# Morphology and flow patterns in highly asymmetric active emulsions

## TL;DR

This study uses numerical simulations to explore how activity influences the morphology and dynamics of highly asymmetric active emulsions, revealing transitions from ordered droplets to complex patterns depending on activity type and level.

## Contribution

It introduces a hybrid lattice Boltzmann simulation to analyze the effects of activity on highly asymmetric active emulsions, highlighting new morphological transitions and defect dynamics.

## Key findings

- Activity reduces defects in extensile emulsions at low levels.
- High activity induces aster-like rotating droplets in extensile systems.
- Contractile activity leads to elongated structures at high levels.

## Abstract

We investigate numerically, by a hybrid lattice Boltzmann method, the morphology and the dynamics of an emulsion made of a polar active gel, contractile or extensile, and an isotropic passive fluid. We focus on the case of a highly off-symmetric ratio between the active and passive components. In absence of any activity we observe an hexatic-ordered droplets phase, with some defects in the layout. We study how the morphology of the system is affected by activity both in the contractile and extensile case. In the extensile case a small amount of activity favors the elimination of defects in the array of droplets, while at higher activities, first aster-like rotating droplets appear, and then a disordered pattern occurs. In the contractile case, at sufficiently high values of activity, elongated structures are formed. Energy and enstrophy behavior mark the transitions between the different regimes.