Characterization of different beam shapes for piezoelectric energy harvesting

This paper deals with the analysis of different beam shapes for piezoelectric energy harvesters. The theory is based on the well-established Rayleigh-Ritz method for piezoelectric compound structures. It is validated by experiments with triangular-shaped and rectangular-shaped beams. It turns out that triangular-shaped beams are more effective than rectangular-shaped ones in terms of curvature homogeneity independent of the proof mass. This effect is opposed by the adverse mass distribution and the increased stiffness of triangular-shaped beams. Therefore, the overall efficiency is only weakly influenced by the beam shape. Nevertheless triangular-shaped beams drastically outperform rectangular ones in terms of tolerable excitation amplitude and maximum output power.