Biofabrication in architecture: 3D bioprinting of nature-sourced multi-material powder hydrogels, material testing, and prototyping

Abstract

Persistent architectural interest in material recycling and biodegradability is driving the utilization of living materials in construction. In this study, the authors explored the use of natural powder-mixed bioprintable hydrogels for cold-processing, robot-assisted extrusion additive manufacturing (EAM). We sought to develop a building-scale bio-composite ink capable of rapid gelation, vertical stacking, and minimal dry shrinkage for large 3D printing. Assorted combinations of natural polymeric and organic powders were empirically compounded to evaluate their extrudability and shape durability. The research revealed that a hydrogel construct consisting of xanthan gum, chlorella, cellulose, eggshell, and charcoal exhibited optimal performance, attributed to the composition's ability to enhance flowability while maintaining structural strength. Utilizing this ink, architectural designs were prototyped to showcase real-scale feasibility. Mechanical testing demonstrated that the architectural form of the bio-sourced mixture performed comparably to traditional materials, indicating its viability for future 3D printing in building construction.