Nano researchers make world's smallest car

Nov 21, 2011, 13:30 GMT

London - The world's smallest car is made of just one molecule and measures around one nanometre - a billionth of a metre - in length.

Ben Feringa of Groningen University in the Netherlands reports on his research in the latest issue of the British scientific journal Nature, describing how the tiny vehicle is electrically powered. His electric nano car even has four-wheel drive.

The nano car is not the first externally powered molecule, but it is the first that uses its own power to move in a directed way across a surface, according to the researchers. They regard their design as a step towards developing nano machines capable in the future of carrying out work at the molecular level.

To make their electric nano car, Feringa and his co-researchers mounted four previously developed molecular motors onto a central beam. Each of the molecular motors then becomes a drive wheel. The team has yet to find a way of reliably producing cars in which all the drive 'wheels' travel in the same direction. Currently they have to select by trial and error those nano cars that do actually move forwards.

Electricity is provided by means of a scanning tunnelling microscope which transmits current through its extremely fine point to get the molecular car moving. A brief pulse of half a volt changes the configuration of the molecular motors, and provided they all move in the same direction, the nano car moves forward around 0.7 of a nanometre.

The team got its molecular four-wheel drive to move around six nanometres across a copper surface with the aid of 10 pulses. The car drove forward in an almost perfect straight line.