Saturday, September 17, 2005

The Progress of Materials Science

What an age we live in:
ARGONNE, Ill. (August 30, 2005) – Researchers at the U.S. Department of Energy's Argonne National Laboratory have combined the world's hardest known material – diamond – with the world's strongest structural form – carbon nanotubes. This new process for “growing” diamond and carbon nanotubes together opens the way for its use in a number of energy-related applications.

The technique is the first successful synthesis of a diamond-nanotube nanocomposite, which means for the first time this specialized material has been produced at the nanometer size – one-millionth of a millimeter, or thousands of times smaller than the period at the end of this sentence.

The result established for the first time a process for making these materials a reality, setting the stage for several fundamental advances in the field of nanostructured carbon materials.

The resulting material has potential for use in low-friction, wear-resistant coatings, catalyst supports for fuel cells, high-voltage electronics, low-power, high-bandwidth radio frequency microelectromechanical/nanoelectromechanical systems (MEMS/NEMS), thermionic energy generation, low-energy consumption flat panel displays and hydrogen storage.
Meanwhile, the idea of a space elevator is becoming much more likely:
Scientists have created the ultimate ribbon. A thousand times thinner than a human hair and a few centimetres wide, the carbon sheet is stronger than steel for its weight, and could open the door to everything from artificial muscles to a space elevator capable of sending astronauts and tourists into orbit.

The team of nanotechnology experts from the University of Texas at Dallas and the Commonwealth Scientific and Industrial Research Organisation in Australia have developed a way to assemble a form of carbon called "nanotubes" into flat sheets.

The cylindrical version of carbon, which combines lightweight flexibility and incredible strength with the ability to conduct both heat and electricity, has had engineers salivating since it was discovered in 1991.

The new research, published today in the journal Science, addresses one of the biggest problems with these remarkable molecules - how to turn them into large-scale materials. Ray Baughman, who led the Texan team, said the breakthrough was "elegantly simple".[John: aren't they always "elegantly simple"? I love scientists.]

Using sticky paper similar to a Post-it Note, the scientists teased out long sheets of the material from clumps of carbon fibres prepared in their laboratory. The sheets were initially full of holes but could easily be squeezed into dense ribbons capable of supporting drops of water and orange juice some 50,000 times their weight.

The scientists are now working with the US government and various companies to find uses for their technique. The first could be in sandwiching the thin carbon layers between plastic sheets, for example to make heated car windows or transparent radio antennae.

The research could also revive interest in the science fiction concept of a space elevator, as nanotube ribbons are the only material strong enough to make a track that would stretch thousands of miles from the Earth's surface along which electrical cars could speed into space.

"I believe that our carbon nanotube sheet does substantially improve the possibility," Professor Baughman said. "It does not enable a space elevator to be constructed, but we're getting there."
First off, interest in space elevators never, ever has to be "revived". The nerd fanboy demographic is basically always on high alert.

Also, there's another project that this could make plausible that's a bit more down to Earth. (Pun intended.) It's "only" 40 miles across the Bering Strait from Alaska to Asia. Surely if we can build suspension bridges out of carbon nanotubes, we could bridge this distance? (My understanding is that with current technology, the bridge is possible but would be ruinously expensive.) A high-speed train line from Asia to America could remove some of the need for air and sea travel powered by oil. Of course, if you can make maglev trains run through evacuated tunnels at Mach 3, the words "high speed train" suddenly have a very different meaning.

No comments: