Quantification of feather structure, wettability and resistance to liquid penetration.

Birds in the cormorant (Phalacrocoracidae) family dive tens of metres into water to prey on fish while entraining a thin layer of air (a plastron film) within the microstructures of their feathers. In addition, many species within the family spread their wings for long periods of time upon emerging from water. To investigate whether wetting and wing-spreading are related to feather structure, microscopy and photographic studies have previously been used to extract structural parameters for barbs and barbules.

Optimal design of permeable fiber network structures for fog harvesting.

Fog represents a large untapped source of potable water, especially in arid climates. Numerous plants and animals use textural and chemical features on their surfaces to harvest this precious resource. In this work, we investigate the influence of the surface wettability characteristics, length scale, and weave density on the fog-harvesting capability of woven meshes.

Fluoroalkylated silicon-containing surfaces-estimation of solid-surface energy.

The design of robust omniphobic surfaces, which are not wetted by low-surface-tension liquids such as octane (γlv=21.6 mN/m) and methanol (γlv=22.7 mN/m), requires an appropriately chosen surface micro/nanotexture in addition to a low solid-surface energy (γsv).

Scale dependence of omniphobic mesh surfaces.

We provide a simple design chart framework to predict the apparent contact angle on a textured surface in terms of the equilibrium contact angle on a chemically identical smooth surface and details of the surface topography. For low surface tension liquids such as methanol (gamma(lv) = 22.7 mN/m) and octane (gamma(lv) = 21.

Thermal annealing treatment to achieve switchable and reversible oleophobicity on fabrics.

Surfaces that are strongly nonwetting to oil and other low surface tension liquids can be realized by trapping microscopic pockets of air within the asperities of a re-entrant texture and generating a solid-liquid-vapor composite interface. For low surface tension liquids such as hexadecane (gamma(lv) = 27.5 mN/m), this composite interface is metastable as a result of the low value of the equilibrium contact angle.