A simple diagram describing the selective reflectance of light from a pigment. See Image:complex_reflectance.svg for a more detailed diagram. (Photo credit: Wikipedia)Scientists have found nature's way of creating color that never fades, a technique they say could replace pigments used in industry with natural plant extracts in products from food coloring to security features in banknotes.
Layers of cellulose that reflect specific wavelengths of light - "structural color" found in peacock feathers, scarab beetles and butterflies, make a particularly intense blue in the Pollia condensata plant, scientists say.
Samples of the fruit in plant collections dating back to the 19th century had not lost any shine or intensity, they found.
"By taking inspiration from nature, it is possible to obtain smart multifunctional materials using sustainable routes with abundant and cheap materials like cellulose," said University of Cambridge physicist Silvia Vignolini.
"It is 10 times more intense and bright than any color achieved with a pigment," said Vignolini, who led the study with plant scientist Beverley Glover.