Structured illumination for multi-wavelength 3D-printing via tomographic reconstruction

Tomographic volumetric 3D printing (TVP) offers layer-free, rapid fabrication of objects with high design freedom, but is limited to relatively small curing volumes because of the optical constraints imposed by an assumed need for telecentricity. This thesis addresses these scalability challenges through an integrated approach involving computational modeling, validation studies, and a practical upscaling methodology. First, it introduces TomoPrint, a GPU‑accelerated software framework that couples full 3‑D ray‑tracing, radiative‑transfer modeling and free‑radical photopolymerisation kinetics. By explicitly modeling non‑telecentric beams, refraction, reflection and beam divergence, TomoPrint predicts dose build‑up with voxel precision while retaining minute‑scale compute times, providing a reusable, open framework for rapid TVP design space exploration. Second, validation studies are conducted to verify TomoPrint’s capabilities in simulating complex optical behaviors within non-cylindrical containers and multi-wavelength photopolymerization setups. A surface‑area‑heuristic bounding‑volume hierarchy (SAH‑BVH) is employed to accelerate raytriangle intersections, enabling accurate pattern generation for non‑cylindrical containers. Successful validation using a 74×74×74 mm3 cubic vat demonstrates how multifaceted refraction influences polymerization dynamics, a behavior that conventional Radon-based tools cannot capture. Additionally, a new pattern-generation algorithm is introduced for vat-free multi-wavelength TVP employing a binary photoinhibitory system and is validated by presenting several representative workpieces. Finally, scalability constraints are addressed by developing a multi-projector "virtual stitching" method. Two synchronized, off-the-shelf DLP projectors positioned around a 125 mm diameter resin container significantly expand the printable area to approximately 138 × 104 mm², preserving a native 48 μm pixel resolution. Through calibrated intensity scaling, volumetric attenuation correction, and angular compensation, this approach reliably produces centimeter-scale objects, including calibration phantoms and life-sized anatomical models, measuring up to 78.2 mm in height and 70.9 mm laterally, within minutes. Collectively, these advances position TVP closer to industrial adoption by providing an adaptable computational toolset, removing constraints imposed by cylindrical geometries, and outlining a scalable path toward large-scale part fabrication. The methodologies and insights presented establish a robust foundation for future advancements and broader implementation of TVP technology.