Metasurfaces, planar structures made on a subwavelength scale, enable state-of-the-art manipulation of light and have become a promising solution for compact optical devices. However, fabrication of these nanoscale structures relies on demanding processes, limiting their integration into diverse structures, including three-dimensional ones. In this study, we develop a manufacturing and transfer technique that renders the manipulation and deposition of metasurfaces achievable with high freedom by embedding the nanostructure into a flexible polymer matrix. A metasurface consisting of a TiO2 nanoparticle array fabricated by nanoimprint lithography was encapsulated within a poly(methyl methacrylate) (PMMA) layer through spin-coating. The layer containing the metasurface was then detached from the original SiO2 substrate using wet-etching, becoming a free-standing soft sheet carrying nanostructures that can be transferred onto various surfaces. After the transfer, the layer thickness was further tuned through reactive ion etching to modulate the optical response. Incident-angle-resolved transmittance exhibited no significant change in optical bands before and after transfer, confirming that the nanostructure, as well as the photonic band, was well preserved. Thickness reduction of the PMMA cladding induced a clear optical resonance shift, demonstrating controllability of the optical response. This approach provides a versatile route for the installation of metasurfaces and expands the design possibilities for nanophotonic devices.
Shen et al. (Mon,) studied this question.