The invention relates to a method of producing nanostructures in membranes, in which method a membrane consisting of a polymer material is irradiated with charged particles, especially ions, to produce particle tracks. The particle tracks in the membrane are etched using an etching liquid and the etching...http://www.google.com/patents/US6908552?utm_source=gb-gplus-sharePatent US6908552 - Method of producing nanostructures in membrances, and asymmetrical membrane
