Strong water repellent surfaces discovered in nature
Through the investigation of insect surfaces, Penn State researchers have detailed a previously unidentified nanostructure that can be used to engineer stronger, more resilient water repellent coatings.
With an enhanced ability to repel droplets, this design could be applied to personal protective equipment (PPE) to better resist virus-laden particles, such as COVID-19, among other applications.
“For the past few decades, conventionally designed water repellent surfaces have usually been based on plants, like lotus leaves,” said Lin Wang, a doctoral student in the Department of Materials Science and Engineering at Penn State and the lead author of the paper.
Classical engineering theories have used this approach to create superhydrophobic, or water repellent, surfaces. Traditionally, they are manufactured with low solid fraction textures, which maintain an extremely thin layer of air above a low density of microscopic, hair-like nanostructures, which the researchers liken to an air hockey table.
“The reasoning is if the droplet or object is floating on top of that air, it won’t become stuck to the surface,” said Tak-Sing Wong, the Wormley Early Career Professor of Engineering, associate professor of mechanical and biomedical engineering and Wang’s adviser.
