A single plane of carbon atoms, graphene was isolated in 2004 through a method that could hardly be more low-tech: The University of Manchester’s Andrey Geim and colleagues used common cellophane tape to peel off weakly bound layers from bulk graphite. Once gently rubbed onto an oxidized silicon surface, the rare graphene flakes were then spotted among macroscopically thick graphite pieces in the interference patterns of an optical microscope image. Because it yields nearly defect-free crystals, that time-consuming process has largely remained the method of choice, particularly among researchers exploring the material’s astonishing two-dimensional electron-gas physics (see the article by Geim and Allan MacDonald in Physics Today, August 2007, page 35).
Despite the material’s low-tech beginnings, much of its allure lies in the advantages it brings to high-tech applications. Graphene can sustain current densities a million times higher than copper, exhibits record strength and thermal conductivity, is impermeable...
