Bio-inspired quad-stable piezoelectric energy harvester for low-frequency vibration scavenging

Due to the unique and diverse nonlinear characteristics, bionic structures can effectively broaden the acquisition bandwidth and improve the performance of harvesters. Inspired by dipteran flight motion, a novel bionic quad-stable piezoelectric energy harvester (BQPEH) is designed to collect low-frequency ambient vibration. The novelty of this bionic energy harvester lies in the combination of the “click” mechanism and “snap-through” motion, thus broadening the application scenarios and improving adaptability for the harvesters. A mass block and a post-buckled piezoelectric beam are connected by a rigid bar to create quadruple-well potentials. The static bifurcation analysis is performed to identify the quad-stable region in the parameter space. The dynamic responses of the system are investigated theoretically and numerically under constant and swept-frequency excitations and then verified experimentally. Broadband low-frequency and high-power energy harvesting are obtained through the inter-well motion induced by the combined nonlinearity of the BQPEH. The results indicate the potential of the bionic strategy for powering wireless devices in low-frequency environments and provide a novel concept for the innovative development of energy harvesters.