Modeling and experimental validation of a buckled compressive-mode piezoelectric energy harvester

This paper presents a novel buckled compressive-mode piezoelectric energy harvesting device (BC-PEH) to improve the energy harvesting capability. The BC-PEH synthesizes the merits of the force amplification effect of the flexural motion and the broad bandwidth of buckled-beam structures. In this paper, both theoretical and experimental investigations are performed on the BC-PEH, under both harmonic and random excitations. Taking negative stiffness, nonlinear damping and nonlinear piezoelectric coupling into account, we build an analytical model that provides a comprehensive insight into the nonlinear electromechanical coupling system. The influence of parameters on the performance is thoroughly discussed via the harmonic balance method and numerical technique. The analytical results closely render the experimental data and demonstrate a considerable performance enhancement. Compared with state-of-the-art energy harvesters, the BC-PEH prototype not only exhibits its superiority in terms of power density, normalized power density and power normalized by mass and acceleration, but also indicates a 194% broader working bandwidth.