Improving Power Density of a Cantilever Piezoelectric Power Harvester Through a Curved L-Shaped Proof Mass

This paper presents a cantilever piezoelectric power harvester with a curved L-shaped proof mass. With this novel proof mass, a lower fundamental frequency and a higher power density (output power per unit volume) were achieved. Three prototypes of 0.242 cm³ in volume were fabricated and tested. A power density of 1.45 mW/cm³ was achieved for the sinusoidal excitation of 0.75 g. The power harvester was also tested on a shoe at various walking speeds, and it generated an average power of 49 ??W at 3.0 mi/h.