A game-changing 3D printing technique developed by The University of Texas at Austin researchers could revolutionize prosthetics, medical devices and stretchable electronics by seamlessly integrating soft and hard materials in a single object.
Inspired by nature’s ability to blend toughness and flexibility, such as the combination of rigid bone with pliable cartilage, researchers at The University of Texas at Austin have pioneered a novel 3D printing method. This technique is precise and swift, integrating both soft and hard materials into a single object using different colors of light.
This exciting development, published in Nature Materials, has groundbreaking implications for the future of prosthetics, medical devices and flexible electronics, ultimately enabling devices to move more naturally with the human body.
“What really motivated me and my research group is looking at materials in nature,” corresponding author Zak Page, an assistant professor of chemistry at UT Austin, said in a news release. “Nature does this in an organic way, combining hard and soft materials without failure at the interface. We wanted to replicate that.”
A related paper, published in ACS Central Science on May 29 by Page and his colleagues, underscores the importance of this work, describing it as “the future of 3D printing.” The journal’s editors lauded it in a “First Reactions” commentary, highlighting how light can be harnessed not only for curing resin but also as a precise tool for crafting intricate designs in additive manufacturing.
“This approach could make additive manufacturing more competitive for higher-volume production compared with traditional processes like injection molding. Just as important, it opens up new design possibilities,” added Keldy Mason, the lead author of the ACS Central Science study and a graduate student in Page’s lab. “This gives engineers, designers and makers more freedom to create.”
One of the persistent challenges in fabricating items with varied physical properties is the material interface, which often fails over time. The team’s novel 3D printing method surmounts this issue by employing a custom resin activated by dual-light exposure to initiate distinct chemical reactions.
Violet light results in a stretchy, rubber-like material, while higher-energy ultraviolet light produces a rigid, durable substance. This allows for the creation of objects with precise zones of softness and hardness in a single print.
“We built in a molecule with both reactive groups so our two solidification reactions could ‘talk to each other’ at the interface,” Page added. “That gives us a much stronger connection between the soft and hard parts, and there can be a gradual transition if we want.”
The researchers demonstrated their breakthrough by printing a functional knee joint with flexible ligaments and rigid bones. They also printed a stretchable electronic device with a gold wire capable of bending and stretching. Both prototypes showcased the potential for seamless integration in real-world applications.
“Honestly, what surprised me most was how well it worked on the first try. That almost never happens with 3D printing resins,” Page added. “We were also shocked by how different the properties were. The soft parts stretched like a rubber band and bounced back. The hard parts were as strong as plastics used in consumer products.”
This innovative process not only enhances speed and precision but also makes the technology considerably more accessible due to its simplicity and affordability. The potential applications are extensive, from prototyping surgical models to creating wearable sensors and even soft robots.
“It could be used to prototype surgical models, wearable sensors or even soft robots,” Page added. “There’s so much potential here.”
Co-authors of the study includes Ji-Won Kim, Lynn M. Stevens, Henry L. Cater, Ain Uddin, Marshall J. Allen, Elizabeth A. Recker, Anthony J. Arrowood, Gabriel E. Sanoja, Benny D. Freeman, Ang Gao, Wyatt Eckstrom and Michael A. Cullinan.
Page, Allen and Kim have already filed a patent on the new technology.
Source: University of Texas at Austin