Pattern curvature to control pore shape and its ordering

Triangular pore in inverse-hexagonal packing was fabricated by anodizing Al with convex pattern in hexagonal packing. The convexly patterned Al was prepared \textit{via} replication of the concave structure formed in self-assembled anodized aluminum oxide (AAO). Self-assembled AAO without pre-patterning produces hexagonal packing circular pores. Exploitation of the inversed structure was found to create well-defined triangular pores in inverse-hexagonal packing. Anisotropic pore feature was discussed to come from the alternating distance between the pits and the curvature of the pattern. Also, by controlling the topography of the convex pattern around pits, we investigated the effect of pattern topography on pore initiation.