 Process for producing reinforced microporous membrane |
| OF THE INVENTION The inner and outer membranes of the reinforced laminated filtration membrane of ... |
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| Process for producing supported celluosic membranes and products |
| OF THE INVENTION The supported microporous cellulosic filter according to the present invention ... |
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| Asymmetric porous polyamide membranes |
| This invention provides an asymmetric, porous polyamide membrane permeable to fluid flow comprising:... |
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| Supported microporous filtration membrane and method of using same |
| The present invention provides a supported microporous filtration membrane comprising a porous ... |
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| Multiple layer coating method |
| The system of the present invention coats a plurality of simultaneously applied layered coating ... |
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| Sizing table employing variable pitch augur |
| OF THE PREFERRED EMBODIMENT Referring to FIG. 2, a sizing table 10 includes a frame 12 which ... |
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| Apparatus and process for membrane filtration |
| It is therefore an object of the present invention to provide an improved apparatus for the ... |
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| Apparatus and method for the autotransfusion of blood |
| In accordance with the primary purpose of the present invention, there is provided a high speed ... |
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| Filter assembly |
| It is an object of the present invention to provide an improved filter assembly which overcomes, or ... |
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| Filter base assembly |
| OF THE PREFERRED EMBODIMENT With reference to the drawings wherein like numerals represent like ... |
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Microfabricated diffusion-based chemical sensor
| Details |
Inventors: Weigl, Bernhard H.; Yager, Paul; Brody, James P.; Holl, Mark R.; Kenny, Margaret; Schutte, David; Hixson, Gregory; Zebert, M. Diane; Kamholz, Andrew; Wu, Caicai; Altendorf, Eric;
Assignee: University of Washington (Seattle, WA)
Primary Examiner: Snay; Jeffrey
Assistant Examiner:
Attorney, Agent or Firm: Greenlee, Winner and Sullivan, P.C.
A channel-cell system is provided for detecting the presence and/or measuring the presence of analyte particles in a sample stream comprising: a) a laminar flow channel; b) two inlets in fluid connection with the laminar flow channel for respectively conducting into the laminar flow channel (1) an indicator stream which may comprise an indicator substance which indicates the presence of the analyte particles by a detectable change in property when contacted with the analyte particles, and (2) the sample stream; c) wherein the laminar flow channel has a depth sufficiently small to allow laminar flow of the streams and a length sufficient to allow particles of the analyte to diffuse into the indicator stream to the substantial exclusion of the larger particles in the sample stream to form a detection area; and d) an outlet for conducting the streams out of the laminar flow channel to form a single mixed stream. |
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DETAILED DESCRIPTION Microfluidic devices allow one to take advantage of diffusion as a rapid separation mechanism.
Flow behavior in microstructures differs significantly from that in the macroscopic world.
Due to extremely small inertial forces in such structures, practically all flow in microstructures is laminar.
This allows the movement of different layers of fluid and particles next to each other in a channel without any mixing other than diffusion.
On the other hand, due to the small lateral distances in such channels, diffusion is a powerful tool to separate molecules and small particles according to their diffusion coefficients, which is usually a function of their size.
This invention provides a channel cell system for detecting the presence of analyte particles in a sample stream also comprising larger particles comprising: a) a laminar flow channel; b) at least two inlet means in fluid connection with said laminar flow channel for respectively conducting into said laminar flow channel (1) indicator stream, said indicator stream preferably comprising an indicator substance, for example, a pH-sensitive dye, which indicates the presence of said analyte particles by a detectable change in property when contacted with said analyte particles, and (2) said sample stream; c) wherein said laminar flow channel has a depth sufficiently small to allow laminar flow of said streams adjacent to each other and a length sufficient to allow analyte particles to diffuse into said indicator stream to the substantial exclusion of said larger particles in said sample stream to form a detection area; d) outlet means for conducting said streams out of said laminar flow channel to form a single mixed stream.
In the simplest embodiment of this invention, a single indicator stream and a single sample stream are used; however, the methods and devices of this invention may also use multiple sample and/or indicator streams, and reference or calibration streams, all in laminar flow with each other.
The preferred embodiments of this invention utilize liquid streams, although the methods and devices are also suitable for use with gaseous streams
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Semiconductor manufacture 
