Tangential flow cassette-HF emulation
A biocompatible polymeric membrane includes pores defined between two material layers, where the first membrane material layer includes strips, and the second membrane material binds to each of the plurality of first membrane material layer strips includes a plurality of windows exposing each of the first membrane material strips. The biocompatible polymeric filtration membrane comprises pores defined by uniform passages defined by the first membrane material layer strips and the second membrane material layer within each window.
1. A method of making a biocompatible polymeric filtration membrane comprising the steps of:
(a) depositing a first membrane material layer on a substrate;
(b) patterning the first membrane material layer into a plurality of strips;
(c) depositing a pore-defining sacrificial layer on the first membrane material strips;
(d) patterning the pore-defining sacrificial layer into strips orthogonal to the first membrane material strips;
(e) depositing a second membrane material layer over the substrate;
(f) etching a plurality of windows in the second membrane material layer to expose the pore-defining sacrificial layer;
(g) selectively etching the pore-defining sacrificial layer to create pores that are exposed within each window in the second membrane material layer, the pores being positioned between the plurality of strips of the first membrane material layer and the second membrane material layer.
2. The method of claim 1 , wherein the step (b) of patterning the first membrane material layer comprises depositing a hardmask layer on the first membrane material layer.
3. The method of claim 1 , wherein the step (f) of etching a window in the second membrane material layer to expose the pore-defining sacrificial layer comprises depositing a hardmask layer on the second membrane material layer.
4. The method of claim 1 , wherein the first membrane material layer and the second membrane material layer comprise polyimide.
5. The method of claim 1 , wherein the uniform passages have a thickness of 20 to 1000 nm.
6. The method of claim 1 , wherein the biocompatible polymeric filtration membrane has a thickness in the range of 2-10 microns.
7. The method of claim 1 , wherein the first membrane material layer has a thickness in the range of 1 to 5 microns.
8. The method of claim 1 , wherein the second membrane material layer has a thickness in the range of 2.5 to 20 microns.