It sounds like the theoretical impossibility of perpetual motion, but engineers at the University of Michigan have created a pacemaker that is powered by the beating of your heart — no batteries required.
The technology behind this new infinite-duration pacemaker is one that we’ve discussed before at length on ExtremeTech: piezoelectricity. Piezoelectricity is literally
pressure electricity, and it relates to certain materials that generate tiny amounts of electricity when deformed by an external force. Piezoelectricity is exciting because it can harvest energy from kinetic energy that is currently wasted — the vibration of machines, the straining of floorboards in public/commercial spaces, the wobbling of bridges, the soles of your feet as you walk.
A conventional pacemaker. The long electrode is embedded in the heart. The main unit must be replaced when the battery runs out.
Or, in the case of the perpetual pacemaker, the vibrations in your chest as your heart pumps blood around your body. Piezoelectric devices generate very small amounts of power — on the order of tens of milliwatts — but it turns out that pacemakers require very power, too. In testing, the researchers’ energy harvester generated 10 times the required the power to keep a pacemaker firing — via redwolf.newsvine.com