Scalable Fabrication of Thin-Shell Oxide Nanoarchitectures via Proximity-Field Nanopatterning—Toward Ultrahard and Flexible Nanocomposite Film

Nanoarchitectures that combine the nanomechanical size effects with conventional structural engineering offer the opportunity to establish a new kind of property-structure-process relationship. In spite of the successful demonstration of the proof-of-concept, scalable, and facile fabrication techniques enabling macroscopically producing nanoarchitectures at a low cost are required to utilize these unique materials for specific applications. Unlike conventional nanofabrication techniques, Proximity-field nanoPatterning (PnP), one of the interference lithographic processes, is capable of simultaneously obtaining the high spatial resolution and scalable fabrication in synthesizing such nanoarchitectures in the form of an inch-scale film. We reported continuous and ordered thin-shell (<60 nm) oxide nanoarchitectures fabricated by PnP and material conversion techniques, and applied them to inch-scale multifunctional nanocomposite film. The Al₂O₃ nanoarchitectures evenly embedded in the polymeric matrix are capable of maximizing load transfer between oxide reinforcement and matrix, achieving metal-like hardness (~1.3 GPa). In addition, the transmittance of nanocomposite films is nearly unchanged even after 20,000 bending motions (>82.0 % at 550 nm), showing high transparency and flexibility. The nanocomposite film reinforced by thin-shell oxide nanoarchitectures can be a promising option for the protective film of foldable and flexible optodevices.