Controllable Piecewise Linear Dual Piezoelectric Cantilever Beams for Energy Harvesting

Abstract Recently, vibration energy harvesting has gotten increased attention. Various methods have been developed to collect unused energy from physical vibrations sources such as ocean waves. This paper presents and tests a dual piecewise-linear (PWL) piezoelectric energy harvester design. A previous study was conducted with a single piezoelectric cantilever beam with a mechanical stopper and showed the potential to improve the energy generation of piezoelectric energy harvesters by controlling the gap size. This work further improves the performance of PWL piezoelectric energy harvesters by replacing the mechanical stopper with another piezoelectric cantilevered beam. A new two degree-of-freedom model is proposed and investigated both computationally and experimentally. The good agreement between the bench-top system and the computational simulations validates the new computational approach. This paper also uses an improved methodology to identify the system dynamics from the experimental measurements. An improvement in both overall performance and operating frequency range of the new energy harvester is demonstrated in this work.