Engineers Mimic Birds’ Blue Hues

Studying feathers informs everything from eco-friendly dyes to technological advances.

Locked within the beautiful blue plumes of a blue jay or common kingfisher is the solution to a physical mystery. Ornithologists and physicists have discovered that these non-iridescent azure hues are created by the intricate, spongelike nano-architecture of the birds’ feathers. “These structural colors never fade with time,” says Vinod Saranathan of Oxford University. By mimicking these natural templates, engineers can create myriad applications, from eco-friendly, nontoxic dyes and cosmetics to lasers and more efficient fiber-optic cables.