Scientists at the Rochester Institute of Technology (RIT) are investigating ways to make 3D printed materials more durable by developing polymers that can repair themselves when damaged.
Led by Christopher Lewis, the research focuses on creating stimuli-responsive photopolymers that can self-heal when damaged, improving the resilience of 3D printed products. These materials begin as liquid resins similar in consistency to superglue, and through the lithography process, solidify selectively, layer by layer during printing. Once cured, they exhibit self-healing properties that could extend the lifespan of printed parts.
As a professor in RIT’s College of Engineering Technology, Lewis said the team’s goal aims to produce synthetic materials that replicate the restorative capabilities found in biological systems. While living tissue can regenerate after injury, “it is not true for synthetic materials or man-made objects,” said Lewis. “Our work in self-healing materials is a [futuristic] look at how we can develop systems that mimic those natural material properties.”
Overcoming weaknesses in 3D printing materials
One of the ongoing challenges in additive manufacturing is material brittleness, especially for components used in load-bearing applications. Cracks can form over time, leading to failure. To address this, Lewis’s group combined an ultraviolet-curable resin with a thermoplastic additive to create a stronger blend that can reinforce damaged regions. The material also displays shape memory behavior, meaning it can return to its original form after deformation.
Supported by the U.S. Department of Defense (DoD) and conducted in partnership with RIT’s AMPrint Center, the project is now focused on fine-tuning the chemistry of the resin to balance light sensitivity and viscosity. Both qualities are essential for achieving consistent and reliable printing performance.
The self-healing capability arises from a process known as polymerization-induced phase separation (PIPS). When exposed to light, the liquid resin begins to cure, and the thermoset and thermoplastic components gradually separate. This creates a dynamic internal structure that shifts and stabilizes during solidification, resembling the gentle motion of a lava lamp.
Lewis explained that this phase separation is key to how the material repairs itself. Earlier studies on thermoplastic blends showed that similar structural dynamics allow polymers to close cracks and restore integrity. Those insights guided the team’s current experiments with photo-reactive systems.
Researchers believe that self-healing polymers could lead to 3D printed parts that are more reliable for use in robotics, electronics, and biomedical devices. By improving resilience and reducing maintenance needs, the technology could help lower production costs and expand the capabilities of additive manufacturing.
Self-healing materials for 3D printing
The self-healing properties are also desirable in 3D printing, and the ability to integrate similar features into printing materials could potentially open up brand new areas to AM.
In recent years, researchers have made notable progress toward self-healing technologies across multiple fronts. For instance, scientists successfully 3D printed a shrimp-derived biopolymer that may pave the way for self-repairing wearable devices, and others have demonstrated 3D printed materials capable of repairing damage in smartphone and computer screens.
At the University of Southern California, researchers developed a 3D printed rubber capable of repairing itself, a breakthrough that could extend the lifespan of products such as shoes, tires, soft robotic components, and electronic devices. Similarly, researchers at Lamar University used stereolithography (SLA) to fabricate cactus-inspired structures designed to perform autonomous self-repair.
In Taiwan, scientists at National Central University engineered a self-healing emulsion glass resistant to both ultraviolet light and heat. Meanwhile, a collaboration between Texas A&M University and the U.S. Army Research Laboratory resulted in a new class of recyclable, self-healing polymer materials suitable for 3D printing.
Help choose the 2025 3D Printing Industry Awards winners – sign up for the Expert Committee now!
To stay up to date with the latest 3D printing news, don’t forget to subscribe to the 3D Printing Industry newsletter or follow us on LinkedIn.
While you’re here, why not subscribe to our Youtube channel? Featuring discussion, debriefs, video shorts, and webinar replays.
Featured image shows Christopher Lewis developed a self-healing materials solution to improve 3D printing. Photo via RIT.
