Flexible fabrication of new-type porous anodic alumina membranes with tunable geometric features by low-cost nanoimprint lithography

A novel process for the flexible fabrication of new-type porous anodic alumina (PAA) membranes with tunable geometric features is described. In this process, the conventional PAA template as a cost-effective nanoimprint stamp is employed to transfer the anti-structure nanopits onto aluminum sheet substrates, and the subsequent guided anodization of the pre-patterned substrates leads to new-type PAAs. By further adjusting the anode voltages of PAA stamps, imprinting pressures and guided anode voltages, a series of new-type PAAs with controlled para-pore spacing, surface topography and nanopore arrangement are achieved. The new-type PAAs provide a low-cost flexible option for the preparation of arrays with utility in photonic, electronic and magnetic devices.