Synthesis of bio-inspired multilayer polarizers and their application to anti-counterfeiting

Abstract

Some insects, such as Papilio blumei and Suneve coronata, are known for exhibiting polarization effects on light such as color contrast or geometrical polarization rotation by reflection on their wing scales. The photonic structures found on these species that show these properties are multilayered spherical cavities or triangular grooves which polarize the light due to multiple inner reflections. These polarization effects, in addition to the intrinsic color-mixing properties of these photonic structures, are of interest in the anti-counterfeiting field due to their invisibility to the naked eye. In this paper, we report micro-fabrication techniques to produce bio-inspired cylindrical grooves (C-grooves) and triangular grooves (V-grooves) that demonstrate the same properties. Theoretical analyses were carried out by using multi-scale simulation (MS) as well as by finite-difference time-domain (FDTD) in order to compare the polarization capability of both structures. The V-grooves show greater polarization contrast than the C-grooves, but the spectrum is specular. The C-grooves exhibit lower polarization effects but have a dispersive spectrum. In both cases, the structures show additional optical properties, such as diffraction, macroscopic color contrast under a polarizer, and contrast inversion due to geometries which contribute to their uniqueness.

Mining the Smartness of Insect Ultrastructures for Advanced Imaging and Illumination

“…The structural coloration inspired by the wings of butterflies and beetles boasts optical properties such as iridescence, polarization caused by interference, scattering, and diffraction. In Figure , biologically inspired structures for structural coloration are anatomically categorized, depending on approach and process design from a single‐layer level, a multilayer level, a sculpture level, to a quasi‐ordered level . Textures on the layer itself, for example, holes, C‐grooves, and zigzags in Figure a, produce structural colors.…”

“…Textures on the layer itself, for example, holes, C‐grooves, and zigzags in Figure a, produce structural colors. Poncelet et al fabricated bioinspired cylindrical and triangle grooves for reproducing color contrast and polarization effect from the cuticle of Papilio blumei in Figure b . Umh et al reported nanobowl structures of TiO 2 , analogous to the cuticle of Cicindela oregona .…”

“…Copyright 2016, American Chemical Society. b) U‐groove/V‐groove, Reproduced with permission . Copyright 2015, IOP Publishing.…”

Facile fabrication of micro-grooves based photonic crystals towards anisotropic angle-independent structural colors and polarized multiple reflections

“…Furthermore, multiple reflections would induce a geometric polarization rotation of the light which had been widely found in living organisms, such as the wing of Papilio butterfly [32]. Many efforts have been made on mimicking those structures, such as layer deposition techniques, conformal-evaporated-film-by-rota tion and lithography [33][34][35]. However, all those methods are high cost, difficult to prepare in large scale, and require complex manufacture process.…”

Polysulfide microspheres with chemical modification for generation of interfaces with macroscopic colour variation and biomimetic superhydrophobicity

“…The phenomenon is attributed to the interference, diffraction and dispersion of light with facile periodic morphologies. [15][16][17] Materials with this characteristic have been widely used in many elds such as sensing, 18,19 bioassay, 20,21 anti-counterfeiting, 22 and optical components. 23 There are many materials with improved optical properties that have been developed and reported to obtain materials with structural colour, including silicon dioxide, polymethyl methacrylate and polystyrene, [24][25][26][27][28][29][30][31][32][33][34][35] since the fabrication of structural materials from colloidal spheres is low-cost and facile.…”