Free Electricity from Nano GeneratorsThrow away your batteries. Tiny nanowires could power medical implants, even your iPod.
Today's portable electronics (except for self-winding watches and crank radios) depend on batteries for power. Now researchers have demonstrated that easy-to-make, inexpensive nanowires can harvest mechanical energy, possibly leading to such advances as medical implants that run on electricity generated from pulsing blood vessels and cell phones powered by nanowires in the soles of shoes.
"When you walk, you generate 67 watts. Your finger movement is 0.1 watt. Your breathing is one watt. If you can convert a fraction of that, you can power a device. From the concept we've demonstrated, we can convert 17-30 percent of that," says Zhong Lin Wang, professor of materials science at Georgia Tech and one of the researchers of the work, published in the journal Science. Their results confirm a theory: zinc oxide nanowires will show a powerful piezoelectric effect, which is the production of electricity in response to mechanical pressure. Ordinarily the positive and negative charges of zinc and oxygen ions in these crystalline nanowires cancel each other out. But when the wires, which are chemically grown to stand on end on top of an electrode, bend in response to, say, a vibration, the ions are displaced. This unbalances the charges and creates an electric field that produces a current when the nanowire is connected to a circuit. [For illustrations and images, click here.] Although each nanowire alone produces very little power, Wang says, "with simultaneous output from many nanowires, we can generate high power," enough to run a small medical implant. The work reported in Science involved only single nanowires, but Wang says his lab has already developed technology to harvest power from multiple nanowires. Because the chemical process by which the wires can be grown is inexpensive, at some point it may be practical to produce large arrays that are capable of providing enough power for consumer electronics. "We can grow these on polymer substrates at very low cost," Wang says. "Our goal is to one day put these into people's shoes so you can generate electricity when you're walking." Before any devices powered by nanowires can be developed, though, researchers will need to find ways to connect all the nanowires to circuits. That, says Yi Cui, professor of materials science and engineering at Stanford University, will be a challenge but should be feasible. Indeed, Wang estimates that based on his current progress, prototype devices will be working within five years. One early application of the "nanogenerators" is providing power for a glucose sensor implanted under the skin of the arm. Such a sensor would transmit blood sugar readings to a wrist watch and, says Cui says, one day the sensor implant could automatically releases insulin when needed. Piezoelectric materials are frequently used in microscale devices. What's new about this application is the ease with which nanogenerators can be made at the nanoscale, says Jun Liu, researcher at the Pacific Northwest National Laboratory. Such thin wires can be bent more than bulk zinc oxide without breaking -- making it possible to apply more strain and so generate more electricity. "I think it's a very significant piece of work," Liu says. "[Wang] has done things that people suspected were possible, but never made work." |










Comments
04/27/2006
Posts:1
04/27/2006
Posts:1
05/01/2006
Posts:1
05/21/2006
Posts:1
07/05/2006
Posts:1
reply to:vivekineee59@gmail.com
07/05/2006
Posts:1
reply to:appu_7286@yahoo.co.in
jagadeeson_l
02/09/2007
Posts:2
the output pipes are lined by "nano generators".
The water moving by them provides the mechanical energy to move the strands...
are nano generators able to run under water?
04/27/2006
Posts:1
04/28/2006
Posts:1
05/01/2006
Posts:1
07/08/2006
Posts:1
07/13/2006
Posts:1
I think The large white windmills look cool, but a lot of people think they are unsightly and wouldn't want one in their back yard/neighborhood. But what if this technology could be imbedded in trees (or tall grasses) to hardness wind power? Or what if it could be imbedded in roof tops to hardness the power in rain?
Combined with Solar power (passive and active) could a house be designed to gather all it's energy needs from it's environment?
loganbeary
08/20/2006
Posts:1
lougeog
09/21/2007
Posts:1
energy produced is very less , no one want ths
think advanced research is make easier
vijay
01/30/2007
Posts:1
fati
04/26/2007
Posts:1
I think that these materials could enable new micro or nano applications, as the authors note, but even the example of the glucose sensor could be solved with existing materials. The bending limit issue is easy to solve.
04/27/2006
Posts:1
04/28/2006
Posts:1
05/07/2006
Posts:1
I think that these materials could enable new micro or nano applications, as the authors note, but even the example of the glucose sensor could be solved with existing materials. The bending limit issue is easy to solve.
04/27/2006
Posts:1
04/28/2006
Posts:1
04/29/2006
Posts:1
05/02/2006
Posts:1
perhaps a bionic ear could be
designed.
05/02/2006
Posts:1
"If this can scale up, and they solve the collection problems, It may be worth keeping an eye on:
The 30% conversion efficiency is what they have in the lab now. I've asked Dr. Wang if he can speculate on the theoretic peak efficiency or what he feels is realistically achievable in commercial production after fine tuning of his process.
http://www.gatech.edu/news-room/release.php?id=932 "
This Lead to a series of papers being exchanged with Dr. Wang of GIT.
He claims His Diode Arrays will be able to rectify raidio noise to electrical power.
I do wish him luck in finding funds, but his contentions about the second law of thermo dynamics being violated at n
05/09/2006
Posts:1
05/18/2006
Posts:1
08/06/2006
Posts:1
vibrate due to cavitation phenomena and this vibration could
possibly be utilized to produce electrical energy
by being fitted with nanogenerators. Rather than using the power for general utility could it be
used to dampen the vibrations in a cyclic fashion
to reduce erosion of the tips??
abcarterjr
12/29/2006
Posts:45
Guest(yont)
02/05/2007
Posts:2
reply to:appu_7286@yahoo.co.in
jagadeeson_l
02/09/2007
Posts:2
ALSO I WOULD LIKE TO KNOW WHETHER ANY RESEARCH HAS GONE IN THIS AREA.
coolsean
06/08/2007
Posts:1
Mikael
08/23/2007
Posts:1
prasad
09/04/2007
Posts:1
billakranthi...
03/15/2009
Posts:1