Scientists make electric motor from single molecule

Scientists have created the smallest electric motor ever: one made from a single molecule.

A paper on the breakthrough was published online Sunday by the journal Nature Nanotechnology.

One of the paper's authors, Tufts University associate professor Charles Sykes, told MSNBC that molecular motors could lead to new types of electrical circuitry. While scientists in the past have created molecular motors powered by light or chemical reactions, up until now no one has been able to control nanometer-sized motors one at a time.

"People have found before that they can make motors driven by light or by chemical reactions, but the issue there is that you're driving billions of them at a time – every single motor in your beaker," Sykes told the BBC. "The exciting thing about the electrical one is that we can excite and watch the motion of just one, and we can see how that thing's behaving in real time."

According to the BBC, the motor was created by putting a molecule of butyl methyl sulphide on a clean copper surface, where a single sulfur atom in the molecule could act as a pivot. A scanning tunnelling microscope, with a tip just one or two atoms wide, was then used to send electricity to the motor, as well as take pictures of it as it spun.

By modifying the molecule slightly, it could be used to generate microwave radiation or to couple into what are known as nano-electromechanical systems, Dr Sykes said.

"The next thing to do is to get the thing to do work that we can measure – to couple it to other molecules, lining them up next to one another so they're like miniature cog-wheels, and then watch the rotation propagation down the chain," he said.

But the technology still has a ways to go, Sykes told MSNBC. The experiment was conducted at 5 degrees Kelvin (a chilly -450 degrees Fahrenheit) so that the molecule would stay frozen in place when no current was applied. Getting the technology to the point where it works in real-world temperatures could take a few decades, Sykes said.

"There is nothing fundamentally preventing us from designing a different surface and a different molecule to make those energy barriers much higher so you could have some that turn on and off at room temperature, for example," he said.

In the meantime, Sykes and his colleagues have reached out to the Guinness Book of World Records, the BBC reports.