Kudernac et al. described a specially designed molecule that has four motorized "wheels". By depositing the molecule on a copper surface and providing them with sufficient energy from electrons of a scanning tunnelling microscope they were able to drive some of the molecules in a specific direction, much like a car, being the first single molecule capable to continue moving in the same direction across a surface. Inelastic electron tunnelling induces conformational changes in the rotors and propels the molecule across a copper surface. By changing the direction of the rotary motion of individual motor units, the self-propelling molecular four-wheeler structure can follow random or preferentially linear trajectories. This design provides a starting point for the exploration of more sophisticated molecular mechanical systems, perhaps with complete control over their direction of motion.
This electrically driven nanocar was built under supervision of University of Groningen chemist Bernard L. Feringa, who was awarded the Nobel Prize for Chemistry in 2016 for his pioneering work on nanomotors, together with Jean-Pierre Sauvage and J. Fraser Stoddart.