Graphene – a single layer of carbon atoms – may be the most amazing and versatile substance available to mankind. In simple terms, Graphene is a one-atom-thick layer of carbon atoms arranged in a hexagonal lattice.
Graphene was first isolated in 2004. Since then, graphene has found hundreds of innovative applications, from sensors and electronics to energy storage and healthcare. Besides, research in graphene spun out the discovery of a new family of two-dimensional and layered materials. Combined with graphene –the same way you mix different ingredients in a sandwich– they open a whole new world of possibilities.
Despite being an atomically thin layer of carbon atoms, graphene shows outstanding properties that make it an attractive material for many applications.
Graphene is world's thinnest material – it is only one atom thick, one million times thinner than a human hair. However, it is very strong, stronger than steel and diamond. This allows many applications in composite materials with outstanding stiffness and durability. Graphene is also very flexible, which makes us dream of applications in wearable devices and foldable electronics. It would be a great fit for bendable screens, as it is also transparent. Besides, graphene is a great conductor of electricity and heat. Some producers have uses these two principles to make conductive inks and paints for electronic circuits and gels that dissipate heat. Graphene's conductive properties can even make longer lasting batteries. And, of course, graphene is light – it is just a layer of carbon atoms! The automotive and aviation industries are investigating graphene to make cars and planes less heavy, which will reduce fuel consumption and carbon emissions.
Graphene has come a long way since the first graphite pencil was created in the 1560's
When Andre Geim and Kostya Novoselov first isolated graphene in 2004, they used a piece of sticky tape to 'peel-off' atomically thin layers from graphite. Graphite is the main ingredient of pencil leads – if you have ever scribbled with a pencil, it is likely that you have made your own graphene!
Of course, this method is hard to scale up – imagine having to manufacture all the graphene we need with chunks of graphite and sticky tape. Luckily, scientists have envisioned new ways of producing graphene that are cheap, efficient and scalable.
Graphene for applications in electronics and photonics needs to have extraordinary purity and quality. We use a process called 'chemical vapour deposition' to make graphene by reducing the carbon atoms in methane. Carefully controlling the conditions, atoms arrange in the perfect hexagonal lattice on a support that is normally removed, to transfer graphene to more useful platforms such as silicon, plastic or quartz. Other applications, such as composite materials, paints and inks work perfectly with 'bulk' graphene flakes. We can manufacture graphene flakes thanks to liquid phase exfoliation, a method that uses ultrasound to 'shake' graphite and separate its layers. Moreover, graphene can be manufactured on-demand for applications in sensing and filtration. Chemists can modify its structure and craft atomically precise holes – microscopic sieves – or add functional groups that react selectively with interesting compounds.
Since 2013, the Graphene Flagship has brought together academic and industrial researchers to push graphene and layered materials to the forefront of European scientific research. But when –and how– did everything begin? Discover the history of graphene. (Picture: Adam Baker, Flickr).
