GRAPHENE updates by (NTNU) Norway

Mobile phones that bend, self-powered nano devices, new and improved solar cell technology and windows that generate electricity are but a few of the potential products from the union of semiconductors and graphene.

Semiconductors grown on graphene at the Norwegian University of Science and Technology (NTNU) may be the most important research breakthrough of 2012 in Norway. At the centre of the research efforts are Professor Helge Weman, Professor Bjørn-Ove Fimland and post-doctoral fellow Dong Chul Kim. The team is now working on translating the results of their basic research into an initial prototype.

Just one atom thick

In the 1960s, researchers envisioned that graphite (pure carbon) could be cut into layers measuring only one atom in thickness -- resulting in the material known as graphene.

In the 1990s, researchers managed to create a layer as thin as 100 atoms, but there was no progress after that until 2004, when Russian-born Andre Geim grabbed a tape dispenser from his desk at the University of Manchester, pressed a bit of tape over a thin layer of graphite and peeled it away. When he examined the tape under a microscope, he discovered a layer only one carbon atom thick. Graphene was born!

In 2010, Dr Geim and his colleague, Konstantin Novoselov, were jointly awarded the Nobel Prize in Physics for their work in demonstrating the unique properties of graphene.

Ahead of the pack at NTNU

Six months before Dr Geim and Dr Novoselov arrived in Stockholm to receive their prize, and before graphene had become an item of interest, South Korean post-doctoral fellow Dong Chul Kim at NTNU had suggested to Professors Helge Weman and Bjørn-Ove Fimland at the Department of Electronics and Telecommunications that they should take a closer look at precisely this material. The suggestion came shortly after a research group in their department had succeeded in growing semiconductor nanowires made of gallium arsenide (GaAs) on silicon substrates. This led Dr Weman to wonder if it would be possible to grow semiconductor nanowires directly on graphene instead.

The collective expertise of Professor Weman, Professor Fimland and Dr Kim proved to be a fruitful combination. The researchers quickly achieved their first breakthrough, in September 2010, and in the summer of 2012 they succeeded in placing nanowire semiconductors on a one-atom-thick base. These active semiconductors normally grow to be one micron (a millionth of a metre) in thickness.

Will silicon become obsolete?

Graphene is definitely the hottest topic right now among nanomaterial researchers. The pure-carbon material is by far the thinnest and strongest known to exist. It is 200 times stronger than steel, conducts electricity 100 times faster than silicon and is superior to any other material in conducting heat. It is impenetrable, yet pliable and transparent at the same time. And inexpensive large-scale production of graphene is now becoming a reality.

At present, electronics and solar cells are placed on top of thick silicon substrates. But silicon has clear limitations, including size. Large technology companies are struggling to produce silicon-based products that are smaller than those currently on the market. Another challenge with using silicon is that silicon-based electronics generate a great deal of heat. Many people consider graphene to be the prime candidate for replacing silicon.

Large multinational corporations such as IBM and Samsung have poured a lot of effort into research on both semiconductors and graphene. But the real breakthrough in growing semiconductors on graphene actually took place at NTNU in Trondheim.

The findings of these researchers in Trondheim can be used to make electronics and solar cells that are several hundred times thinner than current models. This will make it possible to produce electronics that are both pliable and transparent, in addition to being less expensive and more energy-efficient.

More efficient solar cells and LEDs

It will probably not be long before simple graphene products begin appearing on the market. Some of them will be based on semiconductor technology.

Semiconductors are a main component in almost all modern electronics. Without them, it would not be possible to have computers, smartphones, solar cells, LED lights or devices using lasers, i.e. everything from printers to fibre communications. All these items can be made smaller and better using graphene. Graphene can both supplant the semiconductor substrate and serve as a transparent electrode for a pliable nanowire solar cell.

"Solar cell and LED technology will be the initial areas to see new products using graphene-based semiconductors," Dr Weman believes.

Under-priced fossil-fuel energy is the primary contributor to global warming. Sunlight is an alternative source with enormous potential, but solar energy will have to become less expensive and more efficient. Semiconductor nanowires based on graphene may just finally tip the scales in favour of solar energy.

"If semiconductor nanowires grown on graphene are used in solar cells, the same amount of sunlight can be converted to energy using one-tenth the volume of materials used in thin-film solar cells. And that means we've cut down on even more material by growing the semiconductors on graphene instead of on a thick semiconductor substrate. New research also shows that graphene has additional unique properties that enhance the efficiency of a solar cell," Dr Weman explains.

LED light bulbs are superior in terms of energy efficiency, but have been more expensive to produce because of costly semiconductor substrates. Semiconductor nanowires on graphene will make it possible to supply the world with LED bulbs that are far cheaper and much more efficient while also being more pliable and weighing less than today's bulbs.

Industrialisation on the horizon

The work on graphene at NTNU has drawn the attention of many international companies interested in collaborating with the Trondheim-based researchers and their company, CrayoNano. But the potential industrial queries so far have come solely from Asia and the US. Actors in Norway and Europe have yet to express any interest.

"We are pioneers in that we are using graphene for something other than basic research. We may already have our first prototype in place by the end of 2013, but we don't wish to reveal what it is yet," Dr Weman says.

"The field we are working with -- using graphene as a replacement for silicon and other semiconductor substrates in electronics and solar cells -- entails many new opportunities. But the potential is just as great for applications using graphene in areas other than electronics, such as in the medical sector. Graphene can be used in the body without causing any harm," Dr Weman explains.

"In a world where drinking water is in short supply, employing oxygen-modified graphene filters to purify water is yet another exciting application. It's a whole new way to turn seawater into fresh water."

In any case, research and development activities will be needed for many years. Dr Weman likens the current state of graphene research to where silicon was in the early 1960s.

Research Council funding paved the way

The Research Council of Norway has been a key source of funding for the Trondheim-based researchers throughout. Helge Weman makes it clear that funding under the Commercialising R&D Results (FORNY2020) programme and the Funding Scheme for Independent Basic Research Projects (FRIPRO) is what made it possible to achieve the unexpected research breakthrough. The researchers have also benefited significantly from funding allocated under the Research Programme on Nanotechnology and New Materials (NANOMAT) and the Large-Scale Programme Clean Energy for the Future (RENERGI).

The professor points out that NTNU's strategic initiative on nanotechnology launched in 2005 is a good example of what future-oriented research policy can help to achieve.

A three-minute video on is available on YouTube in which Helge Weman explains this research: http://www.youtube.com/watch?v=3wLOXHRVVw
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Semiconductors Grown on Graphene

Researchers at the Norwegian University of Science and Technology (NTNU) have patented and are commercializing GaAs nanowires grown on graphene a hybrid material with competitive properties. Semiconductors grown on graphene are expected to become the basis for new types of device systems and could fundamentally change the semiconductor industry. The technology underpinning their approach has recently been described in a publication in the American research journal Nano Letters.

The new patented hybrid material offers excellent optoelectronic properties, says Professor Helge Weman, a professor at NTNU's Department of Electronics and Telecommunications, and CTO and co-founder of the company created to commercialize the research, CrayoNano AS. "We have managed to combine low cost, transparency and flexibility in our new electrode," he adds.

The patented method of growing semiconductor nanowires on atomically thin graphene uses MBE (Molecular Beam Epitaxy) to grow the nanowires.

"We do not see this as a new product," Weman says. "This is a template for a new production method for semiconductor devices. We expect solar cells and light emitting diodes to be first in line when future applications are planned."

Sunny outlook for nanowires

"Graphene is experiencing tremendous attention worldwide," Weman says. "Companies like IBM and Samsung are driving this development in the search for a replacement for silicon in electronics as well as for new applications, such as flexible touch screens for mobile phones. Well, they need not wait any more. Our invention fits perfectly with the production machinery they already have. We make it easy for them to upgrade consumer electronics to a level where design has no limits."

This invention is thus thought to be an enabler for a future platform for electronics and optoelectronics devices. One possible device with very large market potential is a nanowire solar cell. This type of solar cell has the potential to be efficient, cheap and flexible at the same time. The invention also makes it possible to imagine a future with self-powered nanomachines and advanced 3D integrated circuits built on graphene and semiconductor nanowires, enabling smaller and more efficient electronics.

Weman himself envisions flexible self-powered consumer electronics integrated into everything from clothes to notepads, and of course traditional cell phones, tablets and exercise accessories.

"Semiconductors grown on graphene could become the basis for new types of device systems, and could transform the semiconductor industry by introducing graphene as a preferred substrate for many applications," he says.

Graphene to Improved Information Processing

Graphene-based System Could Lead to Improved Information Processing

Published on: 21st Jun 2013

Note -- this news article is more than a year old.

By: Ian Mansfield

Researchers at MIT have proposed a new system that combines ferroelectric materials the kind often used for data storage with graphene a two dimensional form of carbon known for its exceptional electronic and mechanical properties. The resulting hybrid technology could eventually lead to computer and data storage chips that pack more components in a given area and are faster and less power hungry.

The new system works by controlling waves called surface plasmons. These waves are oscillations of electrons confined at interfaces between materials; in the new system the waves operate at terahertz frequencies. Such frequencies lie between those of far-infrared light and microwave radio transmissions, and are considered ideal for next-generation computing devices.

The findings were reported in a paper in Applied Physics Letters by associate professor of mechanical engineering Nicholas Fang, postdoc Dafei Jin and three others.

The system would provide a new way to construct interconnected devices that use light waves, such as fiber-optic cables and photonic chips, with electronic wires and devices. Currently, such interconnection points often form a bottleneck that slows the transfer of data and adds to the number of components needed.

The team's new system allows waves to be concentrated at much smaller length scales, which could lead to a tenfold gain in the density of components that could be placed in a given area of a chip, Fang says.

The team's initial proof-of-concept device uses a small piece of graphene sandwiched between two layers of the ferroelectric material to make simple, switchable plasmonic waveguides. This work used lithium niobate, but many other such materials could be used, the researchers say.

Light can be confined in these waveguides down to one part in a few hundreds of the free-space wavelength, Jin says, which represents an order-of-magnitude improvement over any comparable waveguide system. "This opens up exciting areas for transmitting and processing optical signals," he says.

Moreover, the work may provide a new way to read and write electronic data into ferroelectric memory devices at very high speed, the MIT researchers say.

In addition to Fang and Jin, the research was carried out by graduate student Anshuman Kumar, former postdoc Kin Hung Fung (now at Hong Kong Polytechnic University), and research scientist Jun Xu.

Graphene Medical applications

Neurosurgeons get ready to bring graphene to the operating table

• By John Hewitt on May 1

Share This ArticleWhen any exotic new material is found researchers often ask the same questions. Can it store bits? Can it store energy? Sooner or later, particularly if the material is really exotic, someone wants to put it in your head. In a feature story for the latest issue of the journal Neurosurgery, doctors are looking to graphene to solve some of the most challenging issues in their field.

With graphene you can pretty much name your favorite physics phenomenon, and there will be some way that the material can be used to exploit it. Graphene is so thin that it’s transparent — but also, per gram, one of the most light-sensitive materials in the world. Unlike many other metamaterials, it is also a good absorber in the IR and UV ranges. What excites some neurosurgeons is that past a certain threshold of illumination, graphenedisplays what is called “saturable absorption” — beyond this illumination point ,graphene releases extra energy in the form of heat which can potentially be harnessed to kill tumors.

Graphene oxide fiber, up close and personal

Graphene’s high surface area (approximately 2630 square meters per gram) leads to remarkable conductivity. It also provides great access for various modifier molecules to bind or bioconjugate with it, and transform its behavior. Agents like poly(ethylene oxide), poly(vinyl alcohol), polyurethane, and poly(methyl methacrylate), can be used to generate all manner of useful graphene-polymer composites. Nowadays we don’t just have graphene, but also have its various derivatives like graphene fluoride, graphene oxide, and reduced graphene oxide (rGO). Not only does each form have unique material properties, but potentially unique ways of interacting with the tissues of the body.

One area that has been generating a lot of buzz in the neurosurgery field is the development of materials to bridge and even stimulate nerves. The authors suggest graphene may be ideal as an electroactive scaffold when configured as a three-dimensional porous structure. That might be a preferable solution when compared with other currently vogue ideas like using liquid metal alloys as bridges. Graphene has already been shown to make an ideal E-field stimulator and was even used in that capacity to enhance blood flow within the brain.

A view of the human hippocampus, with fluorescent proteins and confocal microscopy

Among the other things researchers can do with graphene is exploit the special property of having delocalized pi electrons on its surface. This allows energy to be readily exchanged with nearby neighbors. In practice, this becomes useful as a quencher of fluorescence. To do fast, real time fluorescence studies, the limitation is not so much how fast you can activate but rather how fast you can turn things down. Neurosurgeons have been turned on to the idea of intraoperative imaging during various oncologic and vascular procedures. Being able to rapidly turn on different tissues — and therefore see them — is a game changer in the surgical theater.

The authors go a little overboard though, in leaping to the idea that graphene could be useful in quantum computing applications — inside your head no less. We certainly applaud their vision, but might also suggest that getting quantum computers to “work” anywherewould be a more realistic goal for now. If all this talk of graphene has whetted your appetite, be sure to check out our feature on the wonderful world of wonder materials.

3D printing in graphene

3D printing in graphene is coming and it will be big.

Graphene is a one-atom-thick layer of carbon atoms arranged in a hexagonal lattice. It holds an immense array of astonishing properties, repeatedly receiving the title “wonder material”. It is truly a material that could change the world, with unlimited potential for integration in almost any industry. Graphene is the thinnest material known to man, but is also incredibly strong – about 200 times stronger than steel.

Researchers say it would take an elephant balanced on a pencil to puncture a graphene sheet. On top of that, graphene is an excellent conductor of heat and electricity, and is even sometimes regarded as a substitute for silicon – being stronger, more flexible and a much better conductor.

Graphene Chart

Graphene is one of the most diverse materials in the world, and can be combined with other elements (including gases and metals) to produce different materials possessing a myriad of superior properties. Researchers all over the world continue to constantly investigate and patent graphene to learn its various properties and possible applications, which include ink, airplane wings, transistors, computer chips, batteries, flexible touch screens, tires, DNA-sequencing devices, saltwater filters, tennis rackets, antennas, solar cells, organic tissue applications and much more.

Graphene-enhanced nanocomposite materials greatly improve traditional materials used in 3D printing, like plastics. Graphene nanoplatelets added to polymers make materials that are mechanically stronger and with improved thermal and electrical conductivity. Graphene 3d printing has the potential to enable printing of computers, solar panels, electronics and even cars and airplanes. An interesting video demonstrating 3D printing of a working battery can be found on this link. 3D printing is already in use in major industries like aerospace, automotive and defense, and is expected to further grow, spread and revolutionize ways of production as we know them.

Graphene 3D printing is an exciting and bustling field of R&D interest, always in pursuit of a better, cheaper or more efficient way of utilizing graphene in 3D printing.

Stratasys and Graphene Technologies announced a partnership in July 2014 to co-develop graphene-enhanced 3D printing materials. In addition, Graphene 3D Labs (a joint-venture between Graphene Labs and Lomiko Metals) plans to begin production of graphene filaments for 3D printing in the near future, and is working towards a target of reaching commercial production around the first half of 2015. Graphene 3D labs also recently displayed a prototype for a 3D printable batteries based on graphene. These batteries can potentially outperform current commercial batteries. Angstron Materials, a US based company, began to offer graphene-enhanced polymers (in pellet of strands form) for use in FDM 3D printing

GRAPHENE TECH 2

The silicon, plastic, and glass that make up much of our tech these days could soon be replaced with something old, yet completely new: Graphene.

If graphene sounds like something that could fell a superhero, you're almost right. It’s the thinnest substance known to science, yet it’s 300 times stronger than steel and harder than a diamond. High-quality graphene is also transparent and flexible, and it’s an excellent conductor of heat and electricity.

We’ve known of graphene’s existence since the mid-1800s, but scientists have been able to experiment with graphene only in the past decade. In 2004, two researchers at the University of Manchester isolated graphene for the very first time, using—believe it or not—a chunk of graphite and a roll of adhesive tape.

So what exactly is graphene?

Graphene is a crystalline structure composed entirely of carbon atoms, arranged in a hexagonal, honeycomb-like pattern. Graphene's single-atom thinness (meaning it has length and width, but no height) makes it as close to 2D as any substance can be.

Graphene is also a fundamental component of other allotropes (structurally different forms of the element carbon). These include charcoal, carbon nanotubes, and other fullerenes (molecules composed solely of carbon).

MARCO CHIAPETTA

Graphene's atomic structure renders it one of the strongest materials known.

It is graphene’s unique structure and composition that endows it with so many valuable properties. Carbon atoms have four electrons in their outer shell, three of which form strong covalent bonds with the electrons in neighboring carbon atoms. This gives graphene its signature hexagonal shape. The fourth electron in each carbon atom, now known to be fermions, behave like relativistic particles described by the Dirac equation (which, in another sci-fi twist, also implies the existence of antimatter).

Graphene is lightweight, flexible, impermeable to other elements, and virtually transparent

Getting back to graphene, it is those free electrons, in conjunction with the material’s relative uniformity, that make graphene such an excellent electrical and thermal conductor, superior to copper and silver respectively. The strong covalent bonds between the carbon atoms, meanwhile, give graphene its strength.

Layers of graphene are bonded by weak van der Waals forces (the sum of attractive forces between two surfaces, accounting for a lizard’s ability to climb vertical walls, among other things). The bonds between the carbon atoms in each layer of graphene, on the other hand, are incredibly strong; in fact, a hammock fabricated from a single-atom-thick sheet of graphene could support a load of nearly 9 pounds.

High-quality graphene is also lightweight, flexible, impermeable to other elements, and it’s virtually transparent. Thanks to the space between its atoms, the material absorbs just 2.3 percent of white light, allowing 97 percent to pass through.

How graphene might be used

Potential applications for graphene are nearly limitless. Numerous projects are already underway in industries ranging from consumer electronics to sporting goods. To date, graphene-based consumer products have been limited to items that use a small amount of the substance in protective coatings. Once the mysteries of graphene manufacturing have been unlocked—more on that later—you can expect to find the material everywhere.

One area where graphene is likely to have the most immediate impact is the manufacture of flexible and transparent electronics, such as touchscreens. Graphene could replace indium, which is one of the rarest elements on Earth. (Carbon—the foundation of graphene—is one of the most abundant elements on the planet.) Graphene is also lighter, thinner, and stronger than indium. Ultra-strong windshields that double as display clusters are not out of the realm of possibility. Neither is Tony Stark’s transparent smartphone.

IDGNS

The case for this smartphone prototype is made from glass. A graphene enclosure would be lighter and just as transparent.

Graphene’s electrical properties also render it an ideal material for building integrated circuits. During a Q&A session at the 2013 Intel Developers Forum, Intel CEO Brian Krzanich said the company is evaluating graphene’s potential use in chip manufacturing, replacing silicon. Routine use, he said, would be a “few generations” out, putting it roughly in the 2020 timeframe.

Graphene might also serve as the foundation for next-generation solid-state capacitors that charge more quickly than today’s offerings and hold a charge for much longer. And graphene could usher in an age of ultra-powerful, lightweight batteries with far more capacity than anything available today. By super-cooling graphene and surrounding it in strong magnetic fields, researchers have also been able to alter the direction of the flow of electrons along graphene’s surface, based on the spin of the electrons, which opens up possibilities for quantum computing.

Graphene won’t be relegated solely to electronics and display technology. Its excellent strength-to-weight ratio could also pave the way for strong, lightweight vehicles, while its transparency and electrical conductivity make it a good candidate for future solar panels. Punching nano-sized holes in a sheet of otherwise impermeable graphene could be used in machines that pull a single strand of DNA through the hole, for rapid DNA sequencing, or water purification or desalination.

Manufacturing graphene

Before those fantastical devices can become reality, however, industry must first develop a reliable, cost-effective manufacturing process. That's where the majority of current graphene research effort is concentrated.

Graphene is being manufactured today using a number of methods: The “Scotch tape” method (also known as mechanical exfoliation or the cleavage method), is the simplest. This is how Andre Geim and Konstantin Novoselov isolated graphene from a larger hunk of graphite in 2004—research that led to their being awarded the Nobel Prize in Physics in 2010.

Andre Geim and Konstantin Novoselov received the Nobel Prize in Physics in 2010 for their work isolating graphene. The pair donated this autographed tape dispenser, a chunk of graphite, and a graphene transistor to the Nobel Museum.

The adhesive tape is used to extract small pieces of graphite from a larger chunk. A layer of graphene is peeled away from the graphite by continually folding the tape over the pieces and then separating the tape. The strength of the adhesive overcomes the weak van der Walls forces holding the layers of graphite together until there is a single layer, yielding graphene.

Graphene could become as ubiquitous as plastic.

Mechanical exfoliation can be used only to isolate relatively small pieces of graphene, however, so researchers are experimenting with other methods to produce larger quantities.

Chemical vapor deposition (CVD) is one of the most promising. In this process, chemical vapors are evaporated in a furnace, leaving a graphene deposit on a thin metal substrate. A similar process has been used in the manufacture of very large integrated circuits (VLSI) for many years. Graphene can also be isolated by submerging graphite in a liquid and blasting it with ultrasonic waves to separate its individual layers, or by slicing an edge of a cylinder formed from graphene (also known as a carbon nanotube).

Using these methods, scientists have been able to produce pieces of graphene of various qualities and sizes, including long graphene strands that have already been used to make super-capacitors. While some companies—most recently Samsung—have claimed breakthrough achievements in graphene manufacturing, most of the known work remains academic and has not yet scaled to real-world industrial applications.

We’re still a ways off from widespread availability of graphene-based microprocessors, flexible touchscreens, and similarly exotic new devices. But when industry perfects a practical and inexpensive means of manufacturing graphene, you can bet it will become as ubiquitous as plastics are today.

GRAPHENE TECNOLOGY

Forming the only known foil capable of being folded as many times as necessary without breaking, a graphene sheet is a million times thinner than a human hair, 200 times more resistant to breakage than steel (its tensile force is in excess of 130 gigapascals), more conductive than copper, perfectly transparent, and totally flexible. Furthermore, graphene is impermeable to all gases. Typically, it takes a new material thirty to forty years to be integrated into consumer products. And this particular one, in the opinion of its Mancunian discoverers, could one day revolutionize electronics, energy, aerospace and biotechnology. Already it is being used in photovoltaic cells, electric vehicle batteries, and data centers processors.

Physically, the pattern of a graphene sheet is that of a honeycomb lattice. If sheets are stacked, you get graphite, which is the gray charcoal matter that makes up our pencil leads. In just one millimeter of graphite, there are three million sheets of graphene stacked… As a matter of fact, this amazing material made it to the Hall of Fame of legendary research in the most uncanny manner, in 2004, when Andre Geim and Konstantin Novoselov, two professors at the University of Manchester – Nobel prizes in 2010 – isolated a graphene layer from a pencil lead… by simply using a roll of adhesive tape to extract ever thinner graphite layers one by one – until they formed but one single layer of atoms.

Multiple uses
Of all the materials consisting of a single layer of atoms, graphene seems to be the most promising one. An MIT team has modeled the use of these materials in photovoltaic cells. The PV industry needs a radical technological revolution because its economic model, which is largely based on government grants, is floundering. By stacking a layer of carbon atoms – graphene – with a layer of molybdenum disulfide (MoS2), one obtains a solar cell whose performance is admittedly poor – but 1% – but that is infinitely small: but one nanometer thick, i.e. one millionth of a millimeter thick. In total, it therefore generates 30 times more power per volume unit than the thinnest solar cells known (made either of gallium arsenide, silicon, or indium selenide) which are one micron thick, and whose performance near 30 %.

Modelling of a graphene sheet

Researchers have calculated that by stacking six layers – three graphene layers and three layers of molybdenum disulfide – performance could theoretically reach 10%… for a thickness of only 3 nanometers. Unprecedented energy efficiency! Should such a minute graphene solar cell get to be manufactured on an industrial scale, it would beat all records in terms of power density. It is nevertheless true that at this stage, such a revolutionary cell remains purely theoretical: it has not even been tested in the laboratory.

Graphene is also capable of conferring considerable strength to ordinary materials. The Korean Advanced Institute of Science and Technology has just demonstrated that by stacking copper layers with graphene layers, the material obtained is 500 times stronger. Even though graphene only amounts to 0.00004 % of the material’s weight, it increases its overall strength by a factor of several hundred.

Graphene is also keenly anticipated to finally advance research on the battery of the future. In theory it would be possible to charge a smartphone in less than ten minutes. A graphene battery powering an electric car would be able to bestow a real autonomy to the vehicle, and would at long last make it a true mass consumption product. With graphene, which is highly conductive, a battery charges much faster – for only half the weight.

With a leading edge on the subject, a team from UCLA, led by Professor Richard Kaner, has developed an electrochemical capacitor consisting of a network of graphene micro-capacitors (watch video presentation). This “ultracapacitor” boasts performance which is incommensurate with the most efficient lithium-ion battery: it is 100 to 1000 times more powerful and three to four times denser. What we are witnessing here is a true technological breakthrough that paves the way for future electric vehicles equipped with ultra-reliable capacitors instead of expensive and heavy batteries whose performance is irregular. In particular, it would do away with the performance degradation that inevitably takes place over time, and with the eventual premature wear that batteries experience in case of prolonged non-use of vehicles. Electric vehicles could then directly compete with the heat engine, for a fraction of the cost of transport – of the order of just one euro for 100 km…

The UCLA team also successfully overcame a major challenge: the actual production of graphene. How did they pull it off? Richard Kaner and colleagues used quite the ordinary laser – that of a Lightscribe optical drive, ordinarily used to burn DVDs. After covering the DVD with a film of graphite oxide, the laser “bombards” it and produces a graphene electrode, called LSG (Laser Scribed Graphene). One day, researchers hope, it will be possible to “print” graphene on rotaries just like newspapers… But there’s still a long way to go. And, of course, both the adhesive tape technique and the DVD laser one are obviously unable to provide large quantities. However, it is undeniable that progress has been made. While in 2004, Geim and Novoselov had produced a graphene “piece” too small to be visible to the naked eye, Samsung Electronics, in 2013, managed to showcase a sheet a full 76 centimeters in diameter.

Graphene vs. silicon
In the world of electronics, where silicon has reigned unchallenged for decades, does graphene have a destiny? It could certainly perform as a coolant. Johan Liu, a professor at the Chalmers Institute of Technology in Sweden, explains it: “In a computer, the hottest spots – microprocessors for the most – reach temperatures that range between 55 and 115°C (160 to 240°F). By applying a layer of graphene, we have lowered the average temperature by 13°C (55°F).” Suffice to say that a 10°C working temperature can halve the life of electronic equipment and that half of the energy consumed by a data center is attributable to cooling to understand that this is a tremendous gain in energy efficiency. The future may thus bring chips, microprocessors and transistors that operate at impressive speeds, and yet that do not heat up. We’re one step closer to the mythical “cold computer!”

Proponents argue that graphene will make it possible to manufacture cell phones so thin that they can be integrated into paper or tissue. Due to its simple structure, it will be possible to craft transparent screens affixed to walls, windows or even glasses. In short, electronic devices won’t be “manufactured” in plants anymore. Having become ultrathin, they will simply be printed out. One can already picture electronic paper and roll-up communication devices! Incidentally, researchers at Northwestern University in Chicago have developed a highly conductive graphene ink that will make such communication tools possible. One significant challenge remains, though – maintaining ink conductivity after printing.

Among the innumerable proposed applications for graphene are desalination filters. To date, the process of desalination is one very expensive operation – still unaffordable in many countries – due to the amount of energy required. Lockheed Martin is developing a graphene filter, the perforene, which could revolutionize reverse osmosis desalination. Perforene is about 500 times thinner than the best filters available on the market – its membrane being even thinner than the atoms it filters! As for the energy and pressure required filter the salt, they are about a hundred times lower.

While graphene is the most famous of 2D materials to have been discovered, it is not the only one anymore. A dozen of them are being studied worldwide. They demonstrate complementary properties that, by combining with the graphene, will add further functionality. Boron nitride, for example, is also just one atom thick but unlike graphene, it is an insulator – and the most effective ever. As for molybdenum disulphide, three atoms thick, it forms a semi-conductor which is much lighter and sturdier than silicon. In Manchester, Konstantin Novoselov’s lab has combined the highly conductive graphene with dichalcogenide, a transition metal that absorbs sunlight and converts it into electricity. The combination could lead to exterior paints capable of producing the electricity needed to operate the household equipment within a building.

When cutting edge becomes literal, expect a backlash
As might be expected, the graphene-mania, as well as the funding it attracts, have caused a backlash in the scientific community. Some point out that the new carbon atom frameworks have often turned out to disappointing. Fullerenes, for instance, much touted in the 1980s, and carbon nanotubes (rolled up graphite sheets), which had prompted great excitement in the 1990s, have found no real commercial application so far.

It is true that graphene does not yet have all the qualities to revolutionize electronics. For the time being, industry giants will have to do with silicon as graphene is still hindered by certain shortcomings: for example, the output frequency of graphene devices is sometimes disappointing. It is not a semi-conductor, nor is its conduction band good enough to allow it to perform as a stand-alone transistor, the basic building block of electronics. In such an iconic market, graphene would therefore have to settle for narrower niches, such as high frequency electronics components.

Professor Novoselov himself acknowledges it: the craze has gone too far. From his point of view, commonly used materials should only be replaced whenever the characteristics of the new material can lead to applications competitive enough to justify the cost and the inconvenience of such a changeover. In short, the future of graphene depends on the development of applications designed specifically around it. Now this raises a problem of industrial culture. Mark Goerbig, professor at the Ecole Polytechnique Engineering School in Paris, explains it: “It will take a generation to train engineers who are comfortable with graphene.” What is more, according to this researcher, silicon is not done achieving electronic efficiency gains in terms of Moore’s Law (the doubling of the power of transistors every 18 months), even though graphene is certainly capable of outperforming silicon at some point in the future, but it is still uncertain when that might happen.

The economic equation is a tough one. In 2013, it costs $ 800 to produce one gram of graphene, which means the golden years are far from over for silicon and its derivatives. Especially so considering that on top of the difficulty of manufacturing, there are handling hazards to cope with. When a material is but one atom thick, any action on it is likely to modify its very structure. Furthermore, no one knows the consequences, in terms of wild fusion, in the case of a juxtaposition of several different nanomaterials. And in particular, any addition of solvent threatens the very conductivity of graphene.

As a result, graphene is raising the same concerns as other nanomaterials. According to studies conducted by Brown University in Rhode Island, the sharp edges of graphene may pierce body cells, therefore allowing the substance to get into the human cell and to disrupt its normal functioning. Researchers suggest there are very real nano-toxicity hazards: fragments may penetrate the cells up to a depth of 10 microns. Issues might then arise should we manage, for example, to create graphene-based artificial retinas. Backlash for the eyelash…

As for the strength of the material, which is its iconic property, it happens to also be questionable. Researchers at Rice University in Texas have shown that on the edges of a graphene “sheet”, the hexagonal structure of the material degenerates into pentagons and heptagons, which are considerably less robust. There is, according to them, a risk that the slightest imperfection in a sheet creates long rips that spread, just like a crack in a windshield does.

What of the geopolitics of graphene? Even though the initial breakthrough was achieved in Manchester, UK, Europe is lagging behind. The inventory of patents made by Cambridge IP, a British consultancy specialized in technological strategy, established that by Q4 2012, there were 2,204 patent publications on graphene in China, 1754 in the United States, 1160 in South Korea – and only 54 in the UK. So, the Europeans stepped up. In January 2013, the European Commission launched the Graphene project with a massive budget: a billion dollars over ten years. Its stated objective: to develop industrial applications for graphene, and for the wider family of two-dimensional materials. The project is led by a consortium of 74 academic and industrial partners from 17 countries. It brings together 126 research groups (including five French laboratories), that will work on eleven projects: materials, health & environment, basic research on graphene, two-dimensional materials, high-frequency electronics, optoelectronics, spintronics, sensors, flexible electronics, energy applications, nano-composite materials, and production technologies.

What should we retain from all this excitement? First, the challenge this diruption represents in basic research: it’s been less than ten years since this material was first isolated, and everything remains to be done to master its physics and to explore the immense possibilities it opens up in many a field. Second, even if serious questions remain about the potential dangers that could derive from mass production (think of asbestos), it now seems self-evident that in vital sectors such as photovoltaics, computer components or electric batteries, graphene can lead to technological breakthroughs that would bring about radically game-changing results. The next stage? Moving to industrial production – a case to follow closely.