Modern technology that has been looking around the nature to learn its techniques has stumbled upon a unique technology used by the Namib Desert Beetle that collects airborne water despite living in the world’s hottest places.
Virginia tech researchers emulated the same technique using photolithography to pattern chemical arrays that attract water on surface that repels water, thus controlling the spread of frost.
The Namib Desert Beetle has a bumpy shell and the tips of the bumps attract moisture which forms into drops but its sides are smooth and repel water that is channelized directly into the beetle’s mouth. Essentially, controlling dew drops from growing is the key prevent frost, whose journey across a surface begins with a single, frozen dew drop, the researchers said.
“The twist is how ice bridges grow. Ice harvests water from dew drops and this causes ice bridges to propagate frost across the droplets on the surface. Only a single droplet has to freeze to get this chain reaction started,” said Jonathan Boreyko, an assistant professor of Biomedical Engineering and Mechanics in the Virginia Tech College of Engineering, who led a team of researchers at the Oak Ridge National Laboratory to develop their beetle-inspired, frost-controlling chemical pattern on a surface of about one centimeter.
“Dew drops preferentially grow on the array of hydrophilic dots. When the dots are spaced far enough apart and one of the drops freezes into ice, the ice is no longer able to spread frost to the neighboring drops as they are too far away. Instead, the drops actually evaporate completely, creating a dry zone around the ice,” Boreyko said.
Armed with the results, researchers are confident that creating frost-free zones on larger surfaces can have a variety of applications. For instance, the water that forms and freezes on heat pump coils or the deicing with harsh chemicals that has to take place on wind turbines or airplane wings or car windshields can be prevented saving huge expenditure on energy to remove them.
C. Patrick Collier, co-author of the research paper and a scientist at the Nanofabrication Research Laboratory Center for Nanophase Materials Sciences at Oak Ridge National Laboratory echoes the optimism when he said, “We are paying more attention to ways to control water condensation and freezing. It could result in huge cost savings.” If designed properly with this beetle-inspired pattern, it creates a dry zone rather than frost on all these surfaces.
The study has been published in Scientific Reports, an online journal from the publishers of Nature.