Improving energy harvesting by nonlinear dual-beam energy harvester with an annular potential energy function

In this paper, we develop a nonlinear dual-beam energy harvester for broadband energy harvesting. Two identical piezoelectric cantilevers are placed orthogonal to each other and coupled by repulsive magnetic force. Analytical and experimental studies indicate that the combination of the resonant motions of the two beams yields an annular potential energy function, where the oscillator can circumambulate around the potential barrier. The advantages of the design concerning a conventional bistable piezoelectric cantilever were examined. It is proved that the proposed harvester has a bandwidth of 3.4 Hz and a voltage output performance 298.7% better than that of a bistable one under excitations of 0.5 g.