Published in Physics World, 9 Nov 2011
A “four-wheel drive car” less than one billionth the length of an average SUV has been built and operated by researchers in the Netherlands and Switzerland. The molecular machine is about 1 nm long and uses electrons as fuel as it navigates across a copper surface. The tiny device could find use in nanometre-sized robotics or as tiny transporters that shift molecules around.
Molecular machines are common in nature. Motor proteins, for example, can move along a surface to transport molecular-sized cargo and are often used to build structures within living cells. Scientists would like to make their own versions of motor proteins, and indeed they have already designed and demonstrated single molecules that can move across surfaces. But these have been mostly passive: to ensure that they travel in a certain direction, they have had to be pulled or pushed. […]
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