fuel cell, and it's certainly a good bit tinier than anything we've seen. The itty-bitty battery measures 3 mm x 3 mm x 1 mm and is comprised of just four layers: a water reservoir, a thin membrane, a chamber of metal hydride, and an assembly of electrodes. It can produce 0.7 volts and a 0.1 milliamp current for about 30 hours, with a newer model boasting similar voltage and 1 milliamp of current. That's not gonna juice your BlackBerry anytime soon, but scientists suggest it could be used for simple electronics and microbots. As for future application, we're hoping one day can power a fingernail-sized smartphone.
[Via Register Hardware]