Structure and colour-production of the blue barbs of Agapornis roseicollis and Cotinga maynana

Electron tomography, three-dimensional Fourier analysis and colour prediction of a three-dimensional amorphous biophotonic nanostructure

“…all keratin channels and all air voids are interconnected with one another, respectively. This connection and their overall amorphous organization support the proposal that they are formed through a process of self-assembly similar to that observed in block copolymers (Dyck 1971;Prum 2006). Some of these polymers self-assemble into amorphous, bicontinuous structures that bear striking resemblances to spongy tissue (Shimizu et al 2004).…”

Kingfisher feathers – colouration by pigments, spongy nanostructures and thin films

“…The spectral peak depends on the dimensions of the sponge structures (Dyck, 1971;Finger, 1995;Shawkey et al, 2009). Spongy barbs are widespread among birds (Prum et al, 1999;Shawkey et al, 2003;Prum, 2006;Shawkey et al, 2006), but so far the optics of the sponge structures have evaded ready analysis because of the complexity of the structures and the deviations from regularity (Prum, 2006).…”

Structure and optical function of amorphous photonic nanostructures from avian feather barbs: a comparative small angle X-ray scattering (SAXS) analysis of 230 bird species

“…90 nm), low-resolution, two-dimensional slice of a three-dimensional nanostructure, such as aliasing, binning, etc. Nevertheless, most studies of avian structural colours have used twodimensional electron microscopy to characterize their underlying three-dimensional biophotonic nanostructures [3,[7][8][9]14,[17][18][19][21][22][23][24][25]. However, fundamental uncertainty remains about the exact organization of these three-dimensional amorphous feather barb nanostructures.…”