Figure 3.

A surface evolver simulation of the wetting phenomena on a one-dimensional model a bird feather by different liquids [36]. As the pressure differential across the air–water interface increases from (a) zero, (b) 80 Pa and (c) 160 Pa, higher and higher fractions of the solid texture is wetted by water. The response of the same feather in contact with (d) ethylene glycol (γ_lv = 44 mN m⁻¹, θ_adv = 100°), (e) hexadecane (γ_lv = 27.5 mN m⁻¹, θ_adv = 80°) and (f) octane droplet (γ_lv = 21.6 mN m⁻¹, θ_adv = 60°) with negligibly small pressure differential is depicted. (Online version in colour.)