Here’s a new type of renewable power to add to the list — ear power. Human ears are basically a fleshy battery: There’s a membrane in there that allows ions to cross it. The two sides of the membrane have different balances of potassium and sodium ions, and as those ions try to sort themselves out — boom, electricity.

This is pretty old news, actually. But now scientists are close to harnessing this power, CNET reports:

What they have demonstrated in experiments on guinea pigs (actual, literal guinea pigs) is that the tiny, low-power devices they attached to electrodes implanted in the animals’ ears were able to wirelessly transmit data about the chemical conditions of the ear to an external receiver, and that the guinea pigs still responded normally to hearing tests.

The next big leap forward would be to hook up your ear power source to medical devices, like hearing aids. Current models need way more power than your ears can provide.

In other words, ear power is not going to be juicing your iPod through your earbuds anytime soon. But perhaps they will figure out the hearing aid thing by the time the generation of people who ruined their hearing by sticking pieces of plastic in their ears and blasting music needs them! Since we’re all going to start going deaf by 40, ear-powered devices would mean there are a lot of hearing aid batteries that wouldn’t even need to be made.

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