Flowing Blood Could Power iPods and Cell Phones

Power generated from flowing blood, simple body movements or a gentle breeze could one day be converted to electricity to charge iPods, cell phones and other personal electronic devices.

Researchers reported today they can harvest energy by converting low-frequency vibrations, like simple body movements, the beating of the heart or movement of the wind, into electricity by using zinc oxide nanowires that conduct the electricity. The nanowires are piezoelectric — they generate an electric current when subjected to mechanical stress.

Other schemes have been devised to generate power in a backpack as you hike or from a device attached to the knee. Those are comparatively bulky, however.

Nano devices are tiny. The diameter and length of the wires used in the new technique are 1/5,000th and 1/25th the diameter of a human hair.

"This research will have a major impact on defense technology, environmental monitoring, biomedical sciences and even personal electronics," said lead researcher Zhong Lin Wang, Regents' Professor, School of Material Science and Engineering at the Georgia Institute of Technology.

Wang's team first announced the nanogenerator in 2006 and refined it to create power from ultrasonic waves in 2007. Today he said the latest incarnation of the device has much broader application.

The nanowires can be grown on metals, ceramics, polymers and clothing. If the resulting nanogenerators can be developed into production, they could run electronic devices used by the military when troops are far in the field, Wang and colleagues suggest. Or they could power biosensors implanted under the skin.

"Quite simply, this technology can be used to generate energy under any circumstances as long as there is movement," Wang said in a statement. No timetable was given for commercial production.

The work, funded by the Defense Advanced Research Projects Agency, the Department of Energy, the National Institutes of Health and the National Science Foundation, was presented today at a meeting of the American Chemical Society.

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