3D-printed hydrogels as radiation protection in space

Protection from cosmic radiation is one of the greatest challenges for future long-term missions in space. Researchers at Ghent University are investigating the use of 3D-printed hydrogels as an alternative to conventional shielding materials. These special polymers can absorb and store large amounts of water, efficiently absorbing radiation while providing structural stability.

Water is considered an effective shield against high-energy particle radiation, as the hydrogen atoms it contains attenuate the radiation. However, integrating water reservoirs into spacesuits or modules is problematic due to leakage risks and uneven distribution.

“The beauty of this project is that we are working with a well-known technology,” explains Lenny Van Daele. “Hydrogels are found in many things we use every day, from contact lenses to diapers and sanitary products. Our research group has experience with applications in the medical field – using hydrogels as a soft implantable material to repair damaged tissues and organs.”

Hydrogels, which bind water in a stable, non-flowing form, could solve these problems. The researchers are focusing on superabsorbent polymers (SAP), which can store several hundred times their own weight in liquid. In their swollen form, they form a hydrogel-like material that is suitable for various applications.

“The material could also potentially be applied to uncrewed missions – in radiation shields for spacecraft, or as water reservoirs once we have optimised the method of retrieving water from the hydrogel,” adds Malgorzata Holynska of European Space Agency’s Materials, Environments and Contamination Control Section.

By using 3D printing, tailor-made structures can be produced that are optimized for spacesuits or spacecraft.

 “The superabsorbent polymer that we are using can be processed using multiple different techniques, which is a rare and advantageous quality amongst polymers,” adds Manon Minsart. “Our method of choice is 3D printing, which allows us to create a hydrogel in almost any shape we want.”

The researchers are currently working on further optimization of the material properties and industrial implementation in order to make hydrogels usable as a practical radiation protection solution for space.

Lead of the project Peter Dubruel comments: “There is a constant search for lightweight radiation protection materials. In our Discovery activity we successfully demonstrated that hydrogels are safe to use under space conditions. In this follow-up project, we are applying different techniques to shape the material into a 3D structure and scale up the production process, so that we can come a step closer to industrialisation.”