One-step fabrication of superhydrophobic fabrics with stable mechanical performance in harsh conditions.

Developing robust water-repellent textiles is critical for outdoor, protective, and industrial applications. However, achieving long-lasting water repellency under mechanical stress remains a significant challenge. Conventional approaches typically rely on nanoparticle assemblies or PFAS-based finishes, which often detach or degrade when subjected to abrasion or harsh conditions. Here, we demonstrate a molecularly assembled robust superhydrophobic shell (MARS) technique that directly constructs an ordered, covalently bonded, fluorine-free silica shell on individual yarn fibers via a one-step process. MARS eliminates the need for discrete nanoparticles or fluorinated chemistries and is compatible with a wide range of natural and synthetic fibers. This fiber-level treatment maintains superhydrophobicity even after the fibers are woven or knitted into finished textiles, while preserving breathability and mechanical resilience. MARS combines biomimetic inspiration with practical, scalable fabrication to meet urgent performance needs. Unlike conventional coatings that progressively degrade, the permanently bonded MARS coating endures intensive abrasion, high-velocity water impacts, steam exposure, and extreme temperature cycles. By addressing key challenges such as PFAS restrictions and the fragility of traditional coatings, the MARS method paves the way for next-generation water-repellent fabrics that balance sustainability and high performance across outdoor, protective, medical, and industrial applications.