Stress reorganisation and response in active solids

TL;DR

This paper introduces a microscopic model of a disordered active solid that combines passive elastic elements with active molecular motors, revealing how their interactions produce a highly responsive material with deformation-dependent mechanical properties.

Contribution

It develops a new microscopic model for active solids that captures the collective behavior of active and passive components and their impact on macroscopic mechanics.

Findings

System exhibits a highly responsive mechanical behavior.

Dynamic response depends strongly on deformation.

Active-passive interactions influence macroscopic properties.

Abstract

We present a microscopic model of a disordered viscoelastic active solid, i.e. an active material whose long time behaviour is elastic as opposed to viscous. It is composed of filaments, passive crosslinks and molecular motors powered by stored chemical energy, e.g. actomyosin powered by ATP. Our model allows us to study the collective behaviour of contractile active elements and how their interaction with each other and the passive elastic elements determines the macroscopic mechanical properties of the active material. As a result of the (un)binding dynamics of the active elements, we find that this system provides a highly responsive material with a dynamic mechanical response strongly dependent on the amount of deformation.