A Nobel Locked in a Pencil

Single layers of ordinary graphite used in pencils turn out to have extraordinary properties

It is a material all of us are familiar with in some way. Every time you write with a pencil, you are leaving thin layers of graphite on the paper. If you consider a mono-layer, a single layer of graphite, what you have is graphene, the wonder material that has brought the Nobel Prize for Physics to Andre Geim and Konstantin Novoselo, scientists of Russian origin now based at the University of Manchester.

In 2004 they used strips of Scotch-tape to tease apart single layers from pieces of graphite. When they started studying this material they found that it had some very exceptional properties that marked it out. As the Nobel Prize announcement states, ‘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.’ A graphene-based transistor has already been tested and shown to be 10 times faster than the fastest Silicon chip. Its strength is another factor that will spur a whole host of applications.

According to researchers at Columbia University’s Fu Foundation School of Engineering who proved that graphene is the strongest material ever measured, “It would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap.” A new generation of composite materials incorporating graphene will soon find its way into aircraft and automobile bodies. Its strength, combined with the fact that it is almost transparent, is also likely to ensure that graphene-based touch screens are in use soon. According to Geim, “I can only accurately predict the past, not the future. I would compare this situation with the one 100 years ago when people discovered polymers. It took quite some time before polymers went into use in plastics and became so important in our lives.”

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