Graphene, the Two-Dimensional Powerhouse
Short Talks From The Hill is a podcast highlighting research and scholarly work across the University of Arkansas campus. Each segment features a university researcher discussing his or her work. In this episode, Paul Thibado, professor of physics in the J. William Fulbright College of Arts and Sciences, discusses graphene, a two-dimensional material that is a mere single atom in thickness, and its potential role in the development of next-generation of electronic devices.
Chris Branam: Hello and welcome to Short Talks from the Hill, a podcast from the University of Arkansas. I’m Chris Branam. On this episode, Paul Thibado, a professor in the department of physics, discusses graphene. One of the strongest, lightest and most conductive materials known to man. Hello Dr. Thibado.
Paul Thibado: Hi Chris.
CB: So, tell us about graphene.
PT: Graphene is a single atomic plane of graphite, and its all carbon. Made of all carbon atoms. And the carbon atoms are arranged in a honeycomb lattice similar to chicken wire.
CB: And, graphene hasn’t been around for very long, or at least it was only discovered about 10 years ago, right?
PT: Yeah, that’s an interesting point you’ve raised. Back in the 1920’s it was actually theoretically predicted that no material as thin as a single atom sheet could exist in nature. And in the 50’s there was a ton of experimental evidence that proved yeah, that theory was correct. So it was pretty shocking in the early 2000s when physicists first isolated a single sheet of graphene basically by thinning graphite down thinner and thinner until it got down to about 50 atomic planes thick. And then at that point, you can almost imagine it like a deck of cards. If you press down in a deck of cards and you slide your hand sideways, you’ll spread out all the cards, and that’s essentially what they did. They could then look and find a single sheet of graphene and it was big enough that they could do electrical transport measurements on it and say this is a single sheet of graphene that had the predicted behavior from theory.
CB: What makes it so strong?
PT: Basically, since it’s made of carbon, the carbon bonds are the strongest bonds known to man. And they exist everywhere in the structure, and it pretty much forms a perfect carbon structure. There’s very few defects in it. So you have this great strength in the material with very few defects. So it’s basically a fundamental property of the carbon bonds.
CB: One of the things that you’ve talked about is that its excited people because it holds the promise for many different applications, including some that are pretty; I would consider sort of science fiction-type things. Can you talk about some of these applications people are talking about?
PT: One thing that’s very interesting about graphene is that it’s a metal. So electrons are free to flow through the material. But since it’s only 1 atom thick light can pass right through it. So it’s transparent, you have a transparent metal. That’s interesting because if you have a metal surface, then when you put your hand down on it, it can sense where your hand is being placed due to the static charge. And since it’s transparent, you can see through it. So a perfect application that is being talked about is basically your screen for your smart phone. Right now, the material that your smartphone is made out of has the same property but it’s very expensive material and it’s also very brittle. So it makes the phone; it’s kind of the most brittle part of the phone. If you could replace that part of the phone with graphene, it would be a lot cheaper, plus it would be a lot stronger. Another interesting aspect of that is that the phone would become flexible. So you could imagine folding up your tablet and sticking it in your pocket.
CB: So not only would you not have to worry about dropping your smartphone, you could just fold it up and put it in your pocket.
PT: Exactly. I would be a pretty nice; you could also maybe imagine your newspaper being like an interactive device that you’re flipping through and looking up articles on.
CB: So tell us what you’ve been doing with graphene over the last few years.
PT: My key area of research uses a technique called Scanning Tunneling Microscopy. It’s a very high resolution technique that we can look at individual atoms on a surface. And the interesting thing about graphene is its all surface. So it was a perfect fit for me to study graphene. One thing that we started researching was if you separate graphene from graphite, you can basically study the properties as it transitions from one environment to the next. I didn’t mention this earlier, but one really interesting aspect of graphene is when the electrons move through the material they behave as mass-less particles. So there’s just a charge moving through space, kind of like light moving through space. But when you put the graphene down on graphite it acquires that mass again. So what we’ve been doing is incrementally lifting the graphene off graphite and in the process observing how the electron goes from being massive to losing its mass. And that’s a very interesting physics question. Recently in the news, we’ve heard about the Higgs-Boson being discovered by particle physicists. What’s interesting about that particle is it gives mass to all matter. Here in kind of a desktop experiment we’re seeing that same phenomenon. Something very similar, so it’s very interesting.
CB: Well thank you, Paul. I look forward to hearing a lot more about your graphene research in the future.
PT: Thank you, appreciate it.
CB: Music for Short Talks from the Hill was written and performed by Ben Harris, guitar instructor at the University of Arkansas. For more information and additional podcasts, visit kuaf.com or researchfrontiers.uark.edu, the home of research news at the University of Arkansas.