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Not all surfaces and materials respond to water in the same way. Hydrophobic surfaces, for example, shed or repel water due to an absence of attraction. Hydrophilic surfaces, on the other hand, are water-loving and more receptive to water’s advances. While some surfaces and materials might possess one or the other of these characteristics, other surfaces can possess both.
Scientists funded by the National Science Foundation are studying a Namibian beetle, whose backside is a patchwork of hydrophobic and hydrophilic areas that help to collect and disperse water as needed. When thirsty, the beetle simply tilts up its backside, allowing accumulated water droplets to fall into its mouth. Engineers are now mimicking the beetle’s back and reproducing similar hydrophobic-hydrophilic surfaces, materials and products at the nanoscale. Already, as a result of this work, superhydrophobic chemical coatings have reached the marketplace by way of water-repellant shoes, shirts and mobile phones. Further applications could include everything from energy-saving power plants to self-cleaning windows.Image credit: Adam Paxson, Kyle Hounsell, Jim Bales, James Bird, Kripa Varanasi
