MIT researchers have developed a 3D printing method that uses a light-sensitive resin capable of forming both durable structures and dissolvable supports—depending on the type of light it’s exposed to. Ultraviolet (UV) light hardens the resin into strong, permanent shapes, while visible light produces weaker supports that can be dissolved in specific solvents. The new method eliminates manual post-processing such as cutting or filing, accelerating production and minimizing waste.
“You can now print — in a single print — multipart, functional assemblies with moving or interlocking parts, and you can basically wash away the supports,” said Nicholas Diaco, an MIT graduate student involved in the project. “Instead of throwing out this material, you can recycle it on site and generate a lot less waste. That’s the ultimate hope.”
Published in Advanced Materials Technologies, the work is a collaboration between Diaco and researchers Carl Thrasher, Max Hughes, Kevin Zhou, Michael Durso, Saechow Yap, Professors Robert Macfarlane and A. John Hart. The project was supported by the Center for Perceptual and Interactive Intelligence (InnoHK) in Hong Kong, the U.S. National Science Foundation, the U.S. Office of Naval Research, and the U.S. Army Research Office.
How It Works: Dual-Cure Resin Innovation
Traditional vat photopolymerization (VPP) begins with a 3D digital model that includes both the object and small support structures. This model is sliced into thin layers and sent to the VPP 3D printer, where it is built layer by layer. Once printing is complete, the platform lifts the part out of the resin bath, excess resin is rinsed away, and the temporary supports are manually removed and discarded. “For the most part, these supports end up generating a lot of waste,” Diaco says.
To address this challenge, the MIT team developed a dual-cure resin consisting of two monomers that respond distinctly to light. Exposure to UV light induces the formation of strong, permanent structures, while visible light triggers the creation of weaker, soluble supports engineered to degrade in various food-safe liquids, including baby oil. Notably, these supports can also dissolve in the primary liquid component of the original resin, facilitating continuous recycling of the material.
Initially, the approach faced a challenge: on 3D printers using lower-intensity LEDs than the lab’s benchtop setup, the UV-cured resin failed to hold up in solution. The weaker light only partially bonded the monomer chains, leaving the structure too loosely connected to remain intact. The researchers overcame this limitation by introducing a third “bridging” monomer that helped bond the two original monomers under UV light, creating a much stronger framework. This improvement allowed them to print durable 3D structures and dissolvable supports at the same time by alternating UV and visible light during a single printing process. The team used the method to successfully print a range of designs, including interlocking gears, lattice frameworks, and a miniature dinosaur encased in a dissolvable egg-like shell.
“With all these structures, you need a lattice of supports inside and out while printing,” Diaco says. “Removing those supports normally requires careful, manual removal. This shows we can print multipart assemblies with a lot of moving parts, and detailed, personalized products like hearing aids and dental implants, in a way that’s fast and sustainable.”
Professor John Hart emphasized that the technique opens new possibilities for scaling polymer 3D printing more sustainably. “We’ll continue studying the limits of this process, and we want to develop additional resins with this wavelength-selective behavior and mechanical properties necessary for durable products,” said Hart. “Along with automated part handling and closed-loop reuse of the dissolved resin, this is an exciting path to resource-efficient and cost-effective polymer 3D printing at scale.”
MIT Advances 3D Printing for Robotics and Bioengineering
In March, MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL), in collaboration with Zhejiang and Tsinghua universities, introduced “Xstrings”, a new method for 3D printing cable-driven mechanisms capable of humanlike motion—bending, coiling, screwing, and compressing. Traditionally, embedding cables requires manual labor, but Xstrings uses multi-material FDM printing to integrate cables directly into the structure in a single step. A complementary digital tool enables users to design and print complex, motion-capable components without manual assembly.
Separately, MIT researchers developed a new way to grow artificial muscle tissue that contracts in multiple directions, mimicking the movement of natural muscles more closely than ever before. Published in Biomaterials Science, this technique introduces a microtopographical stamping method that precisely controls how muscle fibers form and align. With potential applications in biohybrid robotics, regenerative medicine, and muscle disease research, the findings could help bridge the gap between engineered and biological tissue.
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Featured image shows Dissolvable Supports. Image via MIT.
