Chemistry Nobel honors pioneers of world’s smallest machines | Science News for Students

Chemistry Nobel honors pioneers of world’s smallest machines

These three chemists paved the way for molecular motors
Oct 5, 2016 — 5:24 pm EST
nanocar nobel

This microscopic automobile is a “nanocar.” The creators of miniature machines such as this one have won the 2016 Nobel Prize in chemistry.

  RANDY WIND/MARTIN ROELFS; NATURE

The world’s smallest motors — ones far too small to see with the eye — may soon drive new innovations in chemistry, biology and computing. Three pioneers of such nanotechnology were honored with the 2016 Nobel Prize in chemistry.

The Nobel Committee in Stockholm, Sweden, announced the winners on October 5. Jean-Pierre Sauvage works at the University of Strasbourg, France. James Fraser Stoddart is at Northwestern University in Evanston, Ill. And Bernard Feringa works at the University of Groningen in the Netherlands.

“If you had to choose three people at the top of the field, that’s it. These are the men,” says James Tour. He’s a nanomachines chemist at Rice University in Houston, Texas. To his mind, “It is a well-warranted prize.” That means that the Nobel committee selected the right people.

Giving attention to the skyrocketing field of molecular motors (which this award will certainly do) should inspire more children to become scientists, says Donna Nelson. She’s an organic chemist at the University of Oklahoma in Norman. She’s also president of the American Chemical Society, based in Washington, D.C. This attention will likely also draw more funding for work in this area. As such, she says, this award “will benefit not only these three chemists, it will benefit the entire field of chemistry.”

Why create nano-bots?

Scientists have envisioned machines built on the scale of molecules since at least the 1960s. But reliably building their complex structures proved challenging. That began to change in 1983. That’s when Sauvage figured out how to loosely link ring-shaped molecules into a chain. These were known as catenanes (KAT-eh-nayns). These chains set the stage for the rest of the field.

(Story continues below image)

copper bond
In 1983, Sauvage described how to forge a chain of molecules by creating a new type of mechanical bond. The technique uses copper ions to glue together two halves of crescent-shaped molecules. They then interlock with rings. This work set the stage for chemists to create more intricate structures, including knots and motors.
© JOHAN JARNESTAD/THE ROYAL SWEDISH ACADEMY OF SCIENCES

Stoddart improved the efficiency of making these chains. Before long, he could produce large quantities of them. By 1991, he had clipped such ring-shaped molecules to a central axle. That created what’s now known as a rotaxane. He and his colleagues learned to control how the rings slide along the axle. This formed a simple molecular switch. One day, such switches might be used to make molecular computers or new systems to deliver drugs to a desired site in the body.

Stoddart designed molecular “muscles” with interlocking ring molecules and axles. His group has since gone on to make molecular elevators and pumps, working with the same molecules.

Feringa ramped things up another notch in 1999. That’s when he fashioned the first molecular motor. Things move so differently at the molecular scale that many researchers weren’t sure anyone could precisely control the motion of molecular motors, recalls Raymond Dean Astumian. He works at the University of Maine in Orono. But Feringa got it to work. His innovation was to devise asymmetric molecules that would spin in only one direction when hit with a pulse of light.

These were very tiny motors. Some 50,000 of them could fit side-by-side across the width of a human hair, notes Tour. Alone, one spinning motor wouldn’t do much. Harnessed together in large numbers, however, these motors could accomplish quite a lot, he says. Groups of the whirring devices, powered by light, can rotate a glass rod thousands of times their size. Feringa even harnessed his motors into a four-wheel-drive “nanocar.”

The promise of nano-machines

Over the decades, molecular machines have seen big improvements. And the work of the three new Nobel winners contributed a lot to that, says Rigoberto Advincula. He’s a chemist at Case Western Reserve University in Cleveland, Ohio.

Scientists today have a better understanding of how to create molecules that more reliably bend, loop and connect to form desired shapes. "You don't have tweezers to put them together," Advincula notes. Engineers have to design a template. Then they arrange to have a particular chemical reaction occur on that template. Depending on the reaction, it might make a thread go through some ring, for instance. That, he explains, might help the ends of two threads meet.

Ever newer techniques make it easier to create more challenging shapes. One day, scientists expect to be able to scale up the process. That could allow for the design of molecular machines for everything from energy harvesting to manufacturing complex chemicals.

But that’s still a long way off. Right now, no one really knows what particular sorts of useful machines chemists will put assemble from their molecular toolboxes.

nanocar nobel
Feringa and colleagues "bolted" four molecular motors that all spin in the same directionto a tiny chassis. That created a “nanocar” that could bump along a surface.
© JOHAN JARNESTAD/THE ROYAL SWEDISH ACADEMY OF SCIENCES

Indeed, when people ask Feringa what his nano-motors might be used for, he says he “feels a bit like the Wright brothers.” Right after their first flight, these airmen would have had a hard time explaining why the world needed a flying machine. Feringa suspects there are “endless opportunities” for making good use of super miniscule motors. They might include nanomachines that seek and destroy tumor cells throughout the body, he says. Or maybe they will deliver drugs to just the cells that need them.

Stoddart applauded the Nobel committee for recognizing “a piece of chemistry that is extremely fundamental in its making and being." Sauvage, in particular, created a new type of molecular bond in order to forge his chain, Stoddart noted during a press conference. “New chemical compounds are probably several thousand a day, worldwide. New chemical reactions, well, maybe a dozen or two a month.” But when it comes to creating new bonds, he noted, “they are few and far between. They are really the blue moons. So I think that’s what’s being recognized, more than anything."

Sauvage, Stoddart and Feringa will receive their awards at a December 10 ceremony in Stockholm. They will share a prize of 8 million Swedish kronor (or about $931,000).

Their award is named for Alfred Nobel. Best known as the inventor of dynamite, he was a wealthy man when he died on December 10, 1896. In his will, Nobel left much of his fortune to create prizes to those who have done their best for humanity in the fields of physics, chemistry, physiology or medicine, literature and peace.

In this animation, a nanocar moves across a metal surface.
Francis Villatoro

Power Words

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asymmetry     (adj. asymmetric) Not symmetrical, such as not the same shape on the left and right sides.

biology     The study of living things. The scientists who study them are known as biologists.

bond     (in chemistry) A semi-permanent attachment between atoms — or groups of atoms — in a molecule. It’s formed by an attractive force between the participating atoms. Once bonded, the atoms will work as a unit. To separate the component atoms, energy must be supplied to the molecule as heat or some other type of radiation.

cell     The smallest structural and functional unit of an organism. Typically too small to see with the naked eye, it consists of watery fluid surrounded by a membrane or wall. Animals are made of anywhere from thousands to trillions of cells, depending on their size. Some organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.

chemical     A substance formed from two or more atoms that unite (become bonded together) in a fixed proportion and structure. For example, water is a chemical made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H2O. Chemical can also be an adjective that describes properties of materials that are the result of various reactions between different compounds.

chemical reaction     A process that involves the rearrangement of the molecules or structure of a substance, as opposed to a change in physical form (as from a solid to a gas).

chemistry     The field of science that deals with the composition, structure and properties of substances and how they interact with one another. Chemists use this knowledge to study unfamiliar substances, to reproduce large quantities of useful substances or to design and create new and useful substances. (about compounds) The term is used to refer to the recipe of a compound, the way it’s produced or some of its properties.

colleague     Someone who works with another; a co-worker or team member.

compound     (often used as a synonym for chemical) A compound is a substance formed from two or more chemical elements united in fixed proportions. For example, water is a compound made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H2O.

dynamite     A type of explosive.

engineer     A person who uses science to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need.

fundamental     Something that is basic or serves as the foundation for another thing or idea.

innovation     (v. to innovate; adj. innovative) An adaptation or improvement to an existing idea, process or product that is new, clever, mo re effective or more practical.

link     A connection between two people or things.

manufacturing     The making of things, usually on a large scale.

molecule     An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).

motor     A device that converts electricity into mechanical motion. Or some system that mimics the actions of a motor.

muscle     A type of tissue used to produce movement by contracting its cells, known as muscle fibers. Muscle is rich in a protein, which is why predatory species seek prey containing lots of this tissue.

nano     A prefix indicating a billionth. In the metric system of measurements, it’s often used as an abbreviation to refer to objects that are a billionth of a meter long or in diameter.

nanotechnology     Science, technology and engineering that deals with things and phenomena at the scale of 100 billionths of a meter or less.

organic     (in chemistry) An adjective that indicates something is carbon-containing; a term that relates to the chemicals that make up living organisms. (in agriculture) Farm products grown without the use of non-natural and potentially toxic chemicals, such as pesticides.

physics     The scientific study of the nature and properties of matter and energy. Classical physics is an explanation of the nature and properties of matter and energy that relies on descriptions such as Newton’s laws of motion. Quantum physics, a field of study which emerged later, is a more accurate way of explaining the motions and behavior of matter. A scientist who works in that field is known as a physicist.

physiology     The branch of biology that deals with the everyday functions of living organisms and how their parts function. Scientists who work in this field are known as physiologists.

tumor     A mass of cells characterized by atypical and often uncontrolled growth. Benign tumors will not spread; they just grow and cause problems if they press against or tighten around healthy tissue. Malignant tumors will ultimately shed cells that can seed the body with new tumors. Malignant tumors are also known as cancers.

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Citation

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Journal:​ N. Koumura et al. Light-driven monodirectional molecular rotor. Nature. Vol. 401, September 9, 1999, p. 152. doi: 10.1038/43646.

Journal:​ B. Odell et al. Cyclobis (paraquat-p-phenylene). A tetracationic multipurpose receptor. Angewandte Chemie International Edition. Vol. 27, November 1988, p. 1547. doi: 10.1002/anie.198815471.

Journal:​ C.O Dietrich-Buchecker, J.P. Sauvage and J.P. Kintzinger. Une nouvelle famille de molecules: les metallo-catenanes. Tetrahedron Letters. doi: 10.1016/S0040-4039(00)94050-4.