Abstract: The invention relates to a method for producing a nanostructured substrate comprising an array of protruding nanostructures, which method comprises at least the following steps: a) providing a primary substrate; b) depositing at least one layer of a material capable to be removed by means of reactive ion etching (RIE) onto said primary substrate which layer comprises a predetermined gradient of its thickness; c) depositing a nanostructured etching mask onto the graded layer deposited in step b); d) generating protruding structures, in particular nanopillars, in the graded layer deposited in step b) by means of reactive ion etching (RIE), wherein simultaneously at least 2, preferably 3, predetermined continuous gradients of geometric parameters of the protruding structures are generated on the same substrate—More specifically, the geometric parameters are selected from the group comprising the height, diameter and spacing—of the protruding nanostructures.