'Micro-windmills' smaller than a grain of rice could one day power our phones.
Forget hand-cranked chargers. Forget solar-powered cases. The latest way to charge your phone could simply use thin air.
Researchers from Texas have developed a minuscule 'micro-windmill' that is just 1.8mm wide, and it could change wind energy into electricity.
The team says the tiny design could be fitted to a phone case. You would simply charge your phone by waving it in the air.
You could even just place your phone in front of a fan. It then charges the phone in just minutes.
The technology was built by micro-engineering experts at the University of Texas Arlington (UTA).
The windmill is made of flexible nickel alloy components. This means it is capable of taking strong winds without breaking. And yet, they are so small that ten of them could fit onto a single grain of rice.