Chemistry: electrical and wave energy – Apparatus – Electrophoretic or electro-osmotic apparatus
Reexamination Certificate
2000-09-14
2004-08-10
Nguyen, Nam (Department: 1753)
Chemistry: electrical and wave energy
Apparatus
Electrophoretic or electro-osmotic apparatus
C204S450000, C204S451000, C204S453000, C204S600000, C204S601000, C422S091000, C422S105000
Reexamination Certificate
active
06773567
ABSTRACT:
BACKGROUND OF THE INVENTION
Microfluidic technology has been heralded as a significant technological advance in a number of areas, including biological research, clinical diagnostics, environmental monitoring, pharmaceutical screening, and a variety of others. The advantages associated with this technology are myriad and compelling. For example, the use of small material volumes, digitally controlled fluidics, and sensitive chemistries and detection schemes allows rapid, automatable, reproducible and accurate analytical methods in the above-described areas.
Unfortunately, some of the benefits of microfluidic technology can be difficult to realize. For example, microfluidic systems require only very small amounts of material to perform a given analysis, e.g., in the picoliter to nanoliter range. However, conventional fluid handling technologies, e.g., pipettors, pumps, dispensers and the like, typically are not capable of operating at such small volumes, generally operating above the microliter range. As a result, any advantages of reduced volumes are generally lost in introducing fluids into the microfluidic systems, because larger amounts are dispensed into reservoirs of the device.
One particularly useful method of introducing extremely small volumes of materials into the microfluidic devices is described in U.S. Pat. No. 5,779,868, which describes a pipettor capillary that is integrated with the channels of the microfluidic device. Materials are introduced into the channels of the device by sipping them through the capillary element. Using this improvement, one can readily sample nanoliter and even picoliter volumes of materials into the microfluidic system, thereby realizing this promise of microfluidics.
The present invention generally provides improved devices and methods of fabricating microfluidic systems having such a capillary element.
SUMMARY OF THE INVENTION
The present invention generally provides methods of fabricating microfluidic devices that include an external pipettor element having an integrated electrical contact/electrode. The advantages of the present invention are that the electrode is disposed up to the open terminus of the capillary element through a simple fabrication process.
In particular, provided is a method for fabricating a capillary element for electrokinetic transport of materials. The method comprises providing a first capillary element which has a first capillary channel disposed through its length. The capillary channel comprises first and second ends and an outer surface. A continuous layer of an electrically conductive material is applied along a length of the outer surface such that the continuous layer of electrically conductive material extends along the outer surface to a point proximal to, but not up to at least one of the first and second ends. The capillary element is then segmented into at least first and second separate capillary element portions at an intermediate point of the capillary element and the continuous layer. As a result, the first portion of the capillary element comprises the first end and a first intermediate end, and the second portion comprises the second end and a second intermediate end.
REFERENCES:
patent: 3551304 (1970-12-01), Letter et al.
patent: 4390403 (1983-06-01), Batchelder
patent: 4486273 (1984-12-01), Lutfy et al.
patent: 4908112 (1990-03-01), Pace
patent: 5126022 (1992-06-01), Soane et al.
patent: 5429734 (1995-07-01), Gajar et al.
patent: 5498392 (1996-03-01), Wilding et al.
patent: 5571410 (1996-11-01), Swedberg et al.
patent: 5585069 (1996-12-01), Zanzucchi et al.
patent: 5593838 (1997-01-01), Zanzucchi et al.
patent: 5603351 (1997-02-01), Cherukuri et al.
patent: 5630925 (1997-05-01), Pentoney, Jr. et al.
patent: 5635358 (1997-06-01), Wilding et al.
patent: 5637469 (1997-06-01), Wilding et al.
patent: 5685965 (1997-11-01), Allington
patent: 5699157 (1997-12-01), Parce
patent: 5750015 (1998-05-01), Soane et al.
patent: 5779868 (1998-07-01), Parce et al.
patent: 5800690 (1998-09-01), Chow et al.
patent: 5842787 (1998-12-01), Kopf-Sill et al.
patent: 5852495 (1998-12-01), Parce
patent: 5869004 (1999-02-01), Parce et al.
patent: 5876675 (1999-03-01), Kennedy
patent: 5880071 (1999-03-01), Parce et al.
patent: 5882465 (1999-03-01), McReynolds
patent: 5885470 (1999-03-01), Parce et al.
patent: 5890745 (1999-04-01), Kovacs
patent: 6149787 (2000-11-01), Chow et al.
patent: WO 9604547 (1996-02-01), None
patent: WO 9702357 (1997-01-01), None
patent: WO 9800705 (1998-01-01), None
Dasgupta, P.K. et al., “Electroosmosis: A Reliable Fluid Propulsion System for Flow Injection Analysis,”Anal. Chem.66:1792-1798 (1994).
Jacobson, S.C. et al., “Fused Quartz Substrates for Microchip Electrophoresis,”Anal. Chem.67:2059-2063 (1995).
Manz, A. et al., “Electroosmotic pumping and electrophoretic separations for miniaturized chemical analysis systems,”J. Micromech. Microeng.4:257-265 (1994).
Ramsey, J.M. et al., “Microfabricated chemical measurement systems,”Nature Med.1:1093-1096 (1995).
Seiler, K. et al., “Planar Glass Chips for Capillary Electrophoresis: Repetitive Sample Injection, Quantitation, and Separation Efficiency,”Anal. Chem.65:1481-1488 (1993).
Seiler, K. et al., “Electroosmotic Pumping and Valveless Control of Fluid Flow Within a Manifold of Capillaries on a Glass Chip,”Anal. Chem.66:3485-3491 (1994).
Caliper Life Sciences, Inc.
McKenna Donald R.
Nguyen Nam
Starsiak Jr. John S.
LandOfFree
High-throughput analytical microfluidic systems and methods... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High-throughput analytical microfluidic systems and methods..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-throughput analytical microfluidic systems and methods... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3304977