Elastocapillary driven assembly of particles at free-standing smectic-A films

TL;DR

This paper investigates how microparticles assemble within free-standing smectic-A liquid crystal films, revealing new patterns driven by competing elastic and capillary forces, and highlighting potential for reconfigurable material design.

Contribution

It introduces the study of particle assembly in smectic-A films where elasticity and capillarity compete, leading to novel, reconfigurable colloidal structures.

Findings

Discovery of new 1D and 2D colloidal patterns

Assembly sensitive to initial wetting conditions

Potential for optically active, reconfigurable materials

Abstract

Colloidal particles at complex fluid interfaces and within films assemble to form ordered structures with high degrees of symmetry via interactions that include capillarity, elasticity, and other fields like electrostatic charge. Here we study microparticle interactions within free-standing smectic-A films, in which the elasticity arising from the director field distortion and capillary interactions arising from interface deformation compete to direct the assembly of motile particles. New colloidal assemblies and patterns, ranging from 1D chains to 2D aggregates, sensitive to the initial wetting conditions of particles at the smectic film, are reported. This work paves the way to exploiting LC interfaces as a means to direct spontaneously formed, reconfigurable, and optically active materials.