Light, strong, and multifunctional copper microlattices via nano-oxide modulation in laser additive manufacturing

Micro-architected copper (Cu) lattices are emerging as a promising platform for multifunctional applications. However, their laser additive manufacturing has long been hindered by the intrinsically high thermal conductivity and reflectivity of copper. In this work, we propose a nano-oxide-assisted laser additive manufacturing framework for Cu metamaterials that integrates oxygen-content engineering at the material level, high-precision fabrication at the processing level, and functionality-driven lattice design. The architecture, printability, mechanical strength, and thermal/electrical conductivity of Cu microlattices can be deliberately tailored to meet application-specific requirements. For lightweight and mechanical load-bearing applications, high-oxygen Cu was intentionally designed to maximize mechanical strength, achieving a superior specific energy absorption exceeding 10 J/g at densities below 0.5 g/cm 3 . For thermal management in highly power-dense electronics, our design framework inversely selects low-oxygen conditions, the generated gyroid cold plates maintain high intrinsic conductivity while improving geometric fidelity, delivering a 20% reduction in stabilized-temperature of heat source and significantly reduced pressure drops compared to pure Cu. Moreover, for electromagnetic devices where extreme geometric precision is paramount, medium-oxygen conditions are used to provide optimal geometric precision for feature-sensitive structures, enabling the successful fabrication of sixth-order 3D Sierpinski fractal antennas that exhibit over threefold stronger signal intensity and excellent multi-band resonance. Overall, this work establishes oxygen-content tuning as a practical design variable for selecting manufacturability–performance windows in architected Cu, enabling application-specific optimization across mechanical, thermal, and electromagnetic functions.