Researchers at West Virginia University in the US are studying how 3D printing works in a weightless environment with the aim of supporting long-term exploration and habitability on spacecraft, the Moon or Mars.

© wvutoday.wvu.edu / WVU Photo / Brian Persinger

 

Prolonged missions in deep space require the manufacturing of crucial materials and equipment in situ due to the difficulty of transporting machinery for this from Earth. So 3D printing is the most viable technology.

 

Recent experiments by the West Virginia University research team focused on how a microgravity environment affects 3D printing and used titanium foam, a material with potential applications ranging from UV blocking to purification. of the water. The journal ACS Applied Materials and Interfaces published their findings.

 

"A spacecraft cannot carry infinite resources, so you have to maintain and recycle what you have, and 3D printing allows this," said lead author Jacob Cordonier, a doctoral student in mechanical and aerospace engineering in the Faculty of Mechanical Engineering. and Aerospace from WVU. “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 look at the role of gravity in how foam exits the 3D printer nozzle and spreads on a substrate. We have seen differences in filament shape when printing in microgravity compared to Earth's gravity. And by changing additional variables in the printing process, such as writing speed and extrusion pressure, we can paint a clearer picture of how all of these parameters interact to adjust filament shape.”

 

Konstantinos Sierros, associate professor and research chair in the Department of Mechanical and Aerospace Engineering, has supervised the microgravity research team's titanium foam studies since 2016. The work is now done in their WVU laboratories, but originally required travel by a Boeing 727. There, students printed foam lines on glass slides during 20-second periods of weightlessness when the plane was at the top of its parabolic flight path.

 

"Transporting even one kilogram of material in space is expensive and storage is limited, so we are investigating what is called 'in situ resource utilization,'" says Sierros. “We know that the moon contains deposits of minerals very similar to the titanium dioxide used to make our foam, so the idea is that it will not be necessary to transport equipment from here to space because we can extract those resources on the moon and print the necessary equipment for a mission.” That 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 portion of ultraviolet light, but not all of it, which is why we get sunburned," says Cordonier. "In space or on the moon, there's nothing to mitigate it other than your spacesuit or whatever coating your spacecraft or habitat has." To measure the titanium foam's effectiveness at blocking UV waves, "we would shine light from the ultraviolet wavelengths all the way up into the visible light spectrum," he explains. “We measured how much light passed through the titania foam film we had printed, how much was reflected, and how much was absorbed by the sample. We show that the film blocks almost all UV light reaching the sample and very little visible light passes through. Even at just 200 microns thick, our material is effective at blocking UV radiation.”

 

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