Active shape-morphing elastomeric colloids in short-pitch cholesteric liquid crystals

TL;DR

This paper demonstrates how active elastomeric liquid crystal particles can be dynamically morphed and controlled using light-induced heating mediated by gold nanocrystals, enabling shape control and locomotion in cholesteric liquid crystal hosts.

Contribution

It introduces a method to create and control shape-morphing elastomeric colloids in cholesteric liquid crystals using magnetic fields and light, bridging liquid crystal solids and active colloids.

Findings

Particles can be dynamically morphed and stabilized in desired shapes.

Shape changes induce realignment and transformation of director structures.

Nonreciprocal shape morphing enables particle locomotion.

Abstract

Active elastomeric liquid crystal particles with initial cylindrical shapes are obtained by means of soft lithography and polymerization in a strong magnetic field. Gold nanocrystals infiltrated into these particles mediate energy transfer from laser light to heat, so that the inherent coupling between the temperature-dependent order and shape allows for dynamic morphing of these particles and well-controlled stable shapes. Continuous changes of particle shapes are followed by their spontaneous realignment and transformations of director structures in the surrounding cholesteric host, as well as locomotion in the case of a nonreciprocal shape morphing. These findings bridge the fields of liquid crystal solids and active colloids, may enable shape-controlled self-assembly of adaptive composites and light-driven micromachines, and can be understood by employing simple symmetry considerations along with electrostatic analogies.