Role of Micro-Architectures on Insects' Elytra Affects the Nanomechanical and Optical Properties: Inspired for Designing the Lightweight Materials

Abstract

The structural coloration of insects has received significant attention in the field of nanophotonic which has related properties with bio photonic crystals. The main focus in this study is on structural and mechanical features of wasp and beetle elytra such as Chrysidinae (is the specimen of parasitoid or kleptoparasitic wasp), Rhomborhina gigantea (RG is the specimen of bettle in the family of Cetoniidae) and chrysolina coerulans (CC is a species of beetle in the family Chrysomelidae) . The nanostructures present on the surface of elytra show the optical and deformable material properties. Surface morphology has been measured by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The depths of the hemispherical cavities present on the elytra have been analyzed using AFM. The optical and nanomechanical properties of the beetle elytra have also been studied. To measure the reflectivity in transverse electric (TE) and transverse magnetic (TM) mode, UV-visible spectroscopy has been used. The value of the average index of refraction is observed as 1.8 in all three species and the half-pitch of elytra’s varies from 0.139-0.136 μm in CC, 0.123-0.114 μm in Chrysidinae, and 0.154-0.161 μm in (RG). Nanoindentation was used to measure the modulus and hardness of the different beetle’s elytra. Higher value of elastic modulus (1.72 GPa) and hardness (0.89 GPa) in RG of elytra plays a significant role in resisting force. The photonic structure exhibits optical intrinsic color mixing properties which are used in the anticounterfeiting fields (currency and passport identification codes). The structural properties of beetle elytra would help to design the light-weight, high strength, anti coating sensor, color-changing micro air vehicles and novel optical materials.

Molecular Orientation-Dependent Photonic Polarization Engineering in Organic Single-Crystal-Filled Microcavities

“…9−13 However, it is challenging to manipulate the polarization or pseudospin of light, because it is almost immune to external fields such as electric and magnetic fields. An efficient method for modulating light in micro-or nanoscale structures is by means of light−matter interaction that can endow photonic systems with active control 14,15 and nonlinear effects through complex multiparticle interaction and dynamics. 16,17 Planar semiconductor microcavities 18 that have been intensively investigated in the past several decades provide the opportunity for cavity photons to strongly couple with the inserted materials with excitonic resonances.…”

“…The manipulation of the polarization degrees of freedom of photons has received more attention − due to its potential application in optical analogues to topological electronics, such as the photonic spin Hall effect − and the realization of topological states. − However, it is challenging to manipulate the polarization or pseudospin of light, because it is almost immune to external fields such as electric and magnetic fields. An efficient method for modulating light in micro- or nanoscale structures is by means of light–matter interaction that can endow photonic systems with active control , and nonlinear effects through complex multiparticle interaction and dynamics. , Planar semiconductor microcavities that have been intensively investigated in the past several decades provide the opportunity for cavity photons to strongly couple with the inserted materials with excitonic resonances. Furthermore, the intrinsic momentum-dependent transverse electric–transverse magnetic (TE–TM) splitting of the optical modes in such microcavities − has been demonstrated as an important platform for manipulating the pseudospin of photons.…”