Computed axial lithography (CAL) is a volumetric additive manufacturing process for photopolymers that defines 3D geometries through tomographic reconstruction of a light dose in a vat of material. Current research seeks to expand the range of macromolecules processable with CAL, demonstrate initial applications, and, crucially, probe the minimum feature sizes and maximum component sizes that are practically achievable. This talk will offer a framework for assessing the geometric capabilities of CAL, addressing both physical and computational considerations. I will describe the position- and orientation-dependent spatial modulation transfer function that is inherent in CAL. I will also discuss computational approaches to optimizing light dose delivery for complex and heterogeneous geometries.

5 THINGS YOU WILL LEARN DURING THIS SESSION:

1. Spatial resolution in CAL depends on position and geometric orientation in the printing volume
2. The computational phase of CAL may be accelerated by using a voxel-free representation of the desired geometry
3. Where dimensional accuracy is paramount, it may be advantageous to focus on optimizing light doses at the surface of the desired object instead of on a regular spatial grid
4. Diffusion of oxygen and other species can play an important role in determining spatial resolution and accuracy in objects printed with CAL
5. Optimization of the delivered light dose distribution needs to consider the effect of subsequent post-processing on the final geometry of the component

Hayden Taylor, Associate Professor of Mechanical Engineering, University of California, Berkeley