Imagine picking up the paper one morning, and using it to help power your appliances—or your car. Better yet, imagine taking that same paper and using the blood coursing through your body as the electrolyte so that it can power a pacemaker or other medical device. That’s what Researchers at the Rensselaer Polytechnic Institute (Troy, NY; www.rpi.edu) have in mind for the flexible paper battery they currently are developing. The battery contains carbon nanotube electrodes embedded in a sheet of paper wet with ionic electrolytes. Because the paper battery is an integrated device, it could prove to be cheaper to make, potentially more environmentally friendly, and usable in a wide variety of devices. However, researchers admit the technology is still a long way from commercialization, but that its advantages—it can be rolled or folded, voltage is increased by stacking sheets together or decreased by cutting the paper into separate pieces, and it can be used to power implanted devices by using the body’s own blood as the electrolyte—make it worthy of further study. At this point, no one knows whether the newspaper-sized sheets necessary to power a vehicle can be produced with adequate output, in quantity, or at a competitive price, but the researchers at RPI already are investigating whether it will be possible to make them using commonly available newspaper-style rolling printers.