Moiré pattern nanopore and nanorod arrays by focused ion beam guided anodization and nanoimprint molding

Nanoporous anodic aluminum oxide has been intensively studied as templates in the fabrication of various nanomaterials. Most of the research focuses on highly ordered hexagonal nanopore arrangement with homogeneous area-specific pore density. Anodic aluminum oxide with alternating area-specific nanopore densities has seldom been addressed. In this study, focused ion beam patterned concave arrays created by overlapping two periodic patterns show the exceptional ability of guiding the subsequent anodization and fabricating porous anodic aluminum oxide with Moiré patterns, which have a wide range of interpore distances and area-specific pore densities. The periodicity of the Moiré patterns can be predicted by the interpore distance of the initial patterns and the rotation angle. The depth of the nanopores of these Moiré patterns is around 1 μm. Vertically aligned and high aspect ratio h-PDMS nanorod arrays with Moiré pattern arrangements have been successfully synthesized using the patterned porous anodic aluminum oxide as templates.