C60 molecular bearings.

An ultralubricated system is reported which confines a C60 monolayer between graphite plates. C60 molecules act as molecular bearings, assisted by the nanogears of six-membered carbon rings between C60 molecules and graphite, in which the mean dynamical frictional forces are zero up to a high load of 100 nanonewtons. A stick-slip rolling model with a step rotation of a C60 molecule is proposed. This ultralubricated system, very promising for the realization of nano- and micromachines, is expected to open a new field of molecular bearings.