Electronic implantable medical devices all generally suffer from a limited lifespan because the batteries inside of them can’t last forever. Yet, the body is full of various sources of energy that are waiting to be tapped. Perhaps the most obvious are the beating and pulsating heart and lungs, and now researchers headed by John A. Rogers of the University of Illinois at Urbana–Champaign are reporting the development of a flexible integrated device that can harvest mechanical energy of moving organs and turn it into stored electricity.
The harvesting device is made by layering a piezoelectric material called lead zirconate titanate onto flexible silicone, adding rectifiers and batteries, and surgically implanting it on the organ without unduly restricting its motion. The device achieved around a 2% operating efficiency (0.2 microwatts per square centimeter), and tests on pigs, sheep, and cows have demonstrated the viability of the technology to power implants while providing insight into how to improve the current design of the device.
Here’s a video of the device being applied to an animal heart and subsequent power generation