WE'VE been putting pencil to paper to write and draw for centuries. But it turns out that the marks we have been making with graphite pencils contain minuscule flakes of a two-dimensional material that could revolutionise the electronics industry.

The substance, called graphene, is a film of carbon atoms arranged like a honeycomb. While graphite crystals are made of stacks of many such hexagonal layers, graphene's single layer was believed to be too unstable to exist on its own. The layers were thought to crumple into sooty lumps.

"We now know these single layers exist," says Andre Geim of the University of Manchester in the UK, who isolated them with colleagues from the Institute of Microelectronics Technology and High Purity Materials in Chernogolovka, Russia.

Graphene is the basic structural unit behind many other forms of carbon, including graphite, buckyballs and carbon nanotubes. For example, nanotubes can be thought of as ...