Nematic ordering in active fluids driven by substrate deformations: Mechanisms and patterning regimes

TL;DR

This study demonstrates that substrate deformations can induce long-range nematic order in active fluids, revealing a mechanism where environmental mechanical feedback reorganizes active matter dynamics and pattern formation.

Contribution

The paper introduces a model showing how substrate deformations can trigger nematic ordering in active fluids, a novel mechanism for environmental control of active matter behavior.

Findings

Contractile active nematics become ordered on deformable substrates.

Patterning regimes depend on active stresses and substrate mechanics.

Environmental feedback can induce nematic order in otherwise disordered systems.

Abstract

The interplay between active matter and its environment is central to understanding emergent behavior in biological and synthetic systems. Here, we show that coupling active nematic flows to small-amplitude deformations of a compliant substrate can fundamentally reorganize the system's dynamics. Using a model that combines active nematohydrodynamics with substrate mechanics, we find that contractile active nematics-normally disordered in flat geometries-undergo a sharp transition to long-range orientational order when the environment is deformable. This environmentally induced ordering is robust and enables distinct patterning regimes, with wrinkle morphologies reflecting the nature of the active stresses. Our results reveal a generic mechanism by which mechanical feedback from soft environments can lead to ordering in active systems.