Equivalent circuit model of piezoelectric vibration energy harvesters composed of trapezoidal unimorph cantilevers

Abstract

We have constructed a time-resolved equivalent circuit model of the piezoelectric vibrational energy harvesters (PVEHs) with the trapezoidal unimorph structure not only to optimize the dimensional parameter of trapezoidal PVEHs but also to anticipate the output power by a variety of external vibrations. To calculate the output responses by arbitrary mechanical input accelerations such as impulses or sinusoidal, we have formulated simultaneous first order differential equations based on this model. In order to express dynamics with large amplitudes enough to drive actual devices such as micro-sensors with BLEs, we have considered the nonlinear effects, and successfully reproduced experiments by our calculations.