The researchers, led by Michael McAlpine, and assistant professor of mechanical and aerospace engineering at Princeton, see lots of potential uses for this material. Rubber sheets could be put into your shoes, which would generate enough power from walking (or nervous tapping of your foot) to charge your cell phone. Where does the breathing part fit in? The researchers envision that “the new electricity-harvesting devices could be implanted in the body to perpetually power medical devices, and the body wouldn’t reject them.” For example, someone with a pacemaker could have this material implanted next to their lungs to allow the breathing motions to power the pacemaker. That would eliminate the need for surgery to replace batteries.