Controlling the geometry of the AAO template. (a) Periodicity of the nanopore array can be adjusted by varying the anodization voltage and the acid used. (b) Diameter of the nanopores is controlled by a chemical etching in phosphoric acid (7 wt.%, 30°C), the plot is for a 40-V alumina.
Dupré et al. Nanoscale Research Letters 2013 8:123 doi:10.1186/1556-276X-8-123