Graphene: our miracle material
Graphene is harder than diamond, just a single molecule thick and conducts electricity. Kat Hannaford talks to the two Nobel prize-winning scientists who discovered it about why it could revolutionise everything.
Graphene is a planar sheet of carbon atoms arranged in a hexagonal pattern. Stacked graphene sheets form graphite, used in pencils.
They say diamonds are a girl’s best friend, but in the coming years that could all change. Stronger than diamonds, more conductive than copper, so stretchable that just one gram could cover several football pitches, graphene is being hailed as the miracle material that could one day replace silicon.
It’s not often that a new substance comes along that is so useful it defines an era. We named the Bronze Age after a metal that kick-started the early civilisations, and the next age after an even more helpful metal — iron.
The Plastic Age sounds less impressive somehow, but it was the last new discovery that had such a profound and pervasive effect on our world.
But what about the Graphene Age? It’s the latest wonder stuff which resulted in two Russian-born Manchester University professors winning the Nobel prize for physics in October, “for groundbreaking experiments regarding the two-dimensional material graphene”.
Ironically, Englishman Alexander Parkes collected a mere bronze medal for exhibiting the first plastic at London’s Great Exhibition of 1862, but like polymer, graphene has a huge potential. Professors Andre Geim and Konstantin Novoselov obtained the first samples simply by applying a piece of Sellotape to a pencil tip and peeling off layers of graphite.
Graphite consists of weakly bonded layers of graphene, which is itself comprised of carbon atoms arranged in linked hexagons, measuring just one atom thick and therefore having just two dimensions.
Professor Geim described graphene as having “a range of superlatives which no other material can be proud of”, including its incredible thinness and conductive qualities which see electric currents passing 100 times faster than copper manages.
You’d think having such attributes - not to mention its high flexibility and impregnability to gas and liquid - would make it suitable for various applications. That is true, but what Professor Geim calls a “fertile and huge area” is also a juvenile one: “Graphene is really only five years old, and despite thousands of researchers working on it, it remains a badly investigated area, with some patches remaining completely undiscovered.”
So what’s it good for? Rather a lot of things, actually. IBM and Samsung are already trying it out in numerous electrical devices, with the first fruit borne by IBM in the shape of a transistor, which uses graphene to achieve the record-setting speed of 100GHz.
The fastest alternative using silicon is 40GHz, and given that graphene can be tooled in exactly the same way to produce these components, many experts are speculating that silicon’s days are now numbered - including Professor Geim, who says that thanks to “silicon running out of its potential, we are standing at the same stage as we were back in the 20th century, when people found polymer”. While he admits that graphene is not substituting plastic, he does credit it as being “equally pervasive as plastic”.
Meanwhile, Samsung has realised that being both transparent and conductive, graphene could be perfect for the company’s many touchscreen devices. Ever since the iPhone rendered buttons unfashionable, touchscreen interfaces for smartphones, tablets and even computer monitors have proved extremely lucrative for many consumer electronics companies.
The ever-ambitious graphene’s resume doesn’t stop there. Researchers at Rice University have found a way to synthesise graphene using table sugar, giving the material impeccable green credentials.
In the same American state, engineers at the University of Texas have even discovered that by replacing the carbon used in ultra-capacitors with graphene, it’s possible to store double the amount of energy. That in itself could revolutionise the renewable energy industry that is currently looking for a new way to store the energy produced by its burgeoning solar and wind farms. If the so-called “smart grid” is to prove successful, a way to store energy for when it’s not sunny or windy is essential.
It’s not just industrial energy storage where graphene could step in and save the day, either. We use batteries for many electronic devices, and they’re all too often the limiting factor. If graphene really can double battery capacity at a stroke, it could catch on very quickly.
Over at Linköping University in Sweden, scientists have been exploiting a very different property. By passing a small electrical current through a transparent electrode made of graphene, a very pure light is emitted. Given that the bulk of energy we use every day is in lighting, graphene provides a very attractive low-carbon alternative to traditional solutions.
According to Ludvig Edman from nearby Umeå University: “This paves the way for inexpensive production of entirely plastic-based lighting and display components in the form of large flexible sheets. This kind of illumination or display can be rolled up or applied as wallpaper or on ceilings.”
Thanks to its flexible nature, graphene could also prove to be the ideal building material, with the trick being to incorporate it into a matrix like a polymer or a metal, where the load is borne by the graphene layer.
So far we’re only limited by the lack of a super-strong material to incorporate graphene, but once that’s discovered, we can expect the average household to be as aware of graphene as they are of plastics.
Professor Geim concludes: “At the moment it’s a dream, but it’s a good dream - and in 20 years from now, who knows, graphene may replace silicon.”
Professor Geim described graphene as having “a range of superlatives which no other material can be proud of”, including its incredible thinness and conductive qualities which see electric currents passing 100 times faster than copper manages.
You’d think having such attributes - not to mention its high flexibility and impregnability to gas and liquid - would make it suitable for various applications. That is true, but what Professor Geim calls a “fertile and huge area” is also a juvenile one: “Graphene is really only five years old, and despite thousands of researchers working on it, it remains a badly investigated area, with some patches remaining completely undiscovered.”
So what’s it good for? Rather a lot of things, actually. IBM and Samsung are already trying it out in numerous electrical devices, with the first fruit borne by IBM in the shape of a transistor, which uses graphene to achieve the record-setting speed of 100GHz.
The fastest alternative using silicon is 40GHz, and given that graphene can be tooled in exactly the same way to produce these components, many experts are speculating that silicon’s days are now numbered - including Professor Geim, who says that thanks to “silicon running out of its potential, we are standing at the same stage as we were back in the 20th century, when people found polymer”. While he admits that graphene is not substituting plastic, he does credit it as being “equally pervasive as plastic”.
Meanwhile, Samsung has realised that being both transparent and conductive, graphene could be perfect for the company’s many touchscreen devices. Ever since the iPhone rendered buttons unfashionable, touchscreen interfaces for smartphones, tablets and even computer monitors have proved extremely lucrative for many consumer electronics companies.
The ever-ambitious graphene’s resume doesn’t stop there. Researchers at Rice University have found a way to synthesise graphene using table sugar, giving the material impeccable green credentials.
In the same American state, engineers at the University of Texas have even discovered that by replacing the carbon used in ultra-capacitors with graphene, it’s possible to store double the amount of energy. That in itself could revolutionise the renewable energy industry that is currently looking for a new way to store the energy produced by its burgeoning solar and wind farms. If the so-called “smart grid” is to prove successful, a way to store energy for when it’s not sunny or windy is essential.
It’s not just industrial energy storage where graphene could step in and save the day, either. We use batteries for many electronic devices, and they’re all too often the limiting factor. If graphene really can double battery capacity at a stroke, it could catch on very quickly.
Over at Linköping University in Sweden, scientists have been exploiting a very different property. By passing a small electrical current through a transparent electrode made of graphene, a very pure light is emitted. Given that the bulk of energy we use every day is in lighting, graphene provides a very attractive low-carbon alternative to traditional solutions.
According to Ludvig Edman from nearby Umeå University: “This paves the way for inexpensive production of entirely plastic-based lighting and display components in the form of large flexible sheets. This kind of illumination or display can be rolled up or applied as wallpaper or on ceilings.”
Thanks to its flexible nature, graphene could also prove to be the ideal building material, with the trick being to incorporate it into a matrix like a polymer or a metal, where the load is borne by the graphene layer.
So far we’re only limited by the lack of a super-strong material to incorporate graphene, but once that’s discovered, we can expect the average household to be as aware of graphene as they are of plastics.
Professor Geim concludes: “At the moment it’s a dream, but it’s a good dream - and in 20 years from now, who knows, graphene may replace silicon.”
We feel that it's rather difficult to imagine graphene as a replacement to silicon 