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This work reveals the intricate interplay between curvature, shell thickness, and anchoring asymmetry in governing structural transitions, dynamic behavior, and defect morphologies in highly chiral cholesteric liquid crystal shells. 

Blue phase (BP) liquid crystals represent a fascinating state of soft matter that showcases unique optical and electro-optical properties. Existing between chiral nematic and isotropic phases, BPs are characterized by a three-dimensional cubic lattice structure resulting in selective Bragg reflections of light and consequent vivid structural colors. However, the practical realization of these material systems is hampered by their narrow thermal stability and multi-domain crystalline nature. This feature article provides an overview of the efforts devoted to stabilizing these phases and creating monodomain structures. In particular, it delves into the complex relationship between geometrical confinement, induced curvature, and the structural stability and photonic features of BPs. Understanding the interaction of curved confinement and structural stability of BPs proves crucially important for the integration of these materials into flexible and miniaturized devices. By shedding light on these critical aspects, this feature review aims to highlight the significance of understanding the coupling effects of physical and mechanical forces on the structural stability of these systems, which can pave the way for the development of efficient and practical devices based on BP liquid crystals. 

Abstract Blue phases (BPs), formed through the self‐assembly of chiral liquid crystal molecules into 3D nanolattices with cubic symmetries, exhibit dynamic photonic bandgaps in the visible spectrum, offering transformative opportunities for advanced optical circuits, sensing and communication technologies. However, their thermal stability is restricted to a narrow temperature range (0.5–1.0 K), limiting practical applications. Polymer stabilization of bulk BPs has extended thermal stability but often compromises the dynamic behavior essential for fast‐response functionalities. Here, experimental and computational approaches are integrated to investigate the effect of curvature and interfacial interactions on BP polymer stabilization. It is demonstrated that photo‐polymerization of reactive monomers within BP microdroplets produces polymer shells, a few hundred nanometers thick, featuring BPs disclination network nano‐architecture. This nano‐architected shell provides surface topology and anchoring conditions to direct BP nucleation and growth, with the degree of curvature dictating the stabilized BP lattice structure within microdroplets. Remarkably, while enhancing thermal stability across a broad temperature range, this polymer shell enables reconfigurable crystal‐to‐crystal transformations in stabilized BP droplets. This work introduces a novel approach to tailoring BP properties by leveraging curvature, confinement, and interfacial interactions to create thermally stable, reconfigurable photonic crystals, paving the way for adaptive sensors and next‐generation fast‐response optical devices.