Good vibrations mean green power
3 Dec 2009 by Evoluted New Media
An endless supply of free, environmentally sound power could be right under our noses – and all we need to harness it is a rather clever spring
An endless supply of free, environmentally sound power could be right under our noses – and all we need to harness it is a rather clever spring
Harnessing the energy of vibrations from the environment could provide a clean source of energy to power devices such as heart monitors and mobile phones.
Researchers from the University of Bristol are exploring how vibrations from machines such as helicopters and trains can be used to produce power. They will also look at how to harness vibrations from household appliances and movement of the human body.
Energy-harvesting devices use a spring with a mass on the end, which exploit resonance to amplify small vibrations enabling useful energy to be extracted. “Even just a few milliwatts can power small electronic devices like a heart rate monitor or an engine temperature sensor, but it can also be used to recharge power-hungry devices like MP3 players or mobile phones,” study leader Dr Stephen Burrow said.
The Bristol team are developing a device where the mass and spring resonate over a wide range of frequencies – existing devices can only utilise a narrow range, and if vibrations don’t occur at the right frequency, little power can be produced. This is a particular problem with human movement and transport where the frequency of vibrations varies.
The team hope to achieve this by exploiting the properties of non-linear springs which will allow an energy harvester to respond to a wider range of vibration frequencies.
Energy harvesters generate low-level power, and are suited to applications where hard-wiring would be impractical, vulnerable to damage or difficult to access. They could provide power for wireless monitoring and diagnostic sensors that generate data on heart rate, temperature or blood pressure, stresses experienced by engine components and structural elements in buildings.
“There’s a huge amount of free, clean energy out there in the form of vibrations that just can’t be tapped at the moment,” said Dr Burrow, “Wider-frequency energy harvesters could make a valuable contribution to meeting energy needs more efficiently and sustainably.”
