The Polymer Society of Korea

Abstract

Wavelength-selective digital light processing (DLP) 3D printing enables spatial control of mechanical properties within a single printed structure by modulating photopolymerization pathways. A dual-curable epoxy–acrylate resin system incorporating spectrally orthogonal photoinitiators allows selective activation of radical and cationic polymerizations under violet and UV light, respectively. This approach achieves voxel-level tuning of stiffness within each layer, facilitating the direct fabrication of multimaterial architectures without post-processing. Demonstrated structures include helically reinforced composites, compliant-to-rigid transitions, and bioinspired assemblies mimicking musculoskeletal interfaces. Additionally, selectively reinforced soft domains support the creation of durable stretchable electronics. This scalable and high-resolution printing platform offers new opportunities in soft robotics, wearable systems, and functional polymer materials.