Reversal in Thermally Driven Rotation of Chiral Liquid Crystal Droplets

TL;DR

This paper demonstrates that the rotational direction of chiral liquid crystal droplets can reverse depending on size and temperature, revealing complex thermomechanical coupling influenced by molecular order.

Contribution

It uncovers size- and temperature-dependent reversal of droplet rotation in chiral liquid crystals, highlighting the role of molecular order in thermomechanical behavior.

Findings

Rotation reversal depends on droplet size and temperature

Thermomechanical coupling varies with molecular order

Reversal occurs even under fixed temperature gradient

Abstract

For chiral liquid crystals that express topologically protected defects and thermally driven mechanical rotation, the size- and temperature-driven reversal of the rotational direction of their droplets was demonstrated even under a fixed temperature gradient. This unconventional reversal indicates the dependence of thermomechanical coupling on the molecular orientational order, this dependence is justified through an examination of the size, temperature, and molecular structure as well as by phenomenological arguments on the order parameter.