Scientists from the University of Texas have designed a micro-windmill that's capable of generating enough energy to recharge phone batteries.
The miniature windmill is a mere 1.8mm at its widest point, meaning a single grain of rice could hold around ten windmills in total.
Now there's a sentence we never thought we'd say.
If hundreds of windmills were embedded in a smartphone sleeve then you could theoretically charge your phone simply by waving it around, or prop it up on your window sill while Mother Nature breathes life back into it.
You could even mount millions of windmills on the walls of houses or use them to power micro-robots. Again, in theory.
Will you be charging your next smartphone with nothing but your breath? Probably not, but it's an interesting concept nonetheless.
Now if you'll excuse us, we're off to design a stress-powered battery.
It'll be made from industrial-grade foam and it charges up every time you squeeze it in rage.