A flexible body comprises a polymer film having a first surface and an opposing second surface. The polymer film has a plurality of apertures extending from the first surface to the second surface and a plurality of raised lips protruding from the first surface such that each of the plurality of apertures is surrounded by one of the plurality of raised lips. A method of producing a polymer film comprises placing a polymer solution into a one sided mold having a plurality of protrusions extending from a bottom of the mold wherein the polymer solution is characterized by a viscosity that inhibits the unaided flow of the polymer throughout the mold; urging the polymer solution around each of the plurality of protrusions; and solidifying the polymer solution.