Description: During this flight demonstration, a series of metal oxide foam test specimens (i.e. nanoparticle-based Titanium Dioxide (TiO2) aqueous foam emulsions or inks) will be printed in microgravity (µG), using two parabolic aircraft flights. The hypothesis is that when the foams are created and printed in microgravity, they should be more stable and more uniform than when similar processes are used to print and post-treat the foam under normal Earth gravity conditions. Also, based on the Nakahara effect, which states that memory can be imprinted on pastes or emulsions, it is hypothesized that the µG conditions will induce distinct memory effects on the printed specimens. Such processing-specific memory effects may be manifested in distinct mechanical and microstructural properties. Technology Maturation The payload apparatus consists of an in-house built pneumatic-based extrusion 3D printer that will be integrated into an existing payload frame and enclosure. Mechanical, electrical, and microstructural post-flight characterization data from the µG-printed specimens will be compared with similar data for a series of otherwise identical baseline Earth-printed specimens.

2021 Paper: Direct foam writing in microgravity

Benefits: Foams have promise for space applications, including radiation shielding for future human space exploration missions, solar cell arrays and/or batteries, embedded sensors, and water and/or air photocatalytic treatment. When foams are created and printed in microgravity, they should be more stable and more uniform than when similar processes are used to print and post-treat foam under normal Earth gravity conditions. In addition, it may be possible that memory effects can be obtained on the printed specimens. Such processing-specific memory effects may be manifested in distinct mechanical and microstructural properties. Future Customers The proposed foams have promise for space applications, including use for radiation shielding for future human space exploration missions, use in solar cell arrays and/or batteries, use in embedded sensors, and for water and/or air photocatalytic treatment.