There’s electricity in the air—and from it.
A group of British scientists has reported a biofuel cell that can make electricity from plain old air, as long as it has enough pure hydrogen. That’s a rather simplistic explanation, but you get the idea. The key point is that their fuel cell has no platinum, which weighs down other batteries in both mass and price.
The scientists constructed their fuel cell by encasing a pair of electrodes coated with enzymes from bacteria that oxidize hydrogen inside a container filled with air and 3 percent more hydrogen. (For those who keep track of things, that’s below the explosion threshold.) Interestingly, the enzymes are from Ralstonia metallidurans, a bacterium thought to have been one of the first forms of life on the planet.
Trials of the fuel cell produced enough electricity to make a watch go. Light bulb power can’t be far behind. Conceivably, larger versions can power larger machines. And it probably goes without saying that the only waste product is plain old water.