Tomography-Driven Registration of Embedded Objects for High-Precision Overprinting in Volumetric Additive Manufacturing

Volumetric Additive Manufacturing (VAM) is an optical 3D printing technique in which patterned light is projected into a volume of photoactive resin from multiple angles. As the resin absorbs light and the energy dose accumulates, polymerization occurs, transforming the resin from liquid to solid and forming a volumetrically printed object. By enabling simultaneous printing of an entire object, VAM offers unique capabilities compared to other additive manufacturing techniques, including “overprinting”—the ability to print inside, around, or alongside an object embedded in the resin. In this work, we present a novel approach to detect and correct misalignment in a computed tomography system, enabling high-resolution 3D tomographic reconstructions even in misaligned systems. Using this reconstruction, we accurately determine the seven degrees of freedom (3 spatial, 3 angular, and 1 size) of an object embedded in the resin. Finally, we demonstrate how this information is used to precisely print an object relative to the embedded object, enhancing the accuracy and potential of overprinting in VAM.