Butterlfly photonic crystals and beyond: Minimal surfaces and periodic nets – Niels Bohr Institute - University of Copenhagen

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Butterlfly photonic crystals and beyond: Minimal surfaces and periodic nets

Triply-periodic minimal surfaces are found commonly as the self-assembled spatial structure of several soft-matter systems, including lipids, copolymers, mesoporous silicates and biological membranes. These surfaces subdivide space into two domains each of which has a network-like structure spanning infinitely. One of the more recent occurrences of a minimal surface structure, the so-called Gyroid surface, is in the porous chitin structure in the wing scales of some butterfly species. In these wing scales the structural length is approximately 300nm, commensurate with the wavelengths of visible light. This periodic structure acts as a photonic crystal and contributes to the coloration of the wings.

Interestingly, the Gyroid structure is chiral (or handed) and hence allows for a discriminating response to circularly polarised light. In this talk, I will review the Gyroid structure and other minimal surfaces and its formation by self-assembly, and also discuss chiral generalisations of the Gyroid structure. Gyroid-like structures are not only intriguing in their occurrence and possible function in nature, but may represent inspiring designs for photonic crystals and optical meta-materials.

Talk by: Gerd Schröder-Turk - Institute for Theoretical Physics, Friedrich-Alexander-Universität, Erlangen