An ultralubricated system is reported which confines a ${\mathrm{C}}_{60}$ monolayer between graphite plates. ${\mathrm{C}}_{60}$ molecules act as molecular bearings, assisted by the nanogears of six-membered carbon rings between ${\mathrm{C}}_{60}$ 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 ${\mathrm{C}}_{60}$ 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.

• Received 30 June 2002

DOI:https://doi.org/10.1103/PhysRevLett.90.055509