Polar bear fur could be key to advances in anti-icing solutions

The international study found that a unique mix of lipids in the fur’s sebum – an oily substance produced by the skin - reduces ice adhesion. This natural design could help prevent ice buildup on infrastructure such as frozen wind turbine blades or aeroplane wings.

Key to this discovery are the advanced quantum chemical simulations carried out by Surrey University’s computational chemistry team, which investigated molecular interactions between the fur’s sebum and ice. The team’s findings are detailed in Science Advances.

In a statement, co-author and study lead Dr Marco Sacchi, an Associate Professor at Surrey’s School of Chemistry and Chemical Engineering, said: “We found that specific lipids in the sebum, such as cholesterol and diacylglycerols, exhibit very low adsorption energies on ice. This weak interaction is what prevents ice from adhering to the fur.”

Experiments confirmed these theoretical findings, measuring ice adhesion strength before and after the fur’s natural oils were removed. Researchers found that untreated polar bear fur performed on par with high-performance fluorocarbon coatings used in sports and industry. However, when it was washed to remove the sebum, ice adhesion was four times higher than unwashed samples.

The study also explored the fur’s hydrophobicity and how it delays the onset of freezing in the Arctic, where temperatures drop below -40°C. According to the team, these properties alone could not explain the superior anti-icing performance.

Using techniques such as gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS/MS), and nuclear magnetic resonance (NMR), the team found it was a unique mix of lipids – particularly an abundance of cholesterol and diacylglycerols – responsible for this ability.

Dr Sacchi said: “It’s fascinating to see how evolution has optimised the sebum’s composition to avoid ice adhesion. We found squalene, a common lipid in other marine mammals, was almost entirely absent in polar bear fur. Our computational simulations revealed squalene strongly adheres to ice, and this absence significantly enhances the fur’s ice-shedding properties.”

The study was led by the Norwegian Polar Institute and the University of Bergen, with contributions from Trinity College Dublin, University College London, the National Museum of Denmark, and insights from Inuit communities.