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Shashank Priya of the University of Texas, Arlington has developed a windmill with a diameter of just 10cm which works by flexing piezoelectric crystals as it rotates, causing them to generate a current. A 'gentle breeze' of 16km/h is enough to generate the 7.5mW necessary to power a small electronic sensor.

Priya's windmills are a designed to solve the problem of powering Wi-Fi kit in remote locations. Geologists, for instance, can monitor seismic activity using wireless-enabled sensors located across large geographical areas.

Previous attempts to solve the problem of powering such devices looked to solar technology, but too many cloudy days proved an insurmountable obstacle to a constant power supply. Piezoelectric materials however are a relatively efficient way of converting kinetic energy generated by movement to electrical energy.

According to Nature, other scientists are looking at using piezoelectric technology to power sensor networks on bridges, using the vibrations caused by crossing cars, or on aircraft.