Devices powered by energy generated and harvested from one’s own body have been of tremendous interest to me. Last year I mentioned some research in this area by Professor Zhong Lin Wang at Georgia Tech (Georgia Institute of Technology) in a July 12, 2010 posting. Well, Wang and his team recently announced that they have developed the first commercially viable nanogenerator. From the March 29, 2011 news item on Physorg.com,

After six years of intensive effort, scientists are reporting development of the first commercially viable nanogenerator, a flexible chip that can use body movements — a finger pinch now en route to a pulse beat in the future — to generate electricity. Speaking here today at the 241st National Meeting & Exposition of the American Chemical Society, they described boosting the device’s power output by thousands times and its voltage by 150 times to finally move it out of the lab and toward everyday life.

“This development represents a milestone toward producing portable electronics that can be powered by body movements without the use of batteries or electrical outlets,” said lead scientist Zhong Lin Wang, Ph.D. “Our nanogenerators are poised to change lives in the future. Their potential is only limited by one’s imagination.”

Here’s how it works  (from Kit Eaton’s article on Fast Company),

The trick used by Dr. Zhong Lin Wang’s team has been to utilize nanowires made of zinc oxide (ZnO). ZnO is a piezoelectric material–meaning it changes shape slightly when an electrical field is applied across it, or a current is generated when it’s flexed by an external force. By combining nanoscopic wires (each 500 times narrower than a human hair) of ZnO into a flexible bundle, the team found it could generate truly workable amounts of energy. The bundle is actually bonded to a flexible polymer slice, and in the experimental setup five pinky-nail-size nanogenerators were stacked up to create a power supply that can push out 1 micro Amp at about 3 volts. That doesn’t sound like a lot, but it was enough to power an LED and an LCD screen in a demonstration of the technology’s effectiveness.

Dexter Johnson at Nanoclast on the IEEE (Institute of Electrical Engineering and Electronics) website notes in his March 30, 2010 posting (http://spectrum.ieee.org/nanoclast/semiconductors/nanotechnology/powering-our-electronic-devices-with-nanogenerators-looks-more-feasible) that the nanogenerator’s commercial viability is dependent on work being done at the University of Illinois,

I would have happily chalked this story [about the nanogenerator] up to one more excellent job of getting nanomaterial research into the mainstream press, but because of recent work by Eric Pop and his colleagues at the University of Illinois’s Beckman Institute in reducing the energy consumed by electronic devices it seems a bit more intriguing now.

So low is the energy consumption of the electronics proposed by the University of Illinois research it is to the point where a mobile device may not need a battery but could possibly operate on the energy generated from piezoelectric-enabled nanogenerators contained within such devices like those proposed by Wang.

I have a suspicion it’s going to be a while before I will be wearing nanogenerators to harvest the electricity my body produces. Meanwhile, I have some questions about the possible uses for nanogenerators (from the Kit Eaton article),

The search for tiny power generator technology has slowly inched forward for years for good reason–there are a trillion medical and surveillance uses–not to mention countless consumer electronics applications– for a system that could grab electrical power from something nearby that’s moving even just a tiny bit. Imagine an implanted insulin pump, or a pacemaker that’s powered by the throbbing of the heart or blood vessels nearby (and then imagine the pacemaker powering the heart, which is powered by the pacemaker, and so on and so on….) and you see how useful such a system could be.

It’s the reference to surveillance that makes me a little uneasy.