According to West Virginia University (WVU), students and faculty are exploring how 3D printing can support long-term exploration and habitation on spaceships, the moon, and Mars. Members of the university’s Microgravity Research Team believe that 3D printing is the way to manufacture crucial materials and equipment on-site, rather than transporting those items from Earth. The team’s recent experiments focused on how a weightless microgravity environment affects 3D printing using titania foam, a material with potential applications ranging from UV blocking to water purification. The findings were published by ACS Applied Materials and Interfaces.
“A spacecraft can’t carry infinite resources, so you have to maintainu and recycle what you have and 3D printing enables that,” said lead author Jacob Cordonier, a doctoral student in mechanical and aerospace engineering at the WVU Benjamin M. Statler College of Engineering and Mineral Resources. “You can print only what you need, reducing waste. Our study looked at whether a 3D printed titanium dioxide foam could protect against ultraviolet radiation in outer space and purify water… The research also allows us to see gravity’s role in how the foam comes out of the 3D printer nozzle and spreads onto a substrate. We’ve seen differences in the filament shape when printed in microgravity compared to Earth gravity. And by changing additional variables in the printing process, such as writing speed and extrusion pressure, we’re able to paint a clearer image of how all these parameters interact to tune the shape of the filament.”
Co-authors include current and former undergraduate students Kyleigh Anderson, Ronan Butts, Ross O’Hara, Renee Garneau, and Nathanael Wimer. Also contributing to the paper were John Kuhlman, professor emeritus, and Konstantinos Sierros, associate professor and associate chair for research in the Department of Mechanical and Aerospace Engineering.
Sierros has overseen the Microgravity Research Team’s titania foam studies since 2016. The work now happens in his West Virginia University labs but originally required taking a ride on a Boeing 727. There, students printed lines of foam onto glass slides during 20-second periods of weightlessness when the jet was at the top of its parabolic flight path.
“Transporting even a kilogram of material in space is expensive and storage is limited, so we’re looking into what is called ‘in-situ resource utilization’,” said Sierros. “We know the moon contains deposits of minerals very similar to the titanium dioxide used to make our foam, so the idea is you don’t have to transport equipment from here to space because we can mine those resources on the moon and print the equipment that’s necessary for a mission.”
Necessary equipment includes shields against ultraviolet light, which poses a threat to astronauts, electronics, and other space assets.
“On Earth, our atmosphere blocks a significant part of UV light – though not all of it, which is why we get sunburned,” said Cordonier. “In space or on the moon, there’s nothing to mitigate it besides your spacesuit or whatever coating is on your spacecraft or habitat.”
To measure titania foam’s effectiveness at blocking UV waves, “we would shine light ranging from the ultraviolet wavelengths up to the visible light spectrum,” he explained. “We measured how much light was getting through the titania foam film we had printed, how much got reflected back and how much was absorbed by the sample. We showed the film blocks almost all the UV light hitting the sample and very little visible light gets through. Even at only 200 microns thick, our material is effective at blocking UV radiation.”
Cordonier said the foam also demonstrated photocatalytic properties – meaning that it can use light to promote chemical reactions that can do things like purify air or water.
“We’re trying to integrate research into student careers at an early point. We have a student subgroup that’s purely hardware and they make the 3D printers. We have students leading materials development, automation, and data analysis. The undergraduates who have been doing this work with the support of two very competitive NASA grants are participating in the whole research process. They have published peer-reviewed scientific articles and presented at conferences,” said Sierros.