Transient behaviour of a polymer dragged through a viscoelastic medium

TL;DR

This paper models the dynamics of a polymer pulled through a viscoelastic medium, revealing subballistic motion and providing insights into tension propagation and polymer shape evolution.

Contribution

It introduces a Rouse model with memory-dependent drag to analyze polymer behavior in viscoelastic environments, a novel approach for such systems.

Findings

Center of mass exhibits subballistic motion

Polymer length and shape evolve over time

Tension propagates through the polymer in a specific manner

Abstract

We study the dynamics of a polymer that is pulled by a constant force through a viscoelastic medium. This is a model for a polymer being pulled through a cell by an external force, or for an active biopolymer moving due to a self generated force. Using a Rouse model with a memory dependent drag force, we find that the center of mass of the polymer follows a subballistic motion. We determine the time evolution of the length and the shape of the polymer. Through an analysis of the velocity of the monomers, we investigate how the tension propagates through the polymer. We discuss how polymers can be used as a probe of the properties of a viscoelastic medium.