The leaf-inspired surface helps prevent frost

By adjusting the surface texture, scientists can reduce the ability of ice and frost to form 60 - 80% on all materials.

The new design has the potential to be practical, saving time and energy in defrosting the surface of equipment such as aircraft wings, reducing the risk of delays or cancellations. The research, conducted by experts from Northwestern University, was published in the Proceedings of the US National Academy of Sciences on March 10.

Frost appears less in leaf veins (sunken area).(Photo: Phys).

"The idea comes from leaves in the wild," said team leader Kyoo-Chul Park from Northwestern University. "Observations show that more ice and frost occur in the convex regions of the leaf. Meanwhile, on the recesses (veins), frost appears less. This is due to the geometrical structure of the leaves." trees rather than material properties ".

Frost, or hoarfrost , is the phenomenon of water vapor in the air freezing when exposed to cold surfaces below 0 ° C. It is common in cold climates in the winter, causing a lot of annoyance. Frosting is also observed inside the refrigerator or freezer, significantly reducing energy efficiency on the appliance.

Through tests and computer simulations, Park and his colleagues found that frost formation was enhanced on top of the ridge and decreased in grooves (recesses) on wavy surfaces. Only a small amount of water condenses in these channels and then evaporates, resulting in some areas that are not frosty. Even when using a material with a surface that absorbs water, water still evaporates the indentations at temperatures below the freezing point.

Park used this information to find the surface texture that best prevents frost formation. Accordingly, a rippled surface with a series of millimeter-sized peaks and grooves will help reduce frost formation by 60 - 80%.

"Because frost only appears on the tops of rippling surfaces, it helps reduce the time and energy savings in defrosting. All we need to do now is provide instructions for designing." this wavy surface, " Park said.