/ 5 October 2010

Lattice to replace chips in computers to come

For more than half a century, computers have been obeying “Moore’s Law,” a principle named after Gordon Moore, the co-founder of chip maker Intel.

Under it, the number of transistors that can be incorporated in a chip has doubled every 18 months or so, which explains the extraordinary rise in processing speed and memory capacity at the heart of modern gadgets.

The “law” was predicted by Moore to endure until the mid-1970s, yet it is still going strong — but not for much longer.

As early as 2015, according to the gloomiest estimates, engineers working in silicon and other existing materials will run smack into another law: the limits of miniaturisation, when too many circuits cramped into too small a space leads to higher temperatures which in turn crimps efficiency.

This is why graphene, the material that on Tuesday unlocked the Nobel Prize for Russian-born physicists Andre Geim (51) and Konstantin Novoselov (36) has been greeted with such excitement.

Graphene is a novel form of carbon that comprises a single layer of atoms arranged in a honeycomb-shaped lattice.

Even though the substance is chemically very simple, it is a stellar performer in strength, in conducting electricity and dissipating heat.

That makes it a fabulous candidate to replace semiconductor chips — and explains why microchip giants such as IBM and Intel have been investing heavily in a material that today only exists in tiny flakes.

“Diamonds may be a girl’s best friend but graphene gives an unexpected and a wholly new way to put the electron in carbon country,” said Marshall Stoneham, president of the Institute of Physics in London.

Graphene transistors would in theory run at far higher speeds and cope with much higher temperatures than silicon counterparts.

As graphene is nearly transparent, it would also be suitable for making touch screens, light panels and possible solar cells.

Plastics with graphene added to them can become heat-resistant and — thanks to the robustness of the carbon lattice — mechanically strong. They could be incorporated as composite materials in the satellites, planes and high-performance cars of the future.

“Graphene has become known as a wonder material,” Geim, a professor at the University of Manchester, north-western England, said last year as he accepted an honour at Britain’s prestigious Royal Society.

“Not only is it the thinnest material in the universe, but also the strongest ever measured. It can sustain current densities a million times higher than that of copper, shows record thermal conductivity and stiffness and allows the investigation of quantum relativistic phenomena in a bench-top experiment.

“The full list is long and is yet to be completed.”

Graphene was aired as a theoretical substance in 1947, but for decades, many physicists thought it would be impossible to isolate, suggesting that such thin crystalline sheets were bound to be unstable.

Showing smartness and arguably the cheapest technology around, Geim and Novoselov in 2004 extracted graphene by painstakingly using ordinary sticky tape to pick up a flake from a piece of graphite — the carbon form found in pencils.

Graphene still remains firmly a laboratory substance, produced only in flakes of a fraction of a millimetre, which of course is far too small to be useable in electronics.

But in January this year, European scientists demonstrated how graphene production could be scaled up by “growing” one layer on another on silicon carbide. – AFP