The Substance That Will Shape Our Future
Researchers have created a substance from individual carbon atoms that could change the world: graphene. It’s being hailed as the material that can catapult us into a new era— even though it shouldn’t exist at all…
An incredible material that shouldn’t even exist
“GRAPHENE’S PROPERTIES ARE UNIQUE— SO DISTINCTIVE, IN FACT, THAT THERE IS NO COMPARABLE SUBSTANCE IN THE WHOLE OF SCIENCE.” Michael Strano, Massachusetts Institute of Technology (MIT)
How do you make some of the most prestigious physicists of our time jump for joy? Very easily. Talk about perhaps the most groundbreaking discovery made in the last 100 years: graphene—the first two-dimensional material in the world. It’s considered a miracle substance and, for many experts, the start point for radically changing our lives in the future.
The odd part: Graphene consists of nothing more than carbon, which is utterly ubiquitous on this planet— for instance, it’s in everything from the air and vitamins to pencil leads. But the fact is that we still know very little about this substance, which is involved in approximately 90% of all chemical compounds. Only in recent years have we gotten a rudimentary glimpse into its unique capabilities: “Graphene embodies an unusually large number of superlatives,” says Jurgen Smet, a nanophysist at the Max Planck Institute for Solid State Research. It can conduct heat and supply energy more effectively than copper; it’s transparent, yet it also absorbs light. What’s more, though it’s over 266,000 times thinner than a human hair, it’s also stronger than concrete; it’s more than 200 times stronger than steel, it’s extremely flexible, and it’s so dense that even helium—the smallest noble gas— can’t pass through it. To Klaus von Klitzing, winner of the 1985 Nobel Prize for Physics and a professor at the Max Planck Institute for Solid State Research, graphene is really a “superhero among the materials.” It is hardly limited in its capabilities. “Depending on its form, graphene is able to develop different powers.” But what makes this substance so special, and how do scientists want to apply it to shape our future?
HOW CLEAR TAPE HAS CHANGED THE WORLD
Until October 22, 2004, graphene did not have a good standing in the scientific community. It was viewed as a substance that couldn’t exist. The reason for this view: graphene’s special structure, which consists of individual carbon atoms arranged together to form uniform hexagons. Because graphene is composed of a single layer of atoms—and so it is no thicker than one carbon atom—it is referred to as a two-dimensional substance. The problem: Physics considers 2- D materials unstable, therefore graphene was thought to be physically impossible. It was an unprecedented misjudgment that was eventually exposed by Nobel Prize winners Konstantin Novoselov and Andre Geim in the fall of 2004— in an extremely simple way. In fact, these two University of Manchester researchers created the first stable 2-D material in the world using little more than a strip of adhesive tape and a chunk of graphite—a coal-like material that’s also found in pencils. To make a single layer of graphene from graphite, the scientists simply pressed a length of adhesive tape
against the block of graphite and then pulled it off again. This resulted in a very thin—but still multilayered— strip of carbon remaining on the tape. To remove more layers, they placed the segment of carbon-covered tape against a silicon plate that had been coated with photoresist (a material that is sensitive to light)—and then pulled the tape off again. The result: high-quality stable graphene, and the refutation of an alleged law of nature.
HOW HARD IS A FINGERPRINT?
Today graphene is at the center of a multibillion- dollar market. However, new methods are necessary in order to cover the rapidly growing demand. Now a research team from Saarland University may have come up with a solution to this pressing problem. In a spectacular process, they managed to obtain the graphene from sweat, which contains carbon compounds. Their study subjects were asked to leave fingerprints on a film that was baked in a vacuum oven at 1,300°F. The result: graphene. They called this manufacturing procedure chemical vapor deposition. In the near future, this method should make it possible to obtain graphene on a large scale from any liquid that contains carbon compounds (such as acetone). The advantage: Such liquids are widely available and relatively inexpensive. So mass production of the precious material should soon be within reach.
REVOLUTION FROM OUT OF A PENCIL
Even though graphene is considered a material of the future, it’s already starting to be used. The Uk-based company Graphene Lighting is now on the verge of bringing a graphene lightbulb to the market. This product is supposed to “use less energy than the energy-efficient LED technology, have lower production costs, and be produced with sustainable materials,” says Colin Bailey, deputy president of the UK’S University of Manchester. The use of this miracle substance is still in its infancy, but the potential technical innovations already sound like the stuff of science fiction films. In 2014, the South Korean tech giant Samsung reportedly filed for a patent for the manufacture of transparent film-thin graphene computer modules that can serve as a phone as well as a high-resolution touchscreen—and can be folded or rolled.
Graphene has another impressive property: It is transparent, yet at the same time it’s light-absorbing—which makes it perfect for capturing solar energy via a special window glass.
Researchers at Spain’s Institute of Photonic Sciences have achieved an efficiency level of about 50% in solar cells made with graphene, and 60% should be possible—dizzying values that are twice as efficient as current commercially available solar cells. But this is far from all the capabilities of the new wonder material. Physicists are developing ways to harness the conductivity of graphene in order to revolutionize our energy technology. But perhaps the most significant way to use graphene has been developed by the American defense contractor Lockheed Martin: a graphene filter for removing sodium and chlorine from water. To transform graphene into a salt filter, the superdense material is furnished with holes only big enough to allow water to pass through; other substances (drug residue, impurities) are blocked. This filter is 500 times thinner than the thinnest previously developed salt filters and requires only about 1% of the energy to make seawater potable. This technique has already been utilized in desalination plants. Projects like these have made graphene one of the most promising discoveries of the 21st century, and ongoing research should yield untold benefits for the future for humanity.
“FLEXIBLE AND TRANSPARENT TOUCHSCREENS ARE ONE OF THE EARLIEST APPLICATIONS OF GRAPHENE.” Klaus von Klitzing, Max Planck Institute for Solid State Research, Stuttgart, Germany