The miracle material that will change the world
A corrugated graphene sheet has a 'chicken wire' look
It's been hailed as the miracle material of the 21st century, but what is graphene and why is it so important? Theoretically possible since the 1940s, graphene was discovered – and produced – by Konstantin Novoselov and Andre Geim at the University of Manchester in 2004. Both scientists won the Nobel Prize in 2010 for their pioneering work, and since then the race has been on to make graphene a commercially viable industrial material.
Almost a decade later that race is well under way, and along the way scientists are discovering even more miracle properties of graphene, uncovering an array of possibilities that could change the world around us.
Two hundred times stronger than steel, graphene sheets are described as 'chicken wire made of carbon atoms'. It's a near-transparent sheet of carbon graphite molecules just one atom in thickness.
A miracle innovation?
“The importance of graphene is that electrons can travel across it at close to the speed of light,” says Kevin Curran, senior member at the Institute of Electrical and Electronics Engineers (IEEE). “This is about one hundred times faster than they move at present through silicon, the de facto substrate for computers … it is also super-thin, super-strong, super-flexible and an excellent conductor.” Calling it a Holy Grail material in the world of electronics and photonics, Curran thinks graphene could form the basis for a whole range of devices, starting with ultrafast transistors.
That's the killer app for graphene, it seems, but there is a problem. “The most obvious dramatic usage for graphene is to replace traditional silicon as it is now approaching the limits of what is physically possible in terms of size reduction and speed,” says Curran, though for this to happen scientists need to solve the problem of the on-off state. “Currently graphene transistors are difficult to turn off, and that can be a game-stopper because in digital electronics you need the off-state to block current flow, and to have no dissipation when the transistor is in the off-state.”
University of Manchester
Magnetic graphene could replace silicon-based semiconductor technology
However, a team of scientists at the University of Manchester has just made a significant breakthrough, demonstrating that graphene can be made magnetic, and this magnetism switched on and off at the press of a button. With magnetic materials so integral to electronic gadgets using hard disks, memory chips and sensors – all use miniature magnetic components – this could be a game-changing discovery. “This work opens the doors for new magnetic devices that are atomically thin and can be easily controlled externally with the application of ordinary electric fields,” says Professor Antonio Castro Neto, director of the Graphene Research Centre in Singapore, and co-author of the report. “It is a true breakthrough."
'Graphene guru' Geim, who also co-authored the report, added: “I wonder how many more surprises graphene keeps in store. This one has come out of the blue. We have to wait and see for a few years but the switchable magnetism may lead to an impact exceeding most optimistic expectations.”
Perfect for gadgets
The surprises are likely to continue for some time. A team at the University of Illinois in June revealed that it had made digital circuits from graphene that operate at over 1GHz, making the material practical for mobile devices. Just 50 MHz had been its previous high.
Another key area for graphene to revolutionise our world is telecommunications. “Researchers have already demonstrated incredible speeds over 100 times the current speed of the internet backbone in transmitting information,” says Curran. “At present, optical switches, which route information over optical cables, respond at a rate of a few picoseconds – around a trillionth of a second. With graphene, this can be improved to one hundred femtoseconds, which is almost 100 times quicker than at present.”
Graphene could help aircraft become lighter, and therefore more fuel-efficient
The multi-purpose material
Other uses for graphene are myriad. “There are also a multitude of applications in the car industry, medical, aerospace, chemical and industrial processes which can be enhanced by graphene,” says Curran. It could also revolutionise batteries; in future, a smartphone could be recharged by plugging it into the wall for just a few seconds. It's even been suggested that perforated layers of graphene could form molecular sieves in desalination plants to catch the salt in seawater. The benefits of that to humankind as a whole are huge.
Philip Shapira, professor of innovation management and policy at Manchester Business School, says that graphene-related patents suggest the wonder material could soon be used in smartphones, electric vehicles, aircraft, medical diagnostic devices, sports equipment, renewable energy systems and buildings. “There is speculation that graphene’s strength might enable super-high buildings or new urban forms with huge walls of light,” says Shapira. Graphene could be used as the base material for solar cells, which could lead to innovations like photovoltaic paint; the walls of a house could literally soak up energy from the sun.
University of Manchester
Graphene could be used to create super-slim solar panels
Plenty of competition
However, graphene could find its future clouded by incumbent technologies – such as silicon in semiconductors – and slowed by the endless safety tests demanded of new materials by the aviation industry, for example. “Thousands of graphene patent applications have been filed so there is movement,” says Shapira, who's nonetheless not wholly optimistic about the material's future. “If the experience of other new technologies is a guide, many of the initial expectations for graphene will not materialise – it's not like software where quick results can appear.”
Graphene is already being used in HEAD tennis rackets
The shape of the future?
Still, graphene is not just a futuristic material – it's already being used as an add-on material in inks designed for printed electronics, tennis rackets (such as HEAD's YouTek Graphene Instinct – which is already used by tennis players such as Maria Sharapova and Tomas Berdych – and is about to be pioneered in display screens.
Plastic Logic has just signed a collaboration agreement with Cambridge University’s Graphene Centre to research the use of graphene in flexible plastic electronics – and that means bendable smartphones, Kindles and iPads. “It has fantastic potential for flexible electronics,” says Mike Banach, director of research at Plastic Logic, which was founded by researchers from the Cavendish Laboratory at Cambridge University. “We want to use graphene as a transparent conductor for a flexible display – perhaps using LCD technology – which we would expect to see in the next few years,” he says, adding that, “the push for flexible electronics is coming now.”
Plastic Logic is working on displays with Cambridge University's Graphene
Your flexible friend
Using graphene as the completely transparent conductive layer on plastic, the aim is to create flexible, unbreakable LCD and OLED displays, a market forecast to be worth £25 billion by 2020. Expect revolutionary new bendable designs for gadgets including tablets, smartphones, smart wristwatches and other wearable devices. The days of dropping a phone and smashing its screen could soon be over.
“These early applications offer useful improvements to existing applications and products,” says Shapira. “It is likely to be rather longer before more far-reaching applications of graphene are available.”
For all the high-tech applications of the miracle material, its super-thin, super-strong and super-flexible properties make it very likely that your first glimpse of graphene will be as a coating on Andy Murray's next tennis racket.
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