By all measures, graphene should not exist. The fact it does comes down to some neat loophole in physics which sees with an impossible 2D sheet of atoms behave like a good 3D material.
New research has delved into graphene’s rippling, discovering a physical happening on an atomic scale which could be manipulated as a means to make a virtually limitless source of clean energy.
The group of physicists led by researchers in the University of Arkansas didn’t set out to discover a radical new way to power electronics.
Their aim was much more humble — to only observe how graphene shakes.
We’re all familiar with the gritty black carbon-based substance known as graphite, which is often blended with a ceramic substance to generate the so-called ‘lead’ in pencils.
The thing that we see as smears left from the pen are actually stacked sheets of carbon atoms arranged in a ‘chicken wire’ pattern. Since these sheets aren’t bonded together, they slip easily over one another.
For years scientists have believed if it had been possible to isolate the individual sheets of graphite, leaving a 2-dimensional airplane of carbon ‘chicken wire’ to stand on its own.
In 2004 a set of physicists in the University of Manchester achieved the impossible, isolating sheets by a lump of graphite that were an atom thick.
To exist, the 2D material had to be cheating in some way, behaving as a 3D material in order to offer some level of robustness.
It turns out the ‘loophole’ has been the random jiggling of atoms popping back and forth, giving the 2D sheet of graphene a handy third dimension.
To put it differently, graphene was possible because it wasn’t perfectly flat at all, but vibrated on a nuclear level in such a way that its own bonds didn’t spontaneously unravel.
In order to correctly measure the level of the jiggling, physicist Paul Thibado recently has directed a team of grad students in a very simple study.
They placed sheets of graphene across a reassuring copper grid and observed the changes in the atoms’ positions with a scanning tunneling microscope.
While they could record the bobbing of atoms at the graphene, the numbers did not really fit any anticipated version. They could not replicate the data they were collecting from one trial to another.
“The students felt we weren’t likely to learn anything useful,” states Thibado, “but I thought if we were asking too easy a question”
Thibado pushed the experimentation into another direction, searching for a pattern by altering the way that they looked at the information.
“We separated each image into sub-images,” states Thibado.
“Looking at large-scale averages hid the various patterns. Each region of one image, when viewed over time, generated a more purposeful pattern.”
Patterns of small, random fluctuations combining to form sudden, dramatic shifts are known as Lévy flights. While they have been observed in complex systems of climate and Science, this was the first time they’d been seen within a nuclear scale.
While Thibado was measuring the rate and scale of those grapheme wave, he figured it might be possible to exploit it as a ambient temperature power source.
Put electrodes to both sides of sections of the buckling graphene, and you’d have a miniature shifting voltage.
This movie clip below explains the procedure in detail: