Spray-on repellent could protect airplanes, wind turbines from ice

The spray-on formula combines several synthetic rubbers, adding a clear, rubbery coating the causes ice to slide off of car windshields, wind turbines and airplane wings.

"Researchers had been trying for years to dial down ice adhesion strength with chemistry, making more and more water-repellent surfaces," Kevin Golovin , a doctoral student in materials science and engineering at Michigan , said in a news release. "We've discovered a new knob to turn, using physics to change the mechanics of how ice breaks free from a surface."

Previously, researchers have focused on keeping surfaces ice-free by making them either slippery or water-repellent. The new technique does neither. Instead, researchers reshaped the bond between ice and surface materials by using rubber.

"Nobody had explored the idea that rubberiness can reduce ice adhesion," said Anish Tuteja , associate professor of materials science and engineering. "Ice is frozen water, so people assumed that ice-repelling surfaces had to also repel water. That was very limiting." Lab tests showed the rubber coating was able to weaken the bonds that develop between ice and surface material, so that even the slightest of forces -- gravity or a light breeze -- can separate the two. Testing also proved the new coating to be durable and relatively cheap to make. The coating's formula can be adjusted to alter the balance between softness and ice repellency. The softer the rubber coating, the more ice repellent -- but the less durable.

"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 explained. "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."

Scientists detailed the new coating in the journal Science Advances.