Buprestidae metamorphosis-inspired stiffening photonic elastomers for shape-color integrated memory and information encryption

Integrating shape memory polymers into the device provides multifunctionality and recyclability. However, complex programming steps and the immutability of material properties hinder their applications. Here, inspired by the Buprestidae sclerotization process, linear long side chains are introduced into chiral liquid crystal elastomers (CLCEs), a class of polymeric photonic crystals, enhancing the phase transition tendency of the system. Through microphase separation between the more ordered structure (smectic and crystalline phases) and the primary chiral nematic (N*) phase, self-enhancement of the material is achieved at room temperature while retaining the selective reflection of the N* phase. Within 48 hours, the Young’s modulus increases by 1854%, and the strain energy density in the 0–100% strain range increases by 1533%. This induces a shape-color integrated memory effect which can be fully restored upon heating. Cyclic utilization of a single CLCE film is demonstrated through programming, achieving the memory of colorful shapes and high-fidelity textures. Furthermore, local regulation of microphase separation enables encrypted information writing and recycling. Programmable shape memory polymers are of interest for smart materials, meanwhile the integration of shape and color enriches the applications. Here the authors use chiral liquid crystal elastomers affording a shape and color changing material, with dynamic mechanical properties.