Simultaneous vibration isolation and energy harvesting: Simulation and experiment

Abstract

Passive vibration isolators that use post-buckled beams as spring elements have received considerable research attention because the buckled beams exhibit low stiffness and less static deflection relative to similarly soft linear springs. This work considers such a vibration isolation system, but with the additional novelty of using piezoelectric film on the surface of the buckled beams. While the isolator is in operation, the piezoelectric film flexes along with the beam to produce an electric current. This electric current can then be used to passively power sensors, wireless networks, or charge batteries. The entire device operates passively on ambient vibration with no required external power or control system. The structural system is modeled using the elastica in conjunction with shooting methods. The structural response is then coupled to the circuit equation to determine the output voltage and corresponding power of the energy harvesting circuit. The simulated vibration isolation and energy harvesting performance is compared to experimental results. Both theoretical and experimental data suggest that there is not necessarily a trade-off between vibration isolation and harvested power. That is, over certain frequency ranges, improved vibration isolation will be accompanied by an increase in the harvested power.