Sensor diaphragm under initial tension: Nonlinear responses and design implications

In this article, recent investigations into the dynamic behavior of a pressure-sensor diaphragm under initial tension are presented. A comprehensive mechanics model based on a plate with in-plane tension is presented and linear analysis is carried out to examine the transition from plate behavior to membrane behavior. It is shown that, for certain tension parameter values, it is appropriate to model the diaphragm as a plate–membrane structure rather than as a membrane or a plate. In the nonlinear analysis, the effect of cubic nonlinearity on the response is studied when the excitation frequency is close to either one-third of the first natural frequency or the first natural frequency. The nonlinearity limits the sensor bandwidth and dynamic range. It is discussed as to how a high bandwidth and high sensitivity can be realized by decreasing the diaphragm thickness and applying an appropriate tension. However, as the in-plane tension is changed, there is a trade-off between the sensitivity and dynamic pressure range. The analyses and related results should be valuable for carrying out the design of circular diaphragms for various sensor applications, in particular, for designing sensors on small scales.