Denali

As an avid hunter from South Arkansas, I became obsessed with concept of biomimicry clothing for waterproofing and warmth. Gore-Tex and similar materials are cool, but I’m not a fan of the PFAS, synthetics, etc. A duck’s coat is a superb natural waterproof, temperature-regulating membrane. Though different from Gore-Tex, a duck’s coat is the most similar naturally occurring waterproofing system to it. Both rely on micro-geometric shapes. Features small enough that liquid water can't penetrate while still allowing some gas/vapor interaction. Gore-Tex does this with fixed microholes; duck feathers do it with a fibrous mesh that traps air. Duck feathers have a hierarchical structure: a central rachis with branching barbs, which in turn have interlocking barbules and tiny hooks (barbicels). This creates a tight, porous mesh. Water sits on the surface, with air trapped in the micro-sized gaps. So droplets bead up and roll off rather than wetting through. Preen oil from the the duck's gland coats the feathers, enhances hydrophobicity, lubricates the mesh, and helps maintain flexibility/integrity. But he physical structure is the primary waterproofing mechanism; the oil is more of a conditioner and enhancer. I'll make another post or two about clothing options, but I found it extremely fascinating that one of the most popular synthetic waterproofing materials worked so similarly to something found in nature. But like always, mother nature always wins.