Polymer translocation into a confined space: Influence of the chain stiffness and the shape of the confinement

Abstract

Using two-dimensional Langevin dynamics simulations, we investigate the dynamics of polymer translocation into a confined space under a driving force through a nanopore, with particular emphasis on the chain stiffness and the shape of the confinement. We observe that with increasing the chain stiffness κ, the translocation time τ always increases for different shapes of confinements. For an ellipse, τ is different for the translocation through its minor and major axis directions. Under the weak confinement, the translocation through the minor axis direction is faster than that through the major axis direction for different κ, while this is true only for high κ under strong confinement. Particularly, for both weak and strong confinements we find that packaging into an ellipse through its minor axis direction is faster than that for a circle of the same area for high κ. These results are interpreted by the chain conformation during the translocation process and the time of an individual segment passing through the pore.