Biomimetic Superhydrophobic Metal Layers on 3D-Printed Resin via Laser for Flexible Electronics and Magnetic Droplet Manipulation.

3D-printed flexible electronics have the advantage of flexible shapes and the freedom to customize 3D structures to further enhance functionality. However, conventional fabrication methods involve printed conductive inks or multi-material 3D printing, which bring a series of problems for the adhesion strength of the conductive layer and the fabrication complexity. In addition, the metal conductive layer is exposed to air and faces the problem of being susceptible to deterioration. Here, this work proposes a new flexible electronics fabrication strategy that combined flexible 3D printing with laser-induced selective metallization, successfully patterning flexible conductive copper layers in 3D with high precision. To further improve the weather resistance of the copper layer, this work also electroplates a nickel layer on its surface. The nickel and copper layers automatically acquire superhydrophobicity after only a few days in the air, giving them enhanced weather resistance. The nickel layer obtained is also ferromagnetic, enabling high-precision custom magnetic parts patterning. On this basis, this work successfully manufactures personalizable flexible electronics, including magnetic field-driven flexible robots. By patterning the ferromagnetic nickel layer, this work also achieves 3D manipulation of magnetic droplets on the superhydrophobic metal layer. The 3D-printed multifunctional devices prepared by this strategy provide a new idea to flexible electronics.