Laser-Induced Synthesis and Passivation of Intrinsically Antioxidative Nano-Copper for Durable Electronics

The ever-increasing costs, along with rigorous storage requirements, are the primary obstacles to the sustainable development of pure metallic inks for advanced electronics. The chemically reductive conversion of copper (Cu) from its much cheaper oxides offers a comparable alternative, whereas suffering from the intrinsic oxidation issues that lead to conductivity failures. Here, we report laser-induced synthesis and passivation of robust nano-Cu, achieving superior durability under harsh humid-thermal conditions (190°C and 90°C, 90% RH) in the absence of additional encapsulations. Through selective and controllable metallization, the nascent Cu is equipped with well-defined dual-ligand barriers at interface, which are functionalized by formate crystallographic coordination and oleylamine hydrophobization. Such surface modification imparts the as-formed Cu with limited resistance increase over prolonged humid-thermal fluctuations. As demonstrations, we create conformal and wearable sensor systems with passivated Cu interconnects that withstand humid-thermal erosion and provide signal alerts. This laser technology bridges the gap between high-performance Cu nanomaterials and cost-effectiveness, empowering endurable electronics for real-life extremes.