Method of topographical and electrical nanostructuration of a thin film of electret polymer and thin film of electret polymer obtained

Method for structuring a thin film (6) of polymer electret having a free surface, called the treated surface (5), and an opposing surface, called the rear face (7), in which:

• in a first step, a surface of a mould (2), called the structuring surface (4), which includes relief nanometric patterns, called structuring patterns, and is made from a conductive or semi-conductive material, is brought into contact with at least part of the treated surface (5) of said thin film (6) of polymer electret,
• in a second step, nanometric patterns are formed in said thin film (6) of polymer electret, said nanometric patterns that are formed having peaks and troughs, by exerting a pressure by the structuring surface (4) on the treated surface (5) of said thin film (6) of polymer electret for a duration T1,
• characterised in that
• in a third step, once said nanometric patterns have formed in the thin film (6) of polymer electret, an electrical voltage is applied between said structuring surface (4) of the mould and said rear face (7) of said thin film (6) of polymer electret for a duration T2 which is suitable for inducing a differential distribution of electrostatic charges between the peaks and troughs of the patterns formed, and
• in a fourth step, said application of electrical voltage is stopped and the mould (2) is withdrawn from the surface of said thin film (6) of polymer electret.