Invitation to submit manuscript to Festschrift for Juan de Pablo in honour of his 60th Birthday: Curved Confinement Directs Anchoring-Mediated Structural Transitions in Highly Chiral Liquid Crystal Shells

Abstract

Cholesteric liquid crystals (CLCs) confined in curved geometries exhibit a rich spectrum of defect-mediated morphologies governed by the interplay between chirality, curvature, surface anchoring, and confinement. This study systematically investigates structural transitions in highly chiral CLC shells under asymmetric anchoring conditions, focusing on the effects of shell thickness and curvature on pitch axis reorientation and defect formation. Utilizing microfluidic techniques, we generate core-shell droplets with independently tunable anchoring at inner and outer aqueous interfaces. Transitioning from planar-planar to planar-homeotropic boundary conditions via surfactant-mediated modulation induces profound reorganizations in the director field, giving rise to focal conic domains (FCDs), stripe patterns, and hybrid textures. Optical microscopy reveals that thicker shells favor coherent FCD nucleation, while thinner shells exhibit asymmetric, fragmented domains due to increased spatial frustration and constrained elastic relaxation. In small-diameter shells, high curvature suppresses defect nucleation, promoting the emergence of periodic stripe textures as an energetically favorable alternative. Complementary continuum simulations based on the Landau–de Gennes framework reproduce experimental trends, highlighting anchoring energy thresholds that delineate morphological regimes and confirm the dominance of curvature in stabilizing non-defect-based modulations. The ability to engineer defect architectures and direct pitch axis orientation via geometrical and boundary condition control can open new avenues for designing responsive and reconfigurable optical materials and photonic elements.