Scientists unlock ice-repelling secrets of polar bear fur for sustainable anti-freezing solutions

Polar bear fur’s natural ability to resist ice formation could pave the way for safer, more sustainable solutions to prevent ice buildup across industries such as aviation and renewable energy, according to researchers at the University of Surrey.

An international study published in Science Advances has explored the anti-icing properties of polar bear fur in extreme Arctic conditions, revealing a unique mix of lipids in the fur’s sebum – an oily substance produced by the skin - that drastically reduces ice adhesion. In the face of climate change, 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 the University of Surrey’s computational chemistry team, which investigated molecular interactions between the fur’s sebum and ice.

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. Dr Marco Sacchi, Associate Professor and Royal Society University Research Fellow in Physical and Computational Chemistry, Theme Leader in Sustainable Energy and Materials Research

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 – its water-repelling properties – and how it delays the onset of freezing in the harsh Arctic, where temperatures drop below -40°C. Yet 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.

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. Said Dr Sacchi

Led by the Norwegian Polar Institute and the University of Bergen – with contributions from Trinity College Dublin, University College London, and the National Museum of Denmark – the research also highlights the importance of Indigenous knowledge of the Arctic and builds on that. Inuit communities have long recognised the unique properties of polar bear fur, using it in tools and garments.

Our findings highlight the power of interdisciplinary collaboration. We combined experimental evidence, computational chemistry and Indigenous Arctic insights to uncover a fascinating natural defence mechanism – which could transform how we combat ice in everything from aviation to renewable energy. Dr Sacchi added

Dr Sacchi’s computational team at Surrey included Dr Neubi F. Xavier Jr. and Adam Pestana Motala, who carried out the molecular modelling that underpins the study’s conclusions.

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Notes to editors