Agitating – Stationary mixing chamber
Reexamination Certificate
2002-03-11
2004-05-11
Drodge, Joseph (Department: 1723)
Agitating
Stationary mixing chamber
C366S165100, C366S348000, C417S048000, C417S050000
Reexamination Certificate
active
06733172
ABSTRACT:
BACKGROUND
1. Field of Endeavor
The present invention relates to microfluidics and more particularly to ma magnetohydrodynamic (MHD) driven microfluidic system.
2. State of Technology
Microfluidics is the science of designing, manufacturing, and formulating devices and processes that deal with volumes of fluid on the order of nanoliters (symbolized nl and representing units of 10
−9
liter) or picoliters (symbolized pl and representing units of 10
−12
liter). The devices themselves have dimensions ranging from millimeters (mm) down to micrometers (&mgr;m), where 1 &mgr;m=0.001 mm. Microfluidics hardware requires construction and design that differs from macroscale hardware. It is not generally possible to scale conventional devices down and then expect them to work in microfluidics applications. When the dimensions of a device or system reach a certain size, as the scale becomes smaller, the particles of fluid, or particles suspended in the fluid, become comparable in size with the apparatus itself. This dramatically alters system behavior. Capillary action changes the way in which fluids pass through microscale-diameter tubes, as compared with macroscale channels. In addition, there are unknown factors involved, especially concerning microscale heat transfer and mass transfer, the nature of which only further research can reveal.
The volumes involved in microfluidics can be understood by visualizing the size of a one-liter container, and then imagining cubical fractions of this container. A liter is slightly more than one U.S. fluid quart. A cube measuring 100 mm (a little less than four inches) on an edge has a volume of one liter. Imagine a tiny cube whose height, width, and depth are {fraction (1/1000)} (0.001) of this size, or 0.1 mm. This is the size of a small grain of table sugar; it would take a strong magnifying glass to resolve it into a recognizable cube. That cube would occupy 1 nl. A volume of 1 pl is represented by a cube whose height, width, and depth are {fraction (1/10)} (0.1) that of a 1-nl cube. It would take a powerful microscope to resolve that.
Microfluidic systems have diverse and widespread potential applications. Some examples of systems and processes that can employ this technology include inkjet printers, blood-cell-separation equipment, biochemical assays, chemical synthesis, genetic analysis, drug screening, electrochromatography, surface micromachining, laser ablation, and mechanical micromilling. Not surprisingly, the medical industry has shown keen interest in microfluidics technology.
Magnetohydrodynamics (or MHD) is the theory of the macroscopic interaction of electrically conducting fluids with a magnetic field. Magnetohydrodynamics applies the Lorentz force law on fluids to propel or pump fluids. Under the Lorentz force law, charged particles moving in a uniform magnetic field feel a force perpendicular to both the motion and the magnetic field. In the viscous incompressible case, MHD flow is governed by the Navier-Stokes equations and the pre-Maxwell equations of the magnetic field. The latter will in general transcend the region of conducting fluid and, ideally, extend to all of space. It is mostly this feature, the electromagnetic interaction of the fluid with the outside world, which gives rise to challenging problems of mathematical analysis and numerical approximation.
SUMMARY
Features and advantages of the present invention will become apparent from the following description. Applicants are providing this description, which includes drawings and examples of specific embodiments, to give a broad representation of the invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this description and by practice of the invention. The scope of the invention is not intended to be limited to the particular forms disclosed and the invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
The present invention provides a magnetohydrodynamic fluidic system for mixing a first substance and a second substance. A first substrate section includes a first flow channel and a first plurality of pairs of spaced electrodes operatively connected to the first flow channel. A second substrate section includes a second flow channel and a second plurality of pairs of spaced electrodes operatively connected to the second flow channel. A third substrate section includes a third flow channel and a third plurality of pairs of spaced electrodes operatively connected to the third flow channel. A magnetic section and a control section are operatively connected to the spaced electrodes. The first substrate section, the second substrate section, the third substrate section, the first plurality of pairs of spaced electrodes, the second plurality of pairs of spaced electrodes, the third plurality of pairs of spaced electrodes, the magnetic section, and the control section are operated to move the first substance through the first flow channel, the second substance through the second flow channel, and both the first substance and the second substance into the third flow channel where they are mixed.
The invention is susceptible to modifications and alternative forms. Specific embodiments are shown by way of example. It is to be understood that the invention is not limited to the particular forms disclosed. The invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
REFERENCES:
patent: 4818185 (1989-04-01), Alexeff
patent: 4906877 (1990-03-01), Ciaio
patent: 5181016 (1993-01-01), Lee
patent: 5560543 (1996-10-01), Smith et al.
patent: 5669433 (1997-09-01), Sterett et al.
patent: 5795457 (1998-08-01), Pethig et al.
patent: 5810988 (1998-09-01), Smith, Jr. et al.
patent: 5842787 (1998-12-01), Kopf-Sill et al.
patent: 5876187 (1999-03-01), Forster et al.
patent: 5876615 (1999-03-01), Predetechensky
patent: 5925324 (1999-07-01), Greer
patent: 6146103 (2000-11-01), Lee et al.
patent: 6154226 (2000-11-01), York et al.
patent: WO 96/15576 (1996-05-01), None
patent: WO 96/42004 (1996-12-01), None
patent: WO 97/25152 (1997-07-01), None
patent: WO 98/14272 (1998-04-01), None
PGPUB Document US2003/0123322, Chung et al, published Jul. 3, 2003.*
Morris, C. J., et al., “Optimization of a circular piezoelectric bimorph for a micropump driver, ” J. Micromech. Microeng. 10 (2000), pp. 459-465, IOP Publishing Ltd., UK.
Lemoff, A.V., “Field Driven Microfluidic Actuators for Micro Total Analysis Systems: Magnetohydrodynamic Micropump and Microfluidic Switch, Electrostatic DNS Extractor, Dielectrophorertic DNS Sorter, ” Dissertation for degree of Doctor of Philosophy, University of California Davis, (Jun. 2000), 97 pages.
TSAI, Jr-Hung, et al., “A Thermal Bubble Actuated Micro Nozzle-Diffuser Pump,” IEEE, (2001), pp. 409-412.
Stenne. E. et al., “A valveless diffuser
ozzle-based fluid pump,” Sensors and Actuators A., 39 (1993), pp. 159-167, Elsevier Sequoiz.
LEMOFF, et al., “An AC magnetohydrodynamic micropump,” Sensors and Actuators B Chemical B 63, (2000), pp. 178-185, Elsevier Science S.A.
Lee Abraham P.
Lemoff Asuncion V.
Miles Robin R.
Drodge Joseph
Scott Eddie E.
Thompson Alan H.
LandOfFree
Magnetohydrodynamic (MHD) driven droplet mixer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetohydrodynamic (MHD) driven droplet mixer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetohydrodynamic (MHD) driven droplet mixer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3201445