Photopolymer 3D printer from a domestic video projector creates objects without layers

A fundamentally different approach to photopolymer 3D printing, developed at the University of California at Berkeley, allows you to create 3D prints in a few minutes and supplement existing objects with 3D printing parts.

Based on the article by Kara Manke from the University of California at Berkeley, Berkeley News. Translated and adapted by Top 3D Shop .


Most 3D printing methods involve adding material layer by layer. This places some restrictions on the use of 3D printed objects, for example, printing new objects in combination with existing ones is extremely difficult, usually you cannot install a damaged part in a 3D printer and print a broken fragment.
The same technique allows such operations.
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Metal microscrew with a handle printed on it.

Designed by: Brett E. Kelly, Indrasen Bhattacharya, Hossein Heidari;
Co-authors: Maxim Shusteff, Christopher M. Spadaccini;
Head of the laboratory and correspondent: Hayden K. Taylor.
Scientific publication in Science 3'2019.

Kelly and colleagues presented another method of manufacturing - 3D printing by rotating a photopolymer in a dynamically developing light field. This allowed them to print entire complex objects in one full turn of the vessel with photopolymer, bypassing the need for layering.

Additive production with a new method promises geometric freedom and the ability to combine materials to obtain a combination of different properties in one piece.

The developers demonstrated simultaneous printing of all points in a three-dimensional object, by illuminating the rotating volume of the photosensitive material with a dynamically developing light pattern. During the tests, elements as small as 0.3 millimeters in engineering acrylate polymers and soft structures with extremely smooth surfaces in a gelatin methacrylate hydrogel were obtained.


“The fact that you can take a metal component or something from another production process and add a new part with custom geometry, I think, can change the way products are designed.

In fact, you can take a conventional video projector, literally bring it from home, connect it to a laptop and use it to project a series of computed images onto a rotating cylindrical tank with a thick photopolymer resin.


Obviously, there also have their own subtleties, first of all - in the calculation of the projected images, but with the creation of the hardware, there will be no significant difficulties , ”said Taylor.


Taylor and the team used the printer to create a series of test objects - from the tiny model of the statue of Rodin "The Thinker" to the jaw model for individual orders.


Currently, they can make objects with a diameter of up to 10 cm.

“This is the first time that we don’t need to create three-dimensional parts in layers; this makes 3D printing really three-dimensional , ”says Brett Kelly, co-author of the scientific work.


For their technology, researchers have formulated a thick syrup-like photopolymer, which polymerizes only at a strictly defined intensity of the acting light.


3D printing resin consists of liquid polymers mixed with photosensitive molecules and dissolved oxygen. Light activates a photosensitive compound that depletes oxygen. Only in those areas where all the oxygen was used, do polymers form bonds that convert the resin from a liquid to a solid. Unused resin can be recycled by heating in an oxygen atmosphere.

“Our technique creates almost no waste, and uncured material can be reused 100% ,” says Hossein Heidari, a graduate student at the Taylor Laboratory at the University of California at Berkeley and co-author of the work.



“We hope that this will open the way for many other researchers in this exciting field of technology,” said Maxim Shusteff, an engineer, co-author of the work.


This is one of those ideas that “hover in the air”, and it remained just an idea, until these guys guessed to create a special suitable photopolymer.

The detail of the samples obtained is not yet impressive, but the method itself is at least interesting. It is possible that when obtaining a photopolymer with an even more accurate transition boundary (the word is followed by chemists), as well as with the improvement of image calculation algorithms, the detailing of prints created by this method will increase.

Do you think it is possible to use this method for home 3D printing? Where will he be most in demand?

Will there be any serial samples of 3D printers based on this principle? Would you buy one for yourself? Share your opinion in the comments.