Ceramic paste for space stereolithography 3D printing technology in microgravity environment

Additive manufacturing techniques have demonstrated great potential in space manufacturing for long-duration human spaceflight and colonization on alien planets. Herein, we present the design and manufacturing of previously inaccessible complex ceramic components with high precision in a microgravity environment. The proposed approach is based on controlling the rheological properties of ceramic slurry in reduced-gravity. Briefly, HE-cellulose and carbomer 940 are added as thickening agents to transform the ceramic slurry into a ceramic paste(soft matter), which exhibits Bingham pseudoplastic behavior and is not sensitive to gravity variations during parabolic flight. Additionally, X-ray computed tomography (XCT) results reveal that the as-prepared alumina samples, 3D printed in a microgravity environment, render a higher density of 99.3% after sintering. The proposed route can be applied to fabricate complex-shaped ceramic components in space, enabling various possibilities of manufacturing structural and functional materials, including gradient materials, solid fuel cells, active insulation ceramic structures and piezoelectric sensors.