Researchers in the University of Texas Arlington have developed a micro-windmill that could help recharge phone batteries.
The device is about 1.8 mm at its widest point and the windmills are so small, you would be able to fit ten of them on a single grain of rice.
The researchers say that hundreds of the windmills could be embedded in a sleeve for a phone.
Holding the phone up on a windy day or waving the phone around would generate the electricity needed to help charge its battery.
The metal alloy used to create the micro-windmill is flexible and durable and the researchers say they can withstand strong winds without fracturing.
Taiwanese tech company WinMEMS has struck a deal with the team to explore the opportunities for commercialisation.
Here’s one of the windmills in action, although whether you will see them on a product remains to be seen.