A piezoelectric buckling beam-type bistable energy harvester under rotational excitations

This paper proposes a novel piezoelectric buckling beam-type bistable energy harvester (PBBEH), which aims to efficiently harvest energy from rotational motions. The designed PBBEH is most made up of a piezoelectric buckling beam and a rotational disk which is used to provide low-speed rotational motions. A lumped parameter model is used for numerical analysis and the energy harvesting features of the PBBEH are analyzed. More importantly, experiments indicate that the PBBEH has excellent energy harvesting performance in the frequency range of 1-9 Hz, and experimental results indicate that the presented PBBEH has the output power of 28 μW. Additionally, the PBBEH has obvious nonlinear broadband dynamic characteristics. Both experimental and numerical results show that the output power curve has the tendency to increase and then decrease. Overall, in this paper, a good performance of this proposed harvester in ultra-low frequency rotational motions is verified, and it provides a possible design for self-powered wireless sensors used for structural heath monitoring in the wind turbine, the automobile wheel and other rotational machines.