Modeling and design of an electrically actuated resonant switch

We present modeling and simulation of a new device concept of an electrically actuated resonant switch (EARS), which can be tuned to be triggered at low levels of acceleration, as low as those of earthquakes. The device is realized by mounting an electrostatically actuated cantilever microbeam with a mass at the tip 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 the Euler-Bernoulli beam model. 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. We conduct a parametric study showing several curves of dynamic pull-in threshold for various values of electric voltage loads and frequency of excitations. We show that the device can be triggered at a wide range of acceleration ranging from 0.4g-200g for various values of the DC and AC voltages.