Irreversible Mechanochromic Imprinting in Cholesteric Liquid Crystal Elastomers via Plasticity‐Mediated Strain Transfer

Cholesteric liquid crystal elastomers (CLCEs) exhibit vivid mechanochromic responses but are inherently limited to fully reversible behavior due to their elastic polymer networks. Here, we report a substrate‐coupled CLCE architecture that overcomes this intrinsic limitation and enables irreversible mechanochromic imprinting without modifying CLCE chemistry. By laminating CLCE films onto plastically deformable polymer substrates, plastic strain is geometrically transferred and locked into the cholesteric helix, producing permanent, wavelength‐selective color changes. Distinct deformation modes‐including folding, pressing, and shearing—generate stable and mode‐specific optical patterns that encode mechanical damage history. The resulting CLCE–plastic hybrids function as passive optical damage‐recording layers that preserve visible mechanical history without embedded electronics, while external optical readout can be used for quantitative analysis. Ultimately, this approach offers a new functional materials platform for safety monitoring, biomedical diagnostics, and smart mechanochromic sensing.