Last week, the European Commission announced the investment of 1bn Euros (1,000,000,000€) in graphene research and its development as a new material. It was great news for science and I wanted to know more about this new material that was all over the media.
Graphene is a one-atom-thick sheet made of carbon atoms arranged in a honeycomb (hexagonal) lattice and it is one million times thinner than human hair. If graphene layers are stacked one on top of another they form graphite (the mineral). It was isolated in 2004 by researchers at the University of Manchester.
It has very advantageous properties and all of them are found in the same material, which is the reason for its popularity. Graphene is a great electricity conductor: electrons can travel through graphene easier than through copper and they travel very fast. It conducts heat (thermal conductivity) better than other materials, which is essential to dissipate heat and keep it cool. It is harder than diamond and 300 times harder than steel for a one-atom-thick layer. It can be stretch up to 20 % of its initial length and it comes back to its original shape. It transmits 97% of the light, which makes it almost transparent to the naked eye; however, it can be modified with certain chemicals to reflect light at a certain wavelength or colour. Graphene is quite sticky, which means that it can easily adhere and release atoms and other molecules.
These properties make it a great material with numerous applications: it can be used to create flexible touch-screen displays for mobile devices and LCD screens; it could produce very light and hard composite materials to be used in aircraft and car manufacture; it could be used to produce high-speed electronics for computers and communication technologies; it can be used to produce batteries, fuel cells and photovoltactic cells; it could make chemical sensors; and these are only some examples.
The main challenge of graphene technology is its production method. There are several ways to produce graphene, but I would like to explain the exfoliation of graphite method because it was the one used by Univeristy of Manchester researchers when they first isolated graphene and I think it is a bit rudimentary for such a cutting edge technology. It involves the use of Scotch tape to peel-off layers of graphite. This has to be repeated several times until you get super thin sheets of graphene that cannot be seen with the naked eye (you can watch a video about this in the Resources section bellow). All the production methods have in common that it is very expensive to produce graphene, they produce very small quantities and they are difficult to scale up. This makes graphene one of the most expensive materials on earth.
However, despite the limitations of the production methods, graphene is a very promising material with lots of great properties and innumerable applications. The EU investment in graphene research will definitely improve the production methods and boost research to find new and exciting applications for a technology that is often referred as the ‘21st century material’.
Introducing graphene (University of Cambridge): http://www.youtube.com/watch?v=dTSnnlITsVg
How to make graphene (PhysicsWorldTV): http://www.youtube.com/watch?v=ehvksWx3AJQ
University of Manchester Graphene research. http://www.graphene.manchester.ac.uk/
Park, Sungjin, and Rodney S. Ruoff. Chemical methods for the production of graphenes. Nature nanotechnology 4.4 (2009): 217-224.