Self‐Assembled 3D Blue Phase Liquid Crystals for Intelligent Photonic Crystals and Functional Devices

Abstract Liquid crystal (LC) materials, with their supramolecular self‐assembly nanostructures and stimulus‐responsive properties, offer inherent advantages in the development of advanced intelligent functional materials. Among various LC phase, blue phase liquid crystals (BPs) are regarded as promising candidates for intelligent photonic crystals due to their unique 3D periodic nanostructures and the capability to selectively reflect circularly polarized light within the visible spectrum. Over the past decades, various methodologies are developed to synthesize BP materials with superior thermal stability, high‐quality optical properties and excellent stimulus‐responsibility, yielding significant research outcomes in the design and application of visual functional devices. Herein, this review summarizes the recent advancements in BPLCs. It comprehensively covers the structural characteristics and preparation methods of BP photonic crystals, detailing significant research findings in their optical, electrical, mechanical, and humidity‐responsive properties, as well as their pivotal applications in sensors, optical devices, stimulus response, and anti‐counterfeiting devices. Finally, the challenges and prospective development directions of this novel soft matter intelligent material are discussed. It is anticipated that this review will provide valuable insights for scientists and engineers in interdisciplinary fields, including materials science, photonics, chemistry, and physics, facilitating the fabrication of advanced functional soft materials.