Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems
First Claim
1. A low-dispersion device for turning the direction of transport of a moving sample that comprises:
- a microchannel system comprising at least one turning channel having an inlet end and an outlet end, an inner wall and an outer wall, and an included turn angle, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and outlet ends and wherein the turning channel has a cross-section that is rectangular, trapezoidal, or triangular.
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Accused Products
Abstract
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.
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Citations
63 Claims
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1. A low-dispersion device for turning the direction of transport of a moving sample that comprises:
- a microchannel system comprising at least one turning channel having an inlet end and an outlet end, an inner wall and an outer wall, and an included turn angle, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and outlet ends and wherein the turning channel has a cross-section that is rectangular, trapezoidal, or triangular.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A low-dispersion device for turning the direction of transport of a moving sample that comprises:
- a microchannel system comprising at least one turning channel having an inlet end and an outlet end, an inner wall and an outer wall, and an included turn angle, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and the outlet ends, and wherein the contraction and expansion regions define inner and outer walls of the turning channel that are substantially equal in length.
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19. A low-dispersion device for turning the direction of transport of a moving sample that comprises:
- a microchannel system comprising at least one turning channel having an inlet end and an outlet end, an inner wall and an outer wall, and an included turn angle, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and the outlet ends, and wherein the outer wall of the turning channel comprises linear segments at the inlet and outlet ends joined by an arc of fixed radius spanning the included turn angle and wherein the inner wall of the turning channel is configured to form the contraction and expansion regions.
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20. A low-dispersion device for dividing a sample that comprises:
- a microchannel system comprising at least one branching junction having one inlet end and at least two outlet ends, wherein the branching junction comprises contraction and expansion regions such that a portion of the branching junction is constricted to a width that is smaller than the width of at least one outlet end and wherein the branching junction has a cross-section that is rectangular, trapezoidal, or triangular.
- View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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29. A low-dispersion device for dividing a sample that comprises:
- a microchannel system comprising at least one branching junction having one inlet end and at least two outlet ends, wherein the branching junction comprises contraction and expansion regions such that a portion of the branching junction is constricted to a width that is smaller than the width of at least one outlet end and wherein an included turn angle between the inlet end and at least one outlet end is about 22.5 degrees.
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30. A low-dispersion device for dividing a sample that comprises:
- a microchannel system comprising at least one branching junction having one inlet end and at least two outlet ends, wherein the branching junction comprises contraction and expansion regions such that a portion of the branching junction is constricted to a width that is smaller than the width of at least one outlet end and wherein an included turn angle between the inlet end and at least one outlet end is about 45 degrees.
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31. A low-dispersion device for dividing a sample that comprises:
- a microchannel system comprising at least one branching junction having one inlet end and at least two outlet ends, wherein the branching junction comprises contraction and expansion regions such that a portion of the branching junction is constricted to a width that is smaller than the width of at least one outlet end, and wherein the joining of adjacent junction walls interior of the outlet ends defines a cusp.
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32. A low-dispersion device for dividing a sample that comprises:
- a microchannel system comprising at least one branching junction having one inlet end and at least two outlet ends, wherein the branching junction comprises contraction and expansion regions such that a portion of the branching junction is constricted to a width that is smaller than the width of at least one outlet end, and wherein the contraction and expansion regions of the branching junction define a first distance of travel along one outer junction wall and a second distance of travel starting at the center of the inlet end and proceeding along the junction wall interior of one outlet end, and wherein the first and second distance of travel are substantially equal.
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33. A low-dispersion device for dividing a sample that comprises:
- a microchannel system comprising first, second, and third branching junctions and at least two turning channels wherein each branching junction comprises one inlet end and at least two outlet ends, and the outlet ends of the first branching junction are joined by turning channels to the inlet ends of the second and third branching junctions and at least one of said first, second and third branching junctions comprises contraction and expansion regions such that a portion of the branching junction is constricted to a width that is smaller than the width of at least one of its outlet ends.
- View Dependent Claims (34)
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35. A low-dispersion device for joining two or more samples that comprises:
- a microchannel system comprising at least one confluence junction having at least two inlet ends and one outlet end, wherein the confluence junction comprises contraction and expansion regions such that a portion of the confluence junction is constricted to a width that is smaller than the width of at least one inlet end and wherein the confluence junction has a cross-section that is rectangular, trapezoidal, or triangular.
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36. An apparatus for analyzing chemical or biological samples containing a plurality of species that comprises:
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a substrate fabricated to define a microchannel system disposed therein, the microchannel system comprising at least one turning channel having an inlet and an outlet end, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the width of the inlet and outlet ends, and wherein the turning channel has a cross-section that is rectangular, trapezoidal, or triangular;
means for introducing a sample into the microchannel system;
means for separating the sample into two or more components; and
means for detecting the two or more different components. - View Dependent Claims (37, 38, 39, 40, 41, 42)
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43. An apparatus for analyzing chemical or biological samples containing a plurality of species that comprises:
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a substrate fabricated to define a microchannel system disposed therein, the microchannel system comprising at least one turning channel having an inlet and an outlet end, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and outlet ends;
means for introducing a sample into the microchannel system;
means for separating the sample into two or more components;
and means for detecting the two or more different components, wherein the separation means comprises electrodes and an electric controller used to create a voltage gradient along some portion of the microchannel system in order to cause species separation by electrophoresis.
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44. An apparatus for analyzing chemical or biological samples containing a plurality of species that comprises:
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a substrate fabricated to define a microchannel system disposed therein, the microchannel system comprising at least one turning channel having an inlet and an outlet end, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and outlet ends and wherein the turning channel has a cross-section that is rectangular, trapezoidal, or triangular;
means for introducing a sample into the microchannel system;
means for separating the sample into two or more components; and
means for detecting the two or more different components, wherein the separation means comprises electrodes and an electric controller used to create a voltage gradient along some portion of the microchannel system in order to cause electroosmotic flow and species separation by chromatography.
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45. A method for analyzing chemical and biological samples by separating a sample into two or more component species wherein the method comprises the steps of:
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providing an apparatus comprising a microchannel system, the microchannel system comprising at least one turning channel having an inlet end and an outlet end, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and outlet ends, and wherein the turning channel has a cross-section that is rectangular, trapezoidal, or triangular;
introducing a sample into the microchannel system;
separating the sample into two or more components; and
detecting the two or more different components. - View Dependent Claims (46)
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47. A low-dispersion microchannel device for turning the direction of transport of a moving sample comprising:
- a turning channel having an inlet end and an outlet end, wherein the turning channel comprises a region in which the cross-sectional area is smaller than that of the inlet end and wherein the turning channel has a cross-section that is rectangular, trapezoidal, or triangular.
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48. A low-dispersion device for turning the direction of transport of a moving sample that comprises:
- a microchannel system comprising at least one turning channel having an inlet end and an outlet end, an inner wall and an outer wall, and an included turn angle, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and the outlet ends, and wherein the length of the inner wall along the contraction region is longer than the length of the outer wall along the contraction region.
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49. A low-dispersion device for turning the direction of transport of a moving sample that comprises:
- a microchannel system comprising at least one turning channel having an inlet end and an outlet end, an inner wall and an outer wall, and an included turn angle, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and the outlet ends, and wherein the length of the inner wall along the expansion region is longer than the length of the outer wall along the expansion region.
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50. A low-dispersion device for turning the direction of transport of a moving sample that comprises:
- a microchannel system comprising at least one turning channel having an inlet end and an outlet end, an inner wall and an outer wall, and an included turn angle,
wherein the inner and outer walls at the inlet end are substantially parallel and define a centerline of the inlet end that is midway between and parallel to said inner and outer walls at the inlet end, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and the outlet ends, and wherein the contraction region is asymmetric with respect to the centerline of the inlet end. - View Dependent Claims (51, 52)
- a microchannel system comprising at least one turning channel having an inlet end and an outlet end, an inner wall and an outer wall, and an included turn angle,
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53. A low-dispersion device for turning the direction of transport of a moving sample that comprises:
- a microchannel system comprising at least one turning channel having an inlet end and an outlet end, an inner wall and an outer wall, and an included turn angle,
wherein the inner and outer walls at the outlet end are substantially parallel and define a centerline of the outlet end that is midway between and parallel to said inner and outer walls at the outlet end, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and the outlet ends, and wherein the expansion region is asymmetric with respect to the centerline of the outlet end. - View Dependent Claims (54, 55)
- a microchannel system comprising at least one turning channel having an inlet end and an outlet end, an inner wall and an outer wall, and an included turn angle,
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56. A low-dispersion device for turning the direction of transport of a moving sample that comprises:
- a microchannel system comprising at least one turning channel having an inlet end, an inner wall and an outer wall, and an included turn angle, wherein the turning channel comprises contraction and expansion regions such that a portion of the turning channel is constricted to a width that is smaller than the widths of the inlet and the outlet ends, and wherein the inner wall defines a path having at least one inflection point in the contraction region and having at least one inflection point in the expansion region, and expansion regions.
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57. A low-dispersion device for dividing a sample that comprises:
- a planar substrate patterned to define a microchannel system comprising at least one branching junction having one inlet end and at least two outlet ends, wherein the sum of the widths of the two outlet ends is substantially equal to the width of the inlet end, and wherein the branching junction comprises contraction and expansion regions such that a portion of the branching junction is constricted to a width that is smaller than the width of at least one outlet end.
- View Dependent Claims (58, 59)
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60. A low-dispersion device for joining two or more samples that comprises:
- a planar substrate patterned to define a microchannel system comprising at least one confluence junction having at least two inlet ends and one outlet end, wherein the confluence junction comprises contraction and expansion regions such that a portion of the confluence junction is constricted to a width that is smaller than the width of at least one inlet end.
- View Dependent Claims (61, 62, 63)
Specification