Modeling of light propagation in computed axial lithography with photopolymers

Computed axial lithography (CAL) is a volumetric additive manufacturing method in which a three-dimensional light dose distribution is constructed in a photopolymer from the superposition of illumination patterns from many different angles. The technique’s advantages over layer-by-layer light printing methods stem from the fact that in CAL hydrodynamic stresses are effectively eliminated from the resin precursor material during printing. This key difference allows a wider range of materials to be processed, including high-viscosity or thermally gelled precursors, and allows polymeric objects to be printed around pre-existing solid objects (‘overprinting’). In this talk we describe some of the current limitations on spatial resolution, printing speed, and mechanical properties in CAL. We also describe a computationally efficient approach to modeling the occlusion of light by objects suspended in the printing volume, which supports the optimization of overprinting processes.