The 2016 Nobel Prize in chemistry has been awarded to Jean-Pierre Sauvage from the University of Strasbourg, Sir J. Fraser Stoddart affiliated with Northwestern University, and Bernard L. Feringa from the University of Groningen for their work on molecular machines — nano-scale mechanisms capable of performing various tasks.
Molecular machines are teeny-tiny assemblies with the potential to spark a huge revolution. In essence, their purpose is to do the same things machines do for us today — transport, crafting, repairs — but on the molecular scale. And, just as you can’t make a car without first making some wheels, they need to be built from even smaller parts.
The trio’s work led to the creation of the most advanced such parts we’ve yet put together. Sauvage created the first molecular chain — or “catenane” — in 1983. Stoddart designed a “rotaxane”, a molecular ring around an axle. Feringa created the first molecular motor by coaxing a blade to spin in only one direction. Just remember, we’re talking about molecules here — far from the solid pieces of steel we use to build our machines in the macroscopic world, these molecular machines are subjected to the same rules as other molecules, such as Brownian motion.
Building on their work, chemists have designed muscles, elevators, and even cars, on an incredibly small scale. At the conference announcing the prize, committee member Sara Snogerup Linse asked if the audience wanted to see some molecular machines. She pulled away a black cylinder to reveal the items with a “Ta-da!” but there was nothing there.
“I’m sorry,” she said. “You can’t see them. They are more than a thousand times smaller than a human hair.”
Committee member Olof Ramstrom went on to present diagrams showcasing how the devices are built and their functionality. Sauvage, professor emeritus at the University of Strasbourg in France, developed a chain-linking process using a copper ion to hold two molecules in place. A third is added to complete the second link, and the copper ion is removed — allowing the two rings to move freely while still staying connected. Stoddart, Board of Trustees Professor of Chemistry at Northwestern University, used the attraction between an electron-starved ring and an electron-rich rod to thread the ring, forming an axle. The loop is then closed, to complete the assembly. Feringa, Jacobus Van’t Hoff Distinguished Professor of Molecular Sciences at the University of Groningen in the Netherlands, coaxed a spinning rotor blade to move in a single direction by driving it with pulses of light.
“They really are very tiny,” Ramstrom agreed.
The trio’s work has “opened this entire field of molecular machinery,” he added. There’s enormous potential in these tiny cogs and gears, as the Nobel Prize website explains:
“2016’s Nobel Laureates in Chemistry have taken molecular systems out of equilibrium’s stalemate and into energy-filled states in which their movements can be controlled. 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. Molecular machines will most likely be used in the development of things such as new materials, sensors and energy storage systems.”
The three scientists share the prize equally. A summary of their research can be read here. A technical explanation is available here.