Volumetric additive manufacturing of complex geometries around complex inserts.

Area of Science:

• Additive Manufacturing
• Polymer Science
• Optical Engineering

Background:

• Tomographic Volumetric Additive Manufacturing (VAM) enables printing polymer structures around pre-existing inserts via projected light into photosensitive resin.
• Printing complex, occluding inserts with VAM remains a significant challenge, limiting the process's applicability.

Purpose of the Study:

• To examine the capabilities and challenges of tomographic VAM when printing around complex, occluding inserts.
• To propose and evaluate an occlusion-based orientation optimization method to enhance print quality and fidelity.

Main Methods:

• Developed a cost function based on light occlusion to predict optical dose quality.
• Optimized insert and print model orientation by maximizing light exposure directions for voxels.
• Conducted simulations and physical printing experiments using a commercial resin.
• Utilized micro-CT imagery for detailed analysis of printed structures.

Main Results:

• Conventional VAM struggles with complex inserts, leading to unprinted regions.
• The proposed orientation optimization significantly improves print quality and reduces unprinted areas.
• Enhanced printing fidelity and increased depth within insert recesses were achieved.
• Physical prints closely matched simulation predictions, validating the method's effectiveness.

Conclusions:

• Orientation optimization is crucial for successful tomographic VAM with complex, occluding inserts.
• This approach expands the capabilities of VAM for printing intricate geometries around challenging geometries.
• The method overcomes limitations of conventional manufacturing for complex overprinting applications.