Complex Spontaneous Flows and Concentration Banding in Active Polar Films

TL;DR

This paper investigates the unique dynamical behaviors of active polar liquid crystalline films, revealing spontaneous flow, concentration banding, and oscillations, with complexity increasing under strong polarity, advancing understanding of active matter systems.

Contribution

It uncovers the distinct flow and banding phenomena in active polar films, including spontaneous oscillations at low activity and increased complexity with stronger polarity.

Findings

Active polar films exhibit spontaneous flow and concentration banding.

They can generate oscillating flows even at low activity levels.

Flow complexity increases with stronger polarity.

Abstract

We study the dynamical properties of active polar liquid crystalline films. Like active nematic films, active polar films undergo a dynamical transitions to spontaneously flowing steady-states. Spontaneous flow in polar fluids is, however, always accompanied by strong concentration inhomogeneities or "banding" not seen in nematics. In addition, a spectacular property unique to polar active films is their ability to generate spontaneously oscillating and banded flows even at low activity. The oscillatory flows become increasingly complicated for strong polarity.