The researchers haven’t built a prototype yet, but they’ve made detailed blueprints and run simulations demonstrating that the concept would work. As reported in the journal Applied Physics Letters, a hundredth-of-an-inch thin slice of a special “piezoelectric” ceramic material would essentially catch heartbeat vibrations and briefly expand in response. Piezoelectric materials’ claim to fame is that they can convert mechanical stress (which causes them to expand) into an electric voltage.-Wes
Karami and his colleague Daniel Inman, chair of aerospace engineering at U-M, have precisely engineered the ceramic layer to a shape that can harvest vibrations across a broad range of frequencies. They also incorporated magnets, whose additional force field can drastically boost the electric signal that results from the vibrations.
The new device could generate 10 microwatts of power, which is about eight times the amount a pacemaker needs to operate, Karami says. It always generates more energy than the pacemaker requires, and it performs at heart rates from 7 to 700 beats per minute. That’s well below and above the normal range.
Tuesday, March 06, 2012
Developing a Hybrid Pacemaker
Much like a hybrid car recaptures energy lost with braking, so too are technologies being developed to recapture the heart's motion to power a pacemaker using piezoelectric crystals and magnets: