Design parameters to consider for high-aspect-ratio nanostructured surfaces that act as biological metamaterials. These are: (A) geometry, including the height, tip-width and base-width of the nanostructure; (B) the spacing between nanostructures; (C) the uniformity of the spacing of the nanostructures (are the nanostructures spaced with a regular periodicity, or stochastically?); (D) the presence of any secondary structure, for example the use of porous materials; (E) the underlying bulk material (e.g. silicon, gold, polymer, etc).