U.S. researchers printed, yes, printed a battery and they're looking to scale up the process to run devices from pacemakers to pickup trucks with batteries printed on a printing press. Rensselaer Polytechnic Institute's team published a description in the Proceedings of the National Academy of Sciences of how they've printed a foldable, rollable, cuttable paper battery a little bigger than a postage stamp that stores enough power to run an LED light.
Printing makes everything from wedding cakes to 3-D plastic models. A printing process adapted to the 20th Century is the heart of every chip fab in the world; without photolithography, the computer you read this with could not be economically made.
How does the experimental battery work? Nanometer-sized carbon nanotubes are the electrodes in the battery. The paper carrier is soaked in ionic liquid electrolytes to conduct the electricity, and that electrolyte could even be blood to power sensors or artificial organs someday.
Paper's long been used as an insulator in capacitors, back to the very earliest electrical experiments, and the economies of printing a one-piece battery are very appealing, as well as this design's ability to serve as a capacitor and deliver quick bursts of energy (for, say, acceleration or cranking an engine starter). Need to run more than an LED? Print more battery sheets and wire them together.
So much for the paperless future.
Yeah, it's a research model, but what's your wager in the anchor pool to guess how long until these arrive at your local hardware store?