In theory, if you have a roll of sticky tape and a pencil lead (for a graphite source, pencil ‘lead’ contains no lead), you can make yourself some graphene – the very latest in advanced materials. That’s exactly how two scientists at the University of Manchester (Andre Geim and Konstantin Novoselov) first isolated graphene, back in 2004. They won the Nobel Prize for Physics for their EPSRC-funded efforts, in 2010. Graphene’s properties are so exciting that the European Commission is funding a special research programme, the Graphene Flagship, to investigate them. Geim and Novoselov continue to work on graphene, and make use of the SuperSTEM facility at the Daresbury Laboratory.
(Credit: Cambridge University)
Graphene is a 2D carbon crystal, which means that it is only one atom thick. It’s a million times thinner than a piece of paper, and yet it’s stronger than steel and conducts electricity better than copper. At the same time it’s flexible, and stretchy, and can be rolled up into carbon nanotubes. Science and industry alike are very excited about its potential.
The existence of graphene was theorised in the 60s, and although it is the most basic form of crystalline carbon, it is the most difficult to isolate because it really doesn’t want to stay as a flat 2D sheet, it would rather roll up. One of the biggest challenges we face in turning graphene into advanced materials is to learn how to mass produce it. But we solved the same problems with silicon around 50 years ago, and solving the graphene conundrum should be just a question of investing time and money.
So why should we make that investment? Well graphene is a superb conductor of heat, and as it is chemically inert it doesn’t react with other substances. In pure form, its electronic structure makes it what we call a semi-metal, although under the right circumstances (when it has been modified by introducing "additives" for instance - a process called doping) it can be turned into a conductor, a semi-conductor or even an insulator.
Electrons move rapidly through graphene, just 300 times slower than the speed of light, and its properties make them effectively massless. Graphene could be the basis for a new generation of faster computer chips and other electrical components.
It might also make an appearance in smartphone touchscreens, where its flexibility and stretchiness combine with conductivity and near-transparency to make it ideal.
And, bound to hydrogen, it can be used to produce a material called graphane, which has the potential to be a novel method for hydrogen storage, which could be the key to the wider use of hydrogen as an energy source.
But the first commercial uses for graphene are likely to be more down to earth, improving existing materials. For example, carbon black is added to car tyres and replacing it with graphene would lead to longer-lasting tyres. Using it in zinc-carbon batteries would improve their longevity and storage capacity as well.
If you’d like to know more about graphene, visit the Story of Graphene section of the University of Manchester website.
The SuperSTEM laboratory is at the forefront of graphene research. The EPSRC-funded facility is home to two state-of-the-art electron microscopes (of which there are only a handful around the world) able to provide images of 2D materials such as graphene, where each and every atom can be identified directly. Some of the very first atomic resolution images of graphene were published by SuperSTEM scientists in Nature Nanotechnology in 2008. Current research at the laboratory focuses on understanding how foreign atoms, or dopants, are incorporated into the graphene sheet, how they bond to their neighbours and how these modifications can change the properties of the material. The ability to control this 'doping' process accurately will allow researchers to tailor the properties of graphene to specific applications. It is an essential stepping-stone towards any practical implementation of graphene devices.
Read more about work on graphene at SuperSTEM: