Hello, I want to know how can SLA, DLP or other vat photopolymerization methods achieve multi-material printing capability? Can they print multiple materials in different regions at the same time?
Multi-material printing is difficult to achieve with resin polymerization but a few methods have been proposed. Some printers have been designed to include two distinct resin compartment:
Article Additive manufacturing of embedded carbon nanocomposite stru...
or the resin can be swapped at a given point in the print:
Article A vat-polymerized 3-dimensionally printed dual-material occl...
but those methods are quite "hand on"
Alternatively mixed resins can be produced to polymerize differently depending on the wavelength they are exposed to:
Article Tough Multimaterial Interfaces through Wavelength-Selective ...
This method allows to achieve sharp interfaces and a fine control on the young modulus of the printed material. That said i wouldn't expose the printed part to post curing...
This approach has also been used for tomographic printing:
https://www.nature.com/articles/s41467-022-28013-4
"Normal" tomographic printing itself can be considered a way to achieve multilateral printing by encapsulating pre-existing objects:
Article Volumetric additive manufacturing via tomographic reconstruction
If you want an overviews of the "non esoteric" methods that have been proposed here is a good reference:
Article Multimaterial Vat Polymerization Additive Manufacturing
Industrial 3d printers capable of producing multi-materials components by vat photopolymerization have emerged in recent years. In general, they use multiple vats, each with a different material.
The following link from a supplier has some very helpful video and images to understand the process.
https://www.soonser.com/CeraRayCR-II.html