A team from the National Research Council Canada and the University of Victoria has developed a fully automatic exposure control system for tomographic volumetric additive manufacturing (VAM), a technique that fabricates entire objects at once using projected light patterns inside a rotating resin vat, significantly improving the process’s accuracy and repeatability. The results, shared in a non-peer-reviewed preprint on arXiv, show that the technique enables hands-free printing with comparable or better feature resolution than commercial SLA and DLP printers, while printing parts up to ten times faster.
Dubbed AE-VAM (Automatic Exposure Volumetric Additive Manufacturing), the new system uses real-time monitoring of light scattering inside the resin to automatically terminate exposure during printing. This eliminates the need for manual adjustments, which previously limited the consistency and commercial viability of VAM.
The researchers demonstrated their system by printing 25 iterations of the widely used 3DBenchy model. AE-VAM achieved an average RMS surface deviation of 0.100 mm and inter-print variation of 0.053 mm. Notably, all fine features, including blind holes, chimneys, and underside text, were successfully reproduced, outperforming prints from commercial SLA and DLP systems in some key respects.
From lab to potential production
Tomographic VAM differs from conventional 3D printing in that it exposes the entire resin volume at once, rather than layer by layer. While this allows for faster printing and the elimination of support structures, previous implementations suffered from unpredictable exposure levels due to resin reuse and light diffusion, often requiring experienced operators and frequent recalibration.
AE-VAM addresses this by using a simple optical feedback system that measures scattered red light during curing. When the measured signal reaches a calibrated threshold, the UV exposure is halted automatically. According to the authors, this makes the process “insensitive to geometry” and viable for multi-part assembly printing, such as gear systems and threaded components.
A step toward commercial VAM
The team benchmarked AE-VAM against the Formlabs Form 2, Form 4, and Asiga PRO4K. While the Form 2 achieved slightly higher accuracy (0.081 mm RMS error), AE-VAM outperformed on small feature reproduction and consistency, especially as resin was re-used. The system printed the same 3DBenchy model in under a minute, compared to over 8 minutes on the fastest SLA system.
“AE-VAM has repeatability and accuracy specifications that are within the range measured for commercial systems,” the authors wrote, noting that it also enables resin reuse up to five times with minimal degradation. They anticipate that broader testing of AE-VAM with different resins could bring the technology closer to commercialization. The team notes the approach is computationally lightweight and suitable for general-purpose use with minimal operator training.
The work has been funded by the National Research Council of Canada’s Ideation program. Several authors are listed as inventors on provisional patents related to the system.
Volumetric 3D printing gains momentum across research and industry
Volumetric additive manufacturing (VAM) has garnered increasing attention in recent years as a fast, support-free alternative to conventional layer-based 3D printing. Previous VAM advancements include Manifest Technologies’ (formerly Vitro3D) launch of a high-speed P-VAM evaluation kit aimed at commercial adoption, and EPFL’s demonstration of opaque resin printing using volumetric techniques. Meanwhile, researchers at Utrecht University have leveraged volumetric bioprinting to fabricate miniature liver models for regenerative medicine, and University College London explored rapid drug-loaded tablet fabrication. More recently, a holographic variant of tomographic VAM (TVAM) showed promise in reducing print times and improving light efficiency. These developments underscore the broad applicability and accelerating pace of innovation in volumetric 3D printing technologies.
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Feature image shows comparison of 3DBenchy models printed with VAM, SLA and DLP. Antony Orth et al., National Research Council Canada / University of Victoria.
