Batteries Smaller Than a Grain of Salt

An anonymous reader writes "Lithium-ion batteries have become ubiquitous in today's consumer electronics — powering our laptops, phones, and iPods. Research funded by DARPA is pushing the limits of this technology and trying to create some of the tiniest batteries on Earth, the largest of which would be no bigger than a grain of sand. These tiny energy storage devices could one day be used to power the electronics and mechanical components of tiny micro- to nano-scale devices."