The science establishment often doesn’t recognize a scientific revolution when it first appears. Science journals rejected the first papers that announced success in making graphene.
Only one atom thick, graphene is now called the most remarkable substance ever discovered. It could lend its name to the next era. Our species had its Stone Age, Bronze Age, Iron Age, and now we’re entering a Graphene Age.
Graphene’s extraordinary range of uses continues to expand dramatically with news from science laboratories around the world. It is the thinnest material ever measured, yet the strongest. Graphene is as pliable as rubber and electrically conductive to an amazing degree.
Even the discoverers of a process for making stable graphene didn’t know that it would naturally ripple, bend, and buckle. The buckling creates a small but constant shifting voltage, which may mean a future power source.
Now, scientists, finding that graphene can turn light into action, may be replacing the older idea of solar sails for fuel-free spacecraft in the future.
A few months ago scientists announced a sponge-like material they made by fusing crumpled sheets of graphene oxide. Recently they noticed that cutting graphene sponge with a laser, propelled the material forward. Natural sunlight did the same. So in the vacuum of space that tiny effect of photons could build up enough thrust to move a spacecraft. That’s speculative, but graphene is doing real work on Earth.
Graphene is made from ordinary graphite, the dark carbon material often combined with a ceramic to make what we call lead in pencils. Not long ago, scientists didn’t think it was possible to isolate single sheets of graphite and have a plane of carbon atoms stand on its own.
They did know that graphite atoms arrange themselves in a honeycomb pattern. Graphite is made up of such layers, stacked. The loose bonding between layers is why pencils leave markings on paper.
It sounds like an easy task to isolate an atom-thick layer, but it wasn’t; because the usual methods of reducing a material to thin layers didn’t work with graphite. Those standard heating processes wrecked the properties of thin layers of graphite, so graphene remained only a theoretical possibility—until an unusual breakthrough in England.
Peer Reviewer: ‘Impossible to Do’
Nature magazine in 2004 rejected the article that the discoverers of graphene first sent out. One peer reviewer’s reason for rejection was that making it two-dimensional (thickness of only one atom) in a stable form is impossible. Another of Nature’s reviewers said that it was “not a sufficient scientific advance.”
The reviewer probably regrets that dismissive attitude; because when the paper was finally published scientists around the world began thinking of uses for graphene and experiments to try.
The graphene discovery story was most thoroughly told in Andre Geim’s lecture “Random Walk to Graphene,” now on YouTube; and in Sarah Lewis’ 2012 book, The Rise: Creativity, the Gift of Failure, and the Search for Mastery; and by journalist John Colapinto in a New Yorker Annals of Innovation issue in December, 2014.
One main character is University of Manchester professor and specialist in thin materials, Andre Geim. He had been born in the Soviet Union in 1958 and eventually came to be known as academically brilliant, possessing a nonchalant sense of humor and a habit of experimenting outside of his area of expertise. In 1990 while scientists in the Soviet Union were impoverished, he was doing science on a shoestring, because there was little in the way of tools or materials and less in funding. It was good training in being resourceful. He ‘MacGyvered’ his way into better jobs in Europe.
Geim’s first brush with fame had been infamy. He was thrust into the spotlight in 2000 after he levitated a live frog in an electromagnetic field and sent a paper about it to the European Journal of Physics under the lighthearted title “Of Flying Frogs and Levitrons.” He was then named winner of the Ig Nobel prize, which annually ridicules what seems to be the silliest research. Horrified colleagues urged him not to accept, but Geim defended his freethinking style and accepted the prize.
The frog caper didn’t directly lead to the graphene discovery, but it does indicate a nonconformist attitude that allowed him and his students to look outside the limitations of what was believed to be possible. Most scientists had thought that the “water magnetism” he used in the frog experiment was not strong enough to counter gravity, but the frog demonstration showed the true force of water that he had put in a strong magnetic field.
Soon after the Ig Nobel disgrace or honor, depending on your point of view, Geim started a practice of casual end-of-week sessions on Friday evenings for his students. Driven by curiosity instead of conformity, they did experiments randomly or deliberately without worrying about textbook assignments. One of the successful experiments resulted in gecko tape.
During one of those Friday night sessions two years later, Geim’s mind was on carbon, he later told New Yorker writer John Colapinto. Geim had been wondering how extremely thin layers of carbon would behave under certain conditions, so he had assigned his doctoral-candidate student the job of getting as thin a sample as possible by polishing a one-inch graphite crystal.
The Ph.D. student polished that chunk of graphite down to a mere speck in a petri dish, but the speck wasn’t graphene. While professor Geim teased him about polishing a mountain to get a grain of sand, another student pointed out the graphite dust smear on some tangles of used sticky tape in a nearby litter bin in the room. If you’ve sharpened pencil or even written with one, you’ve seen that same grey residue on something.
Using Scotch tape to clean samples of material is not unusual, but maybe no one had taken it a step further and placed tape with graphite flakes on it under a powerful microscope before. What Geim saw through the lens were thinner flakes of graphite than what his student had found after using a polishing machine.
The flakes still weren’t one layer thick, so he tried folding a piece of tape so that the grey residues pressed together, and then jerking the tape apart. The result seen under the microscope was even thinner layers. A few months later he got it down to an atom of thickness. Such a layer is described as two-dimensional instead of three-dimensional because there was width and length but no height to measure.
It was time for Geim to start studying the properties of the material. Seen with an atomic microscope, the material is a lattice of hexagons (six-sided geometries) looking like a honeycomb. Physicists were astounded because they had believed it would be impossible to get an isolated atomic layer at room temperature; they figured the atoms would ball up instead of staying in a single plane as Geim was seeing. It developed ripples but remained in one plane.
The professor and a fellow Russian, Ph.D. student Konstantin Novoselov, began working fourteen-hour days, experimenting to learn about graphene and its amazing properties:
- Electrons speed across it freely; in fact, at room temperature an electrical charge flows across graphene up to two hundred and fifty times faster than across silicon.
- It has a huge surface area; one gram of graphene would cover a football field.
- The material is transparent.
- It is stronger than diamonds, thanks to super-strong bonds between atoms, yet flexible.
- Graphene is impermeable to any liquid or gas.
- It can be stretched by a quarter of its length.
- Graphene conducts heat ten times better than copper.
- Extremely sensitive to molecules, it’s used in sensors.
The drawback was that a useful amount of graphene was super expensive. That will change with manufacturing larger amounts.
Geim’s first “eureka!” moment came when he and his student Novoselov showed that graphene could take over silicon’s role in the making of computer chips. They demonstrated that graphene responds, when placed near an electric field, similarly to other materials, which allow control of electrical conductivity.
The game-changing paper they wrote, “Electric Field Effect in Atomically Thin Carbon Films,” was rejected twice by Nature, but was finally published by the journal Science in 2004. Six years later, Andre Geim and Konstantin Novoselov won the Nobel Prize in Physics for their work on graphene. Geim is the only scientist to date to win both a Nobel and an Ig Nobel prize.
In 2012, there was another accidental discovery, across the world at UCLA. Two scientists seeking larger scale manufacture of graphene were playing around with their product and powered a light bulb with a tiny particle. After a few alterations they found that graphene has amazing capacitor qualities that allow it to be used for charging up batteries. Graphene should be able to charge a gadget up to a thousand times faster than before.
What All Can We Do with Graphene?
Geim has said each superlative that describes graphene offers a new and competitive application. In a 2011 lecture, he mentioned ultra-high-frequency transistors. The U.S. military jumped on that one for communications. The other use he mentioned back then was a transparent and conductive material that allows light to come out of devices such as computers, for example. Unlike the transparent material it replaces, graphene is flexible, so imagine a foldable cell phone.
Usually, the awarding of a Nobel Prize marks the close of some area of research. Graphene research, however, is unusual in that way. Scientists at top electronics firms and academic researchers in chemistry, physics, electrical engineering, medicine, and other fields are flocking to graphene.
Geim’s employer, the University of Manchester, and the British government invested sixty million dollars toward a National Graphene Institute. Graphene-related patents pop up for a wide variety of uses: ultra-long-life batteries, bendable computer screens, desalinization of water, improved solar cells, superfast microcomputers, energy generation and storage, and uses in biology.
Graphene went from academia to industry at unprecedented speed, with money from funders ranging from Dow Chemical Company to DARPA, the Defense Advanced Research Projects Administration.
In the rush to experiment, scientists discovered they could make two-dimensional materials from other three-dimensional materials with different properties, whether superconductive, insulating, or magnetic. New materials could be made on demand if layers of various materials are put together.
Earlier this year, a University of Manchester international team overseen by professor Andre Geim announced a photodetector breakthrough, of course using graphene. It could also be another solution to artificial photosynthesis, the process that plants use to employ photons and make food. Artificial photosynthesis traditionally involves a semiconductor. The team’s graphene-based devices not only detect light, but they also produce hydrogen gas in the process. The university’s scientists say they’re working with such an exotic phenomenon that they don’t fully know what it could do in other technologies.
New-Energy Inventors Look to Graphene
Inventors in the breakthrough-energy underground have been watching and waiting for graphene to be made into something wire-like, because its unique structure carries a thousand times more electricity than copper. For instance, John Milewski, Ph.D., looks for superconductors, which create strong magnetic fields. He seeks materials that will work most efficiently with the ether manifestation that he calls Superlight, and he has heard that graphene might even be developed into a room-temperature superconductor.
Since graphene is a superlative conductor, extremely lightweight, chemically inert and flexible with a large surface area, it could solve problems for high-capacity storage of energy.
Here are just a few examples of the amazing things that people all over the world are doing with graphene:
A Swedish team has news regarding future operations for surgical implants, such as hip and knee replacements or dental implants. Their electrical process creates spikes of graphene that stick up vertically instead of lying flat, and bacteria are sliced apart by the sharp flakes. Human cells however are typically 15,000 times larger in volume, so what is a deadly knife attack for a bacterium is a tiny scratch for a human cell. The team predicts that coating implants with a layer of graphene flakes will help protect a patient against infection, eliminate the need for antibiotic treatment, and reduce the risk of implant rejection.
Two Japanese universities report the first ‘helical nanographene’—the world’s tiniest springs. They could be used in nano-mechanics.
Spain’s Institute of Photonic Sciences in Barcelona, along with other members of the Graphene Flagship, have confined light down to the smallest possible space, one atom. The ability to shrink devices that control and guide light will lead to ultra-small optical switches, detectors, and sensors. Light can also function as an ultra-fast communication channel. An official with the Graphene Flagship said, “Having reached the ultimate limit of light confinement could lead to new devices with unprecedented small dimensions.”
Irish startup Bitcart says you’ll be able to wear your wallet. They made a wristband capable of making cryptocurrency payments.
In England, a University of Warwick team finds that adding graphene girders to silicon electrodes could double the life of rechargeable lithium batteries and also increase their capacity.
Iowa State University engineers have made “plant tattoo” sensors—wearable, graphene-based sensors-on-tape for plants, to make it easier to measure water use in crops. The technology could also create sensors for biomedical diagnostics, for checking the structural integrity of buildings, for monitoring the environment, and be modified to test crops for diseases or pesticides. The graphene-on-tape technology has also been used to produce wearable, strain-and-pressure sensors, including sensors built into a “smart glove” that measures hand movements.
Spain has a double home run with graphene. Spanish researchers recently developed a low-cost way to grow graphene with the same band gap that exists in silicon and, therefore may have reopened graphene’s potential as an alternative to silicon for digital logic. The problem had been that graphene, regardless of all its amazing electronic abilities, couldn’t really act as a semiconductor because you couldn’t switch off the excited state. That limited its impact as a replacement for silicon in uses where a built-in band gap is needed to start and stop the flow of electrons. Methods for engineering a ‘band gap’ into graphene have been around for years, but those approaches were imperfect solutions adding cost and complications to use of graphene, and compromising the electronic properties that made graphene a good replacement for silicon.
With such advances, silicon is no longer king of the semiconductor world. Silicon Valley could perhaps be replaced by a graphene international collaboration. The graphene revolution shows what can happen when dollars, euros, yen, and other international currencies flow into research and development of a breakthrough.
The mainstream fervor about graphene holds promise for further breakthroughs, in fields as varied as antigravity, desalination of seawater, and building of space elevators.
Jeane Manning is co-authoring Hidden Energy: Beyond Tesla to a Consciousness Shift and Clean Energy Abundance, with Susan Manewich. They expect the book to be available in September of 2018.