Controlling Convection in Volumetric Additive Manufacturing for Large Volume Structures at Extreme Throughput

ABSTRACT Volumetric Additive Manufacturing (VAM) offers unparalleled speed in creating arbitrary 3D geometries; primarily due to requiring only one degree of freedom (DoF), rotation. A limitation, however, has been its size scale (∼3 cm), which has been attributed to light absorption. Accordingly, efforts have focused on adding translational DoF's to expose more material volume to this light path. The additional translational DoF increases print times, and still has not yielded thicker parts in all axes. This paper focuses on an important challenge to printing arbitrarily thick sections in all axes, thermal evolution from photopolymerization. In this work, we describe a scientific investigation and engineering solution to this issue, along with improvements to remaining challenges by: (i) using the index matching fluid as an active cooling source, (ii) optimizing the resin for deeper light propagation, and (iii) implementing a 4k light engine and large lens for higher intensity projections. With this system, we were able to print at least 70,153 mm 3 part volumes at throughputs of ∼390 mm 3 s −1 . Our printing system produces parts ∼60% larger and ∼400% faster than the next largest VAM method, and ∼1,740% larger and ∼23% faster than the next fastest method.