Modeling and design of an electrically actuated resonant microswitch

Modeling and simulation of a new device concept of an electrically actuated resonant switch (EARS) is presented in this paper. This EARS can be tuned to be triggered at low levels of acceleration, as low as those of earthquakes. The device is made by mounting an electrostatically actuated cantilever microbeam, with a tip mass, on top of a compliant board or a printed circuit board (PCB), which is modeled as a hinged-hinged beam. A distributed-parameter model of the device is derived for the microbeam and the PCB using Hamilton's principle based on Euler-Bernoulli beam theory. The equations are then discretized using the Galerkin procedure. A nonlinear numerical dynamic analysis is performed in order to characterize the behavior and performance of the device when subjected to acceleration pulses. A parametric study showing several curves of dynamic pull-in thresholds for various values of electric voltage loads and frequencies of excitation is conducted. It is shown that the device can be triggered at a wide range of accelerations ranging from 0.33 g to 200 g for various values of DC and AC voltages.