The graphene era
Graphene is an atomic monolayer of carbon arranged on a honeycomb lattice.
In the realm of companies, a ritual called dress-down Friday exists. Each Friday, employees are allowed to swap ties and suits for more comfy and casual clothes. This habit establishes a much less stressful ambiance before the week-end.
Physicists do have their own ritual, namely Friday experiments. Since the week-end is close, there’s no interest in launching big and serious experiments. Instead, to have fun and not lose their precious time, they test crazy, strange, improbable ideas, without really believing in their success.
Yet sometimes, it works!
The story of graphene started as this, a Friday experiment. In 2004, Konstantin Novoselov and Andre Geim, two physicists at the University of Manchester (UK), dared themselves to isolate an atomic monolayer. To give you an order of magnitude, 1 centimeter of a given material contains tens of millions of atomic monolayers stacked one on top of the others.
The achievement of this experiment is so important for science, that they were awarded the physics Nobel Prize few years later (2010).
Graphite, an ideal candidate
“But, which material should we use?”. The two physicists chose graphite. Graphite is the barbarian scientific name that is given to your pencil lead. It is an assembly of carbon atoms. When a unique monolayer is isolated, the suffix “-ite” is replaced by “-ene”. A monolayer is thus called graphene.
To isolate it, we could imagine that they used very sophisticated technologies, huge technical skills, and with Hollywood movies budgets.
Absolutely not, they used adhesive tape!
The researchers started from the simple idea that if a tape is stuck to a graphite sample, then by exfoliating it, the sample becomes thinner. If this process is repeated several times, the thickness goes down until it reaches a monolayer.
The production of graphene is as simple as that, the main issue was the skepticism around its success.
Actually, it is even easier than that. You have probably produced graphene many times in your life. Indeed, each time you wrote with a pencil, you may have produced monolayers. These monolayers were lost within the dust that your pencil creates due to the friction with the paper. The issue however in this case would be to locate those graphene pieces since no microscope would be able to scan such a large area.
Graphene, a toy model
Even though this achievement is tremendous, graphene was well known by the theorists. In fact, Geim and Novoselov chose this system because they knew the amazing properties it exhibits.
As mentioned earlier, the carbon atoms in graphene are arranged on a honeycomb lattice. This particular symmetry results in interesting properties that cover mechanics, electronics, optics etc.
The honeycomb lattice is a toy model. Since the system has no thickness, it is easy to analytically calculate many of its properties. It is usually given as an exercise in condensed matter courses.
After the discovery
Once graphene was isolated, it became popular again. Physicists rushed on the subjects as would Apple fanboys rush for a launch of the new IPhone n (where n is an index running from 1 to infinity). Many other properties were discovered, along with the invention of various production processes.
Nowadays, graphene is still a trendy subject. The following curve shows the number of scientific articles that are published each year about graphene (as of October 2017). The evolution is impressive and the numbers lately become quite frightening.
17465 papers for 2016, which gives an average of 48 papers per day!
If your research is about graphene, you better read fast! Not even mentioning that your results can easily become obsolete.
Graphene anywhere, anytime
No doubt that graphene is a revolution of the 21st century. Ideas of adding graphene appear each and every day. We find proposals of batteries with graphene, electronic devices, conductive inks etc.
This reminds with a clear analogy the story of Radium a century ago. People wanted to surf on the wave of Mme Skłodowska-Curie discovery by adding Radium in clothes, tooth pastes, beauty creams, sodas etc, before realizing that it was extremely dangerous.
- Oh Marie, you radiate today !
- That’s because I used my new Tho-Radia cream. Thanks to Radium, I feel younger than ever !
