Since their widely reported invention, the development of fullerene-wheeled nanocars hasn't stood still. 

In 2005, James Tour and colleagues at Rice University, Texas, US, made headlines when they reported nanocars with fullerenes for wheels and a chassis of fused aromatic rings.¹ The vehicles, three nanometres in size, rolled across gold surfaces observed by scanning tunnelling microscopy. 

Tour made a quintillion (a billion times a billion) vehicles in a single experiment, or as he put it, 'more nanocars than the number of automobiles made in the history of the world.' The cars were powered by externally-applied electric fields.

Now Tour and colleagues have reviewed their recent progress in making a range of nanovehicles.² In one advance, nanocars with light-activated motors move a paddlewheel structure against the surface propelling the vehicle along. And the wheels have changed too: fullerenes have been replaced by carboranes (polyhedral clusters of boron and carbon atoms), which are easier to fit, work better on motorized vehicles and can be modified more effectively. 

Ray Baughman at the University of Texas, Dallas, US, said that Tour's team has made a host of seminal advances that are inspiring a legion of nanotechnologists to build upon them. 'Who would have believed, before this work, that wheel-based vehicles could be made that are a hundred quadrillion times lighter than your car,' said Baughman.  

Michael Smith