The mechanical response of semiflexible networks to localized perturbations

TL;DR

This paper investigates how semiflexible polymer networks respond to localized forces, revealing that a known nonaffinity length scale governs the transition from non-uniform to uniform elastic deformation regimes.

Contribution

It extends previous studies by demonstrating that the nonaffinity length scale controls the mesoscopic response to localized forces and the crossover to continuum elasticity.

Findings

Nonaffinity length scale governs response to point forces.

Crossover from non-affine to affine deformation is characterized.

Mesoscopic response aligns with continuum elastic behavior at large distances.

Abstract

Previous research on semiflexible polymers including cytoskeletal networks in cells has suggested the existence of distinct regimes of elastic response, in which the strain field is either uniform (affine) or non-uniform (non-affine) under external stress. Associated with these regimes, it has been further suggested that a new fundamental length scale emerges, which characterizes the scale for the crossover from non-affine to affine deformations. Here, we extend these studies by probing the response to localized forces and force dipoles. We show that the previously identified nonaffinity length [D.A. Head et al. PRE 68, 061907 (2003).] controls the mesoscopic response to point forces and the crossover to continuum elastic behavior at large distances.