Novel coating could prevent ice build up on wind turbines and aircraft
Researchers in the US have found a way to keep any metal surface free of ice and frost. The breakthrough, they believe, could have direct implications for a variety of metal surfaces used in wind turbines, aircraft and marine vessels.
Called SLIPS, for Slippery Liquid Infused Porous Surfaces, the technology is designed to expose a defect free, molecularly flat liquid interface, immobilised by a hidden nanostructured solid. On these ultra smooth slippery surfaces, fluids, solids, water drops, condensation, frost, and even solid ice can slide off easily.
The challenge, according to lead researcher Joanna Aizenberg, was to apply the technology to metal surfaces, especially as these materials are ubiquitous in the modern world, from airplane wings to railings. The researchers found a way to coat the metal with a rough material that the lubricant could adhere to. The coating, said to be non-toxic and anti-corrosive, is designed to be finely sculpted to lock in the lubricant and can be applied over a large scale, on arbitrarily shaped metal surfaces.
To demonstrate the robustness of the technology, the Harvard University researchers successfully applied it to refrigerator cooling fins and tested it under a prolonged, deep freeze condition. Compared to existing 'frost free' cooling systems, their innovation was said to completely prevent frost far more efficiently and for a longer time.
"Unlike lotus leaf-inspired icephobic surfaces, which fail under high humidity conditions, SLIPS-based icephobic materials, as our results suggest, can completely prevent ice formation at temperatures slightly below 0°C while dramatically reducing ice accumulation and adhesion under deep freezing, frost forming conditions," said Aizenberg.
In addition to allowing for the efficient removal of ice, Aizenberg says the technology lowers the energy costs associated by several orders of magnitude. This means that the readily scalable technology could hold promise for broad application in the aviation industry and in other high humidity environments where an icephobic surface is desirable.
"This new approach to icephobic materials is a truly disruptive idea that offers a way to make a transformative impact on energy and safety costs associated with ice, and we are actively working with the refrigeration and aviation industries to bring it to market," Aizenberg concluded.
