Generic phases of cross-linked active gels: Relaxation, Oscillation and Contractility

TL;DR

This paper analyzes a continuum model of active gels, revealing how increasing motor activity induces transitions from a homogeneous state to oscillations and spontaneous contraction.

Contribution

It provides a unified analytical and numerical framework to understand the dynamical phases of active gels driven by internal stresses.

Findings

Identification of three dynamical states: unstrained, oscillatory, and contracted.

Demonstration of tuning between states via motor activity levels.

Insight into the mechanisms underlying active gel behavior.

Abstract

We study analytically and numerically a generic continuum model of an isotropic active solid with internal stresses generated by non-equilibrium `active' mechano-chemical reactions. Our analysis shows that the gel can be tuned through three classes of dynamical states by increasing motor activity: a constant unstrained state of homogeneous density, a state where the local density exhibits sustained oscillations, and a steady-state which is spontaneously contracted, with a uniform mean density.