Q&A - Three industry experts discuss the role of graphene in their fields

IOM3
,
8 Apr 2013

Ten years ago, graphene was a substance little known to anyone other than materials scientists. But ever since 2004, when researchers at the University of Manchester, UK, isolated graphene in its free form, it has been publicly hailed as the super material to transform gadgets of the future. ‘The UK is actively investing in graphene through industry, university facilities and research projects,’ explains Martin Kemp, Theme Manager of Engineering Applications at the NanoKTN, UK. ‘Graphene has received a lot of media and internet news coverage, with questions about how the UK is developing this area of technology.’

In response, says Kemp, the NanoKTN is coordinating an industrial consultation process on behalf of the Technology Strategy Board and Research Councils to advise on graphene’s future commercialisation potential. ‘We will be looking at how and why graphene is important to UK industry and addressing key questions on the scope of end-user markets and the barriers and timescales to commercialisation.’

Here, three industry experts talk to Melanie Rutherford about the role of graphene in their respective research fields, its potential applications, and how they believe the UK can stay ahead in the global race to exploit this multitasking material.


Professor Ian Kinloch, EPSRC Challenging Engineering Fellow at the School of Materials, University of Manchester, UK

What is your background in the industry?
I have 15 years’ experience working in nanocarbons, beginning with a PhD studying the production and dispersion of carbon nanotubes. Thomas Swan and Co Ltd funded my postdoctorate studies on the development of Elicarb carbon nanotubes, which it licensed for production by the University of Cambridge, UK. During that period we also developed a process for making high-performance carbon nanotubes, which was licensed by Plasan SASA Q-Flo Ltd and is currently going through pilot scale development. This was followed by an EPSRC/Royal Academy of Engineering Research Fellowship in carbon nanotubes, partway through which I took up lectureship at the University of Manchester, UK, working on nanocarbons (including nanotubes) and then beginning to move into graphene as interest picked up.

Where does graphene sit within your area of interest?
My EPSRC Challenging Engineering Fellowship looks at delivering graphene into engineering, focusing on production, and then learning how to process and disperse it into useful structures and forms. We have two target applications – one in electrodes for power storage, and the other in composites and coatings. The University has just been awarded a £3.3m grant for developing membranes and coatings using graphene, and a £2.2m joint grant with the University of Liverpool, UK, on using graphene for energy storage.

What is so special about graphene with regards to these applications?
For composites, we’re seeing graphene as multifunctional. It has an incredibly high modulus – experimentally we’ve shown that it can give the modulus of a terapascal to a composite – that’s 3–4 times better than the carbon fibre currently used in an Airbus. High strength and high modulus are quite tricky to achieve together – normally you only get one or the other. Graphene is also much more processable than other nanomaterials, particularly nanotubes. It has good conductivity, so you can add it to composites to produce an electrically conductive, anti-static application. It even has good barrier properties, so the addition of graphene could stop water ingression into a carbon fibre composite. There are some hints in the literature that it might be able to improve toughness as well, because the addition of a lot of platelets can defect cracks, absorbing energy.

For electrodes (particularly supercapacitors) you’re looking for high surface area. Because graphene is a monolayer material and, therefore, every atom is on both sides, it has a very high surface area – 2,630m2 per gramme to be precise. While for Li-ion storage, you can either add graphene as a conductive additive to the electrode, or you can use a few-layer or even a five-layer graphene and insert the lithium into the gaps.

In light of recent R&D, what application(s) of graphene do you think have the most potential?
In the near-term, using graphene as an additive to batteries is a good goal because it doesn’t have to be the only performing component, it can simply add benefit to an existing system. For example, at the moment a carbon electrode in a battery is a mixture of graphite, carbon black and maybe even some nanofibres, and now we’ll be able to add graphene as another part of the armoury. This method is probably also the easiest to do, as you’re adding to an existing technology rather than performing a complete step change. While step changes generate the most interest and excitement, it’s the gentle modifications that will make the quickest impact because you don’t need to change the technology of production lines.

What challenges does the material pose?
Production is one – no one is really on top of graphene production down to the monolayer. Graphene comes as one layer, two layers and many layers – but by the time you reach 10 layers, most of its physical chemical properties become like graphite. Currently, large-scale production of nanographite is relatively easy but producing one-layer graphene in bulk is quite tricky. The other challenge is actual handling of the material, because the most natural form for graphene is to become graphite. When you start off with graphite and break it apart to make graphene, the first thing it wants to do is restack as graphite. For applications requiring high surface area we need to learn how to handle, disperse and control those systems to stop the material re-aggregating and losing its properties as it reassembles from a 2D flake back into a 3D material.

What opportunities are there in the UK to develop and commercialise graphene?
For production, here at the University of Manchester we’re looking at a couple of routes. We’ve developed a method using electrochemistry, where we drive ions into gaps between graphite. As those ions keep going in, it adds so much strain that the graphite breaks into individual layers. Using this method we can make grammes of few-layer graphene in a simple vial in the lab, and we’re now looking at scaling that up with the aid of EPSRC funding. The University has patented this process, so we’re also looking for companies with whom we can work together to push the technology forward.

What are the most exciting developments in graphene nanotechnology?
That’s a tricky one. While the Li-ion applications will make a lot of impact, they’re developments that already exist. Our main target is to increase cycle life rather than capacity. Most people will be aware that their phone battery dies after a year and loses around half its capacity – our target is to keep that capacity up. This might not generate the same excitement as developing a flexible battery or flexible displays – take Nokia’s Dream Phone concept, which can be switched from a bracelet, to a handheld device, to a flat-screen TV that you hold in front of you – but that’s at least a decade away. This kind of step change is where the real excitement lies, but we’ve got to tackle the problems one by one. There’s also an argument that we haven’t found graphene’s most exciting potential yet. What we really need is for industry to come to us and say, ‘We’ve had this big problem, and this is the solution’.

What opportunities are there in the UK to develop and commercialise the material?
The National Graphene Institute (NGI) is a £61m building in Manchester for which they’ve just started digging the foundations, and will give around 100 research staff access to clean rooms, new chemistry laboratories and new growth facilities. It’s a hub that was announced by the UK Government in January 2013, with the aim of taking graphene from the laboratories to the factory floor, building that all-important conduit between industry and academia. We’re looking for companies to embed their researchers within that building and work alongside academia to realise graphene’s real potential.

What more needs to be done for the UK to stay ahead in the global race to exploit graphene?
By being clever, I guess. Government has put in a substantial amount of money, as has the EPSRC. However, Korea has just put US$600m into graphene. The UK has just put in about US$80m. But we’ve got very bright people in the UK, some of them Nobel Prize winners, and we are staying ahead on science. Things such as the new NGI building and current EPSRC grants will help get graphene into industry.

Dr JT Janssen, Researcher and Fellow of the National Physical Laboratory (NPL), UK

What is your background in the industry?
I received Masters and PhD degrees in physics from the University of Nijmegen in my home country of the Netherlands. My PhD work was on the far-infrared magneto-optical properties of low dimensional semiconductor structures and organic conductors. From 1994 to 1998 I was a Research Fellow at the University of Bristol, UK, where I investigated the Fermi surface properties of heavy Fermion metals and superconductors using the de Haas-van Alphen effect. Since joining NPL in 1998, I have been responsible for the research on quantum electrical standards.

Where does graphene sit within your area of interest?
My interest in graphene is two-fold. Firstly, it has a large number of interesting properties that make it a unique material to develop new measurement standards. Secondly, a large industry is starting to develop based on the unique properties of graphene, and novel metrology is needed to underpin this innovation.

In light of recent R&D, what applications of graphene do you think have the most potential?
The largest application area at the moment is probably flexible touch screen displays. Today, the touch screen displays are made with indium, which is an expensive and scarce metal. Also, the touch screens are rather brittle. Graphene could solve both these problems.

What challenges does the material pose?
Graphene is only one atomic layer thick. When there are many layers, it’s no longer graphene and the properties are very different. Also, anything that sticks to the surface of graphene or the substrate on which it lays will influence its properties. All these things have to be controlled during fabrication on the nanoscale, while at the same time making macroscopically large quantities, such as displays. This problem also emphasises the role of metrology, which should provide methods for real-time quality control.

How can these challenges be overcome?
Some of the sophisticated measurement techniques to establish these properties already exist in specialised laboratories such as scanning RAMAN, AFM, magneto-transport measurements, SIMS, XPS etc. The challenge is to adopt these techniques for use in the factory and also to develop novel, more affordable, faster and traceable methods.

What more needs to be done for the UK to stay ahead in the global race to exploit graphene?
We have got great capability in the UK but it is probably too fragmented. If you look at Asia or North America, they have got very strong national strategies that bring together academia, industry and government, supported by a serious amount of funding. The UK could do much more in this regard.

Professor Alexander Tzalenchuk, Researcher at the Quantum Detection Group, NPL, UK

What is your background in the industry?
I graduated and received my Physics and Mathematics PhD from the AV Shubnikov Institute of Crystallography Russian Academy of Sciences, in Russia, before moving to Sweden where I worked for more than 10 years at Chalmers University of Technology in Gothenburg, mostly in the then booming field of high-temperature superconductivity. I came to work at NPL 11 years ago to continue my research related to quantum information processing using superconducting circuits. This work successfully continues to this day.

Where does graphene sit within your area of interest?
Initially I resisted jumping on the graphene bandwagon because it was not immediately obvious how the NPL research team could contribute. As graphene’s properties became better known, technology advanced and it became clear how metrology can play an important role, the temptation became too strong to resist. Due to the NPL’s expertise in precision measurements and our connections with some of the world-leaders in graphene research, we were able to progress very quickly. Today, graphene metrology is a thriving field at NPL.

What is so special about the material with regards to this?
One of the first things discovered in graphene was the quantum Hall effect. This effect is only observed in two-dimensional (flat) systems, and graphene is the archetypal 2D system. In this effect, under special conditions (very low temperatures and very high magnetic fields) the resistance of the material becomes independent of the size and shape of the material, and is only dependent on two fundamental constants of nature – the electron charge and the Planck constant. This means that the quantum Hall effect is an ideal standard for resistance, which can be reproduced anywhere in the world with almost unlimited precision. Quantum effects are normally very fragile and difficult to observe, but the great thing about graphene is that this quantum effect is extremely strong and even persists up to room temperature. This means that we now have the opportunity to make resistance standards much more widely available to other laboratories and industry.

How close are we to exploiting graphene to its full potential?
Within the metrology world we like to say that we are already exploiting graphene’s unique properties to calibrate resistance standards for industry, which had previously been done using semiconductor devices. Of course, this is a niche application area – but a real one. Importantly this signifies that on performance, graphene can beat the well-established semiconductors with a much longer development history. Based on previous experience in the semiconductor industry, it takes decades for new technologies to come to market. However, technology is developing faster and faster all the time and such is the appeal of graphene that we wouldn’t be surprised if some of the first products are available before the end of the decade.

For your area of interest, what opportunities are there in the UK to develop and commercialise graphene?
At NPL we are developing novel measurement standards based on the unique properties of graphene, and at the same time we are developing measurement techniques for the nascent graphene industry. We are proud to represent the international metrological community in the recently announced European Graphene Flagship project, as the only national measurement institute in the consortium.

For further information, contact:

• Dr Martin Kemp martin.kemp@nanoKTN.com

• Prof Ian Kinloch ian.kinloch@manchester.ac.uk

• Dr JT Janssen jt.janssen@npl.co.uk

• Prof Alexander Tzalenchuk alexander.tzalenchuk@npl.co.uk

Graphene: Tell us your views Is graphene’s potential overstated? Should the UK Government be investing more in graphene research? Email features.editor@materialsworld.org to have your say.