Though pacemakers need only tiny amounts of energy (about one millionth of a Watt), their batteries must get replaced periodically, which means multiple surgeries for patients.
Researchers have looked for ways to prolong battery life - trying to generate energy to power a pacemaker using blood sugar, or the motion of the hands & legs - but these methods either interfere with metabolism or need a more extreme surgical procedure, such as passing a wire from the limbs to the chest area.Aerospace engineers from the University of California in Ann Arbor have developed a prototype device that could power a pacemaker using a source that is surprisingly close to the heart of the matter: vibrations in the chest cavity that are due chiefly to heartbeats.
In their system, vibrations in the chest cavity deform a layer of piezoelectric material, which can convert mechanical stress in to electrical current. Tests indicate that the gizmo could perform at heart rates from 7 to 700 beats per minute (well below and above the normal range), and that it could deliver eight times the energy necessary for a pacemaker. Furthermore, the authors write, the amount of energy generated is always larger than the amount necessary to run a pacemaker, irrespective of heart rate. Though the team has yet to create a prototype that is biocompatible, they say that the potential to package this energy harvester with pacemakers gives it an advantage over competing methods.
