Engineers from Northwestern University have found a new surface technology to inhibit the formation of frost that might one day free humans from the hassles of defrosting the freezers or scraping the cars for ice. Inspired by the natural structure of leaves, this innovative anti-frosting method prevents 100% of frost formation on flat areas for an impressive duration of up to a week, which is a significant improvement over current surfaces that only resist frost for a few hours. This advance could save billions in maintenance and energy inefficiencies across various industries.
The research team led by Kyoo-Chul Kenneth Park found the results from work that was led by researchers, discovering delays in forming frost on changing the texturing of a surface, along with that of the graphene oxide. Such results from new work advance previously observed findings to show that the presence of millimeter-scale peaks and troughs in surfaces reduces the formation of frost by as much as 80%. It mimics the mode of formation of frost on the leafy surface: the veins in concave depressions of the leaf will not encounter frost; at the same time, there is an elevated tendency of encountering frost on convex parts of the structure. Using close experimentations and modeling based on calculations, it was shown by the authors that wavy surface morphologies inhibit valley condensation, thereby making frost formation impossible.
This concept was further built on by the addition of graphene oxide. The encapsulation in the structure of the material prevents the freezing of water vapor due to its acting as a kind of “trap” to the water vapor. In addition to millimeter-scale macrotextures, it further incorporated graphene oxide, hence, giving rise to very robust anti-frosting surface that resisted scratches, cracks, and contaminants. As per their method, they obtained an incredibly better performance compared with those existing anti-frosting solutions that showed merely partial resistance for a rather limited time.
Going beyond the convenience factor, it poses a very major aspect to safety and efficiency. Frost is dangerous when falling from the sky onto the airplanes, for the frosting adds drag to an airplane’s wings and potentially could make flight safety harder to maintain. Additionally, the formation of frost brings lower efficiency for refrigeration systems; as for power lines, an accumulation of frost there tends to snap the wires in a power outage because the weight is too great for the wire. Notably, frost may freeze a sensor in a car that might not work quite properly in order to assure it will operate safely.
Park emphasizes the point that frost prevention must be adaptive. An airplane would require only a few seconds of protection against frosting; power lines, however, in extreme environments demand much longer-term solution effectiveness. Such a hybrid would require that designers redesign airplane wings and power lines to enable less frost adherence, ensuring more safety and saving maintenance costs annually.