Penguin feathers may hold an effective anti-icing solutionMcGill University research team develops chemical-free solution that could be used to de-ice electrical wires, wind turbines and even airplane wings
In 1998, ice build-up on electrical towers and wires caused the ice storm that paralyzed eastern Canada and the northeastern United States, leaving many people in the dark and cold for days and even weeks. Most of the techniques used to remove ice from wind turbines, pylons, drones and airplane wings are time-consuming, costly and energy-intensive, and they also require the use of various chemicals. A research team from McGill University has turned to nature and believes it has found a promising solution inspired by the Papuan penguin, which swims in the icy waters of the South Pole region. Despite surface temperatures well below freezing, this seabird does not accumulate ice on its wings.
"We first looked at the lotus leaf, which is very easy for water to glide over. Unfortunately, it doesn’t get rid of the ice as easily," says Anne Kietzig , who has spent nearly 10 years looking for a solution. An associate professor in the Department of Chemical Engineering at McGill University, she is also director of the Biomimetic Surface Engineering Laboratory. "Before studying the properties of penguin feathers, we had never seen a material from nature that could remove both water and ice. "
Fine wire mesh repels water and ice like a feather
"We found that the hierarchical arrangement of the feathers facilitated water wicking, and the barbs on the surface decreased ice adhesion," says Michael Wood, a newly minted Ph.D., collaborator with Anne Kietzig and co-author of a recent paper in ACS Applied Material Interfaces. "We were able to replicate these same water- and ice-repellent properties in a laser-machined wire cloth. "
Surprisingly, it’s the pores in the fabric, where the water takes refuge when the mercury drops, that hold the secret to the evacuation of the ice," says Kietzig. Since the water stored in these pores is the last to freeze, cracks are created as it expands, like in an ice cube mold. The crack that forms in each of the pores snakes along the surface of the woven fabric; it is then very easy to release the ice. "
Promising preliminary results
By subjecting surfaces coated with the wire cloth to wind tunnel testing, the team found that these surfaces exhibited 95% greater resistance to ice build-up than uncoated polished stainless steel sheet. Because no chemical treatment is required, this new technique could become a "maintenance-free" anti-icing solution for wind turbines, pylons, electrical wires and drones.
Given the risks and regulations for passenger air travel, it is unlikely that aircraft wings will be wrapped in wire cloth," notes Anne Kietzig. However, it is possible that aircraft wings will one day have a surface similar to the one we are studying and that de-icing processes will combine traditional techniques with surface textures inspired by penguin wings. "
More studies are needed, but the results so far are promising.
The study
The paper "Robust Anti-Icing Surfaces Based on Dual FunctionalityâMicrostructurally-Induced Ice Shedding with Superimposed Nanostructurally-Enhanced Water Shedding," by Michael J. Wood, Gregory Brock, Juliette Debray, Phillip Servio, and Anne-Marie Kietzig, was published in ACS Applied Material Interfaces.
https://doi.org/10.1021/acsami.2c16972
