Patternable, high-precision, controllable wettability copper layers for 3D resin-based weather-resistant electronics...

The realization of 3D patterned metal layers with manipulable surface wettability has significant potential, especially in integrating microelectronics with weather resistance and multifunctional liquid manipulation. However, developing a facile and efficient method to bring it to fruition remains a great challenge. In this work, we proposed a novel 3D selective metallization strategy that combines stereolithography 3D printing with laser-induced selective metallization (LISM). Utilizing 355 nm UV or 1064 nm lasers, this strategy can prepare 3D conductive copper patterns (or circuits) with controlled wettability on various 3D-printed resin parts. The copper layer surface prepared via LISM formed microstructures similar to the papillae on the surface of a lotus leaf, and it spontaneously exhibited superhydrophobicity (156.6°) after aging in the air at room temperature. Superhydrophobic 3D circuits with self-cleaning, corrosion-resistant, and anti-condensation performance were successfully fabricated. By further treating the copper layer with a 355 nm UV laser, we realized the transformation of the superhydrophobic copper layer to a superhydrophilic state, enabling us to prepare high-precision superhydrophilic patterns or channels. A 3D self-driven flow channel was fabricated to successfully realize 3D liquid manipulation and small-scale chemical experiments.