Vacuum-moulding graphene into nano-corduroy could unlock electronics potential

Graphene is a very good conductor of electricity, but because of its two-dimensional atomic structure a sheet of graphene tends to conduct electricity randomly across its whole surface, which is not very useful, particularly in electronics; this depends on digital signals, which are either conducting electricity across a defined gap or not at all.

One way to influence the way that graphene conducts electricity is to shape the sheet, which is the research focus of Vikas Berry’s laboratory at the University of Illinois in Chicago. One line of research that might prove particularly fruitful is focusing on wrinkling graphene sheets in defined ways, with the help of bacteria.

Wrinkling a graphene sheet creates ridges and channels along which electrons can travel because the resistance is lower along the channel than across the rippled surface, but it has proven difficult to control how the ridges form. Berry’s team has found a way to do this in a way similar to vacuum-moulding, using bacteria as a mould. The team used a rod-shaped bacterium called Bacillus subtilis, which has two useful properties: first, it can be induced to line up in an ordered array by using electrostatics; and second, when dehydrated the surface of the bacteria wrinkle, forming ridges along the axis of the rod-shaped structure about 33nm apart.