Color Modulation in Morpho Butterfly Wings Using Liquid Crystalline Elastomers

The study of evolutionarily optimized solutions of animals and plants is used in biologically inspired engineering to find inspiration for the development of better devices and technology. In nature, the morphology of living systems is responsible not only for the biological functions but frequently also for their appearance. A fascinating feature based on material architecture is that of structural coloration, which receives growing interest for the development of efficient reflective coatings, photonic devices, and optical sensors. [1-3] An inspiring example is provided by the nanoarchitecture of the butterfly wings. Among them, the color of Morpho menelaus [4-6] is mainly determined by the interaction of light with the wing's complex scale morphology that produces a brilliant blue structural color as a sum of multiple optical effects. A specific characteristic of this species is the low angular dependence of wing coloration that remains bluish over a wide range of viewing angles, in contrast to what is typically observed in many other structural colors. [7] This unique property motivated a profound exploration of the morphology of the wing scales that are constituted by nanostructured cover and ground scales. The scales are nanostructured in ridges with a lamellar structure