Confined Cubic Blue Phases under Shear

TL;DR

This study uses lattice Boltzmann simulations to explore how confined cubic blue phases respond to shear flow, revealing distinct behaviors for blue phase I and II, including oscillatory stress and chaotic defect rearrangements.

Contribution

It provides new insights into the shear-induced dynamics of confined blue phases, highlighting differences between blue phase I and II under flow conditions.

Findings

Blue phase II exhibits oscillatory stress due to network breaking and reforming.

Thick samples show 'stick-slip' motion of the defect network under shear.

Blue phase I displays chaotic defect rearrangements regardless of system size.

Abstract

We study the behaviour of confined cubic blue phases under shear flow via lattice Boltzmann simulations. We focus on the two experimentally observed phases, blue phase I and blue phase II. The disinclination network of blue phase II continuously breaks and reforms under shear, leading to an oscillatory stress response in time. The oscillations are only regular for very thin samples. For thicker samples, the shear leads to a "stick-slip" motion of part of the network along the vorticity direction. Blue phase I responds very differently: its defect network undergoes seemingly chaotic rearrangements under shear, irrespective of system size.