One atom thick, graphene is the thinnest material known and may be the strongest.
Until Andre Geim, a physics professor at the University of Manchester, discovered an unusual new material called graphene, he was best known for an experiment in which he used electromagnets to levitate a frog. Geim, born in 1958 in the Soviet Union, is a brilliant academic—as a high-school student, he won a competition by memorizing a thousand-page chemistry dictionary—but he also has a streak of unorthodox humor. He published the frog experiment in the European Journal of Physics, under the title “Of Flying Frogs and Levitrons,” and in 2000 it won the Ig Nobel Prize, an annual award for the silliest experiment. Colleagues urged Geim to turn the honor down, but he refused. He saw the frog levitation as an integral part of his style, an acceptance of lateral thinking that could lead to important discoveries. Soon afterward, he began hosting “Friday sessions” for his students: free-form, end-of-the-week experiments, sometimes fuelled by a few beers. “The Friday sessions refer to something that you’re not paid for and not supposed to do during your professional life,” Geim told me recently. “Curiosity-driven research. Something random, simple, maybe a bit weird—even ridiculous.” He added, “Without it, there are no discoveries.”
On one such evening, in the fall of 2002, Geim was thinking about carbon. He specializes in microscopically thin materials, and he wondered how very thin layers of carbon might behave under certain experimental conditions. Graphite, which consists of stacks of atom-thick carbon layers, was an obvious material to work with, but the standard methods for isolating superthin samples would overheat the material, destroying it. So Geim had set one of his new Ph.D. students, Da Jiang, the task of trying to obtain as thin a sample as possible—perhaps a few hundred atomic layers—by polishing a one-inch graphite crystal. Several weeks later, Jiang delivered a speck of carbon in a petri dish. After looking at it under a microscope, Geim recalls, he asked him to try again; Jiang admitted that this was all that was left of the crystal. As Geim teasingly admonished him (“You polished a mountain to get a grain of sand?”), one of his senior fellows glanced at a ball of used Scotch tape in the wastebasket, its sticky side covered with a gray, slightly shiny film of graphite residue.
It would have been a familiar sight in labs around the world, where researchers routinely use tape to test the adhesive properties of experimental samples. The layers of carbon that make up graphite are weakly bonded (hence its adoption, in 1564, for pencils, which shed a visible trace when dragged across paper), so tape removes flakes of it readily. Geim placed a piece of the tape under the microscope and discovered that the graphite layers were thinner than any others he’d seen. By folding the tape, pressing the residue together and pulling it apart, he was able to peel the flakes down to still thinner layers.
Geim had isolated the first two-dimensional material ever discovered: an atom-thick layer of carbon, which appeared, under an atomic microscope, as a flat lattice of hexagons linked in a honeycomb pattern. Theoretical physicists had speculated about such a substance, calling it “graphene,” but had assumed that a single atomic layer could not be obtained at room temperature—that it would pull apart into microscopic balls. Instead, Geim saw, graphene remained in a single plane, developing ripples as the material stabilized.
Geim enlisted the help of a Ph.D. student named Konstantin Novoselov, and they began working fourteen-hour days studying graphene. In the next two years, they designed a series of experiments that uncovered startling properties of the material. Because of its unique structure, electrons could flow across the lattice unimpeded by other layers, moving with extraordinary speed and freedom. It can carry a thousand times more electricity than copper. In what Geim later called “the first eureka moment,” they demonstrated that graphene had a pronounced “field effect,” the response that some materials show when placed near an electric field, which allows scientists to control the conductivity. A field effect is one of the defining characteristics of silicon, used in computer chips, which suggested that graphene could serve as a replacement—something that computer makers had been seeking for years.
Geim and Novoselov wrote a three-page paper describing their discoveries. It was twice rejected by Nature, where one reader stated that isolating a stable, two-dimensional material was “impossible,” and another said that it was not “a sufficient scientific advance.” But, in October, 2004, the paper, “Electric Field Effect in Atomically Thin Carbon Films,” was published in Science, and it astonished scientists. “It was as if science fiction had become reality,” Youngjoon Gil, the executive vice-president of the Samsung Advanced Institute of Technology, told me.
Labs around the world began studies using Geim’s Scotch-tape technique, and researchers identified other properties of graphene. Although it was the thinnest material in the known universe, it was a hundred and fifty times stronger than an equivalent weight of steel—indeed, the strongest material ever measured. It was as pliable as rubber and could stretch to a hundred and twenty per cent of its length. Research by Philip Kim, then at Columbia University, determined that graphene was even more electrically conductive than previously shown. Kim suspended graphene in a vacuum, where no other material could slow the movement of its subatomic particles, and showed that it had a “mobility”—the speed at which an electrical charge flows across a semiconductor—of up to two hundred and fifty times that of silicon.
In 2010, six years after Geim and Novoselov published their paper, they were awarded the Nobel Prize in Physics. By then, the media were calling graphene “a wonder material,” a substance that, as the Guardian put it, “could change the world.” Academic researchers in physics, electrical engineering, medicine, chemistry, and other fields flocked to graphene, as did scientists at top electronics firms. The U.K. Intellectual Property Office recently published a report detailing the worldwide proliferation of graphene-related patents, from 3,018 in 2011 to 8,416 at the beginning of 2013. The patents suggest a wide array of applications: ultra-long-life batteries, bendable computer screens, desalinization of water, improved solar cells, superfast microcomputers. At Geim and Novoselov’s academic home, the University of Manchester, the British government invested sixty million dollars to help create the National Graphene Institute, in an effort to make the U.K. competitive with the world’s top patent holders: Korea, China, and the United States, all of which have entered the race to find the first world-changing use for graphene.
The progress of a technology from the moment of discovery to transformative product is slow and meandering; the consensus among scientists is that it takes decades, even when things go well. Paul Lauterbur and Peter Mansfield shared a Nobel Prize for developing the MRI, in 1973—almost thirty years after scientists first understood the physical reaction that allowed the machine to work. More than a century passed between the moment when the Swedish chemist Jöns Jakob Berzelius purified silicon, in 1824, and the birth of the semiconductor industry.
New discoveries face formidable challenges in the marketplace. They must be conspicuously cheaper or better than products already for sale, and they must be conducive to manufacture on a commercial scale. If a material arrives, like graphene, as a serendipitous discovery, with no targeted application, there is another barrier: the limits of imagination. Now that we’ve got this stuff, what do we do with it?
Aluminum, discovered in minute quantities in a lab in the eighteen-twenties, was hailed as a wonder substance, with qualities never before seen in a metal: it was lightweight, shiny, resistant to rust, and highly conductive. It could be derived from clay (at first, it was called “silver from clay”), and the idea that a valuable substance was produced from a common one lent it a quality of alchemy. In the eighteen-fifties, a French chemist devised a method for making a few grams at a time, and aluminum was quickly adopted for use in expensive jewelry. Three decades later, a new process, using electricity, allowed industrial production, and the price plummeted.
“People said, ‘Wow! We’ve got this silver from clay, and now it’s really cheap and we can use it for anything,’ ” Robert Friedel, a historian of technology at the University of Maryland, told me. But the enthusiasm soon cooled: “They couldn’t figure out what to use it for.” In 1900, the Sears and Roebuck catalogue advertised aluminum pots and pans, Friedel notes, “but you can’t find any of what we’d call ‘technical’ uses.” Not until after the First World War did aluminum find its transformative use. “The killer app is the airplane, which didn’t even exist when they were going all gung ho and gaga over this stuff.”
Some highly touted discoveries fizzle altogether. In 1986, the I.B.M. researchers Georg Bednorz and K. Alex Müller discovered ceramics that acted as radically more practical superconductors. The next year, they won a Nobel, and an enormous wave of optimism followed. “Presidential commissions were thrown together to try to put the U.S. out in the lead,” Cyrus Mody, a history-of-science professor at Rice University, in Houston, says. “People were talking about floating trains and infinite transmission lines within the next couple of years.” But, in three decades of struggle, almost no one has managed to turn the brittle ceramics into a substance that can survive everyday use.
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Friedel offered a broad axiom: “The more innovative—the more breaking-the-mold—the innovation is, the less likely we are to figure out what it is really going to be used for.” Thus far, the only consumer products that incorporate graphene are tennis racquets and ink. But many scientists insist that its unusual properties will eventually lead to a breakthrough. According to Geim, the influx of money and researchers has speeded up the usual time line to practical usage. “We started with submicron flakes, barely seen even in an optical microscope,” he says. “I never imagined that by 2009, 2010, people would already be making square metres of this material. It’s extremely rapid progress.” He adds, “Once someone sees that there is a gold mine, then very heavy equipment starts to be applied from many different research areas. When people are thinking, we are quite inventive animals.”
Samsung, the Korea-based electronics giant, holds the greatest number of patents in graphene, but in recent years research institutions, not corporations, have been most active. A Korean university, which works with Samsung, is in first place among academic institutions. Two Chinese universities hold the second and third slots. In fourth place is Rice University, which has filed thirty-three patents in the past two years, almost all from a laboratory run by a professor named James Tour.
Tour, fifty-five, is a synthetic organic chemist, but his expansive personality and entrepreneurial brio make him seem more like an executive overseeing a company’s profitable R. & D. division. A short, dark-eyed man with a gym-pumped body, he greeted me volubly when I visited him recently at his office, in the Dell Butcher building at Rice. “I mean, the stuff is just amazing!” he said, about graphene. “You can’t believe what this stuff can do!” Tour, like most senior scientists, must concern himself with both research and commerce. He has twice appeared before Congress to warn about federal budget cuts to science, and says that his lab has managed to thrive only because he has secured funding through aggressive partnerships with industry. He charges each business he contracts with two hundred and fifty thousand dollars a year; his lab nets a little more than half, with which he can hire two student researchers and pay for their materials for a year. Much of Tour’s work involves spurring the creativity of those researchers (twenty-five of whom are devoted to graphene); they’re the ones who devise the inventions that Tour sells. Graphene has been a boon, he said: “You have a lot of people moving into this area. Not just academics but companies in a big way, from the big electronics firms, like Samsung, to oil companies.”
Tour brings a special energy to the endeavor. Raised in a secular Jewish home in White Plains, he became a born-again Christian as a freshman at Syracuse University. Married, with four grown children, he rises at three-forty every morning for an hour and a half of prayer and Bible study—followed, several times a week, with workouts at the gym—and arrives at the office at six-fifteen. In 2001, he made headlines by signing “A Scientific Dissent from Darwinism,” a petition that promoted intelligent design, but he insists that this reflected only his personal doubts about how random mutation occurs at the molecular level. Although he ends e-mails with “God bless,” he says that, apart from a habit of praying for divine guidance, he feels that religion plays no part in his scientific work.
Tour endorses a scattershot approach for his students’ research. “We work on whatever suits our fancy, as long as it is swinging for the fences,” he said. As chemists, he noted, they are particularly suited to quick experiments, many of which can yield results in a matter of hours—unlike physicists, whose experiments can take months. His lab has published a hundred and thirty-one journal articles on graphene—second only to a lab at the University of Texas at Austin—and his researchers move rapidly to file provisional applications with the U.S. Patent and Trademark Office, which give them legal ownership of an idea for a year before they must file a full claim. “We don’t wait very long before we file,” Tour said; he urges students to write up their work in less than forty-eight hours. “I was just told by a company that has licensed one of our technologies that we beat the Chinese by five days.”
Many of his lab’s recent inventions are designed for immediate exploitation by industry, supplying funds to support more ambitious work. Tour has sold patents for a graphene-infused paint whose conductivity might help remove ice from helicopter blades, fluids to increase the efficiency of oil drills, and graphene-based materials to make the inflatable slides and life rafts used in airplanes. He points out that graphene is the only substance on earth that is completely impermeable to gas, but it weighs almost nothing; lighter rafts and slides could save the airline industry millions of dollars’ worth of fuel a year.
In Tour’s laboratory, a large, high-ceilinged room with tightly configured rows of worktables, a score of young men in white lab coats and safety goggles were working. Tour and I stopped at a bench where Loïc Samuels, a graduate student from Antigua, was making a batch of graphene-based gel, to be used in a scaffold for spinal-cord injuries. “Instead of just having a nonfunctional scaffold material, you have something that’s actually electrically conductive,” Samuels said, as he swirled a test tube in a jeweller’s bath. “That helps the nerve cells, which communicate electrically, connect with each other.” Tour showed me videos of lab rats whose back legs had been paralyzed. In one video, two rats inched themselves along the bottom of a cage, dragging their hind legs. In another video, of rats that had been treated, they walked normally. Tour warned that it takes years before the F.D.A. approves human trials. “But it’s an incredible start,” he said.
In 2010, one of Tour’s researchers, Alexander Slesarev, a Russian who had studied at Moscow State University, suggested that graphene oxide, a form of graphene created when oxygen and hydrogen molecules are bonded to it, might attract radioactive material. Slesarev sent a sample to a former colleague at Moscow State, where students placed the powder in solutions containing nuclear material. They discovered that the graphene oxide binds with the radioactive elements, forming a sludge that could easily be scooped away. Not long afterward, the earthquake and tsunami in Japan created a devastating spill of nuclear material, and Tour flew to Japan to pitch the technology to the Japanese. “We’re deploying it right now in Fukushima,” he told me.
Working at one of the benches was a young man with a round, open face: a twenty-five-year-old Ph.D. student named Ruquan Ye, who last year devised a new way to make quantum dots, highly fluorescent nanoparticles used in medical imaging and plasma television screens. Usually made in tiny amounts from toxic chemicals, such as cadmium selenide and indium arsenide, quantum dots cost a million dollars for a one-kilogram bottle. Ye’s technique uses graphene derived from coal, which is a hundred dollars a ton.
“The method is simple,” Ye told me. He showed me a vial filled with a fine black powder: anthracite coal that he had ground. “I place this in a solution of acids for one day, then heat the solution on a hot plate.” By tweaking the process, he can make the material emit various light frequencies, creating dots of various colors for differentiated tagging of tumors. The coal-based dots are compatible with the human body—coal is carbon, and so are we—which suggests that Ye’s dots could replace the highly toxic ones used in hospitals worldwide. In a darkened room next to the lab, he shone a black light on several small vials of clear liquid. They fluoresced into glowing ingots: red, blue, yellow, violet.
Tour usually declines to take credit for the discoveries in his lab. “It’s all the students,” he said. “They’re at that age, their twenties, when the synapses are just firing. My job is to inspire them and provide a credit card, and direct them away from rabbit holes.” But he acknowledged that the quantum-dot idea originated with him: “One day, I said, ‘We gotta find out what’s in coal. People have been using this for five thousand years. Let’s see what’s really in it. I bet it’s small domains of graphene’—and, sure enough, it was. It was just sitting right there. A twenty-five-per-cent yield. And, remember, it’s a million dollars a kilogram!”
Tour turned to his lab manager, Paul Cherukuri, and said, “We’re going to be rich someday, aren’t we?” As Cherukuri laughed, Tour added, “I’m going to come in here and count money every day.”
Perhaps the most tantalizing property described in Geim and Novoselov’s 2004 paper was the “mobility” with which electronic information can flow across graphene’s surface. “The slow step in our computers is moving information from point A to point B,” Tour told me. “Now you’ve taken the slow step, the biggest hurdle in silicon electronics, and you’ve introduced a new material and—boom! All of a sudden, you’re increasing speed not by a factor of ten but by a factor of a hundred, possibly even more.”
The news galvanized the semiconductor industry, which was struggling to keep up with Moore’s Law, devised in 1965 by Gordon Moore, a co-founder of Intel. Every two years, he predicted, the density—and thus the effectiveness—of computer chips would double. For five decades, engineers have managed to keep pace with Moore’s Law through miniaturization, packing increasing numbers of transistors onto chips—as many as four billion on a silicon wafer the size of a fingernail. Engineers have further speeded computers by “doping” silicon: introducing atoms from other elements to squeeze the lattice tighter. But there’s a limit. Shrink the chip too much, moving its transistors too close together, and silicon stops working. As early as 2017, silicon chips may no longer be able to keep pace with Moore’s Law. Graphene, if it works, offers a solution.
“Five more minutes and I’m all yours, Mr. Antsy.”
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There’s a problem, though. Semiconductors, such as silicon, are defined by their ability to turn on and off in the presence of an electric field; in logic chips, that switching process generates the ones and the zeros that are the language of computers. Graphene, a semi-metal, cannot be turned off. At first, engineers believed that they could dope graphene to open up a “band gap,” the electrical property that allows semiconductors to act as switches. But, ten years after Geim and Novoselov’s paper, no one has succeeded in opening a gap wide enough. “You’d have to change it so much that it’s no longer graphene,” Tour said. Indeed, those who have managed to create such a gap learned that it kills the mobility, rendering graphene no better than the materials we use now. The result has been a certain dampening of the mood at semiconductor companies.
I recently visited the Thomas J. Watson Research Center, the main R. & D. lab for I.B.M., a major fabricator of silicon semiconductor chips. A half hour north of New York City, the center is housed in a building designed by Eero Saarinen, in 1961. A vast arc of glass with an upswept front awning, it is a kind of monument to the difficulty of predicting the future. Saarinen imagined that transformative ideas would emerge from groups of scientists working in meeting areas, where recliners and coffee tables still sit beside soaring windows. Instead, the scientists spend much of the day hunched over computer screens in their offices: small, windowless dens, which seem to have been created as an afterthought.
In one cramped office, I met Supratik Guha, who is the director of physical sciences at I.B.M. and who sets the company’s strategy for worldwide research. A thoughtful man, as precisely understated as Tour is effusive, Guha lamented the “excessive hype” that has surrounded graphene as a replacement for silicon, and talked mournfully about how the effort to introduce a band gap is, at best, “one major innovation away.” He hastened to add that I.B.M. has not written off graphene. In early 2014, the company announced that its researchers had built the first graphene-based integrated circuit for wireless devices, which could lead to cheaper, more efficient cell phones. But in the quest to make graphene a replacement for silicon, Guha admits, they hold little hope.
For now, I.B.M.’s focus remains the single-walled carbon nanotube, which was developed at Rice by Tour’s mentor and predecessor, Rick Smalley. In the eighties, Smalley and his colleagues discovered that molecules of carbon atoms arrange themselves in a variety of shapes; some were spheres (which he called “buckyballs,” for their resemblance to Buckminster Fuller’s geodesic domes) and others were tubes. When the researchers found that the tubes can act as semiconductors, the material was immediately suggested as a potential replacement for silicon. Along with his collaborators, Smalley was awarded the Nobel Prize in Chemistry in 1996, and he persuaded Rice to build the multimillion-dollar nanotechnology center that Tour later took over. Yet carbon nanotubes have resisted easy exploitation. They have the necessary band gap, but building a chip with them entails maneuvering billions of minute objects into precise locations—a difficulty that has bedevilled scientists for almost two decades. Without quite admitting that he has lost interest in carbon nanotubes, Tour told me that they “never really commercialized well.”
At I.B.M., which has invested more than a decade of research and tens of millions of dollars in the material, there is great reluctance to admit defeat. Guha introduced me to George Tulevski, who helps lead I.B.M.’s carbon-nanotube research program. When I mentioned graphene, he evinced the defensiveness that might be expected of a scientist who has devoted nearly ten years to one recalcitrant technology only to be told about a glamorous new one. “Devices have to turn on and off,” Tulevski said. “If it doesn’t turn off, it just consumes way too much power. There’s no way to turn graphene off. So those electrons are going superfast, and that’s great—but you can’t turn the device off.”
Cyrus Mody, the historian, is equally cautious. “This idea that there’s a form of microelectronics that is theoretically much, much faster than conventional silicon is not new,” he told me. He points to the precedent of the Josephson-junction circuit. In 1962, the British physicist Brian David Josephson predicted that electricity would flow at unprecedented speeds through a circuit composed of two superconductors separated by a “weak link” material. The insight led to a Nobel Prize in Physics—and to dreams of exponentially faster electronics.
“A lot of people thought we’d be switching over to superconducting Josephson-junction microelectronics soon,” Mody said. “But when you actually get down to manufacturing a complex circuit with lots and lots and lots of logic gates, and making lots and lots of such circuits with very large yields, the manufacturing problems really make it impossible to keep going. And I think that’s going to be the hurdle that people haven’t really considered enough when they talk about graphene.”
But other scientists argue that the obstacle is not graphene’s physical properties. “The semiconductor industry knows how to introduce a band gap,” Amanda Barnard, a theoretical physicist who heads Australia’s Commonwealth Scientific and Industrial Research Organization, told me. The problem is business: “We’ve got a global investment on the order of trillions of dollars in silicon, and we’re not going to walk away from that. Initially, graphene needs to work with silicon—it needs to work in our existing factories and production lines and research capabilities—and then we’ll get some momentum going.”
Tour has little sympathy for the semiconductor industry’s disappointment with graphene. “I.B.M. is all bummed out because they’re single-minded,” he said. “They’ve got to make computers—and they’ve got Moore’s Law. But that’s their own fault! What other industry has challenged itself with doubling its performance every eighteen months? In the chemical industry, if we can get a one-per-cent-higher yield in a year we think we’ve done pretty well.”
Perhaps the most expansive thinker about the material’s potential is Tomas Palacios, a Spanish scientist who runs the Center for Graphene Devices and 2D Systems, at M.I.T. Rather than using graphene to improve existing applications, as Tour’s lab mostly does, Palacios is trying to build devices for a future world.
At thirty-six, Palacios has an undergraduate’s reedy build and a gentle way of speaking that makes wildly ambitious notions seem plausible. As an electrical engineer, he aspires to “ubiquitous electronics,” increasing “by a factor of one hundred” the number of electronic devices in our lives. From the perspective of his lab, the world would be greatly enhanced if every object, from windows to coffee cups, paper currency, and shoes, were embedded with energy harvesters, sensors, and light-emitting diodes, which allowed them to cheaply collect and transmit information. “Basically, everything around us will be able to convert itself into a display on demand,” he told me, when I visited him recently. Palacios says that graphene could make all this possible; first, though, it must be integrated into those coffee cups and shoes.
As Mody pointed out, radical innovation often has to wait for the right environment. “It’s less about a disruptive technology and more about moments when the linkages among a set of technologies reach a point where it’s feasible for them to change lots of practices,” he said. “Steam engines had been around a long time before they became really disruptive. What needed to happen were changes in other parts of the economy, other technologies linking up with the steam engine to make it more efficient and desirable.”
For Palacios, the crucial technological complement is an advance in 3-D printing. In his lab, four students were developing an early prototype of a printer that would allow them to create graphene-based objects with electrical “intelligence” built into them. Along with Marco de Fazio, a scientist from STMicrolectronics, a firm that manufactures ink-jet print heads, they were clustered around a small, half-built device that looked a little like a Tinkertoy contraption on a mirrored base. “We just got the printer a couple of weeks ago,” Maddy Aby, a ponytailed master’s student, said. “It came with a kit. We need to add all the electronics.” She pointed to a nozzle lying on the table. “This just shoots plastic now, but Marco gave us these print heads that will print the graphene and other types of inks.”
The group’s members were pondering how to integrate graphene into the objects they print. They might mix the material into plastic or simply print it onto the surface of existing objects. There were still formidable hurdles. The researchers had figured out how to turn graphene into a liquid—no easy task, since the material is severely hydrophobic, which means that it clumps up and clogs the print heads. They needed to first convert graphene to graphene oxide, adding groups of oxygen and hydrogen molecules, but this process negates its electrical properties. So once they printed the object they would have to heat it with a laser. “When you heat it up,” Aby said, “you burn off those groups and reduce it back to graphene.”
When that might be possible was uncertain; she hoped to have the device working in three months. “The laser needs more approval from the powers that be,” she said, glancing balefully at the printer’s mirrored base—the kind perfect for bouncing laser beams all over a room. De Fazio suggested that they cover it with a silicon wafer.
“That could work,” Aby said.
“Of course, this could also be confirmation bias from me wanting you to get sick.”
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Palacios recognizes that millennial change comes only after modest, strategic increments. He mentioned Samsung, which, according to industry rumor, is planning to launch the first device with a screen that employs graphene. “Graphene is only a small component, used to deliver the current to the display,” he said. “But that’s an exciting first application—it doesn’t have to be the breakthrough that we are all looking forward to. It’s a good way to get graphene into everyone’s focus and, that way, justify more investment.” In the meantime, one of his students, Lili Yu, has been working on a prototype for a flexible screen.
Palacios, in his office, told me that his most ambitious goal is “graphene origami,” in which sheets of the material are folded to mimic organelles, minuscule structures inside a biological cell. “It’s not that different from what nature does with DNA, a material that is a one-dimensional structure that gets folded many, many, many times to make the chromosomes.” If the method works, it could be used to pack huge amounts of computing power into a tiny space. There might be applications in medicine, he says, and in something he calls smart dust—“things that are just as tiny as dust particles but have a functionality to tell us about the pollution in the atmosphere, or if there is a flu virus nearby. These things will be able to connect to your phone or to the embedded displays everywhere, to tell you about things happening around you.”
For the moment, the challenges are more earthbound: scientists are still trying to devise a cost-effective way to produce graphene at scale. Companies like Samsung use a method pioneered at the University of Texas, in which they heat copper foil to eighteen hundred degrees Fahrenheit in a low vacuum, and introduce methane gas, which causes graphene to “grow” as an atom-thick sheet on both sides of the copper—much as frost crystals “grow” on a windowpane. They then use acids to etch away the copper. The resulting graphene is invisible to the naked eye and too fragile to touch with anything but instruments designed for microelectronics. The process is slow, exacting, and too expensive for all but the largest companies to afford.
At Tour’s lab, a twenty-six-year-old postdoc named Zhiwei Peng was waiting to hear from a final reviewer of a paper he had submitted, in which he detailed a way to create graphene with no superheating, no vacuums, and no gases. (The paper was later approved for publication.) Peng had stumbled on his method a few months before. While heating graphene oxide with a laser, he missed the sample, and accidentally heated the material it was sitting on, a sheet of polyimide plastic. Where the laser touched the plastic, it left a black residue. He discovered that the residue was layers of graphene, loosely bonded with oxygen molecules, which—like the residue on Geim’s tape—could easily be exfoliated to single-atom sheets. He showed me how it worked, the laser tracking back and forth across the surface of a piece of polyimide and leaving with each pass a needle-thin deposit of material. Single layers of graphene absorb 2.5 per cent of available light; as layers pile up, they begin to appear black. After a few minutes, Peng had produced a crisp, matte-black lattice—perhaps an inch wide, and worth tens of thousands of dollars. Cherukuri, Tour’s lab manager, pointed at it and said, “That is the race.”
The tech-research firm Gartner uses an analytic tool that it calls the Hype Cycle to help investors determine which discoveries will make money. A graph of the cycle resembles a cursive lowercase “r,” in which a discovery begins with a Technology Trigger, climbs quickly to a Peak of Inflated Expectations, falls into the Trough of Disillusionment, and, as practical uses are found, gradually ascends to the Plateau of Productivity. The implication is not (or not only) that most discoveries don’t behave as expected; it’s that a new thing typically becomes useful sometime after the publicity fades.
Nearly every scientist I spoke with suggested that graphene lends itself especially well to hype. “It’s an electrically useful material in a time when we love electrical devices,” Amanda Barnard told me. “If it had come along at a time when we were not so interested in electronic devices, the hype might not have been so disproportionate. But then there wouldn’t have been the same appetite for investment.” Indeed, Henry Petroski, a professor at Duke and the author of “To Engineer Is Human,” says that hype is necessary to attract development dollars. But he offers an important proviso: “If there is too much hype at the discovery stage and the product doesn’t live up to the hype, that’s one way of its becoming disappointing and abandoned, eventually.”
Guha, at I.B.M., believes that the field of nanotechnology has been oversold. “Nobody stands to benefit from giving the bad news,” he told me. “The scientist wants to give the good news, the journalist wants to give the good news—there is no feedback control to the system. In order to develop a technology, there is a lot of discipline that needs to go in, a lot of things that need to be done that are perhaps not as sexy.”
Tour concurs, and admits to some complicity. “People put unrealistic time lines on us,” he told me. “We scientists have a tendency to feed that—and I’m guilty of that. A few years ago, we were building molecular electronic devices. The Times called, and the reporter asked, ‘When could these be ready?’ I said, ‘Two years’—and it was nonsense. I just felt so excited about it.”
The impulse to overlook obvious difficulties to commercial development is endemic to scientific research. Geim’s paper, after all, mentioned the band-gap problem. “People knew that graphene is a gapless semiconductor,” Amirhasan Nourbakhsh, an M.I.T. scientist specializing in graphene, told me. “But graphene was showing extremely high mobility—and mobility in semiconductor technology is very important. People just closed their eyes.”
According to Friedel, the historian, scientists rely on the stubborn conviction that an obvious obstacle can be overcome. “There is a degree of suspension of disbelief that a lot of good research has to engage in,” he said. “Part of the art—and it is art—comes from knowing just when it makes sense to entertain that suspension of disbelief, at least momentarily, and when it’s just sheer fantasy.” Lord Kelvin, famous for installing telegraph cables on the Atlantic seabed, was clearly capable of overlooking obstacles. But not always. “Before his death, in 1907, Lord Kelvin carefully, carefully calculated that a heavier-than-air flying machine would never be possible,” Friedel says. “So we always have to have some humility. A couple of bicycle mechanics could come along and prove us wrong.”
Recently, some of the most exciting projects from Tour’s lab have encountered obstacles. An additive to fluids used in oil drilling, developed with a subsidiary of the resource company Schlumberger, promised to make drilling more efficient and to leave less waste in the ground; instead, barrels of the stuff decomposed before they could be used. The company that hired Tour’s group to make inflatable slides and rafts for aircraft found a cheaper lab. (Tour was philosophical about it, in part because he knew he’d still get some money from the contract. “They’ll have to come back and get the patent,” he said.) The technology for the Fukushima-reactor cleanup stalled when scientists in Japan couldn’t get the powder to work, and the postdoc who developed the method was unable to get a visa to go assist them. “You’ve got to teach them how it’s done,” Tour said. “You want the pH right.”
Tour’s optimism for graphene remains undimmed, and his group has been working on further inventions: superfast cell-phone chargers, ultra-clean fuel cells for cars, cheaper photovoltaic cells. “What Geim and Novoselov did was to show the world the amazingness of graphene, that it had these extraordinary electrical properties,” Tour said. “Imagine if one were God. Here, He’s given us pencils, and all these years scientists are trying to figure out some great thing, and you’re just stripping off sheets of graphene as you use your pencil. It has been before our eyes all this time!