Rapid 3D printing of hierarchical nanoporous copper structures with self-disintegration capability.

Micro-architected nanoporous metals are widely used in electrochemical and catalytic systems, but conventional powder metallurgy cannot readily produce structurally complex, microscale variants. We present a micro continuous liquid interface production (µCLIP)-based 3D printing followed by low-temperature sintering to fabricate hierarchical copper architectures with tunable porosity. Copper-monomer mixtures containing nanoporous copper powders and copper nanoparticles are printed into polymer matrix composites at a vertical speed of 4.17 μm·s⁻¹, with predicted and designed capillary imbibition of monomers into nanopores enabling high filler loading (62.21 vol.%). Subsequent sintering under a reducing atmosphere tailors nanoporosity and products' oxidation response. At 400 °C, sintering yields nanoporous networks that exhibit high chemical reactivity and unique self-disintegration behavior upon air exposure under a mechanical load, accompanied by an 8500-fold increase in electrical resistance. At 650 °C, sintering produces dense copper with improved oxidation resistance, exhibiting minimal resistance changes upon air exposure. This work establishes µCLIP as a scalable route to complex, hierarchical porous metal components for applications.