The device is expected initially to be used to power wireless sensors on equipment in manufacturing plants.
The generator's creators say their technology is up to 10 times more efficient than similar devices.
The tiny device, which is less than one cubic centimetre in size, uses vibrations in the world around it to make magnets on a cantilever at the heart of the device wobble to generate power.

Although the generator produces only microwatts this was more than enough to power sensors attached to machines in manufacturing plants, said Dr Steve Beeby, the Southampton researcher who led the development of the device.

"The big advantage of wireless sensor systems is that by removing wires and batteries, there is the potential for embedding sensors in previously inaccessible locations," he said.

Using the tiny generator also made it possible to use larger numbers of sensors because there was no longer the need to visit them to replace or recharge batteries, Dr Beeby added.

The generator was developed to sit inside air compressors but, said Dr Beeby, it could find a future role in self-powered medical implants such as pacemakers.

In a pacemaker, the beating of the human heart would be strong enough to keep the magnets inside the device wobbling.

It could also be used to power sensors attached to road and rail bridges to monitor the health of such structures.

Work on the project was funded by the EU as part of the 14.3m euros (£9.67m) Vibration Energy Scavenging (Vibes) project that is looking at how to use environmental vibrations to generate power.