International.
Instead of applying a de-icing agent to strip ice from the plane's wings before a winter storm, airport staff could in the future simply watch the pieces slide right out without lifting a finger.
Scientists report that they have developed a liquid substance that can make wings and other surfaces so slippery that ice cannot adhere. The slippery substance is secreted from a film on the surface of the wing when temperatures fall below zero and removed back into the film when temperatures rise.
The liquid materials they secrete developed by the researchers are called self-lubricating organic gels, or slugs. "SLUG's technology has a number of formulations and applications, including in gel form that can be encapsulated in a film coating on the surface of a wing or any other device," says research director Atsushi Hozumi, Ph.D.
"We come across this idea when we look at the actual slugs in the environment," explains Chihiro Urata, Ph.D. "Slugs live underground in soils when it's daylight and crawl at night. But we never see slugs covered in dirt. They secrete a liquid mucus into the skin, which repels dirt and dirt slides out. From this, we began to focus on the phenomenon known as syneresis, the expulsion of liquid from a gel."
The gel and liquid repellent substance are created in a silicone resin matrix. The mixture is cured and applied to a surface as an almost transparent and solid film coating, Urata explains. Both Urata and Hozumi are at the National Institute of Advanced Industrial Science and Technology (Japan).
The team examined the antifreeze properties of various types of organic gels under testing at different temperatures, Urata says. The discovery of the thermo-sensitive secretion properties of the material was an unexpected surprise. The tests also showed that secretion is a reversible process. Syneresis gradually begins when temperatures fall below zero. So, although ice can form, it cannot adhere to the surface and slides outward. Once the temperature rises above freezing, the liquids return back to the film.
