In Pictures: 10 really small devices that could ch...
Print your own batteries
Tired of shelling out money for batteries? If researchers at Harvard and the University of Illinois Urbana-Champaign have their way you might someday be printing your own.
Physicists have created lithium-ion batteries the size of a grain of salt with a 3D printer that sprays conductive inks onto a glass substrate with gold wires. The battery's anode and cathode are composed of interlaced walls of lithium titanate and lithium iron phosphate that are 60 microns wide, barely the thickness of a human hair.
These tiny batteries could one day power anything from mobile phones to smart prosthetic implants.
In Pictures: 10 really small devices that could change the world