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Texas Scientists Spin Carbon Nanotube Fiber
RedCard writes "According to this article at news24.com, University of Texas scientists have managed to spin a fiber made of 60% carbon nanotubes that is five times stronger than steel and is "tougher than any natural or synthetic fibre described so far" - including spider silk! Previous attempts at making fibers like this have only produced relatively short lengths, but these guys have produced lengths of 100 metres at the rate of 70cm per minute!"
One can estimate theoretically the ultimate strength of a nanotube be examining the microscopic failure modes, i.e. the ways in which atoms rearrange in response to an external stress (i.e. stretching). In the case of perfect, defect-free nanotubes, there are two modes that seem to be important. First, the rotation of a single carbon-carbon bond by 90 degrees, which converts a patch of 4 hexagons (remember that carbon atoms are arranged in a chicken-wire or honeycomb pattern on the tube wall) into two pentagons and two heptagons (relevant references are Zhang & Crespi from Penn State in Physical Review Letters and work by Bernholc at NC State and Yacobson at Rice I think, but the exact journal escapes me at the moment). This mode is a plastic distortion of the tube; the tube with the bonds rearranged is a bit longer than it was before. The second failure mode is for one of the hexagonal rings of carbon atoms to break open, i.e. for a carbon-carbon bond to break. This is a more catastrophic event, in that the tube then quickly breaks near the point of failure. Which way a tube fails may actually depend on how the honeycomb pattern is rolled into a tube shape. Now that's just the microscopic theory on the ideal, defect-free system. In a real tube, one expects there to be pre-existing defects in the structure. The failure under tension will then be at the defective points But, since nanotubes are so small, it's plausible that a single tube or bunch of tubes might grow entirely defect-free, in which case one can access the ultimate theoretical failure strength. Experiments on trying to stretch and break single bundles of nanotubes (Lieber's group at Harvard) show that one can extend a nanotube by about 6% of it's length before it breaks. This is in good agreement with the theoretical predictions mentioned above (and it's a legit prediction- the theory came first!). So it appears that in small enough systems, one can attain the theoretical mechanical strength.
Kudos to you, my good man.
Just imagine the uses for such a cloth made of this material... not to mention the obvious thing that comes to mind, "Hello Space Elevator!"
This could be the first truly fantastic scientific breakthrough of the 21st century. Now all we need is a room-temperature superconductor, and we're all set.
-- We live in a world where lemonade is artificial and soap has real lemon.
Could this stuff, if produced cheaply enough in the next 20 years, be the end-all of condoms? It sounds like such a stupid thing to ask, but I've known more than one family that became one because latex just doesn't hold up sometimes.
Perhaps weird uses like this could really help out in the end?
Trolls make great pets. Adopt one today!
I seem to recall that a bright source of light can make carbon nanotubes burn up like ignited magnesium.
Yea, I'd be the first to wear or use this fabric.. "Smile for the camera!"
"No, wait!" *clic-FLASH* "AAAARGH THE HUMANITY!"
I'll bet this stuff would be bitchen for a fiberglass type substance. I had read somewhere that they have already tried it but ran into problems with "clumping" of the microscopic nanotubes. But now they are macroscopic, so problem solved. And at the rate they are creating the macroscopic fiber it would seem that they could quickly replace existing carbon/graphite composite materials.
Damn, this is going to really change the aircraft industry. Not to mention golf and tennis.
Yeah, I'm pretty sure the tethers.com guys have a subscription to Nature, but if they don't maybe they could use a short email... hmmm.
Propellantless space transport. Tasty goodness.
The effect only works with single walled carbon nanotubes, and even then only when in air. The effect actually happens because the tubes are very black and very porus, absorbing a large amount of light and rapidly converting it to a violent expansion of the surrounding Oxygen in the air igniting the nanotube. This will never occur if the tubes are incorporated into an epoxy string.
- "Hear that?! The percolations are imminent! Cease your ingress!"
It seems my chances of living to ride the space elevator have just increased.
:-)
AFAIK the space elevator requires a material roughly 30 times stronger than steel. True, these guys are "only" five times stronger, which leaves just another factor of five (ok, six) to reach the required strength. So in a way we are about half-way there
I'm not clear about the cost of their material, though. Anyone have an idea of how hard is it to create enough nano-tubes raw material to feed their process?
This is definately good news, but it is only about 1/6th the strength needed for the elevator. At 5 times the tensile strength of steel (4.2GPa) it matches the strength of graphite whiskers (21GPa).
The elevator becomes feasible at around 130GPa, so there is a little ways to go yet. It is only a matter of time now.
FWIW, the theoretical limit of CNTsis thought to be around 300GPa.
I wonder if this stuff could be use to make ultra-light bullet proof vests. Also, I'm sure exotic car manufactures such as Farrari would be interested in the stuff.
Life is not for the lazy.
Condoms have over 90% effectiveness when used correctly. If you want to know what will really keep population down...
People in first world countries use their free time to watch TV, and look at porn.
People in third-world countries use their free time to have sex and make babies, because they don't have TV's and computers.
I propose, that in order to prevent unsustainable overpopulation in third-world countries, we give them TV's!
Help people in third-world countries! Give them TV's!
Who cares about space elevator: But if it is *five times* stronger than steel, it must be also better than Immodium.
[Use with meal, do not exceed 120 meter recommended daily dose. Spiderman is a copyrighted work of art, ingesting Carbonfibre for this purpose without authorisation of Warner Bros is prohibited.]
I doubt that we will ever figure out - and I suspect that even if we did figure out we couldn't do much about it
Highlift did not go down the toilet. They existed to be an entity to receive money from NASA for the NIAC Phase 1 and Phase 2 grants. Those phases are over, and therefore Highlift has no reason to exist (it wasn't really a 'company' per se).
Contrary to what Slashdot has said, LiftPort (www.liftport.com/www.liftport.org) is not a competitor to Highlift - it was simply the natural next step (in Michael Laine's opinion - Brad Edwards thought that the time wasn't right for a public push yet) of moving from a government-funded research lab to a privately-funded company.
Incidentally, if you haven't been to www.liftport.com recently, they overhauled their website (it looks very good now) and are in an investment phase - they've already received over $1M in funding (not bad!). The "public" end, akin to Highlift, is going to be at www.liftport.org.
whoa...
Everyone concentrates on how strong these fibers are. I'm wondering just how thin they are -- there's an old SF idea of a "monomolecular fiber" that can be used to cut through just about everything because it's VERY strong and VERY thin.
The idea even shows up in "The Santa Clause" when the elves free Santa (Tim Allen) by using tinsel to cut the hinges on a jail cell.
On the other hand, Liftport has raised a million bucks in half the time they expected, and the gonzo attitude appeals to my Heinlein-educated sensibilities. I sent them a few hundred bucks yesterday, just in case.
I think, several challenges to just materials science has to be overcome.
For example, our current science in engineering, relies on models and previous engineering attempts, to build new structures.
If you want to build a structure, say taller than the sears towers for example, you can do so, by using the Sears Towers as a reference, then building perhaps 10-15% taller.
Historically, we buld a large number of structures, not just buildings, a little bigger at a time. We build planes, a little faster at a time.
That is how our engineering science works. Even when we sent men to the moon, as colossal a task as that was, we took very small steps at a time, and it took decades.
Building something like a Space elevator, in the timeframe (10-20 years) I think is ridiculous given our current engineering science and application of Mathematics/Statics etc.
Just because you have a material than can go hundreds of miles straight up doesn't mean your structure will.
Whole new branches of engineering will have to be invented, as well as new mathematics to make this structure work.
Personally I think the work Stephen Wolfram has done so far in FSM's (Finite State Machines), may offer a clue as to how we can take much bigger steps in the sciences, with much more predictability, in our models, and methods of construction, to make a space Elevator possible.
At the very least his work sheds light on the principles of complexity, and why we take baby steps in everything we do.
Specifically, how can we design systems, when we have no working model, and to build such a model requires an order of magnitude in scale our engineering science, historically, has never had to deal with.
I think, after a century or more of using this material in terrestrial structures, to understand how it works better, we can start thinking about such an elevator system.
But I think it is a safe bet you are not going to live to see one anytime soon, much to the contrary some of these guys at the Space Elevator web site will have you believe.
-Hack
Got Geometrodynamics? Awe, too hard to figure out? Too bad.