Pattern formation in odd viscoelastic fluids

TL;DR

This paper investigates how odd viscoelasticity, a property of active matter with broken symmetries, leads to pattern formation such as oscillating vortices, with implications for biological and synthetic systems.

Contribution

It provides an analytical and simulation-based study of pattern-forming instabilities in odd viscoelastic fluids, revealing key features governing vortex dynamics.

Findings

Identification of a vortex pattern-forming instability

Analytical expressions for growth rate, wavelength, and saturation

Potential applications in biological patterning and soft active matter engineering

Abstract

Non-reciprocal interactions fueled by local energy consumption can be found in biological and synthetic active matter at scales where viscoelastic forces are important. Such systems can be described by "odd" viscoelasticity, which assumes fewer material symmetries than traditional theories. Here we study odd viscoelasticity analytically and using lattice Boltzmann simulations. We identify a pattern-forming instability which produces an oscillating array of fluid vortices, and we elucidate which features govern the growth rate, wavelength, and saturation of the vortices. Our observation of pattern formation through odd mechanical response can inform models of biological patterning and guide engineering of odd dynamics in soft active matter systems.