A 3D printing UV-curing resin that enables continuous color change of elastomers

This study introduces a UV-curing resin leveraging the Christiansen effect to achieve dynamic color modulation in phase-separated elastomers (PSE) through solvent composition and temperature control. By matching refractive indices between solvent (dimethyl phthalate/tributyl citrate) and polymer phases, PSE selectively transmits-specific wavelengths, enabling continuous color shifts from red to purple. The elastomers exhibit robust mechanical properties (>600% elongation, >300 kPa modulus) and function across a broad temperature range (-25°C-130°C). Compatible with 3D printing, the resin enables real-time solvent adjustments during fabrication, supporting spatially continuous color transitions without parameter modifications. This approach advances applications in adaptive optical devices, temperature-responsive displays, and multi-material 3D printing, offering a dye-free strategy for structural coloration in smart materials.