  Nano-scale confinement of polymer in cone-shaped geometries occurs in many
experimental situations. A flexible polymer confined in a cone-shaped
nano-channel is studied theoretically and using molecular dynamics simulations.
Distribution of the monomers inside the channel, configuration of the confined
polymer, entropic force acting on the polymer, and their dependence on the
channel and the polymer parameters are investigated. The theory and the
simulation results are in very good agreement. The entropic force on the
polymer that results from the asymmetric shape of the channel is measured in
the simulations and its magnitude is found to be significant relative to
thermal energy. The obtained dependence of the force on the channel parameters
may be useful in the design of cone-shaped nano-channels.
