Molecular Dynamics of a Nanomotor Based on Carbon Nanotubes

A capsule-like carbon nanotube bearing two electric charges was enclosed in a larger one with an open end and the assembly embedded in liquid Ar. Entering through the open end, Ar atoms surrounded the inner capsule and underwent the liquid-gas transition when the capsule was rotated by superimposing an electric field. The expansion of gaseous Ar outside the outer capsule produced the displacement of the whole assembly. The diffusion of Ar atoms inside the assembly in the absence of an electric field and their successive expansion outside occur reversibly, and the whole operation cycle can be repeated.