| Abstract Scope |
We develop a novel dual-component direct ink write (DC-DIW) additive manufacturing (AM) process that mixes a two-part polyurethane foam in the nozzle during extrusion and selectively deposits the ink layer-by-layer to build 3D foam structures. Unique to this process, the material foams and expands 2-3x in size while simultaneously curing after deposition. This transient expansion and curing process is understood and controlled to produce high-quality 3D foam parts. We tune resin rheology through material formulation and investigate how it couples to printing behavior, foaming kinetics, cellular structure, and final mechanical properties. By balancing foaming kinetics and printability, we achieve high-fidelity AM while preserving the foam's inherent soft and elastic properties, producing parts with a compressive modulus below 100 kPa while maintaining highly elastic behavior. These advances work towards the AM of architected foams for impact protection, vibration damping, and thermal management applications. |