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

Wen G. Li, Ryerson University

Date of Award

2009

Degree Type

Thesis

Degree Name

Master of Applied Science (MASc)

Department

Mechanical Engineering

First Advisor

Siyuan He

Second Advisor

Shudong Yu

Abstract

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.