3D Printing

Practical new 3D printing resin optimized for visible light

Practical new 3D printing resi...
An example of a complex object printed from the resin
An example of a complex object printed from the resin
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An example of a complex object printed from the resin
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An example of a complex object printed from the resin

One method of 3D printing involves selectively exposing liquid resin to ultraviolet (UV) light, causing that resin to harden into a solid. Now, scientists have developed a new resin that works with safer, more energy-efficient visible light.

Although it is already possible to use visible light on photosensitive resins, the hardening process is quite slow, making it impractical for real-world use. UV light works much quicker, but its energy requirements – and thus its costs – are significantly higher.

Additionally, excessive amounts of UV light may harm biological tissue. This means that it can't be used in the bioprinting of tissue that contains living cells, or for printing structures within the human body.

UV light also doesn't penetrate as far into resin as does visible light, plus it scatters more.

With these limitations in mind, researchers from the University of Texas at Austin have developed a new resin that is made up of elements including a monomer, a photoredox catalyst (PRC), two co-initiators and an opaquing agent.

The PRC absorbs visible light from LEDs on the printer, prompting the transfer of electrons between the co-initiators. This in turn causes the monomer to polymerize (harden). The opaquing agent helps confine the process to the areas exposed to the light, improving the printing resolution.

In lab tests, the scientists were able to print mechanically uniform stiff and soft objects, with features smaller than 100 micrometers (a micrometer is one one-millionth of a meter).

At 1.8 inches (46 mm) per hour, the fastest print speed was relatively practical for small items, but still less than half the maximum UV light printing speed. That said, the figure could reportedly be improved by boosting the intensity of the visible light, or by adding additional compounds to the resin.

A paper on the research was recently published in the journal ACS Central Science.

Source: American Chemical Society via EurekAlert

1 comment
Techrex
What if they could combine an electrical grounding effect with the visible light lasers doing this 3D printing? That is, when the 3D printed product companies that make metal artifacts manufacture it, they pass a DC electrical current through the molten metal jets from the ceramic printing jets, that is grounded at the base of the artifact being assembled. Anyway, there is an old school science project thing, where you shine a bright light through a Gold Leaf lens, that is, you can stretch gold into a sheet that is so thin, that you can shine a light through it, and a BEAUTIFUL green light comes out of it. But, if Gold is also electrically conductive, what if we passed a DC electrical current through this Gold Leaf lens, while shooting an already-green visible laser light beam through it, and used that laser to 3D print, say, artificial human tissue or organs, which you cannot do with ultraviolet rays, because it kills the bio-materials used, and grounded that electrical current pushed by the laser light, (It's a two-in-one PEB (Particle Emission Beam) and visible laser beam in one device.) at the base of the Bio-materials being 3D printed? Would that make the mass manufacture of 3D printed bio-materials, or artificial organs more effective?