Elastomeric Nematic Colloids, Colloidal Crystals and Microstructures with Complex Topology

TL;DR

This paper demonstrates the fabrication of elastomeric nematic colloids with complex topology that can change shape and symmetry in response to stimuli, enabling tunable colloidal crystals for advanced applications.

Contribution

It introduces a novel method to create elastomeric nematic colloids with switchable topology and symmetry, expanding control over soft matter behaviors.

Findings

Elastomeric microstructures can switch from genus-one to genus-zero topology with heat.

Colloidal crystals exhibit symmetry transformations under external stimuli.

The approach enables responsive colloidal systems for fundamental and applied research.

Abstract

Control of physical behaviors of nematic colloids and colloidal crystals has been demonstrated by tuning particle shape, topology, chirality and surface charging. However, the capability of altering physical behaviors of such soft matter systems by changing particle shape and the ensuing responses to external stimuli has remained elusive. We fabricated genus-one nematic elastomeric colloidal ring-shaped particles and various microstructures using two-photon photopolymerization. Nematic ordering within both the nano-printed particle and the surrounding medium leads to anisotropic responses and actuation when heated. With the thermal control, elastomeric microstructures are capable of changing from genus-one to genus-zero surface topology. Using these particles as building blocks, we investigated elastomeric colloidal crystals immersed within a liquid crystal fluid, which exhibit crystallographic symmetry transformations. Our findings may lead to colloidal crystals responsive to a large variety of external stimuli, including electric fields and light. Pre-designed response of elastomeric nematic colloids, including changes of colloidal surface topology and lattice symmetry, are of interest for both fundamental research and applications.