Nonlinear elasticity of composite networks of stiff biopolymers with flexible linkers

TL;DR

This paper develops an effective medium theory to describe the nonlinear elastic behavior of composite networks of stiff biopolymers with flexible linkers, aligning well with experimental observations.

Contribution

It introduces a novel effective medium model capturing the nonlinear elasticity of biopolymer networks with flexible cross-linkers, bridging theory and experiment.

Findings

Model predicts a crossover from linear to nonlinear stiffening.

Quantitative agreement with experimental data.

Provides insights into biopolymer network mechanics.

Abstract

Motivated by recent experiments showing nonlinear elasticity of in vitro networks of the biopolymer actin cross-linked with filamin, we present an effective medium theory of flexibly cross-linked stiff polymer networks. We model such networks by randomly oriented elastic rods connected by flexible connectors to a surrounding elastic continuum, which self-consistently represents the behavior of the rest of the network. This model yields a crossover from a linear elastic regime to a highly nonlinear elastic regime that stiffens in a way quantitatively consistent with experiment.