When I conduct interviews, I use a small digital recorder that's powered by one AAA battery. I carry extras, but they're so small I often lose them, or they fall through tiny holes in my pockets. And now, world, you want to make one smaller than a grain of sand? I hope that shit's rechargeable, because taking it out and replacing it's gonna be a sumbitch.
Actually, this sucker's made by a 3D printer. I guess if you run out of charge, it's reprint time:
To create the microbattery, a custom-built 3D printer extrudes special inks through a nozzle narrower than a human hair. Those inks solidify to create the battery's anode (red) and cathode (purple), layer by layer. A case (green) then encloses the electrodes and the electrolyte solution is added to create a working microbattery.
There are tons of practical uses for this thing, but somehow I think, knowing humanity as I do, that light-up tattoos will be happening way before cancer-killing miniprobes.
Check out video of the battery being printed after the jump.