Ice on windscreens and plane wings could become a thing of the past with new technology in development that repels ice without heat or chemicals.
By building a pattern of tiny grooves into the surface that needs to be protected, surface ice can end up reduced by 90 percent, researchers said.
Ice building up on windscreens in winter is a huge source of nuisance to drivers – and a potential source of danger. Whether the motorists scrapes it off, pours boiling water on it or blasts it with chemicals, it is a chore for most. Anti-freeze chemicals are often poisonous – and a hazard to the environment in waterways.
In addition, for airplanes, huge amounts of chemicals are used in keeping wings clear from ice, which can stop planes taking off.
It can take thousands of gallons of anti-freeze sprayed on an airplane to rid a wing of ice.
A new discovery by scientists at Virginia Tech is an anti-ice surface that remains 90 percent ice free without chemicals or heating.
The research demonstrates how a passive anti-ice surface can work – and keep surfaces almost entirely frost free without energy or chemicals.
“Frosting is a big issue, and researchers have been working to solve this problem for years,” said Farzad Ahmadi, a doctoral student at Virginia Tech’s Department of Biomedical Engineering and Mechanics.
Traditional approaches to frost have relied on the application of antifreeze chemicals or energy inputs, like heat.
Even the age-old method of throwing salt down on roadways is essentially a chemical treatment.
Other recent advances include special coatings for surfaces that prevent frost formation, but these coatings aren’t durable and tend to wear off easily.
“For this project, we’re not using any kind of special coating, chemicals, or energy to overcome frost,” Ahmadi said. “Instead we’re using the unique chemistry of ice itself to prevent frost from forming.”
The surface has been created using aluminum. A microscopic array of elevated grooves on the surface creates tiny strips where small strips of ice form.
This “sacrificial” ice creates low pressure in the surrounding grooves – and sucks moisture from the air onto the ice stripe, keeping overlapping areas free of frost even in humid, sub-freezing conditions.
These sacrificial ice stripes make up only 10 percent of the material’s surface area, leaving the remaining 90 percent completely dry.
“The real power of this concept is that the ice stripes themselves are the chemistry, which means the material we use is irrelevant,” said Virginia Tech professor Jonathan Boreyko. “As long as you have that proper pattern of sacrificial ice, the material you use could be virtually anything. So, there are a lot of possibilities.”
The researchers said candidates for the surface are aircraft wings and car windshields will also be applications for the patented anti-frosting technology.