Patent ID: 8137569
Filing Date: 2012-03-20
Classification: B01D,B81B,B81C,Y10T

Abstract:
1. A method of fabricating a membrane having a tapered pore, said method comprising the steps: a) providing a substrate, b) depositing an anti-sticking layer on said substrate, c) depositing a first polymeric layer of a first polymeric material on said anti-sticking layer, d) introducing a first aperture into said first polymeric layer, said first aperture having a first diameter, e) depositing a second polymeric layer of a second polymeric material onto said first polymeric layer, which second polymeric layer is located on said first polymeric layer and wherein a part of said second polymeric material also extends into and fills said first aperture, f) introducing a second aperture into said second polymeric layer, said second aperture having a second diameter which is larger than said first diameter, said second aperture being aligned with said first aperture, such that said part of said second polymeric material, which extends into and fills said first aperture, becomes removed, g) repeating steps e) and f) n-times, thus generating a third, fourth, . . . (n+2)th polymeric layer having a third, fourth, . . . (n+2)th aperture in said third, fourth, . . . . (n+2)th polymeric layer, said third, fourth, . . . (n+2)th aperture having a third, fourth, . . . (n+2)th diameter which is increasingly larger with increasing n, n being an integer from 0 to 10, said method thus resulting in a polymeric membrane on an anti-sticking layer and a substrate, said polymeric membrane having a tapered pore comprising (n+2) apertures of increasing diameter, said (n+2) apertures being aligned with each other to form said tapered pore.