Photonic Structures in the Animal Kingdom: Valuable Inspirations for Biomimetic Applications - Biomimetic Architectures by Plasma Processing - page 13

1.4 Two-Dimensional Photonic Structures

Two-dimensional photonic structures (see Fig. 1.2b) have two
periodic directions and are thus essentially made up of locally
parallel fibres in a square or hexagonal lattice. To date, relatively few
2D photonic structures have been found in animals.
Striking examples are the eye spots on the tail feathers of the
peacock, . In the feathers, square lattices of melanin

rodlets surrounded by air act as 2D photonic structures (Fig. 1.6a).
The diversity of different, iridescent colours in the eyespots arises
from a change in the local dimensions and the number of melanin
layers [33].

Pavo cristatus

Figure 1.6 2D photonic structures: (a) The photonic structure that

underlies the brilliant colours of the eye spots of peacock
feathers is a matrix of melanin rodlets in an air environment
that is arranged in a square lattice. (b) Different colours are
reflected due to different dimensions and layer numbers, (c)
green, (d) brown . Figures (a-d) reprinted with permission
from Ref. [33]. Copyright [2003] National Academy of Sciences,
U.S.A. (e) The striking colours of the polychaete worm Beroë

cucumis are due to a (f) 2D lattice of cylinders in the spine .

Figure (e) reprinted from Ref. [35], Copyright 2005, with
permission from Elsevier and Figure (f) Reprinted with
permission from Ref. [34], Copyright 2006, by the American
Physical Society. Bars: (a,e) 1 cm, (b) 1

µ

m and (c,d,f) 500 nm.