Currently, when the battery inside a device such as a pacemaker runs out of power, patients must undergo surgery to have it replaced. Several devices that take advantage of the body’s natural parts have been devised to allow for the creation of electricity internally so that implantable devices can run for a lifetime, preventing the need for additional surgery. Most such devices have been too small to actually charge a real device, however, as they are very much still in the research stage. In this new effort, the research team takes the idea further by creating miniature power plants that are large enough to power real implantable devices.
The new device has nanoribbons that are made of lead zirconate titanate—they are covered by flexible, biocompatible plastic, as are the other two main parts: an integrated rectifier and a rechargeable battery. The device is sewn directly onto the heart, lung or diaphragm—all parts that are in constant motion—as the body parts move, they cause the ribbons to bend slightly, which in turn causes the creation of a small amount of electricity. Thus far, the devices have been tested on cows and other large animals—the team reports that they are able to create enough electricity to power a pacemaker or other implantable device indefinitely.