Dual‐Amide Engineered Blue Phase Liquid Crystal Elastomers: Synergistic Fatigue Resistance, Programmable Mechanochromics and Spatiotemporally Encrypted Photonics

Blue phase liquid crystal elastomers (BPLCEs) hold significant promise for flexible photonic devices due to their 3D periodic photonic lattices and intrinsic soft-matter characteristics. However, achieving an optimal balance between mechanical resilience and dynamic responsiveness remains a critical challenge. This study introduces a dynamic hydrogen-bonding network design strategy, wherein N,N'-bisacryloylcystamine monomers are incorporated to construct a hierarchical energy dissipation system, yielding BPLCEs with remarkable toughness (1.72 MJ m^- ³) and ultralow hysteresis (4.8%). By integrating thermally induced topological bond rearrangement, programmable mechanical gradient films are developed to enable high-precision strain-induced patterning and an adaptive encryption mechanism governed by a "relaxation-concealment/stretching-development" paradigm. Furthermore, leveraging the spatiotemporal gating properties of embedded phosphorescent materials, a dual-mode dynamic verification system is established, facilitating multidimensional information decryption via ultraviolet-triggered rapid visualization and controlled afterglow decay lasting up to 5 s. This study not only mitigates the inherent trade-off between mechanical durability and stimulus responsiveness in soft photonic crystals but also establishes a novel framework for multidimensional synergistic regulation across mechanical, optical, and temporal domains. These findings provide a transformative strategy for advancing next-generation dynamic encryption systems, intelligent sensing technologies, and adaptive photonic displays, paving the way for innovative applications in flexible photonic devices.