Researchers at the University of Michigan have designed a device that harvests energy from the reverberation of heartbeats through the chest.
They say it could power a pacemaker or implanted defibrillator, devices whose battery life currently means replacement surgery every five to ten years.
“The idea is to use ambient vibrations that are typically wasted and convert them to electrical energy,” said aerospace engineer Amin Karami. “If you put your hand on top of your heart, you can feel these vibrations all over your torso.”
Although there is no prototype yet, there is a design and simulations of a harvester that can generate 10µW, which is about eight times the amount a pacemaker needs to operate, said Karami.
It works from 7 to 700 beats per minute, and “always generates more energy than the pacemaker requires”, said the University.
Originally designed to convert power from wing vibrations in unmanned light airplanes, the harvester is piezoelectric, and also appears to contain magnetic elements.
In the abstract of a paper (Powering pacemakers from heartbeat vibrations using linear and nonlinear energy harvesters, Applied Physics Letters), it is described as a combination of “linear low frequency and nonlinear mono-stable and bi-stable energy harvesters”.