It seems to get better and better every day. Every other news report that comes out describes it as something that outlasts, outshines, and outruns every other material out there. But first.... what is it?
Graphene is a 2-dimensional sheet of carbon molecules, packed close together in a hexagon pattern reminiscent of chicken-wire (something a surprising number of nanotech specialists are familiar with). It’s a fairly recent development in physics, not because scientists didn’t know single sheets existed, but because they didn’t know they could be isolated from the bigger 3D graphite. Theoretically, 2D crystals should not exist; the thinner a film of atoms gets, the lower its melting point (remember that temperature is simply the vibration of atoms. The faster the vibration, the more unstable our chicken wire can get). By the time you get to 2D, there should be an indefinite melting point. Hence, no graphene.
But obviously, science messed up.
Researchers at the University of Manchester extracted bits of graphene merely by ripping tape off of the tip of a pencil. Granted, there was some strong thermodynamic evidence to suggest how impossible graphene was, but there were a couple of loopholes that physicists didn't pick up on. The fact that the sheets do come from a 3D structure, and that their atomic bonds are so incredibly strong, makes them stable even at high temperatures. Moreover, they can be bent into all sorts of neat shapes, depending on what you want to make:
Researchers at the University of Manchester extracted bits of graphene merely by ripping tape off of the tip of a pencil. Granted, there was some strong thermodynamic evidence to suggest how impossible graphene was, but there were a couple of loopholes that physicists didn't pick up on. The fact that the sheets do come from a 3D structure, and that their atomic bonds are so incredibly strong, makes them stable even at high temperatures. Moreover, they can be bent into all sorts of neat shapes, depending on what you want to make:
 | ||
| They're just like K'nex: impossible to pull apart, and not as much fun as Legos. |
Though the shape of the graphene certainly carries important properties, it is the graphene itself that is so incredibly remarkable. Remember the concept of a band gap in semiconductors? (You may want to go back to another one of my posts to refresh your memory). Well, graphene doesn’t have one. Instead, the two electron paths touch, creating a cone-like structure called the Dirac cone:
 |
| See? Dirac was EVERYWHERE. |
The center of the Dirac cone is called (surprise) the Dirac point. It’s at this point that graphene really starts to become something amazing. Running an electric current through the sheet in this state makes the electrons go incredibly fast, skipping over entire atoms in their rush to get around; in fact, they can skip around 700 atoms at a time before having to land again, a feat unheard of in other substances. It’s solely due to this one property that graphene has the potential to revolutionize the electronics industry.
It sounds over-the-top, I know, but here are just a couple of new technologies that physicists are developing from this supermaterial:
- A replacement for rechargeable Lithium-ion batteries which charges almost instantaneously.
- Solar cells that never lose energy.
- Faster computer processors and data transfer.
...as well as many, many more. Even discounting other possibilities, imagine what could be done with only those three. It’s simply amazing, the opportunity graphene presents. And new breakthroughs are making the substance, in addition to already being inexpensive, easier to work with as well, for integration into circuits and batteries. While it might still be a while before the public sees a shiny new graphene-powered anything, it’s going to happen, soon.
And I will be there.
If you'd like to learn more about the nitty-gritty of graphene, check out this report by the University of Manchester, the ones who started it all: http://arxiv.org/pdf/cond-mat/0702595
No comments:
Post a Comment