Volumetric additive manufacturing of complex geometries around complex inserts.

In tomographic Volumetric Additive Manufacturing (VAM), light is projected into a rotating vial of photosensitive resin, enabling printing of polymer structures around pre-existing inserts ('overprinting'). However, printing around complex, heavily occluding inserts remains unexplored. In this study, the capabilities and challenges of the tomographic VAM process when printing around such inserts are examined, and an occlusion-based orientation optimization is proposed to address these challenges. A cost function based on light occlusion is introduced to predict optical dose quality and optimize insert and print model orientation. By maximizing the number of directions from which the print model voxels receive light, dose quality and print fidelity are increased. Simulations showed that although the conventional tomographic VAM overprinting works well for simple convex inserts, it struggles for complex ones, and the proposed orientation optimization method improves print quality and reduces unprinted regions. A commercial resin wase used for volumetric overprinting of complex structures. Physical prints closely matched simulation results; micro-CT imagery confirmed that orientation optimization significantly improves tomographic volumetric printing around complex and occluding inserts and increases the possible depth of printing within insert recesses. This approach has enabled printing complex geometries around complex inserts, often unfeasible using conventional manufacturing methods.