Molecular dynamics modelling of an electrical-driven linear nanopump

The dynamics of an electrical-driven linear nanopump, consisting of a carbon nanotube, a C60⁺ molecule and a graphene sheet, has been simulated via the application of the molecular dynamics method. In this nanopump, the nanotube and the graphene sheet are used as the sleeve of the pump and the boundary between the two sides of the nanopump, respectively. By exposing the nanopump to an external alternative electric field, the C60⁺ molecule will be oscillating linearly in the nanotube. We found that the linear oscillating motion of the C60⁺ molecule causes the gas atoms to flow through the nanotube, and a density gradient is generated between the two sides of the nanopump. Also, it was observed that the frequency of the external alternative electric field affected the pump performance in the generation of the density gradient amount. The maximum performance occurred at a specific frequency of the electric field. This specific frequency can be computed by an analytical formula for given materials and temperatures. Moreover, the results indicate that the length of the nanotube can affect the gas pumping.