West Virginia University’s (WVU) students and faculty have been exploring the ways in which 3D printing could support long-term exploration, habitation, and habitation of spaceships on Mars, the Moon, and other planets. 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. ACS Applied Materials and Interfaces published the findings.
“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. John Kuhlman emeritus professor and Konstantinos Sierros, associate professor and chair of research at the Department of Mechanical and Aerospace Engineering, also contributed to the paper.
Sierros has overseen the Microgravity Research Team’s titania foam studies since 2016. Originally, the work was done in a Boeing 727. Now it is being done at West Virginia University. Students printed foam lines onto glass slides while the plane was in weightlessness for 20 seconds.
“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.”
Shields against ultraviolet radiation are necessary equipment. This light is a danger to astronauts, electronics and other assets in space.
“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 found that the film blocked nearly all of the UV light from hitting the sample. Very little visible light was allowed 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. Students are leading the materials development, automation and data analysis. These undergraduates, who are supported by two NASA grants of high competition, have taken part in all phases of the research. They have published peer-reviewed scientific articles and presented at conferences,” said Sierros.