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Title: Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems

Patent ·
OSTI ID:873908
 [1];  [2]
  1. Danville, CA
  2. Cardiff-by-the-Sea, CA
+ Show Author Affiliations

The performance of microchannel devices is improved by providing turns, wyes, tees, and other junctions that produce little dispersions of a sample as it traverses the turn or junction. The reduced dispersion results from contraction and expansion regions that reduce the cross-sectional area over some portion of the turn or junction. By carefully designing the geometries of these regions, sample dispersion in turns and junctions is reduced to levels comparable to the effects of ordinary diffusion. A numerical algorithm was employed to evolve low-dispersion geometries by computing the electric or pressure field within candidate configurations, sample transport through the turn or junction, and the overall effective dispersion. These devices should greatly increase flexibility in the design of microchannel devices by permitting the use of turns and junctions that do not induce large sample dispersion. In particular, the ability to fold electrophoretic and electrochrornatographic separation columns will allow dramatic improvements in the miniaturization of these devices. The low-lispersion devices are particularly suited to electrochromatographic and electrophoretic separations, as well as pressure-driven chromatographic separation. They are further applicable to microfluidic systems employing either electroosrnotic or pressure-driven flows for sample transport, reaction, mixing, dilution or synthesis.

Research Organization:
Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
DOE Contract Number:
AC04-94AL85000
Assignee:
Sandia Corporation (Albuquerque, NM)
Patent Number(s):
US 6270641
OSTI ID:
873908
Country of Publication:
United States
Language:
English

References (6)

Coiled columns and resolution in gas chromatography journal January 1960
Dispersion Sources for Compact Geometries on Microchips journal September 1998
Free boundary problem of ECM by alternating-field technique on inverted plane journal November 1975
Effects of Injection Schemes and Column Geometry on the Performance of Microchip Electrophoresis Devices journal April 1994
Contribution of capillary coiling to zone dispersion in capillary zone electrophoresis journal January 1995
Wormhole growth in soluble porous materials journal September 1990

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method
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reducing
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junctions
microchannel
systems
performance
devices
improved
providing
wyes
tees
produce
dispersions
traverses
junction
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contraction
expansion
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carefully
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greatly
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permitting
induce
particular
ability
fold
electrophoretic
electrochrornatographic
separation
columns
allow
dramatic
improvements
miniaturization
low-lispersion
particularly
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electrochromatographic
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pressure-driven
chromatographic
applicable
microfluidic
employing
electroosrnotic
flows
reaction
mixing
dilution
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sample transport
separation column
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chromatographic separation
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/204/422/