Direct Photopatterning on Polysulfide Polymers for Engineered Surfaces and Anti-Counterfeiting Technology.

Laser modification of polymer surfaces is critical in many contexts, including self-cleaning materials, microelectronics, and biomedical research. Despite their utility, accessing these modified polymers requires expensive or complex materials and multistep fabrication, masking, and washing processes. Here, we present a simple and direct laser writing method for creating diverse, stable, and highly complex patterns on a polysulfide polymer made by inverse vulcanization. The key innovation is the spatial engineering and patterning of the polymer surface by precise control of the laser irradiation time. The polymer's vitrimer-like S-S bond network preserves complex surface patterns with high fidelity and long-term stability. Motifs such as lines, dots, channels, grids, teardrops, checkerboards, and fish scales were reliably and repeatedly created, highlighting the material's robust and versatile patterning capabilities. Hierarchical patterns could also be achieved by combining nanoscale hot-press templating with laser modification. This patterning versatility allows modulation of hydrophobicity, templated self-assembly of gold particles, and precise micrometer-scale optical structures, including diffraction elements and dynamic optical barcodes, with potential for anti-counterfeiting applications.