Squeeze power: First 'practical nanogenerator' developed
Scientists from the Georgia Institute of Technology are claiming to have created the world's first practical nanogenerator (Image: Zhong Lin Wang)
For the past several years, scientists from around the world have been engaged in the development of nanogenerators – tiny piezoelectric devices capable of generating electricity by harnessing minute naturally-occurring movements, such as the shifting of clothing or even the beating of a person's heart. So far, while they may have worked in principle, few if any of the devices have been able to generate enough of a current to make them practical for use in consumer products. Now scientists from the Georgia Institute of Technology are claiming to have created "the world's first practical nanogenerator."
The device was developed by a team led by Dr. Zhong Lin Wang. Its charge comes from zinc oxide nanowires, which generate an electrical current when flexed or strained. Because the nanowires are so tiny (500 of them can fit inside the width of a human hair), Wang's team was able to deposit millions of them onto flexible polymer chips, each chip about a quarter the size of a postage stamp. When five of the chips – each one a separate nanogenerator – were stacked together, their combined output current was about 1 microampere at 3 volts. That's over 150 times the voltage that the team first achieved six years ago, and is about equivalent to that generated by two regular AA batteries.
To charge the nanogenerator, the scientists simply squeeze it between their fingers. In a demonstration at last month's 241st National Meeting & Exposition of the American Chemical Society, they used it to light an LED bulb, and to power a liquid crystal display. Wang believes that by introducing more nanowires per generator, and stacking more generators together, enough power could be produced to run an iPod or charge a mobile phone.
"This development represents a milestone toward producing portable electronics that can be powered by body movements without the use of batteries or electrical outlets," he said. "Our nanogenerators are poised to change lives in the future. Their potential is only limited by one's imagination."
Georgia Tech is now looking for a company interested in producing the nanogenerator commercially, with Wang estimating that it could hit the market within three to five years. Its first use could be in environmental sensors, which would store power in a capacitor, then use it to wirelessly transmit data.
About the Author
An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away.
All articles by Ben Coxworth
As stated above, \"That\'s over 150 times the voltage that the team first achieved six years ago, and is about equivalent to that generated by two regular AA batteries\".
This is progress but it\'s the voltage plus the current generated to make them practical for use in consumer products. \".....few if any of the devices have been able to generate enough of a current to make them practical for use in consumer products. ....their combined output current was about 1 microampere at 3 volts.\"
All of the current formulations of single use AA 1.5 V batteries currently sold have a capacity of approximately 3000mAh. This is 3 million times the current of their nanogenerator. That\'s a lot more nanowires and stacking of generators to run an iPod or charge a mobile phone. That would be the size of 6000 human hairs.
The comparison to 2 AA batts was wrong of course, but amp hours and amps don\'t really compare anyway. We\'re talking generation vs. storage. If you only drew 1 microamp from those 2 AA\'s, that\'s what they would put out-- but they could do it for a very, very long time.
Yes well, we Kiwis have have got this too. The announcement was made about a month ago. When moving/walking the cloths will charge a cell phone so this is a start.
I guess that once it goes on the market ,for while, money earned funds development & further advances are made. This is all exciting styff & new energy inventions are appearing with such rapidy.
Keep up the good work . Cheers John M
All these devices, and the many similar ones depicted below, will generate is research funds from uninformed appropriations committees.
3V and 1uA. Is that at the same time or open circuit/ short circuit? One way the power output is 3uW, the other way 0.75uW. Either way that is so far from a useful output that scaling it up as a usable power source is highly unlikely.
Furthermore, that output will be while it is flexing (moving). To keep the power coming it must be continuously flexed, back and forth, goodness knows how fast. That will generate an alternating current. Taking the 3V as a peak voltage, 3V peak is 2V rms, 1uA peak is 0.7uA rms, so the power is 1.4uW taking the charitable view and 0.375uW taking the conservative view.
Or am I just a silly old know-nothing electronics engineer who is too accustomed to making a few back of the envelope feasibility calculations before wasting my time and my clients\' money?
If I where the guys at Georgia Tech I would take up contact with a tyre manufacturing company. The way how to integrate this into the tyre is of course up to themselves and the R and D of the chosen company. Stacking (and folding ?) should be possible to a relatively satisfying extent. Tyres are constantly moving, flexing and getting compressed. In doing so they could take advantage of the current momentum that the development EV\'s is currently seeing, thus possibly getting acces to a larger budget to furhter their research. Some of you other guys you should take research like this as a stepping stone to build further upon instead of criticising it to oblivion. Try to think in possibilities ....
RB - how would that be different than adding a wind turbine to the top of your car?
Where can I get this device? My project need this device, anyone can help me get it?! thanks a lot !
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