Electric motor made from a single molecule

The minuscule motor could have applications in both nanotechnology and in medicine, where tiny amounts of work can be put to efficient use.

Tiny rotors based on single molecules have been shown before, but this is the first that can be individually driven by an electric current.

"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," said Charles Sykes, a chemist at Tufts University in Massachusetts, US.

"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," he told BBC News.