Electromechanical Modelling and Experiments of a Bistable Plate for Nonlinear Energy Harvesting

Vibration based energy harvesting has received extensive attention in the engineering community in the past decade. It has been mainly focused on linear electromechanical devices excited close or at resonance, where these systems operate optimally. Although much progress has been achieved in this research direction, real harvesting devices would seldom operate in environment with such idealized conditions. Recently, the idea to use nonlinearity to enhance the performance for energy harvesters has been introduced. Nonlinear devices have been shown to have the potential to operate over a wider band of frequencies and deliver higher power. Bistable composites are a new type of composites exhibiting two stable states so far considered for morphing applications. In this paper, we propose to exploit the nonlinear behaviour of a bistable composite plate with bonded flexible piezoelectric patches to obtain a nonlinear energy harvesting device. The response of the structure is investigated revealing several large amplitude nonlinear phenomena over a wide range of frequencies. Resistor sweeps are conducted for representative dynamic regimes giving the optimal electrical load for each type of oscillations. The observed characteristics give the proposed device the potentiality for broadband energy harvesting.