3 Makers of World’s Smallest Machines Awarded Nobel Prize in Chemistry
Three pioneers in the development of nanomachines, made of moving molecules, were awarded the Nobel Prize in Chemistry on Wednesday.“Molecular machines,” the world’s smallest mechanical devices, may eventually be used to create new materials, sensors and energy storage systems, the Royal Swedish Academy of Sciences said in announcing the prize.“In terms of development, the molecular motor is at the same stage as the electric motor was in the 1830s, when scientists displayed various spinning cranks and wheels, unaware that they would lead to electric trains, washing machines, fans and food processors,” the academy said.The three scientists — Jean-Pierre Sauvage, J. Fraser Stoddart and Bernard L. Feringa — will share equally in the prize of 8 million Swedish kronor, or about $930,000.
Why did they win?Nanotechnology — the creation of structures on the scale of a nanometer, or a billionth of a meter — has been a field of fruitful research for a couple of decades. Now, scientists are learning how to construct tiny moving machines about one-thousandth the width of a strand of human hair.“They’ve got it started,” said Donna J. Nelson, a professor of chemistry at the University of Oklahoma and president of the American Chemical Society. “This is just the beginning.”The first step to creating a molecular machine was making a moving part. Chemists have long been able to synthesize ring-shaped molecules, and they knew that interlocking rings might function as molecular parts.But how to create a second ring that passed through the first ring? Dr. Sauvage figured that out in 1983.A charged copper ion essentially acted as a pin around which to form the interlocking rings, he found. Once connected, the copper ion could be removed. These molecules became known as catenanes.Dr. Stoddart made the next advance in 1991. Instead of two interlocking rings, Dr. Stoddart, then at the University of California, Los Angeles, and his colleagues synthesized rotaxane — a ring molecule wrapped around a dumbbell-shaped axle. The ring slides back and forth along the dumbbell, like a bead on an abacus.Indeed, Dr. Stoddart went on to construct a small computer chip that was essentially a molecular abacus, as well as other complex devices.One was composed of three rotaxanes whose rings were connected to form a larger platform that could rise 0.7 billionths of a meter — a molecular elevator. Rotaxanes bending thin layers of gold acted like an artificial muscle, he found.Dr. Feringa, in 1999, became the first person to develop a molecular motor, creating a minuscule rotor blade powered by light that spun continually in the same direction. The first motor was not fast, but 15 years later, he and his research group demonstrated one that spun 12 million times per second.In 2011, they built a four-wheel-drive molecular “car” — four of the molecular motors acted as wheels, connected by a nano-chassis.The three men invigorated the field of topological chemistry, the academy said on Wednesday. They were pioneers in the second wave of nanotechnology, a field that the physicist Richard P. Feynman, also a Nobel laureate, foresaw as early as 1959. He gave a seminal lecture in 1984, toward the end of his life, on design and engineering at the molecular scale.In living organisms, nature has produced a slew of molecular machines that ferry materials around a cell, construct proteins and divide cells. Artificial molecular machines are still primitive by comparison, but scientists can already envision applications in the future.“Think about nanomachines, microrobots,” said Dr. Feringa, who spoke by telephone with journalists assembled in Stockholm at the prize announcement. “Think about tiny robots that the doctor in the future will inject in your blood veins, and they go search for cancer cells or going to deliver drugs, for instance.”The technology could also lead to the creation of “smart materials” that change properties based on external signals, Dr. Feringa said.Who are the winners?Dr. Sauvage, 71, was born in Paris and received his Ph.D. in 1971 from the University of Strasbourg in France, where he is a professor emeritus. He is also director of research emeritus at the National Center for Scientific Research in France.Dr. Stoddart, 74, was born in Edinburgh, received his Ph.D. in 1966 from Edinburgh University, and is a professor of chemistry at Northwestern University in Evanston, Ill. He previously taught at U.C.L.A. and was knighted by Queen Elizabeth II for his services to science.Dr. Feringa, 64, was born in Barger-Compascuum, the Netherlands, and received his Ph.D. in 1978 from the University of Groningen, where he is a professor of organic chemistry.