Some seabirds and semiaquatic mammals such as fur seals and otters trap a layer of air in their feathers and furs for thermal insulation against the ice cold water. While scientists have extensively studied the influence of chemistry and surface roughness on water-repellency of textured surfaces such as skin, little is known about the role of larger flexible objects such as hair, a common feature of the skin of semiaquatic insects, spiders and aquatic mammals.
The trapping of air in hairy surfaces and the water-repellent properties of undeformable hairy textures, which is key for animals’ thermal regulation.
Most earlier research work on water-repellant surfaces has been focused on nano- and micro-scale materials. Now for the first time, the team has demonstrated that larger-scale materials (at the scale of millimeters or centimeters), such as fur, can produce similar water-repellant properties. Such materials are likely to be less challenging to fabricate in large quantities than their smaller-scale counterparts.