High-resolution copper micropatterning on flexible substrates via laser-assisted surface activation

High-performance conductive metal circuits are essential in the modern electronics industry. Additive manufacturing techniques offer significant advantages over traditional photolithography (subtractive methods) in terms of simplicity, cost-effectiveness, and scalability. While various printing techniques have been explored, most are limited by minimum feature sizes in the tens of microns and require high-temperature post-processing to enhance the performance of functional materials. Here, a facile, efficient, and versatile additive manufacturing strategy is proposed for creating high-resolution copper patterns via laser-assisted selective metal deposition. This technique employs an ultrafast UV laser to selectively irradiate areas where copper patterns will be formed, inducing photochemical modifications. The irradiated regions are then seeded and subjected to ECP, resulting in a metal layer deposited on catalytic seed crystals. The copper coating achieved exhibits excellent conductivity (1.77 μΩ·cm) and adhesion (5B, ASTM), comparable to bulk copper. This approach enables the fabrication of high-precision miniature circuits with copper patterns as narrow as 4 μm on various untreated rigid and flexible substrates, accommodating diverse and complex design requirements. The approach is demonstrated for patterning metal interconnects in flexible electronics, including touch screens and thermal heaters, advancing the next generation of printed electronics.