Less than a decade since it was first isolated, graphene is now becoming one of the most fascinating materials in applications as wide-ranging as high performance electronics, optical components, and solar power. It was just 2004 when scientists Andre Geim and Konstantin Novoselov, of the University of Manchester, UK were able to isolate single graphene layers, a discovery for which they were awarded the Nobel Prize for Physics in 2010.
Strictly speaking, graphene is a single atomic layer of graphite, with carbon atoms arranged in a honeycomb structure. One million times thinner than paper, it is so thin that it’s actually considered two-dimensional. The material is very strong, light, and nearly transparent, yet so dense that even the smallest atom, helium, cannot pass through it. It conducts electricity at least as (and possibly more) efficiently as copper and outperforms all other materials as a conductor of heat.
These single layers of carbon atoms provide the foundation for other important materials. Graphite — or pencil lead– is simply multiple layers of graphene. Carbon nanotubes, which are an emerging material in the production of lighter and stronger bikes and tennis rackets, smaller and more efficient batteries, fuel cells, and electronic devices, and even living tissue engineering, are made of rolled graphene.
According to Columbia University mechanical engineering professor and early graphene researcher James Hone, it is so strong it would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap. Touted as the strongest material in the world, its incredibly stable, one-atom-thick structure also makes it the lightest, as a team at Zhejiang University in China earlier this year created a graphene aerogel with a lower density than helium. A cubic meter of the substance would weigh about as much as an iPhone 4 in a case.
Due to its unbroken pattern and secure bonds between carbon atoms, graphene is very strong. These highly stable bonds between graphene’s carbon atoms are also very flexible. They can be twisted, pulled and curved without breaking, which means graphene is bendable and stretchable as well. Coupled with its unique electrical properties, it’s very realistic to think that graphene could be crucial to a new generation of bendable, foldable electronic devices.
Graphene also offers special electrical conductivity properties that make it an excellent choice for future electronics processor applications. Because electrons can move quickly through it, electricity can move quickly; some 200 times more quickly than through silicon. With new research out of MIT promising to solve the “band gap” problem inherent to graphene transistors (namely: it doesn’t have one, which makes switching it off difficult), in a few years we could be talking about processors that measure in the hundreds of GHz instead of today’s silicon-based ones which top out at around four.
In the solar industry, solar cells rely on semiconductors to absorb sunlight and are made of an element like silicon with two layers of electrons. Graphene’s layers of electrons overlap, meaning less light energy is needed to get the electrons to jump between layers. In the future, that property could give rise to very efficient solar cells. Using graphene would also allow for cells that are hundreds of thousands of times thinner and lighter than those that rely on silicon.
Devices such as flat-screen TVs and phones are commonly coated with a material called indium tin oxide, which is transparent and conductive. Manufacturers are actively seeking alternatives that could cut costs and provide better conductivity, flexibility, and transparency (indium tin oxide is inflexible and delicate), and graphene is an emerging option. It is non-reflective, flexible and strong, and appears very transparent. Its conductivity also means that it could work with touchscreen devices.
The potential for graphene is high; new applications for it have emerged seemingly on a weekly basis. It could be used in other applications such as DNA sequencing, water desalination, optical switches, and many more. With continued research graphene could come to redefine a number of different fields.
More information about graphene can be found on these sites, the sources of the research for this article: