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Saturday 2 April 2011

Graphene


In 2010 the Nobel Prize in Physics was awarded to Andre Geim and Konstantin Novoselov for their work on the material known as Graphene. So you'd suppose it's a big deal, this new form of carbon, and you'd suppose right. It is widely regarded as a material made of dreams forged by angels and sent to man to fulfil our destiny.

Background
In 1962 Hanns-Peter Boehm described single-layer carbon foils which got picked up Geim who decided to take a closer look at the flat 2D version of Nanotubes. He fought the general opinion that it shouldn't be stable in this form. He and Novoselov actually lifted off flakes from Graphite (which basically is sheets of Graphene stacked) with tape. After repeating this numerous times they eventually had an ultra-thin single-atom layer flake of Graphene that they placed on a silicone-dioxide surface.
Their research was published in Science in 2004 and describes the properties of Graphene, like the fact that electrons shoot through ballistically, travelling huge distances without scattering and by introducing a Field Effect Transistor, the properties could be dramatically changed

Field Effect Transistor in groovy colours


Why is it special?
Physicists are a bunch of lovely weirdos, from the reality challenged not-crazy Dr Sheldon Cooper (his mother had him tested) with poor social skills & fantastic intellect via sir Isaac Newton who discovered  everything and had the dubious honor to star in the DaVinci Code to Willebrord Snellius who is only here because he has the most fantastic name ever.
What they all have in common though, is that they ponder things. That is basically thinking but with a pipe.
They have spent the better part of a century pondering the properties of Graphene but without something to study it was pretty much guesses and smoke rings
I've been pondering, Bilbo. What awesome wand I could have if we only could isolate a single atom layer of carbon

When Geim and Novoselov managed to produce a flake of Graphene the physicists could start to study it experimentally. And it shows unique electronic properties due to it's hexagon pattern. The electrons spread across the lattice and creates waves of electric charge known as quasiparticles. These particles can be compared to light photons but still retain certain characteristics of electrons (charge and spin). They have now been able to test the Klein Paradox thanks to Graphene, and that is in short that relativistic charged particles can tunnel through any energy barrier. And this is because these particles generate a ghost-version of the anti-particle. From there on it gets a little far out for us with normal minds, jobs and tobacco.

Cool, but what can we use it for?
Well, cooling actually. It dissipates heat better than copper. It also shows great promise to use in processors (doesn't everything that is being invented or discovered nowdays), transmitters and recievers (especially in the terahertz range), batteries, supercapacitors or other forms of energy storage.

Graphene is also transparent which opens up new and exciting possibilities, LCD:s, OLED:s or touchscreens.

It is also the strongest material ever tested with a plethora of materials it can replace when building strong light-weight stuff like cars, planes, space elevators or maybe buildings?

Graphene has also been used as a chemical filter, removing arsenik from drinking water has already been done and can we make cheap and easy-to-use filters that could change the lives of countless people around the world where clean water is hard to come by. 

I may not be a scientist, designer, inventer, genious or heartless CEO but I do smoke pipe and ponder and I can see a future where a child in Africa is using his Graphene cup (GrapCup patent pending) to fill up with water in a nearby stream not thinking about the dead hippopotamus upstream leaking death. And while the cup itself clean the water it also access the internet and sends the homework to the transparent OLED in the lid, tweeting to his mates "guys, there is an enormous carcass here, let's blow it up" the filming them while it rains rotten hippo on the villiage elders and posting it on youtube. And there you are with your swiss armyknife that can open cans AND pick your teeth. Not so proud anymore, are you? 

The lesson here kids is: smoke pipes, don't smoke cigarettes. Oh, and do science, it's awesome.

See also:
The Quantum Hall Effect
Nano Tubes
Klein paradox
Physics World about magnetizing Graphene




References