It’s hard to think about ice right now in Alabama. Temperatures are expected to hit the mid-80s tomorrow. That’s why I love living in the south. For many of you though, winter is still hanging on. And that means ice on your car windshield.
One side was treated with an ‘icephobic’ coating; the other side wasn’t. This coating prevents ice from sticking. What was the solution? Rubber. Synthetic rubber to be precise.
Kevin Golovin, a doctoral student in materials science and engineering, talks about how researchers have been tackling ice-repellent surfaces.
“Researchers had been trying for years to dial down ice adhesion strength with chemistry, making more and more water-repellent surfaces,” said Kevin Golovin, a doctoral student in materials science and engineering. “We’ve discovered a new knob to turn, using physics to change the mechanics of how ice breaks free from a surface.”
The researchers, led by Anish Tuteja (associate professor of materials science and engineering), initially focused on water-repelling surfaces. While great for water, it’s not so good at repelling ice.
During their various experiments, the researchers noticed rubber was great at repelling ice. And, it didn’t even need to be water-repellent. In fact, being water-repellent had nothing to do with getting rid of ice. The rubbery coating was getting rid of ice because of a phenomenon known as “interfacial cavitation.” The press release explains this phenomenon perfectly.
Golovin explains that two rigid surfaces–say, ice and your car windshield–can stick tightly together, requiring a great deal of force to break the bond between them. But because of interfacial cavitation, a solid material stuck to a rubbery surface behaves differently. Even a small amount of force can deform the rubbery surface, breaking the solid free.
“Nobody had explored the idea that rubberiness can reduce ice adhesion,” Tuteja said. “Ice is frozen water, so people assumed that ice-repelling surfaces had to also repel water. That was very limiting.”
Another perk for using a rubbery solution is researchers have complete control to fine-tune it. According to the team, they have developed hundreds of ice-repelling formulas already. Some are smooth and are better at repelling ice but at the expense of durability. Others are rough and more durable.
Golovin explains some of the applications for this spray on coating. “An airplane coating, for example, would need to be extremely durable, but it could be less ice-repellent because of high winds and vibration that would help push ice off,” Golovin said. “A freezer coating, on the other hand, could be less durable, but would need to shed ice with just the force of gravity and slight vibrations. The great thing about our approach is that it’s easy to fine-tune it for any given application.”
And now I just realized something. Flex Seal has been doing this for years.
Alright Michigan researchers, which one of you is getting your ideas from late night infomercials?
Unlike Flex Seal, the Michigan researchers aren’t bullshitting us. There’s still some work that needs to be done before we see this on airplanes and airplanes, but Tuteja believes commercial applications could begin within a year. The first will probably be linings in commercial frozen food packaging.