Investigation of the energy harvesting performance of a Lambda-shaped piezoelectric energy harvester using an analytical model validated experimentally

The principal objective of this paper is to show the efficient and reliable energy harvesting performance of a Lambda-shaped piezoelectric energy harvester (LPEH). The equations of motion of the harvester were derived based on Euler–Bernoulli beam theory. The accuracy of the analytical model was validated by the finite element method and experiment. Then, using the analytical model, the energy harvesting performance of the harvester was compared to that of a conventional cantilever piezoelectric energy harvester. It was found that the LPEH generated much more power than the cantilever piezoelectric harvester when the same amount of substrate and piezoelectric materials were used. Additionally, the effects of the harvester shape angle and excitation direction of the proposed harvester on the energy harvesting performance were investigated. The results showed that the LPEH could produce reliable power even though the harvester shape angle and excitation direction varied. Owing to such reliable energy harvesting characteristics, the proposed harvester has the practical advantages of fitting within limited space and functioning under uncertain excitation direction conditions.