Rheology of Active-Particle Suspensions

TL;DR

This paper develops a hydrodynamic model to understand how activity, order, and flow interact in suspensions of active particles, predicting rheological behaviors relevant to biological and artificial systems.

Contribution

It introduces a set of coarse-grained equations capturing the complex rheology of active-particle suspensions, linking phenomena like cytoplasmic streaming to active matter physics.

Findings

Predictions for rheological behavior in bacterial suspensions and cell extracts.

Explanation of cytoplasmic streaming and mechanosensing phenomena.

Potential tests on artificial active machines.

Abstract

We study the interplay of activity, order and flow through a set of coarse-grained equations governing the hydrodynamic velocity, concentration and stress fields in a suspension of active, energy-dissipating particles. We make several predictions for the rheology of such systems, which can be tested on bacterial suspensions, cell extracts with motors and filaments, or artificial machines in a fluid. The phenomena of cytoplasmic streaming, elastotaxis and active mechanosensing find natural explanations within our model.