3D printing of composites of Martian regolith simulants and cyanobacterial biomass towards sustainable material production on Mars.

The long-term goal of establishing a sustained human presence on Mars requires the capacity to produce essential consumables on-site. To this end, we develop strategies for processing inorganic oxidic powders and biomass into highly particle-filled composites using direct ink writing (DIW) 3D printing. Our approach relies on a simulant of a Martian regolith unit rich in hydrated clay minerals and food-grade spirulina, used as proxies for local regolith and cyanobacterial biomass, respectively. The composites are further reinforced through crosslinking with the plant-based molecule genipin. Detailed rheological analysis was performed for the 3D printing feedstocks, while the printed composites were characterized using thermal gravimetric analysis (TGA), surface area porosity analysis (BET), microscopy and mechanical tests. Dissolution tests demonstrated that genipin effectively crosslinks the cyanobacterial biomass. The outcome is a highly porous, lightweight material with adaptable, complex morphology, which has significant potential for use in the resource-constrained environments of long-duration Mars missions.