It's not often that materials as humble as Scotch tape and the stuff of pencil lead yield a Nobel Prize in physics, but they play a key role in a discovery honored in the 2010 award, announced Tuesday in Stockholm.
What's the big deal? Some researchers are calling graphene a "wonder material" capable of spawning a new generation of electronic displays and solar panels, as well as lighter, stronger composite materials used in everything from bullet-proof vests to airliners and spacecraft.
Graphene in essence is a two-dimensional crystal with atoms neatly arranged in a pattern that looks like chicken wire. Once the winners showed how to separate a layer of graphene from a block of graphite, materials scientists quickly set their sights on it.
Subsequent work has demonstrated that the vanishingly thin material is at least 100 times stronger than steel, conducts electricity more efficiently than copper, is highly flexible and the most transparent material known, and is remarkably efficient at conducting heat.
A true wonder material? "It's on its way," says Phillip Schewe, spokesman for the American Institute of Physics. After ticking off several of the aforementioned list of superlatives scientists have attached to graphene, he asks: "What's there to complain about?"
Graphene "has all the potential to change your life in the same way that plastics did," Andre Geim told The Associated Press after the Nobel Committee announced that he and colleague Konstantin Novoselov had won the $1.5-million prize. "It is really exciting."
Scientists have been scrutinizing graphene since 1947, when physicist Philip Wallace at McGill University in Montreal made the first calculations of what some of graphene's properties would be like – if it could be produced.
Over the next 57 years, graphene remained an artifact of the theorists' blackboards. Few thought graphene could be isolated and remain a stable material.
The reason: Crystalline forms of carbon, such as diamonds, typically form at high temperatures, followed by slow cooling. Many researchers had argued that graphenes would be hard to grow at high temperatures because the heat would keep atoms vibrating vigorously. This motion would discourage the formation of stable bonds between atoms in an ultra-thin two-dimensional crystal. Instead, the atoms would tend to settle into ordered patterns, but only as larger, three-dimensional crystals.
Others reasoned, however, that it might be possible to liberate graphenes from bulk carbon samples at low temperature. Indeed, another group tried to use Scotch tape to peel thin layers of graphite from a graphite block. But the researchers weren't able to pick out any single-atom layers from the slices the tape delivered.
That success fell to Drs. Geim and Novoselov, who published the results of their work in the journal Science in October 2004.
Since then, researchers have been able to use techniques similar to those used to make computer chips to deposit a single layer of graphene on wafers made from elements that weakly bind to carbon. Once formed, the graphene can be separated from its wafer "substrate." Such techniques have allowed researchers to produce graphene sheets nearly 28 inches wide.
Among the many potential applications envisioned for graphene, researchers are looking for ways to incorporate it into nanotechnology – machines and electronic devices whose dimensions are measured in billionths of an inch.
Indeed, the award highlights the growing role carbon has played in the materials-science arena over the past 25 years, particularly in the field of nanotechnology.
Carbon nanotubes – think Lilliputian drinking straws only 1/50,000 as wide as a human hair – have become a hotbed of materials research since the early 1990s. Single-walled tubes essentially are rolled graphenes.
And in 1985, a team that included the late Rice University physicist Richard Smalley discovered "buckyballs," soccer-ball-shaped carbon molecules made of 60 carbon atoms. Cork each end of a nanotube with a buckyball, and you have in effect a nano capsule.
The discovery of buckyballs earned Smalley and two colleagues the 1996 Nobel Prize for chemistry.