Perpetuum cashes in on kinetic energy

Southampton University spin-out Perpetuum has secured £2.2m of venture capital to further develop its microgenerator, which it claims can generate power indefinitely and inexpensively.

Microgenerators harvest kinetic energy, usually from vibrations, which is converted into usable electrical power by Perpetuum’s electro-mechanical devices — details of which the company is not willing to reveal. The power generated is capable of driving sensors, microprocessors and transmitters.

Researchers say the microgenerators can replace batteries in all lower power, wireless electronic devices — and depending upon the level of vibration, the 50mm dia device can produce anything from 200 microwatts to four or five milliwatts of power. A very low level of vibration is required to produce sufficient power to run a sensor, an accelerometer, a microprocessor and an IEEE 802.15.04 or a ZigBee-type transmitter.

The company has initially targeted the condition-monitoring market. However, the sensor systems could be used to monitor stress and find dangerous fractures by being embedded in structures such as bridges and aircraft.

They could also be used to monitor the health of rotating parts, and future developments could lead to an everlasting heart pacemaker.

‘There have been many previous incidents of energy harvesting that have not worked, but this is a technology that really works,’ claimed Perpetuum’s chief executive Roy Freeland.

‘This technology is also practical — you can walk up to most AC power motors, simply stick the microgenerator on and it will instantly produce power,’ he added.

Work is underway to shrink the device to just 18mm in diameter.