SESANS investigation of structural colour in polar bear hair

Structural colour arises not from dyes or pigments, but from light scattering off of the inner geometry of the material itself. This offers greater stability than standard absorbing techniques, as there is no chemical pigment to break down and fade. The occurrence of structural colour in biological materials has been well studied and bio-mimicry of the structures provide multiple industrial applications.While the name structural colour implies visible light, the same concept can be extended into the infra-red. Electron microscopy has shown the presence of micron scale structures within the hair of a polar bear. This places the "colour" near the peak of the polar bear's own thermal radiation, creating an efficient insulator. Recent upgrades to the SESANS apparatus on the Larmor beam-line make this structure accessible to scattering methods for the first time.