Georgia Tech researchers develop environmentally-powered nanogenerators

While the school of the Ramblin' Wreck may be best known for its barrage of engineering graduates, the university has been on quite the medical trip of late, as researchers have reportedly developed a nanometer-scale generator after already cranking out nanowires that monitor your blood pressure. The aptly-named nanogenerators can produce "continuous direct-current electricity by harvesting mechanical energy from such environmental sources as ultrasonic waves, mechanical vibration or blood flow," which translates into easy energy for implanted and worn medical gadgetry of the future. Interestingly, the project was funded by the likes of the National Science Foundation and our pals at DARPA, and while this invention may not quite match up with wireless charging (hey, we're scared of hospitals), the concept is novel nonetheless. So if you were hoping that dreams of implanted analysis of your vitals would suddenly cease, things aren't looking up for you.

[Via MedGadget]

[NewType @ Apr 11th 2007 2:48AM]

"...and while this invention may not quite match up with wireless charging..."

Are you guys nuts? An invention like this, with improvements, has the potential to remove the need to charge anything in the first place! All electronic devices would "self-charge" by grabbing power directly from the environment. Essentially, its a minaturized version of those Seiko kinetic watches that never need to be wound up or have their batteries replaced (cause they don't have one)

[Jonny @ Apr 11th 2007 3:34AM]

The laws of physics dictate that this couldn't be used as a permanent solution for implanted medical devices (actually, in my example, just a heart). The mechanical heart drives the blood flow, the generators get their energy from said blood flow, but they will always generate less than the mechanical heart needs. Otherwise, you would have perpetual motion, which is only possible in a frictionless environment with no outside forces. The kinetic energy the heart produces would not be enough to re-power it. "What if you use more generators?" you may ask. Well, the more generators you use, the more friction you put on the blood flow, meaning it slows down slightly whenever it transfers its motion to a generator. This means the more you have, the less energy each produces. The less you have, the more energy each produces. Either way, they won't be converting the kinetic energy efficiently enough to power the heart. Therefore, you would still have to power it by other means unless you used generators that didn't depend on the blood flow.

[NewType @ Apr 11th 2007 3:46AM]

Just like to point out the article specifies rather clearly that power can be generated from a variety of sources such as "ultrasonic waves, mechanical vibration or blood flow."

Given the size of the devices, a device could derive energy in a number of ways. Don't know why you are suddenly singling out blood flow as the only mechanical source of energy.

Secondly, they are not talking about mechanical hearts here. The amount of energy needed to power something as large as a human heart is clearly enormous, and something that may not be practical for an implanted generators. But can these generators power an artificial ear? How about an implant that helps control epileptic seizures or Parkinson's tremors? Or a pacemaker that only occasionally sends out electric signals to keep a heart beating regularly?

No need to automatically come up with an impractical example for using this technology is all I'm saying.

[Chris @ Apr 11th 2007 9:40AM]

My understanding of perpetual motion is that it is 100% energy efficiency.

If you want to talk about mechanical energy sources, you will never get "perpetual motion" in a living person b/c we are always putting energy into the system (food). These devices could be implanted intramuscularly, where they harvest energy from myofibril contraction. This process is (largely ) ATP driven, and as long as you are still eating, you aren't getting energy generation.

See glycolysis and the TCA cycle.

[kevinoliver99 @ Apr 11th 2007 3:51AM]

I had a really good read on this, very detail, and very useful information.
Thanks.
Flv to avi
http://www.avi-converter.net

[Chris @ Apr 11th 2007 9:44AM]

By "energy generation", I meant near or over 100% energy generation by the generator, not by the biochemical processes.

(pathetic excuse coming) I'm an engineer, please excuse my awkward writing.

[Jonny @ Apr 11th 2007 3:41PM]

Wow, you guys sure jumped on my opinion fast. I was simply stated that it couldn't be used for a heart, I was not saying the technology was a bust. I think its a promising technology, I was just pointing out that it wont replace batteries altogether for every medical implant.

[tequiero @ Apr 13th 2007 3:02AM]

To be technically correct, just as Chris explained it not really a generator, its more of energy converter, converting biochemical energy (if used in body) or other combinations of mechanical energy. And Johnny, I don't see why it can't be used with the heart, because if it can collect energy from the flow, it can also be made to collect energy from body movements which is supplied by ATP process or the food you eat. The same research group is also developing micro/nano turbines which really do produce energy by buring fuel. But further refinement or development can replace batteries in devices such as pacemakers and other small implanted devices.