Method for preparing a membrane

Claim 1

THE METHOD FOR MAKING A MEMBRANE HAVING DISCRETE OPENINGS OF DEFINED SIZE AND SHAPE AND SELECTIVE PLACEMENT THERETHROUGH WHICH COMPRISES SELECTIVELY EXPOSING A PHOTO LITHOGRAPHIC PLATE TO LIGHT IN PATTERNED DISPOSITION TO CREATE HARDENED SPOTS ON SAID PLATE IN POSITION CORRESPONDING TO POINTS OF LIGHT IMPINGEMENT, CHEMICALLY ETCHING SAID PLATE TO REMOVE PLATE MATERIALS FROM NON-HARDENED SURFACES THEREOF WHEREBY HARDNED POSTS THEREOF WILL BE DISPOSED IN BAS RELIEF ABOVE THE PLANE OF SURROUNDING DEPRESSIONS, DEPOSITING A FILM OF RESIN PLASTIC MOLDABLE MATERIAL ON THE ETCHED FACE OF SAID PLATE TO FILL SAID DEPRESSION TO A DEPTH LESS THAN THE HEIGHT OF SAID POSTS, CURING SAID RESIN MATERIAL, AND SEPARATING SAID PLATE AND RESIN MATERIAL WHEREBY A FILTE MEMBRANE IS OBTAINED HAVING SPACED THRETHROUGH IN POSITIONS CORRESPONDING TO THE POSITION OF THE POSTS ON THE FACE OF SAID PHOTO LITHOGRAPHIC PLATE MOLD.

Claim 2

THE METHOD FOR MAKING A MEMBRANE HAVING DISCRETE OPENINGS OF DEFINED SIZE AND SHAPE AND SELECTIVE PLACEMENT THERETHROUGH WHICH COMPRISES SELECTIVELY EXPOSING A PHOTO LITHOGRAPHIC PLATE TO LIGHT IN PATTERNED DISPOSITION TO CREATE HARDENED SPOTS ON SAID PLATE IN POSITION CORRESPONDING TO POINTS OF LIGHT IMPINGEMENT, CHEMICALLY ETCHING SAID PLATE TO REMOVE PLATE MATERIALS FROM NON-HARDENED SURFACES THEREOF WHEREBY HARDNED POSTS THEREOF WILL BE DISPOSED IN BAS RELIEF ABOVE THE PLANE OF SURROUNDING DEPRESSIONS, DEPOSITING A FILM OF RESIN PLASTIC MOLDABLE MATERIAL ON THE ETCHED FACE OF SAID PLATE TO FILL SAID DEPRESSION TO A DEPTH LESS THAN THE HEIGHT OF SAID POSTS, CURING SAID RESIN MATERIAL, AND SEPARATING SAID PLATE AND RESIN MATERIAL WHEREBY A FILTE MEMBRANE IS OBTAINED HAVING SPACED THRETHROUGH IN POSITIONS CORRESPONDING TO THE POSITION OF THE POSTS ON THE FACE OF SAID PHOTO LITHOGRAPHIC PLATE MOLD.