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The sensing of gasses/vapors in the ambient air is the focus of attention due to the need to monitor our everyday environment. Photonic crystals are sensing materials of the future because of their strong light-manipulating properties. Natural photonic structures are well-suited materials for testing detection principles because they are significantly cheaper than artificial photonic structures and are available in larger sizes. Additionally, natural photonic structures may provide new ideas for developing novel artificial photonic nanoarchitectures with improved properties. In the present paper, we discuss the effects arising from the sensor temperature and the vapor concentration in air during measurements with a photonic crystal-type optical gas sensor. Our results shed light on the sources of discrepancy between simulated and experimental sensing behaviors of photonic crystal-type structures. Through capillary condensation, the vapors will condensate to a liquid state inside the nanocavities. Due to the temperature and radius of curvature dependence of capillary condensation, the measured signals are affected by the sensor temperature as well as by the presence of a nanocavity size distribution. The sensing materials used are natural photonic nanoarchitectures present in the wing scales of blue butterflies., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The blue colored males of nine Polyommatine butterfly species were investigated under the aspect of color-structure-species correlation. A large number of individuals from museum collections (in total more than 100) were used to obtain average reflectance spectra to reduce the effect of individual variations as much as possible. Structural characteristics were investigated by scanning electron microscopy and transmission electron microscopy. The relevant structural data were extracted using the Biophot Analyzer software. It was found that the position of the main reflectance peak is decided primarily by the nearest neighbor distance of holes in the perforated layers constituting the pepper-pot type structure. However, very different value of the 2D filling factor may have a large enough effect on the spectral position and the width and asymmetry of the peak to overrule the classification on taking into account only the nearest neighbor distance. The comparison of the structural and spectral data may indicate that the species Polyommatus amandus may constitute an evolutionary link between different groups of species. The examined pepper-pot type nanoarchitectures show that with the alteration of the structural parameters (first neighbor distance, 2D filling factor) the tuning of the reflectance of such nanoarchitectures may be achieved. These type of nanoarchitectures may be attractive for practical applications as their large scale manufacturing may require less strict conditions as compared with fully regular nanoarchitectures.

The aim of our study was to investigate the correlation between structural colour and scale morphology in butterflies. Detailed correlations between blue colour and structure were investigated in three lycaenid subfamilies, which represent a monophylum in the butterfly family Lycaenidae (Lepidoptera): the Coppers (Lycaeninae), the Hairstreaks (Theclinae) and the Blues (Polyommatinae). Complex investigations such as spectral measurements and characterization by means of light microscopy, scanning electron microscopy and transmission electron microscopy enabled us to demonstrate that: (i) a wide array of nanostructures generate blue colours; (ii) monophyletic groups use qualitatively similar structures; and (iii) the hue of the blue colour is characteristic for the microstructure and nanostructure of the body of the scales.

The aim of our study was to investigate the correlation between structural colour and scale morphology in butterflies. Detailed correlations between blue colour and structure were investigated in three lycaenid subfamilies, which represent a monophylum in the butterfly family Lycaenidae (Lepidoptera): the Coppers (Lycaeninae), the Hairstreaks (Theclinae) and the Blues (Polyommatinae). Complex investigations such as spectral measurements and characterization by means of light microscopy, scanning electron microscopy and transmission electron microscopy enabled us to demonstrate that: (i) a wide array of nanostructures generate blue colours; (ii) monophyletic groups use qualitatively similar structures; and (iii) the hue of the blue colour is characteristic for the microstructure and nanostructure of the body of the scales. [ABSTRACT FROM AUTHOR]

Abstract: The color generating nanoarchitectures in the cover scales of the blue (dorsal)–green (ventral) wing surfaces of the butterfly Albulina metallica were investigated by scanning electron microscopy and cross-sectional transmission electron microscopy. A layered, quasiordered structure was revealed in both the dorsal and ventral scales, with different order parameters, associated with their different colors. A successful attempt was made to reproduce the biological structure in the form of a quasiordered composite (SiO/(In & SiO)) multilayer structure using standard thin film deposition techniques. The position of the reflectance maxima of this artificial structure could be tailored by controlling the size of the In inclusions through oxidation. Our results show that photonic band gap materials of biologic origin may constitute valuable blueprints for artificial structures. [Copyright &y& Elsevier]