The miracle material

One million times thinner than a human hair and 200 times as strong as steel, is graphene the stuff of the future? What sort of material is graphene?

It’s a form of graphite – the “lead” found in an ordinary pencil. Essentially, it’s an ultra-thin sheet of graphite, which has been isolated so that it is only one carbon atom thick. Physicists had speculated about the existence of graphene since the 1940s, but had assumed that it could not exist in a stable form at room temperature. Early this century, it was discovered that it can. You can see it under an atomic microscope: a single 2D layer of carbon atoms, like a lattice of hexagons linked in a honeycomb shape.

What’s so great about graphene?

It is the thinnest known material in the universe. It also attracts many other “superlatives”, says one of the scientists who discovered it: “It’s the strongest possible material, the most stretchable, the most permeable [by water], the most conductive… there are other materials that have one of those properties, but here it’s combined in one simple crystal.” Graphene is 200 times stronger than structural steel. “It would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of [cling film],” says James Hone, professor of mechanical engineering at Columbia University. It conducts electricity better than superb conductors such as silver and copper; as a conductor of heat, it outperforms any other material. It is nearly transparent. But it can also stretch by some 20%. It has so many exceptional qualities that it is being touted as the material that will revolutionise the 21st century.

Who discovered graphene?

Two Russian-born researchers at the University of Manchester, Sir Andre Geim and Sir Kostya Novoselov, who first isolated it in 2004, and won the Nobel Prize in Physics for their achievement in 2010. Geim, in particular, is known for his playful approach to research – he has named a hamster as a co-author of one of his research papers and has conducted an experiment in which he made a frog levitate. The technique the two scientists used to isolate graphene was surprisingly low-tech: they used sticky tape to rip off thin flakes from a piece of graphite, then repeated the trick many times over until the flakes were only a few atoms thick. Then they dissolved the tape in acetone and transferred the flakes onto a silicon plate, which allowed them to study the material and reveal its potential.

How might it change our lives?

Graphene’s potential uses appear almost limitless (see box). It could be mixed with plastics, metals or carbon fibre to make new composites: superstrong, super-light materials for building, say, cars or planes – which would be more energy efficient and safer than ever before. Since it is tough, transparent and conducts electricity, it could be suitable for computer touchscreens; or in the future, for whole electronic gadgets that could be rolled up, or stitched onto clothing. It could potentially replace silicon as the semiconductor in transistors, the basis of almost all electronics, making them much faster. Graphene-based electrodes have been shown to greatly improve battery life and charging time. The list of potential applications goes on and on: hyper-efficient solar cells; wallpaper-thin lighting panels; bulletproof vests; biotech implants.

Is it commercially viable?

Graphene has yet to find a mainstream application that could take it to market in a big way. It is still difficult and very expensive to make. In late 2015, pure graphene cost $100 per gram; the best stuff is still mechanically exfoliated, using the sticky tape method on a larger scale, or the energy-intensive chemical vapour deposition (CVD) technique. And though scientists are racing to find better means of production, this remains a major barrier to it being adopted as a substitute material. Samsung is said to have produced working prototypes of graphene touchscreens, but the price remains prohibitive. Besides, in semiconductors, the single biggest area of research, the results have been disappointing: graphene does not perform as well as silicon, because its conductive properties can’t easily be turned off – the essence of a semiconductor. So far, there are only a handful of products on the market that use graphene – anti-corrosion paints, for example, and highly conductive inks for electronics. The market research company Idtechex thinks the graphene market will grow to $300m by 2027: a tiny fraction of the size of the silicon and general electronics markets.

So is it all hype?

In the short term, the results are likely to be disappointing. But the market is undoubtedly growing. Sport, often an early adopter of new materials because marginal gains can make all the difference, has led the way: you can buy bikes with frames made of graphenebased composites, and cycling tyres, which the producer claims are faster, stronger and more puncture-proof than any other. The brand Head has produced a tennis racket, publicised by Novak Djokovic, with a graphene shaft. The key point is that there are so many potential applications that some are bound to come good. Besides, it often takes decades for new materials to be properly exploited: aluminium and silicon, for instance, were first produced in labs way back in the 1820s.

Will Britain be at the forefront?

In Britain, about £120m has been invested in graphene technology: notably, in Manchester University’s National Graphene Institute. Until recently, it had little tangible success to show for it: the institute’s most publicised innovation has been a graphene-coated light bulb filament, to be produced in Taiwan. In fact, a 2015 study by the UK Intellectual Property Office found that China, the US and South Korea were leading the way in graphene patent applications, with the UK trailing far behind. Even so, Britain is still the world’s third biggest graphene producer, after China and the US. And in any case, these figures may prove academic: the real race is to find the first gamechanging commercial application.