title: Flow-induced helical coiling of semiflexible polymers in structured microchannels.
abstract: The conformations of semiflexible (bio)polymers are studied in flow-through geometrically structured microchannels. Using mesoscale hydrodynamics simulations, we show that the polymer undergoes a rod-to-helix transition as it moves from the narrow high-velocity region into the wide low-velocity region of the channel. The transient helix formation is the result of a nonequilibrium and nonstationary buckling transition of the semiflexible polymer, which is subjected to a compressive force originating from the fluid-velocity variation in the channel. The helix properties depend on the diameter ratio of the channel, the polymer bending rigidity, and the flow strength.
authors.affiliation: Theoretical Soft Matter and Biophysics, Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: Raghunath
authors.initials: R
authors.lastname: Chelakkot
authors.forename: Roland G
authors.initials: RG
authors.lastname: Winkler
authors.forename: Gerhard
authors.initials: G
authors.lastname: Gompper