Piezoelectric Energy HarnessingThomas RadziewiczRyan WilsonMike Itenburg

Overview

•Purpose of project•Applications•Functional Process

▫Component Selection▫USB 2.0 Standard

•Alternative Designs•Final Design•Output

Purpose of Project

•Energy is very important in today’s world•Need for renewable energy•Energy when not connected to grid•Piezoelectric mounted in shoes to solve

problem•Ease of design•Useful for variety of applications

Applications

•People in remote locations, no access to grid▫Military personnel▫Rescue personnel▫Extreme hikers

•People exercising•Mobile medical personnel•Body sensors•Personal navigation

Functional Process

The Components

•Step Down Transformer and Full Bridge Rectifier

•Pre-Regulation Filtering

•Integrated Circuit to Produce Standard USB 2.0 Power.

USB 2.0 Standard

•From Source: www.usb.org

•Voltage 5.0V (maximum deviation of 0.1V)

•Current (max) of 500mA (with a response of 10us)

Alternative Design

•Originally planned to directly power a device over the USB protocol but was not feasible.

•Research shows that piezoelectrics stimulated by walking did not generate enough constant electricity to power a device.

•Changed to current design in order to capture harvested energy in useful manner.

Final Design

•Our ultimate design included a multilayered piezo material which would generate power on the scale necessary for this project.

•The circuitry would involve a rectifying bridge to condition the voltage coming from the piezo material.

•The Li-ion battery would then accept the regulated electricity and charge.

Final Design (cont.)

Output• Li-ion batteries would work well as our charge

collector.• By accepting 5V and up to 1 amp, this battery

matches our piezoelectric output specs.• A 300mAh battery is a good compromise because

it will charge up relatively quickly and provide emergency power to a USB device.