Nanostructured Antireflective and Thermoisolative Cicada Wings.
Inter-related mechanical, thermal, and optical macroscopic properties of biomaterials are defined at the nanoscale by their constituent structures and patterns, which underpin complex functions of an entire bio-object. Here, the temperature diffusivity of a cicada (Cyclochila australasiae) wing with nanotextured surfaces was measured using two complementary techniques: a direct contact method and IR imaging. The 4-6-μm-thick wing section was shown to have a thermal diffusivity of α⊥ = (0.71 ± 0.15) × 10(-7) m(2)/s, as measured by the contact temperature wave method along the thickness of the wing; it corresponds to the inherent thermal property of the cuticle. The in-plane thermal diffusivity value of the wing was determined by IR imaging and was considerably larger at α∥ = (3.6 ± 0.2) × 10(-7) m(2)/s as a result of heat transport via air. Optical properties of wings covered with nanospikes were numerically simulated using an accurate 3D model of the wing pattern and showed that light is concentrated between spikes where intensity is enhanced by up to 3- to 4-fold. The closely packed pattern of nanospikes reduces the reflectivity of the wing throughout the visible light spectrum and over a wide range of incident angles, hence acting as an antireflection coating.
Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan.
Junko
J
Morikawa
Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan.
Meguya
M
Ryu
Centre for Micro-Photonics, School of Science, Swinburne University of Technology , John St., Hawthorn, VIC 3122, Australia.|Melbourne Centre for Nanofabrication (MCN), Australian National Fabrication Facility (ANFF), Clayton, VIC 3168, Australia.
Gediminas
G
Seniutinas
Centre for Micro-Photonics, School of Science, Swinburne University of Technology , John St., Hawthorn, VIC 3122, Australia.
Armandas
A
Balčytis
Centre for Micro-Photonics, School of Science, Swinburne University of Technology , John St., Hawthorn, VIC 3122, Australia.
Ksenia
K
Maximova
Centre for Micro-Photonics, School of Science, Swinburne University of Technology , John St., Hawthorn, VIC 3122, Australia.
Xuewen
X
Wang
Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan.
Massimiliano
M
Zamengo
School of Science, Swinburne University of Technology , John St., Hawthorn, VIC 3122, Australia.
Elena P
EP
Ivanova
Centre for Micro-Photonics, School of Science, Swinburne University of Technology , John St., Hawthorn, VIC 3122, Australia.|Center for Nanotechnology, King Abdulaziz University , Jeddah 215589, Saudi Arabia.
Saulius
S
Juodkazis
D000818:Animals; D004058:Diffusion; D006430:Hemiptera; D049329:Nanostructures; D055620:Optical Phenomena; D013696:Temperature; D014921:Wings, Animal