Improving Power Density Of A Class Of Piezoelectic Power Harvesters Through Proof Mass Optimization

This thesis presents a method to optimize the proof mass of the cantilever piezoelectric power harvester. With this novel proof mass, a lower fundamental frequency and a higher power density (output power per unit volume) were achieved. Prototypes of 0.242 cm³ in volume were fabricated and tested and a power density of 1446 μW/cm³ was achieved for sinusoidal excitation of 0.75 g. It was experimentally shown that the new power harvester lowered the fundamental frequency by 26% and increased the power density by 68% in comparison with the conventional harvesters. When tested on a shoe, the new power harvester generated an average power of 48.4 μW at 3.0 mph walking speed on a treadmill.