In the middle of the deep woods, electrical outlets are rare. So if you want to apply power to sensors that alert firefighters of an impending conflagration, what do you do? Those smarty-pants scientists at MIT have it all figured out — tapping tree roots for electrical power.

What, are we talking about man-made solar trees? Nope. It sounds like a miracle, but there's a tiny amount of electricity that can be extracted between tree roots and the soil where they grow, because of the "imbalance in pH between a tree and the soil," says Andreas Mershin, one of the scientists working on the project.

That's enough power to slowly charge up a battery that allows the tree to send back temperature and humidity readings four times a day, or one plaintive cry for help immediately. A wireless network of the trees will undergo its first testing next spring.

MIT, via Boing Boing