Researchers at MIT have discovered a way to harvest an electrical charge from water droplets – and the principle could form the basis for future gadget chargers.
As water condenses (think dewdrops) it can be made to jump from one specially-treated surface to a copper plate, gaining a tiny electrical charge in the process.
The charge may be small, but by building a special device consisting of interleaved metal plates (any conductive metal will work, so it could be made from aluminium, much cheaper than copper) enough energy could be harnessed to charge a mobile phone or other device.
You'll need time and a cave
It wouldn’t be a quick process – the researchers estimate it’d take a cube-shaped charger measuring 50cm on each side about 12 hours to fully charge a phone – but in remote areas where electricity isn’t readily available, it could prove a lifesaver. Literally.
There are other constraints besides time: because the water needs to condense, the process needs to take place in a humid environment and in a location that’s colder than the surrounding air. A cave or river in a rainforest would work.
One for a post-apocalyptic future, perhaps?
Image credit: Steve Wall