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Science

Texas Scientists Spin Carbon Nanotube Fiber 83

Posted by timothy from the when-cotton-just-won't-do dept.
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!"
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Texas Scientists Spin Carbon Nanotube Fiber More

Texas Scientists Spin Carbon Nanotube Fiber

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  • nanotube strength (Score:5, Informative)

    by Artemis P. Fonswick ( 680020 ) on Wednesday June 11, 2003 @05:57PM (#6175887) Homepage Journal
    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.

    • Re:nanotube strength (Score:4, Interesting)

      by fname ( 199759 ) on Wednesday June 11, 2003 @11:23PM (#6178226) Journal
      Agreed. What a lot of the general interest publications is the difference between defect-free theroetical strength and real-world strength. Metals are also very strong if defect-free, but you can't produce them in any sort of bulk.

      This seems like a really clever approadh; all the press has focused on the "unobtanium" properties of the perfect, 100% continuous nanotube fiber. This really "feels"like a real world solution-- 60% nanotube, 100-meter lengths. This is the biggest science story of the year.

      **Please excuse my use of "quotes."

      • This is the biggest science story of the year.

        I also thought this was a big story. It sounds like this technique could lead to a large number of improved products. The article mentions these ...

        They have already spun the fibres into cloth, making supercapacitors - devices that store electricity.

        "Promising electronic-textile applications for these fibres, which are easy to weave and sew, include distributed sensors, electronic interconnects, electromagnetic shields, antennas and batteries," they

      • Carbon Nanotubes are said to be the strongest material ever inveted, "Coming straight from the horses mouth" so to say, I've talk to Dr. Smalley about this at a recent conference I attended. It would be interesting to see how the whole deal with the fibers plays out. Maybe we have a new Noble Prize Winners on our hands.

    • need a new moderation category: "Too Informative" (Score:5, Funny)

      by rfischer ( 95276 ) on Thursday June 12, 2003 @09:15AM (#6180883)
      whoa...
    • 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...

      Or, since they've ALREADY spun 100m lengths of it, merely tie one end to a building and another to your ex's bumper ;)

  • Incredible! (Score:3, Insightful)

    by NetRanger ( 5584 ) on Wednesday June 11, 2003 @06:01PM (#6175909) Homepage
    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.
    • Does anyone have the numbers at hand to see if this makes a "beanstalk" feasible?
      • Does anyone have the numbers at hand to see if this makes a "beanstalk" feasible?

        Yeah, with some refinement, of course. Give carbon nanotube research another 10 or 20 years and a ribbon-style space elevator would be possible. Take a look here [highliftsystems.com]. High Lift Systems, a research company under a large grant from NASA. They are proposing a very thin ribbon of carbon nanotube composite going about 50,000 miles out, or twice GEO orbit, that would be able to carry medium sized payloads. Cost would be around 10 billi

    • Not quite there yet (Re:Incredible!) (Score:3, Informative)

      by Anonymous Coward
      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.

  • ...but these guys have produced lengths of 100 metres at the rate of 70cm per minute!

    Not bad. :-)

    At that rate we should have enough for a space-elevator in just a couple of years. (assuming they don't think of a more down-to-earth use for it in the meanwhile...)
    • I haven't seen the exact figures yet, but from the information in the article the strength/weight ratio of this particular material is not twice as good as Kevlar.

      You need about very roughly 20+ times as good as Kevlar for a space-elevator. Single carbon nanotubes seem to have a limiting strength, in practice, of slightly more than what you need for an elevator, but this is the first cable using them to even beat Kevlar.

  • Get me off this crazy planet!!!

    Damnit, this all we need to build one of these. Someone get jumping on the design!!
    • 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.

  • A Miracle for Population Control? (Score:3, Interesting)

    by portege00 ( 110414 ) <[npbradshaw] [at] [yahoo.com]> on Wednesday June 11, 2003 @06:06PM (#6175949) Homepage
    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?

  • Have they fixed the flashlight insta-burn problem? (Score:5, Funny)

    by sudog ( 101964 ) on Wednesday June 11, 2003 @06:07PM (#6175958) Homepage
    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!"

    • Re:Have they fixed the flashlight insta-burn probl (Score:5, Interesting)

      by deglr6328 ( 150198 ) on Wednesday June 11, 2003 @06:44PM (#6176246)
      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.

  • Construction materials (Score:3, Insightful)

    by Lord Prox ( 521892 ) on Wednesday June 11, 2003 @06:18PM (#6176044) Homepage
    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.

    • Re: Construction materials (Score:2, Informative)

      by booch ( 4157 )
      It seems like apples to oranges when they compare its strength to steel. Steel can be easily formed into large solid structures. Their measurement of nanotube strength is just for a single microscopic strand. You'd have to somehow combine the strands to form a useful macroscopic structure. And the strentgh of that structure would be more dependent on how the strands are connected.
      • I agree with the spirit of your post, however one should note that, in the article, they are only comparing tensile strengths. Steel also has a very high compressive strength which makes it useful for all kinds of structural members. It's unclear whether the nanotubes would be useful for situations where they're being pushed, bent or subjected to shear stress. Perhaps somebody else can shed some light on this.
      • But there are plenty of applications where nanotubes could replace steel. A cable (from an airplane part to a suspension bridge) immediately comes to mind. I would imagine that the strands could be woven together, just like steel cables.
      • This fiber is not measured for a single nano-tube. What they do is taking a gelatine-like glue with tubes dispersed in it and extrude it and bake it. The tubes are aligned and glued together in the process. So this is the real, macroscopic parameter.

        By the way, from the simple chemicals named as a starting material, it seems like they got a good shot at producing this cheaply. You know, until now the nanotubes were pretty expensive. (More than gold by weight)
    • Unfortunately it's only strong in tension. If you have ever worked with carbon fiber, it's REALLY easy to cut, sideways. Think of it like a really strong, really thin nylon string.

  • Space Elevator in our life time? (Score:3, Informative)

    by oren ( 78897 ) on Wednesday June 11, 2003 @07:11PM (#6176396)
    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?

    • Re:Space Elevator in our life time? (Score:5, Interesting)

      by Beryllium Sphere(tm) ( 193358 ) on Thursday June 12, 2003 @01:10AM (#6178750) Journal
      "Requires" is a slippery word, because to some extent you can make up for a weaker material by tapering the cable so it's thicker in the middle where it's holding the "weight" of both ends, and thinner at the ends so there's less load.

      The amount of taper gets absurd in no time for materials weaker than unobtainium. High Lift Systems quotes a taper ratio of 1.7E33 for steel and 2.6E8 for Kevlar, and that's apparently for a cable stressed to the breaking point.

      10 or 20 times stronger than steel would be usable, in other words.
    • Yes, but would you want to ride a space elevator with a safety factor of only 1.00000? So there's probably a factor of ten left to go. I don't think I'll see it in my lifetime.

      In my lifetime, I'd settle for seeing humans get back to the moon. I'd like Mars, but I'll settle for the moon. Of all the things science-fiction writers predicted, reaching the moon and then abandoning lunar flights and letting grass grow on the launching pads was not one of them.

  • Re: (Score:2, Insightful)

    by account_deleted ( 4530225 )
    Comment removed based on user account deletion
    • Not really. It's only strong in one direction, and even then, only in tension. It would make a great cable though.
      • Woven, like a Kevlar vest, it might work quite well. Body armor has some issues other than strength, though. I read an article about building armor out of spider silk. It's got the strength, but it's also so flexible that a bullet would stretch the vest into your body and out your back before the vest bounced it backward.
        • I've heard that Feudal Japanese warriors wore loose, tightly-woven silk undergarments. In addition to being really sexy, they were protection against arrows. The arrow wouldn't cut through the silk, although it would still drive it straight into your flesh. The advantage is that you could remove the arrow by pulling on the fabric. It would keep the barbs from engaging and the arrow would pop right out. I would guess that it would decrease the penetrating ability of the arrow as well.
          • Also remember that most of the damage from a bullet is the exit wound, and with guns like the M-16, when the bullet bounces around the body.

            A fabric with high strength would "tame" the bullet, restricting damage to the entrance wound, and also keeping poisenous lubricants like teflon out of the blood stream.

            Insightful post!

            • Interesting, but I'm not convinced it would be a good thing to do with bullets. It may be that the bullet does more damage on the way out than in, but that may be because as the bullet deforms it sheds more kinetic energy as it passes through flesh. If you stop the bullet inside the body, that means that it gave up all its K.E. to the body. It might be better to have the bullet pass straight through, and take the energy with it (much to the distress of the guy standing behind you).
              • That's not to say that a far better outcome would be for the energy to dissipate by kicking your whole body. The energy of a bullet over 1/2 of a square inch will kill you. Spread over your entire chest would only give you a nasty bruise or some crack ribs.

                The problem is that the bullet doesn't travel straight through you, indeed hollow points are designed not to. The most horrific wounds are inflicted when the bullet shatters inside the body and essentially shreds all of the tissue on its way out. Even i

      • Re:Bullet proof? (Score:3, Informative)

        by sweet reason ( 16681 )
        Not really. It's only strong in one direction, and even then, only in tension.

        the same is true of the kevlar and spectra fibres commonly used in bulletproof vests today.

    • Re:Bullet proof? (Score:4, Interesting)

      by zero_offset ( 200586 ) on Thursday June 12, 2003 @06:52AM (#6180189) Homepage
      Also, I'm sure exotic car manufactures such as Farrari would be interested in the stuff.

      That's a very interesting thought, and worth expanding upon for anyone not familiar with the state of the art, or possibly unfamiliar with cars in general.

      At first I was tempted to dismiss your statement because carbon fiber cloth is easy to get, is relatively cheap (it's the autoclave that makes it so expensive to use/make), is well understood, and works very well -- and has been in widespread use for exotic automotive applications for about a decade. A friend of mine recently had a minor crash in his F50, as an example, and the repairs involved $150,000 worth of new carbon fiber -- 8 layers for most body panels, with each layer being completely different than the others, with each layer put there for specific reasons. Some are straight weaves, some are cross-weaves, and some are honeycombs -- all in a car that is 8 years old. So carbon fiber in general is definitely well-understood.

      However, in thinking about the properties of this specific application, I realized you might be on to something. Where this new strand-format CF might be interesting is places where steel tension cables are used today -- shifter cables, parking brake cables, wing adjustments, support structures, and so on. After all, in certain circles, any weight reduction is worth the money. I would expect to see it first in Formula-1 -- assuming the newly tech-averse rule-making idiots at the FIA don't make carbon fiber illegal, too.

      Definitely an interesting thought.

      • I'm not sure about FIA, but some race sanctioning bodies prohibit the use of Carbon Fibre for anything that "licks the aristream".
      • A friend of mine recently had a minor crash in his F50, as an example, and the repairs involved $150,000 worth of new carbon fiber -- 8 layers for most body panels

        I could have saved your friend about $149,900. (I'm pretty handy with a bucket of bondo and a putty knife.)

  • Synthetic dietary fibre (Score:4, Funny)

    by Muhammar ( 659468 ) on Wednesday June 11, 2003 @10:02PM (#6177715)
    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.]
  • Technology is there. When is someone both rich and smart going to fund it?

    • We got a chance to chat with Michael Laine of LiftPort [liftport.com] at this year's National Space Society [nss.org] annual meeting just a couple of weeks ago. They're looking for small investors already - talk to them if you would like to be involved at all. They will also have a private venture funding round coming up for larger investors, but anybody with a few hundred dollars could get involved at this stage (I think the deadline is June 20).
  • Too bad Highlift went down the toilet...

    Tim

    • Re:Bleh (Score:5, Informative)

      by barawn ( 25691 ) on Thursday June 12, 2003 @12:41AM (#6178621) Homepage
      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.

      • Re:Bleh (Score:3, Informative)

        by Anonymous Coward
        However, they are in competition with ISR [www.isr.us], where Brad Edwards is now director [www.isr.us] of research. ISR is planning a major effort towards a space elevator...Highlift says Brad is directing a team of 70. ISR is a nonprofit, does a lot of other space-related research, has a kick-ass facility under construction, and is already plugged into NASA and related organizations. It's hard for me to envision how Liftport, currently consisting of a small office and a million bucks, is going to successfully compete with ISR for
        • Is ISR actually planning a push to a space elevator? It looked more like they were interested in skyhook/power generation aspects of space tethers.

          We'll see, in time, how things go. Right now ISR's resources aren't needed. Still need to do research - mainly on CNTs, but also on other things as well - and so you don't really only need researchers, so you really only need to give out money. NASA probably isn't so keen on giving money to organizations so they can give out money to other people. :)
  • It may not be strong enough yet, but it won't be long. IT was only a few years ago that they made the first one at a rate of 0.4cm per minute. Give them 2-3 years and it will be all systems go for a space elevator. Then it will be all systems go for space. I volunteer to go to mars. Unless GWB makes it the space elevator illegal as it threatens US supremacy in space.

  • Who said pollution was all bad? (Score:1, Funny)

    by Anonymous Coward
    "Baughman says his achievement is to improve on this method by using nanotubes made from carbon monoxide..."

    So we just hook this thing up to the exhaust on my car, right?

  • Ouch! (Score:2, Interesting)

    by jsrjsr ( 658966 )
    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.
    • But these aren't exactly monomolectular. Sure, the nanotubes themselves are, but they aren't one long nanotube. They are jumbled together.

      One long nanotube might do what you are talking about, but these aren't likely to.
  • I'm not sure about the price for carbon nanotubes, but if it's anything like buckyballs, it'll be more per oz. than platinum which brings up an interesting question:
    What will be some of the first applications?

    I would think in sports equipment as undoubtedly there are many who would pay exorbant amount for an edge.

    Imagine the usual enhancements to golf clubs, tennis rackets, etc.

    Of course, there will be the downside of new technology when the first major leaguer is suspended for having a nanotubed bat.

  • ...when you can use the indestructible metal Adamantium!
  • ... at the America's Cup yacht racing (http://americascup.yahoo.com/) where cutting edge technology is always on display (http://www.cawthron.org.nz/Assets/cawlec98.PDF). Goodbye spectra (http://www.spectrafiber.com/), hello "carbonanoline" or whatever.
  • A lot of people might think I am crazy (I do) but would this material make it possible to build a space elevator? I'm not talking about a building from earth to space, but more a balanced, free-floating structure from the height limit of conventional aircraft into space. This could eliminate the need for rockets as their job could be done by standard jets, with it then joining onto the elevator and unloading the personnel/cargo.

  • Space Elevator (Score:3, Insightful)

    by hackus ( 159037 ) on Saturday June 14, 2003 @05:50AM (#6198216) Homepage
    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
    • I think you misunderstood my post.
      I do not mean an elevator from earth into space.
      What I meant is an elevator from the maximum height conventional aircraft can reach.
      If you had done some research you will have discovered that the space elevator can not possible be built from the ground upwards but from a mid-point in space both downwards and outwards simultaneously. While it is probably almost impossible to build it downward to the ground due to current materials, it may be possible to build it at least far

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