Power Generation With Nanotubes

NubKnacker writes "Business World is carrying an article about how an Indian scientiest at IIT, Bangalore has come up with a new innovative method to produce power by blowing gases over carbon nanotubes. The underlying physics of the idea is quite simple yet no one had thought of it until today."

Comments

Very cool, related story in Nature

[tao_of_biology]

The journal Nature just ran a seperate news story a couple weeks ago about carban nanotubes' properties with regards to temperature. That story can be found here.

From the Nature article:

Ortwin Hess from the University of Surrey, Guildford, UK and colleagues say that if you took the temperature at one end of a 10-micrometre nanotube, it would not necessarily have the same temperature as the other end, no matter how long it was left to reach a thermal equilibrium. Such a nanotube is about as long as a sheet of paper is thick.

Now, I'm definitely no physicist so please pardon my ignorance--maybe someone can help me out. Does this mean that the temperature differential created on the carbon nanotube wire that causes the current to flow won't ever reach equilibrium? Doesn't this seem too good to be true? Just keep blowing gas over the wire, and you'll have limitless energy.

Re:Very cool, related story in Nature

[ToshiroOC]

It costs energy to blow gas over the wire.

Gedanken experiment:
You have two tanks of air at equal pressure, and a nanotube setup like the one described in the article in the valve connecting the two tanks. You open the valve - and no air moves across the nanotube, since the tanks are at equal pressure. Now, you pump air from tank 1 to tank 2, and the nanotube will generate energy - but only an equal or lesser amount of energy than it took to pump the air across the tanks.

Cost prohibitive for non-sensing applications

[ToshiroOC]

Unfortunately, nanotubes are still so expensive, velocity sensors are probably all these would be good for - larger power generating variants would be cost prohibitive. I also wonder how robust any velocity sensor made with nanotubes could be; sure, you could probably put one in a steam pipe or a LNG line and get reasonable data (in fact, in any nanotube-friendly chemical you could probably get good data from this sensor), but if you wanted to put one on the outside of a car or an airplane for velocity measurements, I can see nanotubes being easily damaged; either pulled from their moorings/leads in the device or simply snapped - nanotubes may be strong, but that's not going to help if you have a 500mph tiny sharp projectile impact just a few nanotubes. Also, in 'dirty' environments such as those outside of a car or a plane, you would probably start getting buildup of different pollutions at a reasonable rate, causing a need for either a) constant recalibration or b) sensor replacement.

Re:How was this "unknown"?

[Randolpho]

It's not "unknown", it's just "undone" before. It's been known that you could get a current by creating a temperature differentiation on both wires and nanotubes. It's just that nobody had ever tried to create a temperature difference through the Bernoulli Principle. Nobody did it before this guy, the guy deserves credit for it for thinking of it first, even though it seems so damn obvious to us now.

Think of it this way:

We knew about peanutbutter. We knew about chocolate. We knew they both taste good. But we didn't know they tasted so damn good together until they came out with Reese's Peanutbutter Cups. Thank you Mr. Reese, whomever you are. ;)