Fighting frost inspired by penguin feathers
Although they swim in icy waters and roam on pack ice all year round, penguins never end up with frozen wings. Researchers at McGill University therefore drew inspiration from their feathers to try to create an anti-icing device.
Indeed, the team of academics took an interest in the very structure of penguin feathers to develop a fine metallic web that resists the accumulation of ice. The goal: to offer an alternative to current de-icing methods (for electricity pylons and wind turbines, in particular) which are time-consuming, energy-intensive and generally rely on the use of chemicals.
“We first looked at the lotus leaf, which water slides off very easily. Unfortunately, it does not get rid of the ice as easily, ”explains in a press release Anne Kietzig, associate professor in the Department of Chemical Engineering at McGill University and director of the Biomimetic Surface Engineering Laboratory. “Before studying the properties of penguin feathers, we had never seen any material from nature that could shed both water and ice.”
The microstructure of penguin feathers (left) inspired researchers at McGill University to carve nanogrooves in the surface of a wire mesh (right) to make it more resistant to ice buildup. Photo: Courtesy of McGill University.
In fact, it is both the arrangement and the structure of the feathers of these seabirds that allow them to resist frost. By lasering nanogrooves into the surface of the wire mesh, the researchers were able to create a surface that approximates it and is much easier to defrost.
“Surprisingly, it is the pores of the canvas, where the water takes refuge when the mercury drops, that hold the secret of the evacuation of the ice, explains the professor. As 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 meanders along the surface of the woven fabric; it is then very easy to clear the ice.”
The study published this year by the research team determined that the surfaces covered with wire mesh had a resistance to the accumulation of 95% more ice than a simple sheet of unpolished stainless steel.