The objective of this work is to investigate a novel top-down synthesis route toward the elaboration of nanopatterned polymer surfaces by combining thin polymer structuring (polymer-demixing) and plasma etching techniques. Thanks to this original approach, the adjustment of the parameters during the wet chemical and plasma steps allows independent tuning of the lateral dimension of the polymer structures (diameter) and the height of the pillars. The nanopatterning description of two different polymers, namely polyethylene naphthalate and polyimide, is reported. Johnson-Kendall-Roberts (JKR) adhesion tests are carried out to compare the adhesive property of the patterned and non-patterned polymer surfaces. These measurements allow highlighting the importance of the polymer viscoelasticity for future development of bio-inspired polymer-based dry adhesives.