|Georgia Institute of Technology, www.gatech.edu|
Graphene is widely seen as the most-promising candidate to replace silicon as the building block of ever-smaller, more-complex, and more-numerous transistors. To speed that transition along, engineers at the Georgia Institute of Technology have devised a way to use simple heat to turn specific areas of a graphene-oxide surface from an insulator to a conductor. In the one-step process, an atomic-force microscope tip heated to at least 130°C traces out a path, or wire, on the surface of a graphene sheet, which can be as thin as a single atom of carbon. These wires can be as thin as 12 nm and vary in conductivity by up to four orders of magnitude, a variation controlled by engineers. And there is little or no wear on the AFM and no tearing of the graphene.