Posted on 8/20/2005, 4:45:39 AM by FierceDraka
They're soft, strong, and very, very long.
Large, transparent sheets of carbon nanotubes can now be produced at lightning speed. The new technique should allow the nanotubes to be used in commercial devices from heated car windows to flexible television screens.
"Rarely is a processing advance so elegantly simple that rapid commercialization seems possible," says Ray Baughman, a chemist from the University of Texas at Dallas, whose team unveils the ribbon in this week's Science.
Nanotubes are tiny cylinders of carbon atoms measuring just billionths of a metre across. They are light, strong, and conductive. But for years their promise has outweighed their utility, because the complicated processes involved in making devices from nanotubes were too slow and expensive to be used in large-scale manufacturing.
But now, nanotubes have gone into warp drive. Baughman's team can churn out up to ten metres of nanoribbon every minute, as easily as pulling a strip of sticky tape from a reel. This ribbon can be up to five centimetres wide, and after a simple wash in ethanol compacts to just 50 nanometres thick, making it 2,000 times thinner than a piece of paper.
The ribbons are transparent, flexible, and conduct electricity. Weight for weight, they are stronger than steel sheets, yet a square kilometre of the material would weigh only 30 kilograms. "This is basically a new material," says Baughman.
Nanoforest
Scientists have been weaving carbon nanotubes into fibres and sheets for several years. But until now, the most common way of making large sheets of nanotubes relied on a labour-intensive technique much the same as that used by the ancient Egyptians to make papyrus. Nanotubes suspended in a solvent were slowly filtered to create a mat, which was then dried and peeled off the filter.
Baughman's team instead start with a 'forest' of half-millimetre-long nanotubes sticking upright on an iron-based platform. Pulling gently from the edge of the forest with an adhesive strip, such as a Post-It note, uproots a row containing millions of nanotubes. As these nanotubes pull out, they tangle with the next row, and so on.
The nanotubes tangle together just enough to keep a ribbon growing, without jumbling up into a huge ball. "They've found the magic spot," says Ian Kinloch, a materials scientist at the University of Cambridge. "A lot of people will now try this out with a Post-It in their own labs." The team says a one-centimetre-long forest of nanotubes can produce three metres of nanoribbon.
The researchers had previously used a similar method to draw strings of nanotubes from a forest. Getting them to knit into a wider fabric is a bit trickier, but Baughman says that scaling the work up to produce large sheets will now be "easily do-able".
Patent bonanza
Nanotubes are already replacing graphite in certain commercial devices such as batteries. But this technique could now propel many more nanotube products into the marketplace, agrees Kinloch.
The team has already proved the sheets' usefulness in several applications, filing patents as they go. They have sandwiched a nanoribbon between two Plexiglass plates, for example, using the heat of a domestic microwave oven to weld the layers. This forms a transparent, conductive sheet ideal for a heated car window, they say.
And since bending does not change the electrical properties of the nanotubes they could be used to carry current in a 'rollable TV screen', something that has long been promised by nanotechnologists.
"Things move quickly if you can prove that the supply of the material is good," says Baughman.
A high voltage heats a nanotube sheet until it glows like a light bulb filament.
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Behold the works of free men! This could change the world, folks. The potential applications of this stuff boggle the mind.
Keep an eye on the stocks of any company that invests in this technology.
Since this material might lead to radical advances in aerospace applications, this seems Space Ping-worthy.
Nanotubes continue to amaze me. This, combined with micro LEDs will lead to some really cool technology.
It WILL change the world.
Now for the sake of humanity, I only hope its use will be for good.
I second that.
Say hello to the "Predator Suit" adaptive camouflage for men and machines.
So9
Fullerene Nanotubes: C1,000,000 and Beyond
Metal or Semiconductor?
http://www.americanscientist.org/template/AssetDetail/assetid/28780/page/7
"In these tests both metallic and nonmetallic nanotubes have been found, illustrating the profound sensitivity of the electrical properties to the geometry of a specific tube. However, none of the nanotubes showed an increase in resistance with temperature, a classic attribute of a metal, obscured probably by the multiwall structure and the possible presence of defects. The synthesis of single-wall armchair nanotubes provided a way out of this uncertainty. Their resistivity grows with heat, as it does for all the metal pieces in our home appliances and electric bulbs."
Very large screen TVs (an entire wall) that you can basically tape to the wall. Heads up displays that you can stick to the surface of a pair of glasses. The mind boggles.
Also, imagine video displays as implants in the human eye.
you DO want to see this.
first, the applications possibilities are staggering
second, that there is such a thing as a "sweet-spot" allowing for such organization might have biochemical implications
This really is neat. I wish someone had an engineering ping list. I'll ping a few folks, but this really isn't for what I do with my science ping list.
This should speed up the deployment of Skynet. :-)
RW might have a circle of engineer-types on-tap.
Yo, Doc? is it not nifty?
ping
(buckminster) fullerene tubes in flat sheet form.
I wonder if anyone is playing with its armoring potentials yet?
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