Broadband piezoelectric energy harvesting using an array of mistuned inverted cantilever beams

An energy harvesting device built on the lines of capitalizing the linear resonance of the system works well only when the natural frequency is close to the excitation frequency. To overcome this limitation of the linear harvester, this work investigates the prospect of using an array of mistuned cantilevers for broadband energy harvesting. The common device configuration of inverted beams with tip masses has been adopted in this study. The considered system is highly nonlinear for tip masses beyond Euler buckling load, and it has two potential wells on either side of the unstable zero position. The non-linear characteristics of the harvester are studied as a preliminary investigation to identify the values of mistuning parameters used in the current work. Numerical simulations have been carried out to understand the influence of mistuning parameters such as length of the beams and tip masses on the frequency band of the harvester power. Comparative studies on the power bandwidth of array of mistuned linear and non-linear harvesters are performed. Observations show that an array of non-linear harvesters enhanced the frequency bandwidth of the power more than that of its linear counterpart.