Patent US5753014A successfully refreshed from Google Patents.
US5753014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Membrane filter and a method of manufacturing the same as well as a membrane
Assignee: Individual
•
Filing: 1994-11-14
•
Granted: 1998-05-19
•
Expires: 2014-11-14
Abstract
Abstract A membrane filter comprises a membrane provided with pores with a pore size between 5 nm and 50 μm. The membrane may easily and reliably be processed with use of silicon micromachining through depositing a relatively thin membrane layer on a support, by use of a suitable vapour deposition or spincoating technique, after which perforations are made in the thin membrane layer, for example by etching with aid of photo-lithography or an imprint technique. Such a membrane is very well applicable for the separation of biological cells. A membrane with a thickness smaller than the diameter of the perforations is in particular suited for the separation of vulnerable cells and may be used as a leucocyte filter or as a blood plasma separator of blood concentrates. A microfiltration membrane according to the invention may very well be applied as a support for the deposition of a separation layer for ultrafiltration, gas separation or catalysis.
Inventors
- 👤 Cornelis Johannes Maria Van Rijn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:27
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0039; B01D67/0053; B01D67/006; B01D67/0062; B01D39/00; B01D39/14; B01D39/16; B01D39/1692; B01D67/0058; B01D67/0072; B01D69/00; B01D69/02; B01D69/10; B01D69/108; B01D69/12; B01D69/1218; B01D71/00; B01D71/02; B01D71/0213; B01D71/0215; B01J; B01J35/00; B01J35/50; B01J35/58; B01J35/59; G; G03; G03F; G03F7/00; G03F7/12; B01D2325/00; B01D2325/04; Y; Y10; Y10S; Y10S55/00; Y10S55/05
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
55 words
Membrane filter comprising a membrane provided with pores of a size between 5 nm and 50 μm characterized in that said membrane comprises a substantially flat layer of substantially uniform thickness with a surface roughness which is considerably less than the pore size and in that the pores are etched in said substantially flat layer.
Claim 2
Dependent Claim
55 words
Membrane filter comprising a membrane provided with pores of a size between 5 nm and 50 μm characterized in that said membrane comprises a substantially flat layer of substantially uniform thickness with a surface roughness which is considerably less than the pore size and in that the pores are etched in said substantially flat layer.
Claim 3
Dependent Claim
37 words
Membrane filter according to claim 1 characterized in that the membrane thickness is smaller than the average pore size and in that the membrane has a pore density which is larger than 1 million per square centimeter.
Claim 4
Dependent Claim
46 words
Membrane filter according to claim 1 characterized in that the membrane as well as the inner surface of the pores have a surface roughness less than 100 nm, and in that the membrane has a thickness which is smaller than the averages diameter of the pores.
Claim 5
Dependent Claim
41 words
Membrane filter according to claim 1 characterized in that the pores consist of etched perforations with relatively smooth edges and in that the membrane features a relatively sharp, well defined pore size distribution within a standard deviation of less than 3%.
Claim 6
Dependent Claim
31 words
Membrane filter according to claim 1 characterized in that the membrane is carried by a macroporous support with at least one opening at its surface which is spanned by the membrane.
Claim 7
Dependent Claim
33 words
Membrane filter according to claim 5 characterized in that the pores are provided within said at least one opening merely at a distance from its boundary and at a distance from its center.
Claim 8
Dependent Claim
21 words
Membrane filter according to claim 5 characterized in that the support is at least partially composed of a monocrystalline silicon wafer.
Claim 9
Dependent Claim
50 words
Membrane filter according to claim 5 characterized in that an intermediate layer is present: between the membrane and the support, which intermediate layer provides for bonding enhancement and/or stress relief and comprises a member selected from the group consisting of borax, chromium, nickel, tantalum, aluminum, silicon oxide or phosporous pentoxide.
Claim 10
Dependent Claim
13 words
Membrane of the kind applied in the membrane filter according to claim 1.
Claim 11
Dependent Claim
37 words
Gas separation filter or an ultra filtration comprising a membrane as claimed in claim 9 characterized in that a gas separation layer respectively an ultra filtration layer is provided in or over the pores of said membrane.
Claim 12
Dependent Claim
33 words
Gas separation filter or an ultra filtration filter as claimed in claim 10 characterized in that the gas separation or ultra filtration layer has a thickness below 200 nm and comprises porous silicon.
Claim 13
Dependent Claim
17 words
Fractionating system for sorting particles on size comprising at least one membrane as claimed in claim 9.
Claim 14
Dependent Claim
9 words
Pump comprising a membrane as claimed in claim 9.
Claim 15
Dependent Claim
18 words
Membrane with a monocrystalline molecular sieve crystal obtained by means of the membrane filter according to claim 1.
Claim 16
Dependent Claim
11 words
Leuckocyt filter comprising a membrane filter as claimed in claim 1.
Claim 17
Dependent Claim
88 words
Method of manufacturing a membrane filter comprising a support which is covered by a membrane having pores of a size between 5 nm and 50 μm characterized in that a membrane layer is deposited on said support, in that the pores are etched in the membrane layer is provided with pores by means of a patterned auxiliary layer and in that at least one recess is etched from the backside and over the entire thickness of the support in order to expose the backside of the membrane layer.
Claim 18
Dependent Claim
88 words
Method of manufacturing a membrane filter comprising a support which is covered by a membrane having pores of a size between 5 nm and 50 μm characterized in that a membrane layer is deposited on said support, in that the pores are etched in the membrane layer is provided with pores by means of a patterned auxiliary layer and in that at least one recess is etched from the backside and over the entire thickness of the support in order to expose the backside of the membrane layer.
Claim 19
Dependent Claim
57 words
Method according to claim 16 characterized in that the membrane layer is deposited by means of epitaxial growth, spin coating, vapour deposition or sputtering with a thickness between 20 μm and 5 nm, having a thickness uniformity below 10 nm and 100 nm respectively, and with a surface roughness which is considerably less than the pore size.
Claim 20
Dependent Claim
33 words
Method according to claim 16 characterized in that the auxiliary layer comprises a deposited masking layer which is patterned by means of a homogeneous mixture of particles added to it before its deposition.
Claim 21
Dependent Claim
33 words
Method according to claim 16 characterized in that the pores of the membrane layer are narrowed by coating with an additional layer, by means of spraying, lacquering, spin coating, vapour deposition or sputtering.
Claim 22
Dependent Claim
78 words
Method of manufacturing an ultra filtration filter or gas separation filter in which a silicon substrate is covered by a membrane according to claim 9, characterized in that an ultra filtration layer or a gas separation layer is deposited on said membrane, and in that the substrate is locally etched from its back side towards the membrane on top of it in order to expose the back side of the ultra filtration layer or gas separation layer respectively.
Claim 23
Dependent Claim
130 words
Method of manufacturing a membrane with ultra fine perforations characterized in that a first layer is deposited on a substrate which is provided with substantially parallel grooves which are deeper man wide, in that a sacrificial layer is conformally deposited over the surface, in that the sacrificial layer is provided with substantially parallel grooves which extend substantially traverse to the grooves in the first layer, in that a second layer is deposited over the entire surface covering the sacrificial layer and filling the grooves, in that the second layer is etched back until the lateral parts of the sacrificial layer are exposed, in that the exposed parts of the sacrificial layer are removed by etching and in that the substrate is etched through the realised openings in the sacrificial layer.
Claim 24
Dependent Claim
130 words
Method of manufacturing a membrane with ultra fine perforations characterized in that a first layer is deposited on a substrate which is provided with substantially parallel grooves which are deeper man wide, in that a sacrificial layer is conformally deposited over the surface, in that the sacrificial layer is provided with substantially parallel grooves which extend substantially traverse to the grooves in the first layer, in that a second layer is deposited over the entire surface covering the sacrificial layer and filling the grooves, in that the second layer is etched back until the lateral parts of the sacrificial layer are exposed, in that the exposed parts of the sacrificial layer are removed by etching and in that the substrate is etched through the realised openings in the sacrificial layer.
References Cited (Backward Citations)
US3717525A
Cited
US4329157A
Cited
GB2078539A
Cited
US4483901A
Cited
EP0092840A1
Cited
JPS59213402A
Cited
US4655797A
Cited
JPS61238303A
Cited
US4865630A
Cited
EP0272764A1
Cited
EP0278059A2
Cited
EP0325752A1
Cited
US4801380A
Cited
JPH01262903A
Cited
US4971696A
Cited
US5151110A
Cited
US5429743A
Cited
EP0511739A1
Cited
EP0550071A1
Cited
WO1993023154A1
Cited
JPH067630A
Cited
US5238471A
Cited
US5415891A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-18 | 2001-11-17 | 2002-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-18 | 2005-11-17 | 2006-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-18 | 2009-11-17 | 2010-05-19 | $7700.00 | Window Closed / Lapsed |