Chemistry Nobel for world's smallest machines

On Wednesday (5.10.2016) in Stockholm the baked goods were back. The Nobel Prize committee seems eager this year to explain complicated scientific facts with every day objects.

It was bagels and pretzels on Tuesday. They used them to demonstrate the concept of topology for which David Thouless, Duncan Haldane and Michael Kosterlitz received the Nobel Prize in Physics.

A day later, they used two interlaced pretzels to symbolize the achievements of this year's Nobel Laureates in Chemistry.

Jean-Pierre Sauvage of the University of Strasbourg, France, Scottish-born Sir Fraser Stoddart of Northwestern University in Evanston, US, and Bernard Feringa of the University of Groningen in the Netherlands were honored "for the design and synthesis of molecular machines."

The three chemists synthesized molecules that move like machines when energy is applied, for example in the form of light. They work just like an electric pump that starts as soon as it is plugged in and switched on.

From pretzels to tiny motors

The research field of molecular machines was born in the 1980s when Jean-Pierre Sauvage synthesized a molecule that looked like two interlaced pretzels. Both molecules were connected to each other like two links in a chain, but they could move freely around one another - the premise for a molecular machine.

Fraser Stoddart then created a kind of "molecular elevator," as Olof Ramström of the Nobel Prize committee put it: two interlaced molecules of which one can jump forwards and backwards - like a switch that is in an off or on position.

Later on, in 1999, Bernard Feringa built the first molecular motor in which two molecules rotate around each other like two motor blades under UV light exposure before returning into their starting position.

"It happens over and over again," says Ramström - "up to 12,000 times per second."

Out of two molecules, Feringa even created a car that moved around in a Petri dish. Its movement could only be seen with microscopes that work at an atomic level, like a scanning tunneling microscope.

Scientists now even hold so-called NanoCar Races in which molecular cars compete against each other.

What is it good for?

Before journalists could ask at the Stockholm announcement, Ramström answered the question on everyone's lips: what's it good for? At the moment, said Ramström, building molecular machines is limited to fundamental science.

But then he added: "It is similar to the development of electrical machinery in the 19th century. Now these machines are everywhere."

Who would have thought in the 1830s that various spinning cranks and wheels would lead to electric trains, washing machines and fans?

"I feel like the Wright brothers who were flying for the first time and people asked: why do we need a flying machine?" said Bernard Feringa.

Even if there are no concrete applications at the moment, researchers have plenty of ideas for how to use these new kinds of molecular systems.

Crazy ideas for the future

"Molecular machines could lead to pharmaceuticals that can be switched on and off by light as to minimize their side effects," says Rainer Herges, chemist at the University of Kiel.

It may also be a step forward into the age of molecular electronics in which electronic components are no longer made out of metal but of organic molecules, making their further miniaturization possible.

"Molecular machines could also offer a way to convert sun light into electricity," Herges says.

This indeed would be a much sought after solution for future energy problems.

Rainer Herges does research on molecular machines himself.

He created a tiny excavator which is able to hold other molecules with its four tentacles and put them down elsewhere when it is exposed to a wavelength of light.

These machines may be able to transport pharmaceuticals or other compounds around the human body.

"We also work on new kinds of MRI contrast agents," Herges tells DW. "They can be switched on and off via light, which would be really handy during surgery of a stroke patient."

"Crazy and brilliant"

Molecular engineer Herges is happy his area of research has been honored with a Nobel Prize. "It shows we are on the right track and that we have seen the potential at an early stage," he says.

Herges describes the laureates as "dedicated and completely focused on their research." But still they "are people you can have a drink with."

Wesley Browne works together with Bernard Feringa at the University of Groningen. "As a scientist, Feringa is crazy," Browne tells DW, laughing. "He never lets the law of thermodynamics or physics get in the way of a good idea."

Johannes Teichert at the Technical University of Berlin, who did his PhD under Feringa adds: "He is very creative. Nine out of 10 of his ideas might be crazy and don't work, but one of them is brilliant."

Micron-sized cars and excavators you can't even see - perhaps you have to be a bit crazy to come up with such ideas.