Beetle inspires ultra-white coating for use in paints, food and pharma

The super-thin, non-toxic, lightweight, edible ultra-white coating could also find applications in the cosmetic, food or pharmaceutical industries.

The material, developed by a Cambridge University team working with researchers from Aalto University in Finland, is made from non-toxic cellulose and is said to achieve such bright whiteness by mimicking the structure of the scales found on Cyphochilus beetles. The results are reported in Advanced Materials.

Bright colours are usually produced using pigments, which absorb certain wavelengths of light and reflect others, which are then perceived as colour.

To appear as white, however, all wavelengths of light need to be reflected with the same efficiency. Most commercially-available white products (such as sun creams, cosmetics and paints) incorporate highly refractive particles - often titanium dioxide or zinc oxide - to reflect light efficiently. These materials are safe but not fully sustainable or biocompatible.

The Cyphochilus beetle is different. It produces its ultra-white colouring by exploiting the geometry of a dense network of chitin, which has a structure which scatters light extremely efficiently and results in ultra-white coatings which are very thin and light.