posted on 2019-04-17, 00:00authored byZhiwu Han, Ze Wang, Bo Li, Xiaoming Feng, Zhibin Jiao, Junqiu Zhang, Jie Zhao, Shichao Niu, Luquan Ren
Cicada wings, covered
with arranged nanostructures, were widely studied owing to their high
transparency and low reflection. However, limited by technologies,
their exquisite surface structures and multifunctional features were
not inherited and applied by most artificial materials adequately.
Here, the excellent optical properties of the cicada wing were investigated
in detail experimentally and theoretically. Besides, a flexible self-cleaning
broadband antireflective film inspired by the cicada wing has been
successfully fabricated by a well-designed biological template method
and sol–gel process. The cicada wing (Megapomponia
intermedia) was selected as the original template
directly, and a SiO2 negative replica was obtained by a
sol–gel process. Then, chemical corrosion was used to remove
the original template, retaining the pure negative replica. Subsequently,
the polymethyl methacrylate (PMMA) positive replica could be rebuilt
after another sol–gel process. Compared with a flat PMMA film,
the average reflectivity of the structured PMMA film over the visible
region was reduced from 10 to 2%. Besides, the bio-inspired film with
a thickness of 0.18 mm exhibited satisfactory comprehensive performances
with low reflectance (≤2%) in most of the visible region, as
well as superhydrophobic property and perfect flexibility. Our results
offered a quick and simple method to rebuild the nanostructured functional
materials, promoting the practical applications of the bionic nanostructured
materials. Meanwhile, the modified biomimetic fabrication method provides
a solution for rebuilding exquisite biological materials and designing
multifunctional surfaces. Moreover, the multifunctional antireflective
film with wider universality will exhibit an enormous potential application
value in optical communications, photoelectric devices, flexible display
screens, and antidazzle glasses.