Scientists at the University of Virginia have introduced a new kind of 3D printable material that is compatible with the body’s immune system. The innovation is expected to support safer implantable devices, next-generation drug-delivery systems, and even improved solid-state batteries.
The findings were recently published in Advanced Materials by the Soft Biomatter Laboratory, directed by associate professor Liheng Cai. The publication’s lead author is Ph.D. researcher Baiqiang Huang from UVA’s School of Engineering and Applied Science.
How the Material Gains Its Flexibility
The study presents a redesigned form of polyethylene glycol (PEG) that can form highly elastic networks. PEG is already common in biomedical engineering, but conventional PEG structures — typically made by crosslinking linear chains in water and then dehydrating them — often become stiff and crystalline, which limits how much they can stretch before breaking.
To overcome PEG’s rigidity, the researchers adapted an approach previously developed in Cai’s lab for producing unusually strong synthetic polymers. Their strategy mirrors how resilient rubber is made: by embedding hidden length within the molecular structure.
The resulting “foldable bottlebrush” architecture consists of a backbone surrounded by many flexible side chains. These can compress and expand like an accordion, giving the material the ability to withstand deformation. “Our group discovered this polymer and used this architecture to show that any materials made this way are very stretchable,” Cai said.
Transforming PEG With UV-Triggered Chemistry
Huang applied this molecular design to PEG by briefly exposing a precursor solution to ultraviolet light, initiating polymerization into a bottlebrush-like network. This process enabled the creation of 3D printable PEG hydrogels and solvent-free elastomers with high stretchability.
“We can change the shape of the UV lights to create so many complicated structures,” Huang said. This tunability allows for either softer or more rigid designs that still retain elasticity, opening possibilities for future artificial tissues and precision drug-delivery devices. Cell-culture tests also showed that the material does not harm nearby cells, an encouraging sign for any use inside the body.
The team suggests that PEG could be combined with other components to yield printable materials with custom chemical profiles. “This property highlights the new material as a promising high-performance solid-state electrolyte for advanced battery technologies,” Cai said. “Our team continues to explore potential extensions of the research in solid-state battery technologies.”
Advances in Biomedical 3D Materials
Beyond the UVA team’s work on stretchable PEG hydrogels, other researchers worldwide are also advancing 3D printable materials for medical applications.
A team of researchers in Spain and the Netherlands has created advanced hybrid bioinks capable of 3D bioprinting artery models that closely replicate both the layered structure and some of the functionality of human blood vessels. Scientists at CIC biomaGUNE, part of the Basque Research and Technology Alliance (BRTA), in collaboration with the University Medical Center Groningen (UMCG), the University of the Basque Country, and the MERLN Institute for Technology-inspired Regenerative Medicine, combined biological and synthetic components to produce multilayered cylindrical structures that mimic natural arterial walls.
Elsewhere, researchers at RMIT University and the University of Sydney have designed a novel material with the potential to improve how medical implants are powered and monitored within the body. Published in Advanced Functional Materials, their work features a 3D printed diamond–titanium composite that pairs mechanical durability with electronic functionality. Led by Associate Professor Dr. Kate Fox at RMIT, the project demonstrates how future implants could harvest energy from the body’s natural flows or receive power wirelessly, minimizing reliance on conventional batteries.
The 3D Printing Industry Awards are back. Make your nominations now.
Do you operate a 3D printing start-up? Reach readers, potential investors, and customers with the 3D Printing Industry Start-up of Year competition.
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 Twitter, or like our page on Facebook.
Featured image shows Liheng Cai’s foldable bottlebrush polymers. Image via UVA Engineering.
