Mechanical energy harvester mounted on the bovine heartUNIVERSITY OF ILLINOIS AND UNVERSITY OF ARIZONAThe device: John Rogers, a professor of materials science and engineering at the University of Illinois at Urbana-Champaign, and his colleagues have constructed flexible energy-harvesting devices that can convert the movement of body parts—like the heart and lungs—into energy captured by a battery that could be used to power implantable devices like pacemakers. The devices, which are described in a paper published today (January 20) in PNAS, are constructed of thin ribbons of lead zirconate titanate (PZT) surrounded by flexible, biocompatible plastic, with an integrated rectifier and rechargeable battery.
“The heart is a great place to do mechanical energy harvesting because it’s constantly in motion. One of the challenges, though, with the heart, is that any constraint you apply to its natural motion by gluing a device onto its surface can cause all kinds of adverse reactions in the way that the heart is beating,” Rogers explained. “That requires you to engineer the device so that it’s not just flexible, but ultra flexible, so that the action of the heart is unaltered by the integration of the device onto the organ.”
The researchers grew rat smooth muscle cells on the devices to make sure they were not toxic, and measured flexibility over 20 million cycles of mechanical testing. They showed that bending and unbending ...
