and bandwidth of the sensor. Close-form approximations are obtained for calculation of the static sensitivity and the fundamental natural frequency of the air-backed diaphragm. Different from previous studies, this paper particularly extends the investigation on the effects of the air cavity to the short cavity range, which displays a different coupling phenomenon than the well-studied long cavity range. These results provide important design guidelines for dynamic pressure sensors with air-backed diaphragms.
Journal of the Acoustical Society of America


acoustics, air-backed diaphragm, dynamic pressure, finite element method, modal analysis, pressure, sensors


Liu, H. , Olson, D. and Yu, M. (2014), Modeling of an air-backed diaphragm in dynamic pressure sensors: effects of the air cavity, Journal of the Acoustical Society of America, [online],, (Accessed April 15, 2024)
Created October 6, 2014, Updated October 12, 2021