Mobile phones that fold, razor thin handsets powered by flexible batteries or see-through solar panels built directly into a colourful screen. These visions of our mobile future may seem a world away from our rigid, fragile and power-hungry smartphones today.
But they could all soon become reality thanks to the “wonder material” known as graphene. Believe the hype and these single-atom-thick sheets of carbon could soon replace just about every material and component used in modern day smartphones, making it lighter, faster and with more bells and whistles than ever before.
If these claims seem extraordinary, then so too is the material which could make them possible. Graphene is made of a single element, carbon, arranged in a flat, unchanging crystal pattern that looks like chicken wire. Although it may sound rare and complex it is simply very thin layers of graphite – the same as found in a common pencil. In fact it’s now realised that almost every stroke of a pencil leaves fragments of graphene in the shining grey trace on the paper.
It was discovered in 2004 and could be the latest addition to a long line of material advances that have made our mobile phones possible. Think about the silicon slivers into which millions of electronic components can be etched; the lithium-ion batteries that pack a day or more’s worth of charge, and the low-energy light emitting diodes that can screen video in vivid colours.
What makes graphene remarkable is its ability to take on any of these roles. And what is more, it can conduct electricity better than copper, has strength greater than steel and also shows extraordinary elasticity. So great is its potential that in 2010 its discoverers Andre Geim and Konstantin Novoselov were awarded the Nobel prize for Physics.
Not only have thousands of scientific papers been published describing graphene’s many aspects; over 7,000 patents have been issued, many on technologies that could end up in mobile phones. No wonder electronics giant Samsung has invested huge sums into developing graphene as a material for screens and electronics; Nokia is backing a billion-euro project to exploit the carbon material and IBM has started a formidable research effort.
So far, the smartphone screen is where most attention has been paid publically.
The industry currently depends on a compound called indium-tin-oxide. And it’s the little-known metal indium that’s the problem. Demand has grown massively with the development of flat screens with global production quadrupling in the two decades to 2008. Since then production has levelled off, but the price for the metal peaked at $720 for a kilogramme in 2011, and the industry is concerned about the long-term security of supply.
To further compound the problem indium-tin-oxide is a brittle material, making it difficult to work with.
The material is cheap, see-through and critically is electrically conductive. That makes it ideal for the flat-screen displays used on smart phones that need electricity to power the optical elements, and to respond to the user touch.
Samsung and Nokia [SF: avoiding repetition of a few paras above] have already shown off concepts for “bendy” phones – such as the newly unveiled Samsung “YOUM” screen or the Nokia morph concept -with shapes unlike anything seen today. Although less extreme versions of some of these concepts may first be brought to market using more conventional technology, Nokia researchers believe that “graphene may well be one of the crucial elements of making Morph reality”.
Although these kinds of concepts excite the imagination and show the possibilities of graphene, durability is where the greatest interest lies. What the industry really wants is a touch screen a user can stab thousands of times a day without fear of the electronics ever giving out. Again, that’s what makes graphene so attractive.
Of course it has to be cost effective, too. As recently as 2009, it was only possible to manufacture samples of graphene that were a few centimetres across. But in 2010, Samsung-backed researchers at Sungkyunkwan University in South Korea showed it was possible to create roll of metres of the material, and demonstrated it on touch-sensitive tablet screens. And since then Sony has built a machine that can create rolls of the material 100m long – claimed to be the largest sheets in the world.