Replication of cicada wing’s nano-patterns by hot embossing and UV nanoimprinting

Abstract

The hydrophobicity of the cicada wing originates from its naturally occurring, surface nano-structure. The nano-structure of the cicada wing consists of an array of nano-sized pillars, 100 nm in diameter and 300 nm in height. In this study, the nano-structure of the cicada wing was successfully duplicated by using hot embossing lithography and UV nanoimprint lithography (NIL). The diameter and pitch of replication were the same as those of the original cicada wing and the height was a little smaller than that of the original master. The transmittance of the hot embossed PVC film was increased by 2-6% compared with that of the bare PVC film. The hydrophobicity was measured by water contact angle measurements. The water contact angle of the replica, made of UV cured polymer, was 132 degrees +/- 2 degrees , which was slightly lower than that of the original cicada wing (138 degrees +/- 2 degrees ), but much higher than that of the UV cured polymer surface without any nano-sized pillars (86 degrees ).

Antibacterial properties of PEKK for orthopedic applications

“…12,13 Inspired by cicada wings, which are covered with nanopillar-shaped structures that are capable of killing bacteria through physical means rather than by using drug, scientists have discovered a way to reduce bacteria growth. [14][15][16][17][18][19][20][21][22] Specifically, studies have shown that when bacteria land on such nanopillar surfaces with features much smaller than the bacteria themselves, bacterial membranes are ruptured. 14,15 Therefore, an approach which relies on creating nanostructured surface features on the same material to be implanted may represent a novel nonpharmaceutical or non coating approach to reduce orthopedic implant infections.…”

“…[15][16][17][18][19][20][21][22] More importantly, the tips of cicada wing nanocolumns were round and capped, which was in contrast to the tips of PEKK which were sharp-edged. Future studies will investigate the influence of the geometry of these PEKK nanoscale surface features and the resultant antibacterial response.…”

“…Moreover, researchers have previously reported that nanoroughness alone altered surface energetics, which influenced select enhanced protein adsorption and bioactivity, thereby improving osteoblast adhesion and tissue growth. 21,24,25 Elucidating an exact mechanism of action for the currently observed antibacterial properties on this novel nanostructured PEKK will also be the focus of a future study.…”

Recent progress in direct patterning technologies based on nano-imprint lithography

“…Various types of polymeric molds can be fabricated from a master template by replication process, such as hot-embossing, nano-and micro-molding [56][57][58][59][60]. Among them, a soft polymer mold such as a poly (dimethylsiloxane) (PDMS) is very useful in the NIL process using functional resists containing organic solvents due to its high gas permeability and the capability of absorbing an organic solvent.…”

Fabrication of Organic Solar Cells with Branched Cauliflower-Like Nano Structures as a Back Electrode Replicated from a Natural Template of Cicada Wing Patterns

“…Biotemplates have inspired scientists to make use of natural nanostructures and utilize their especial properties [20,22,23]. Natural surface nanostructures of cicada wing exhibit particular optical properties that originate from its specific surface geometry.…”