Ambient Energy Harvesting

Exhibitor: Mark Parker

Supervisor: Mark Schulz

Research Group: Embedded Systems

Industry Sector: Energy and Utilities

Traditional power supplies for microelectronics are becoming inefficient. Idle microelectronic systems continually drain power unnecessarily from power supplies, unless physically disconnected, over long periods power drain on batteries make this traditional solution unreliable.

As the power requirements for microelectronics continue to decrease Ambient energy sources can replace the traditional battery. In applications where small amounts of energy can be extracted from the surrounding environment ambient energy sources should be considered.

In this tradition, I have investigated two Piezo-Electric materials to be used for ambient energy harvesting, to capitalise on the excess amounts of energy dissipated while walking.

The two materials I have used are:

• PZT (Lead Zirconate Titanate). PZT is a Piezo-ceramic material.
• PVDF (PolyVinylDeneFlouride). PVDF is a Piezo-plastic material.

By placing the two materials in the shoe as shown it is possible to generate enough energy to power a small RF-ID (Radio Frequency IDentification) circuit.

Due to the slow frequency of walking, a custom circuit using a bucket capacitor as a storage element was necessarily designed. The circuit periodically energizes and transmits to a central base station when enough energy is stored to power the RF-ID circuit.

Thesis Document (PDF)