Aerospace engineers have developed a prototype that could power a pacemaker using chest cavity vibrations caused mainly by heartbeats.
Though pacemakers require as little as a millionth of a watt to keep working, their batteries need to be replaced periodically, which means multiple surgeries for patients.
University of Michigan Ann Arbor engineers worked out a method in which vibrations in the chest cavity deform a layer of piezoelectric material, which is able to convert mechanical stress into electrical current.
Tests indicate that the device could perform at heart rates from seven to 700 beats per minute (well below and above the normal range), and that it could deliver eight times the energy required for a pacemaker, according to a university statement.
Researchers have searched for ways to prolong battery life, trying to power a pacemaker using blood sugar, or the motion of the hands and legs.
But these methods either interfere with metabolism or require a more drastic surgery, such as passing a wire from the limbs to the chest area, the journal Applied Physics Letters reported.
Furthermore, the authors write, the amount of energy generated is always larger than the amount required to run a pacemaker, regardless of heart rate.
Though the team has yet to develop a prototype that is bio-compatible, they say that the potential to package this energy harvester with pacemakers gives it an advantage over competing methods.