Optical manipulation of shape-morphing elastomeric liquid crystal microparticles doped with gold nanocrystals

TL;DR

This paper presents a method for optically controlling the shape of liquid crystal elastomer microparticles doped with gold nanocrystals, enabling reversible and irreversible shape changes for advanced applications.

Contribution

It introduces a novel approach combining photothermal heating and liquid crystal elastomers for precise, reversible shape manipulation of colloidal particles.

Findings

Efficient localized heat transfer via gold nanocrystals enables shape control.

Reversible and irreversible shape transformations demonstrated.

Potential applications in optomechanics and microfluidics.

Abstract

We demonstrate facile optical manipulation of shape of birefringent colloidal microparticles made from liquid crystal elastomers. Using soft lithography and polymerization, we fabricate elastomeric microcylinders with weakly undulating director oriented on average along their long axes. These particles are infiltrated with gold nanospheres acting as heat transducers that allow for an efficient localized transfer of heat from a focused infrared laser beam to a submicrometer region within a microparticle. Photothermal control of ordering in the liquid crystal elastomer using scanned beams allows for a robust control of colloidal particles, enabling both reversible and irreversible changes of shape. Possible applications include optomechanics, microfluidics, and reconfigurable colloidal composites with shape-dependent self-assembly.