Flexible 3D Multi‐Material Printing beyond Layer‐by‐Layer Constraints via Sequential Multi‐Printer Fabrication

ABSTRACT Multi‐material 3D printing is a cornerstone of advanced manufacturing, yet conventional techniques are often constrained by layer‐by‐layer assembly or strict optical requirements. In this work, we present a flexible hybrid fabrication strategy that sequentially integrates masked stereolithography (LCD) with Xolography to overcome these limitations. A central challenge in volumetric printing, such as Xolography, is the requirement for high resin transparency, which typically precludes the use of functional, light‐scattering additives. Our strategy addresses this by assigning opaque or highly scattering resins, containing Fe 3 O 4 nanoparticles, to the LCD printing modality, while reserving Xolography for the contactless addition of transparent resins. This strategic division broadens the overall material palette, enabling the integration of chemically and optically distinct materials, such as shape‐memory polymer (SMP) composites loaded with Fe 3 O 4 and stimuli‐responsive hydrogels, into a single construct. By leveraging thiol–ene photochemistry and Michael addition, we demonstrate robust covalent bonding at the material interfaces, confirmed by SEM analysis to be free of delamination. This dual‐platform approach expands design freedom beyond traditional geometric constraints and establishes a foundation for the fabrication of sophisticated, multifunctional soft robotic systems.