Abstract Though additive manufacturing (AM) is well on its way to transform architecture, design, and construction, the integration of sustainable biomaterials capable of reducing the sector’s substantial carbon footprint remains limited. While traditional building materials like concrete, metals and plastics have reached industrial maturity in 3D printing, biomaterials largely remain confined to experimental prototyping due to challenges in performance, durability and scalability. This paper explores the potential of multi-material additive manufacturing (MMAM) to address these limitations and facilitate biomaterial fabrication at architectural scales. Building on a review of material developments in extrusion-based 3D printing, the study proposes and experimentally evaluates novel multi-material strategies that combine slow-curing, paste-based biomaterials with rapidly solidifying thermoplastic biocomposites. Two key approaches are introduced: the “interwoven” strategy layers different materials alternately as internal reinforcement, while the “intertwined” method juxtaposes distinct materials to provide external support. Through small-scale test cylinders and large-scale, application-oriented prototypes, produced with synchronized robotic extrusion systems, the research demonstrates significant improvements in print stability and achievable print height for biomaterial 3D printing. While challenges remain concerning inefficient fabrication workflows, material system optimization, and regulatory validation, the findings outline a viable pathway towards scaling biomaterial 3D printing and advancing a more sustainable, material-conscious architectural production.
Kilian Bauer (Wed,) studied this question.