What is Graphene and what can it do?
Hi, my name is Rory Brown and I’m in the second year of a PhD in theoretical physics. Specifically, I’m a part of the Graphene NOWNANO CDT at the University of Manchester, a programme that takes in students from all STEM backgrounds and trains them to do research in different areas of nanotechnology, mostly related to graphene and other similar materials – I use computer modelling to study how graphene behaves when we combine it with other materials to make electronic devices, and try predict if anything unusual will happen. I’ll tell you a little bit about what graphene is and hopefully explain why it’s so exciting, then what a PhD is like and how you can get there.
In DepthGraphene was discovered here in Manchester in 2004, through an experiment so simple you can do it in 5 minutes at home. We start with graphite, the same material that we use in pencils. If you’ve ever held a piece of graphite, you might notice that it feels slippery and waxy – this is because graphite is made of layers of carbon atoms, organised in hexagons and stacked together like a deck of cards. Each layer is strongly held together but can freely slide over one another, and when you write with a pencil you break these layers apart, leaving some behind on the page. Graphene is a single one of these layers, and for a long time people argued that a single layer couldn’t actually be separated from the others, thinking it would be too unstable. It’s actually surprisingly easy to make – reaching in with a piece of scotch tape, the Manchester team was able to pull these layers apart over and over, until they finally had flakes of single layers of graphene, a material 10,000 times thinner than a human hair. Given that it’s only one atom thick we say it’s a ‘2D’ material, and since its discovery we’ve found a whole family of materials that can be made 2D.
Picture a: a sheet of graphene. Picture b: how graphene stacks are weakly bonded to make graphite.
So now that we’ve made it, what can graphene do? As well as being incredibly thin it has some remarkable properties, being incredibly flexible as well as the world’s strongest material: if you had a sheet big enough it would take the weight of an elephant balanced on a pencil to break through it! Industries are already looking into using graphene to make stronger, lighter materials for e.g. cars and aerospace travel. I’m interested in its electronic properties: electricity in graphene travels without any resistance, only 300 times slower than the speed of light, which gives it a lot of potential for energy-efficient electric devices.
One of the ways to make these devices is to combine graphene and other 2D materials, making thin sandwiches of different materials. What we’re left with is a stack only a few atoms thick, and the atoms in each layer can have different properties – one can be an LED, or a sensor. This is where I come in, making computer programmes to try and describe what happens in these layered materials. Working as part of this big group effort to improve our understanding of this new technology is very exciting and rewarding.
How I got here
My path to doing my PhD was fairly straightforward – I studied an MPhys in Physics here in Manchester, and my interest in graphene led to me staying. This isn’t always the case, and the NOWNANO CDT is a great example of how this can work: the people I work with come from a variety of backgrounds across all of STEM, some having spent time in industry beforehand. I’d love to continue with research, but there’s a lot of potential in PhD studies beyond that: you can go into scientific research or work in industry, or if that’s not your thing the skills that you learn (independent research, problem-solving, numeracy, presenting…) can lead to just about any job you can name. It’s a fascinating position to be in that’s full of opportunities all around the world.
If you’re interested in some of the cutting-edge graphene research facilities that we have in Manchester, I recommend looking at the National Graphene Institute and NOWNANO websites:
The Museum of Science and Industry in Manchester also has an exhibit on graphene and other ‘Wonder Materials’ running until June 2017 that’s worth a visit:
Graphene also tends to pop into the news every now and then because of the promising factors just mentioned, so keep an eye on the science sections!
The National Graphene Institute.