Graphene – Miracle material of the future!
If you haven’t heard of graphene yet prepare to find out about a material that could lead the way in future technologies. Only discovered in 2004 by Dr Konstantin Novoselov and Dr Andre Geim – from the University of Manchester – experimenting with sticky tape and graphite (found in common pencils) they have already been awarded a Nobel Prize for this discovery.
What is graphene?
You may well have heard of it’s little brother, carbon nanotubes which are sheaths of carbon atoms rolled into cylinders with diameters roughly 10,000 times smaller than a human hair. They are incredibly strong, and amazingly conductive, sounding like something from a science-fiction novel but increasingly being used in real world applications today. Research carried out in 2008 shows that adding carbon nanotubes to standard carbon fibre at just a 1% concentration increased the overall strength of the material by 64%!
Graphene itself is a single atomic layer of carbon atoms as found in graphite, this is basically the same as a single layer carbon nanotube unrolled. Carbon atoms are arranged in a hexagonal formation with a carbon atom at every point on the hexagon, these are strongly bonded and create what we know as graphene.
Why is graphene special?
Graphene has a whole host of fantastic properties which will make it valuable to future technology, the list is really quite surprising:
- Strength
- Electrical Conductivity
- Thermal Conductivity
- Transparency
- Stiff
Graphene isn’t just quite strong, research at the University of Columbia calculates that graphene is the strongest material in the world. James Hone from the UoC states “The intrinsic strength of graphene can be considered as an ‘upper bound’ for the strength of materials — rather like diamond is for hardness — that could serve as a goal for engineers who design materials,”
Manchester University’s Dr Leonid Ponomarenko explains graphene has “the highest current density (a million times that of copper) at room temperature; the highest intrinsic mobility (100 times more than in silicon); and conducts electricity in the limit of no electrons”. Breaking this statement down to simple terms it means that graphene is the most efficient electrical conductor, doing this faster and more precisely than any other known material.
Graphene beats diamond in thermal conductivity. It’s in fact better than any other known material at conducting heat.
Graphene absorbs just 2.3% of light making it almost entirely transparent, yet still visible if compared to a plain white background. This could be hugely useful in solar cells and touchscreens, currently most are made from Indium Tin Oxide which absorbs around 10% of light, so this would be a great improvement, not only that but Indium Tin Oxide is brittle whereas graphene is not.
Graphene is also the stiffest known material, stiffer than diamond!
As you can see this is a hugely impressive list for a material that was only discovered 7 years ago, very rapid progress has been made in the production of graphene and the application of it into electronics. This BBC article contains some details on IBM’s progress using it, Dr Yu-Ming Lin, one of the scientists on the project states “This is the first wafer-scale production of graphene-integrated circuit – and we’ve shown that graphene can be integrated with other elements to form a complete function, which enables higher performance and more complex functionalities in a circuit.”
In their paper published in the journal Science, the IBM team explained that the circuit could operate at high frequencies of up to 10GHz (10 billion cycles per second), and at temperatures of up to 127°C, far exceeding the operating specifications of current silicon based processors.
The possibilities that this new material opens up are huge, it seems likely we will be using graphene based CPU’s in the future as well as finding graphene in many consumer electronics.