Figure 30.

Steps involved in the fabrication of a hexagonal array of metallic nanopillars with the anodic alumina template method. (a) An aluminum foil is polished; (b) An array of vertically aligned nanopores is produced by anodization; (c) Pores can be widened by etching with a phosphoric acid solution in order to tune the wall thickness and hence the gap size in the final structure; (d) Silver is electrodeposited in the pores forming nanopillars of controlled hight; (e) Alumina is partially etched to expose the silver nanopillars; (f) The final array is characterized by interparticle distance S, interparticle gap W and nanopillar diameter D. Reproduced with permission from Wang et al. [402]. Copyright (2006), John Wiley and Sons.