Graphene, Amazing Carbon Material, Holds Promise

This story was written by CNET's Stephen Shankland
Two researchers received the Nobel Prize in physics Tuesday for their work on graphene, a super-thin sheet of carbon atoms that has unusual and potentially useful properties.

Andre Geim and Konstantin Novoselov, currently professors at the University of Manchester, won the top physics prize for their work on isolating graphene from graphite - a more ordinary form of carbon used in pencils - and characterizing its behavior.

Graphene holds potential for profoundly transforming materials science - everything from computer chips and flexible displays to solar cells and lighter aircraft. Such products aren't on the verge of hitting store shelves, but the research is active - for example, IBM's work on graphene transistors.

"As a material it is completely new - not only the thinnest ever but also the strongest. As a conductor of electricity it performs as well as copper. As a conductor of heat it outperforms all other known materials. It is almost completely transparent, yet so dense that not even helium, the smallest gas atom, can pass through it," the Swedish Academy of Sciences said in its Nobel Prize announcement. "Carbon, the basis of all known life on earth, has surprised us once again."

Physicists already knew graphite was composed of sheets of carbon atoms arranged in a hexagonal array, but until Novoselev and Geim isolated graphene in 2004, it wasn't clear that graphene could exist in a stable form by itself.

They isolated graphene using an almost laughably mundane technique - peeling a layer off a graphite crystal using Scotch tape. Although their production method may have been low tech, the same can't be said for the hard work necessary to confirm that the layer had been transferred onto a silicon substrate for study.

Graphene is a close relative of other novel arrangements of carbon atoms - nanotubes in which the sheet is rolled into a tube shape and buckminsterfullerene, the 60-atom spheres also called buckyballs.

One of graphene's top properties is its ability to conduct electricity. It's no superconductor, but it loses relatively little energy to resistance compared with most materials. It could be used, for example, to make plastic conductive.

It's also strong - a square meter of graphene tied between two trees would be strong enough to support more than 8 pounds. Not bad for a transparent sheet one atom thick that would weigh less than a thousandth of a gram.

So far, sheets as wide as 70 cm have been fabricated, the academy said.

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