A species of desert beetle in southern Africa may hold the key to understanding how car windshields and airplane parts can be kept from freezing in low temperatures.
In a study featured in the journal Scientific Reports, researchers from the Virginia Tech examined how insects known as Namib Desert beetles (Stenocara gracilipes), or fogstand beetles, are able to thrive in one of the hottest place on Earth by collecting airborne water.
They discovered that the shell of the beetle has ridges that can collect moisture, which form into water droplets. The sides of their shell, on the other hand, serve as channels that help lead the water directly into the mouths of the insects.
The researchers took inspiration from the concept in their development of a special pattern that can control frost. They used a chemical treatment process known as photolithography to recreate the water-absorbing properties of the Namib Desert beetle's shell on a smooth, water-repelling surface.
In nature, frost typically forms when small droplets of water freeze and become connected with other droplets nearby. If these frozen droplets are kept from connecting and confined to only a small area, it will help prevent frost from forming.
Jonathan Boreyko, one of the authors of the study, said that fluids shift from high pressure to low pressure. He is also an assistant professor of biomedical engineering and mechanics at Virginia Tech.
Boreyko explained that ice serves as a form of humidity sink because its vapor pressure tends to be lower than the vapor pressure of water. This difference in pressure is what causes ice to grow.
If their beetle-inspired pattern is exposed to the same varying levels of pressures, it would result in the creation of a dry zone instead of frost.
In their test, Boreyko and his colleagues were able to create a single dry zone, which surrounded a piece of ice.
He said that the dew drops tended to form in areas where there are hydrophilic dots. Spacing the dots far away from each other prevented a frozen dew drop from bridging to others. These isolated drops eventually evaporated, causing a dry zone to form around the ice.
The researchers tested their new anti-frost technology on a small scale at the Oak Ridge National Laboratory. However, they hope that it could also be tested at an industrial scale in future experiments.
The beetle-inspired technology can be used to prevent wind turbines and airplane wings from freezing in cold weather. This would save companies a lot of time and money from having to use large amounts of chemicals just to defrost their equipment.
