Fluid handling – Flow affected by fluid contact – energy field or coanda effect – Means to regulate or vary operation of device
Reexamination Certificate
2000-04-25
2001-04-10
Chambers, A. Michael (Department: 3753)
Fluid handling
Flow affected by fluid contact, energy field or coanda effect
Means to regulate or vary operation of device
C137S833000
Reexamination Certificate
active
06213151
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a microchip design for the fluidic manipulation of chemical and biological materials. More specifically, this invention relates to a microchip device in which the reagent and mixing channels are dimensioned to proportion the fluidic driving forces without the need for external schemes or multiple independent pressure sources, and to reduce the number of fluidic reservoirs needed for operability, relative to known microchip devices. Similar advantages are provided by embodiments for performing dispensing operations.
BACKGROUND OF THE INVENTION
The mixing of two or more liquid-phase materials or the dispensing of a reagent material on a microchip is accomplished by controlling the pressure (vacuum) applied to the various reservoirs or channels to drive the materials housed therein through the channels of the microchip. Heretofore, this process has required external control using individual pressure (vacuum) sources at each reservoir or channel or a pressure (vacuum) manifold to distribute appropriate pressures (vacuums). Such external sources are utilized to effect valving and mixing phenomena in the channel manifold of a microfabricated device.
Therefore, a need has arisen for a microchip that is capable of mixing sample material in various proportions and dispensing variable volumes of a sample material in which the fluid material is driven by a minimum number of pressure (vacuum) sources. In this way, excess hardware needed for a fluid transport can be minimized, and the microchip can be operated with fewer fluidic reservoirs compared to known designs.
SUMMARY OF THE INVENTION
The present invention provides a microfabricated device for liquid phase chemical and biological analysis or synthesis. A device in accordance with the invention includes a substrate on which a series of microchannels are formed. A cover plate is bonded to the substrate to close the open side of the microchannels. Reservoirs are in fluidic communication with the ends of the microchannels. The reservoirs or channels are connected to pressure (vacuum) sources for mixing and/or dispensing fluidic materials contained therein. Here and throughout this application the term “pressure” means a pressure that is either above, below, or equal to the ambient pressure conditions.
The microchip includes a series of tributary channel junctions (“tees” and/or four-way intersections) wherein at least two tributary reagent microchannels communicate with a common mixing microchannel. The tributary reagent channels have either different cross sectional areas, different lengths, or both and, therefore different flow resistances. The material in the tributary reagent channels is mixed at a channel junction depending on the ratio of the channel flow resistances. Such an approach can handle all or a portion of the flow division on the microchip without using techniques external to the microchip. The mixing of two or more materials is achieved using pressure driven transport. In accordance with another aspect of the present invention, there is provided a microfabricated device that is capable of dispensing variable volumes of a sample material. In accordance with a further aspect of this invention, the tributary channels are formed so that a reduced number of material reservoirs can be utilized when performing multiple ratio assays or reactions.
A first category of microfabricated devices in accordance with the present invention provides a flow division technique that utilizes a reduced number of different external pressure sources to effect microfluidic reagent mixing relative to previous devices. A second category of microfabricated devices in accordance with this invention allows dispensing of samples on a multi-port device with a reduced number of pressure sources.
REFERENCES:
patent: 5116471 (1992-05-01), Chien et al.
patent: 5126022 (1992-06-01), Soane et al.
patent: 5180480 (1993-01-01), Manz
patent: 5328578 (1994-07-01), Gordon
patent: 5376252 (1994-12-01), Ekstrom et al.
patent: 5603351 (1997-02-01), Cherukuri et al.
patent: 5750015 (1998-05-01), Soane et al.
patent: 5858187 (1999-01-01), Ramsey et al.
Jacobson Stephen C.
Ramsey J. Michael
Chambers A. Michael
Dann Dorfman Herrell and Skillman, P.C.
UT-Battelle LLC
LandOfFree
Microfluidic circuit designs for performing fluidic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Microfluidic circuit designs for performing fluidic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microfluidic circuit designs for performing fluidic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2521635