MUA IN»Friedel cung cấp một tiên đề rộng: "sáng tạo hơn-hơn breaking-the-khuôn — sự đổi mới là, càng ít có khả năng chúng tôi là để tìm ra những gì nó thực sự sẽ được sử dụng cho." Vậy, đến nay, các sản phẩm tiêu dùng duy nhất kết hợp graphen là bóng vợt và mực. Nhưng nhiều nhà khoa học đã nhấn mạnh rằng thuộc tính bất thường của nó cuối cùng sẽ dẫn đến một bước đột phá. Theo Geim, dòng tiền và các nhà nghiên cứu đã tốc lên dòng thời gian bình thường để sử dụng thực tế. "Chúng tôi bắt đầu với submicron mảnh, hiếm khi nhìn thấy ngay cả trong một kính hiển vi quang học," ông nói. "Tôi không bao giờ tưởng tượng rằng tới năm 2009, 2010, người nào đã làm cho mét vuông của tài liệu này. Nó là cực kỳ nhanh chóng." Ông nói thêm, "một khi ai đó thấy rằng có một mỏ vàng, sau đó thiết bị rất nặng bắt đầu được áp dụng từ nhiều lĩnh vực nghiên cứu khác nhau. Khi mọi người đang nghĩ, chúng tôi đang khá sáng tạo động vật."Samsung, Hàn Quốc điện tử khổng lồ, Giữ số bằng sáng chế, lớn nhất trong graphen, nhưng trong các tổ chức nghiên cứu năm gần đây, không phải các tập đoàn, đã tích cực nhất. Một trường đại học Triều tiên, làm việc với Samsung, là nơi đầu tiên trong số các tổ chức học tập. Hai trường đại học Trung Quốc giữ các khe thứ hai và thứ ba. Ở vị trí thứ tư là đại học Rice, đã đệ trình ba mươi ba bằng sáng chế trong hai năm qua, gần như tất cả từ một phòng thí nghiệm do một giáo sư tên là 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 at
đang được dịch, vui lòng đợi..
