Nanotribology at carbon interface formed by graphene and fullerenes

Abstract

Searching for low friction conditions for moving a microscopic machine is an indispensable requirement for solving the energy saving problem. In order to approach this problem from the viewpoint of nanotechnology, nanoscale friction of the carbon interface formed by graphene and fullerenes is studied by using frictional force microscopy measurement and molecular mechanics simulation. The effects of the loading force, scanning direction, molecular orientation angle, and intercalated fullerene species on nano-scale friction appeared at fullerene/graphene interface (fullerene molecular bearings) and graphene/graphene interface will be discussed. For example, utilization of the loading force for C₆₀ molecular bearing is expected to lead to the development of the device to control the ON-OFF of the superlubric state. The anisotropy of nano-scale friction is explained based on the theory of superlubricity. The friction force is maximized for the commensurate contact of the honeycomb lattice at the interface, although the friction force rapidly decreases due to the increase of the lattice mismatch.