Additive Manufacturing of High-Performance Living Building Materials

The transition to sustainable and intelligent construction materials has accelerated the development of Living Building Materials (LBMs), which integrate biological components into synthetic materials for multifunctional performance. Here, we introduce a 3D-printable bacteria-loaded hydrogel composite that not only grows into mechanically reinforced structures via in-situ microbial biomineralization, but also offers low-carbon fabrication, self-strengthening potential, and advanced 3D printability. The dual-network matrix of alginate and gelatin methacrylate (GelMA) is reinforced with laponite nanoclay and glass sand to improve printability, maintain shape fidelity, and improve early mechanical properties. During curing, Sporosarcina pasteurii (S. pasteurii) embedded in the hydrogel germinates and proliferates, inducing uniform calcium carbonate precipitation throughout the matrix. After 14 days of microbial reaction, the resulting bio-composite achieves a compressive strength of 6.9 MPa and a compressive modulus of 855.1 MPa. Moreover, the embedded printing strategy enables the creation of complex, overhanging, and interlaced geometries that would be unattainable by extrusion alone, opening new design possibilities for functional LBMs. To conclude, this platform merges biological self-assembly with advanced manufacturing, offering self-strengthening, low-carbon materials for applications ranging from heritage conservation to artificial reefs and sustainable construction in resource-limited environments.