Thermal and optical manipulation of morphology in cholesteric liquid crystal microdroplets constrained on microfibers

Liquid crystals (LCs) are distinctive materials that are applicable to a wide range of disciplines, such as continuum mechanics, optics of anisotropic media, statistical physics, and crystallography. The diverse structures and eye-catching topological defects of LCs in confined geometries are affected by nematic elasticity, chirality, and surface anchoring. Herein, we report the formation and detailed configuration of cholesteric LC (CLC) microdroplets with different pitches pierced by electrospun poly(methylmethacrylate) microfibers. Two kinds of surface anchoring, namely, homeotropic anchoring at the air-CLC droplet interface and planar anchoring at the fiber-CLC droplet interface, coexist in this system. By controlling temperature and light irradiation, the system exhibits thermal- and photo-dependent LC morphological and topological evolutions. The observed structures are complemented by numerical simulations of possible director fields decorated by defects. The externally controllable CLC necklaces constitute extraordinary systems for exploring the morphology and topological defects and open a route for applications in topological remote control, nanoscience, biomedical research, and the development of devices based on topologically structured soft media. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Liquid crystals are distinctive materials applicable to various disciplines, with diverse structures and topological defects affected by factors such as nematic elasticity and surface anchoring. This study investigates the interaction between cholesteric LC microdroplets and microfibers, revealing different surface anchoring modes and morphological evolution under temperature and light control. The externally controllable LC structures open up possibilities for applications in fields such as topological remote control, nanoscience, and biomedical research.