Structurally Colored Films with Mechanochromic Shifts via Holographic Recording

Structurally colored materials that change color upon mechanical stimuli have broad potential in stress sensors, wearable devices, and artificial skin. Such materials are conventionally prepared through the self-assembly of colloidal nanoparticles or block copolymers, a process that often involves time-consuming synthesis and purification as well as color inhomogeneity. To enable a simple and scalable route to mechanochromic materials, we employ holographic photopolymerization to fabricate monolithic, structurally colored elastomers. High reflectance and elasticity are achieved by adjusting the matrix formulation, the concentrations of recording monomers and acrylate cross-linker, the film thickness, and the exposure dose. The resulting materials exhibit a relative reflectance above 90% and a reversible mechanochromic shift of approximately 70 nm under 20% tensile strain. This work offers a practical approach to developing mechanically responsive photonic materials for sensing and anticounterfeiting applications.