A study of the anti-reflection efficiency of natural nano-arrays of varying sizes
Sun, Mingxia, Liang, Aiping, Zheng, Yongmei, Watson, Gregory S., and Watson, Jolanta A. (2011) A study of the anti-reflection efficiency of natural nano-arrays of varying sizes. Bioinspiration & Biomimetics, 6 (2). pp. 1-9.
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The dependence of optical reflectivity and wettability on the surface topography of 32 species of cicada wing membranes has been investigated using UV-visible spectrophotometry, contact angle measurements and environmental scanning electron microscopy. The nanoscale hexagonally close packed protrusions have been shown to exhibit an anti-reflection and in some cases an anti-wetting function. The parameters of the structures were measured to be 77–148 nm in diameter, 44–117 nm in spacing and 159–481 nm in height. The transmittance spectrum and static contact angles were measured. At a wavelength range of 500–2500 nm, only minor differences in the anti-reflection performance were observed for each cicada species ascribed to the mechanism of impedance matching between cuticle and air. The transmittance properties of cicada wings were altered successfully through the scanning probe microscope-based manipulation by reducing the protrusion height via the contact mode. A near linear dependence was found between a decrease in protuberance height and a resulting increase in reflectance intensity. A diversity of wettability was observed with contact angles varying from 56.5° to 146.0°. Both effects of anti-reflection and wettability are dependent on the height of protrusions. The anti-reflection is insensitive when the wavelength is larger than the lateral feature size of the nanostructure. The stronger hydrophobic properties are generally associated with a larger diameter, closer spacing and greater height of protrusions when the wing membrane is intact.
|Item Type:||Article (Refereed Research - C1)|
|Date Deposited:||26 Oct 2011 23:57|
|FoR Codes:||02 PHYSICAL SCIENCES > 0299 Other Physical Sciences > 029901 Biological Physics @ 50%
03 CHEMICAL SCIENCES > 0399 Other Chemical Sciences > 039999 Chemical Sciences not elsewhere classified @ 20%
06 BIOLOGICAL SCIENCES > 0699 Other Biological Sciences > 069999 Biological Sciences not elsewhere classified @ 30%
|SEO Codes:||97 EXPANDING KNOWLEDGE > 970106 Expanding Knowledge in the Biological Sciences @ 70%
97 EXPANDING KNOWLEDGE > 970102 Expanding Knowledge in the Physical Sciences @ 20%
97 EXPANDING KNOWLEDGE > 970103 Expanding Knowledge in the Chemical Sciences @ 10%
|Citation Count from Web of Science||