Thanks to an innovation developed in the United States

Jun 4, 2010 09:16 GMT  ·  By

Scientists at the Georgia Institute of Technology (Georgia Tech) announce the development of a new technology that could, in the future, see devices such as pacemakers being powered by a patient's own heart. The innovation is based on zinc oxide nanowires, a class of materials that show great promise for underlying the next generation of electronic devices. The wires the researchers used in their study of unsuspecting lab rats are nearly invisible, and very tiny. They are able to convert the motions of the heart into electricity by using piezoelectric materials, Technology Review reports.

Piezoelectrics are materials, usually certain types of ceramics and crystals, that can convert mechanical stress into electrical potential. This means that whenever such materials are distorted, stretched, or bent, they produce small electrical currents. While the initial amount may seem very small, many of these wires can apparently produce sufficient electricity to power up medical implants such as pacemakers. If the new technology is developed further, and catches on, then patients wearing such devices will no longer have to visit surgeons at regular intervals, to have the batteries in their pacemakers changed.

The Georgia Tech research team, led by expert Zhong Lin Wang, a professor of materials science and engineering, first demonstrated zinc oxide nanowire-based generators back in 2005. Since then, the scientists have been working on improving the technology, and making it suitable for human use. Conceivably, they say, the future could see other sensor devices powered by the human body, other than heart implants. They say that even the energy of the human breath could potentially be harnessed for this purpose. Over the past few years, numerous science groups have focused their attention on using the energy wasted by the human body for powering up various electronic devices.

In the new experiments run on rats, the team developed a nanoscale generator that could work inside a living organism. They used zinc oxide nanowires for the job, placing them on a substrate made out of flexible polymers. They then encased the entire device in another layer of special polymers, so as to shield the electronics from the harmful action of bodily fluids. The generator was then affixed to the diaphragm of rats, where contractions caused by breathing started to produce electricity. The team said that the device generated four picoamperes of current at two millivolts. When they changed the location of the generator and placed it on the heart, it produced 30 picoamperes of current at three millivolts.