Polar Bear Fur: Anti-Freezing Properties

• Polar bear fur possesses unique anti-freezing properties due to a specialized mixture of chemicals in its grease.

Discovering the Secret

• Bodil Holst, a nano-physicist, was inspired by a German quiz show where she learned polar bears are "invisible" to infrared cameras.
• Polar bear fur maintains the same temperature as its surroundings, and does not freeze after the bears emerge from frigid water.
• Typical mammalian hair, like human beards, can freeze in cold, wet conditions.

Hair Grease Composition

• Polar bear fur has a unique combination of greasy compounds and lacks a specific compound that aids in freezing resistance.
• Initial investigations using high-powered microscopes didn't reveal special structural properties in the fur; the anti-icing property was due to a greasy substance.
• Washing the fur removed the grease, which significantly reduced its anti-icing properties.
• Molecular analyses identified high levels of specific compounds in the grease that resist freezing by preventing ice adhesion.
• Polar bear fur lacks squalene, a compound found in other marine mammals that promotes ice adhesion.

Performance and Comparisons

• Lab tests demonstrated that polar bear fur performs as well as fluorinated ski waxes, which have been banned in Norway due to environmental concerns.
• An experiment using human hair showed it lacks the anti-icing properties of polar bear fur, regardless of washing.

Potential Applications

• The research could inspire the creation of environmentally friendly anti-icing materials for various applications.
• Arctic people have known about the anti-icing properties of polar bear fur for centuries.