Bioinspired surface dealloying enables high-laser-absorption copper powders for additive manufacturing

High-thermal-conductivity, highly reflective metals and their alloys present persistent challenges in additive manufacturing due to intrinsically low laser absorptivity and a narrow processing window. Here, inspired by the light-harvesting microstructures of plant leaves, we introduce a bioinspired surface-structuring strategy for copper-alloy powders to enhance laser–powder energy coupling by chemical dealloying, which produces a multiscale hierarchical architecture comprising Cu-rich clusters interconnected by nanoporous networks on the powder surface. Despite the presence of reflective Cu-rich phases, this engineered surface markedly suppresses near-infrared reflectivity, promoting efficient laser absorption. By controlling the dealloying extent, near-pure copper powders with greatly improved laser absorptivity and continuous single-track printing with low energy input are achieved. Furthermore, the dealloying-induced nanopores serve as effective anchoring sites for high-volume-fraction nanoparticle reinforcements. This scalable approach overcomes a long-standing energy-coupling bottleneck in metal additive manufacturing, enabling sustainable, low-energy fabrication of high-performance copper and copper-based nanocomposites.