# US 2010/0167318 A1 · Fluidic Structures Including Meandering and Wide Channels > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0167318 A1 - Document ID: US20100167318A1 - Status: Published application - Kind: A1 - Application number: 11/887,487 - Filed: 2006-04-19 - Published: 2010-07-01 - Earliest claimed: 2005-04-19 - Assignees: President and Fellows of Harvard College - Inventors: Vincent Linder - Web page: https://patentgrep.com/patent/US20100167318A1 ## CPC - G01N 33/54366: {Apparatus specially adapted for solid-phase testing} - B01L 3/502746: {characterised by the means for controlling flow resistance, e.g. flow controllers, baffles or throttle valves} - G01N 21/01: Arrangements or apparatus for facilitating the optical investigation - G01N 21/82: producing a precipitate or turbidity - G01N 33/54373: {involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings} - B01L 2300/0636: Integrated biosensor, microarrays - B01L 2300/0654: Lenses; Optical fibres - B01L 2300/0816: Cards, e.g. flat sample carriers usually with flow in two horizontal directions - B01L 2300/0861: Configuration of multiple channels and/or chambers in a single devices - B01L 2300/0883: Serpentine channels - B01L 2400/0406: capillary forces - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE ## Abstract The present invention relates generally to microfluidic structures, and more specifically, to microfluidic structures and methods including meandering and wide channels. Microfluidic systems can provide an advantageous environment for performing various reactions and analyses due to a reduction in sample and reagent quantities that are required, a reduction in the size of the operating system, and a decrease in reaction time compared to conventional systems. Unfortunately, the small size of microfluidic channels can sometimes result in difficulty in detecting a species without magnifying optics (such as a microscope or a photomultiplier). A series of tightly packed microchannels, i.e., a meandering region, or a wide channel having a dimension on the order of millimeters, can serve as a solution to this problem by creating a wide measurement area. Although this invention mainly describes the use of meandering and wide channels in heterogeneous immunoassays on a microfluidic chip, this invention could be used for amplifying optical signals for other types of reactions and/or assays. ## Claims ### Claim at position 1 1-59. (canceled) ### Claim 60 A device comprising: a microfluidic channel comprising a meandering region defined by an area of at least 0.5 mm2, wherein at least a portion of the area of the meandering region comprises an optical detection pathway, and wherein at least a portion of the microfluidic channel in the meandering region has a cross-section that is completely enclosed; and a detector that allows measurement of a single signal through more than one adjacent segment of the meandering region. ### Claim 61 (depends on 60) A device as in claim 60, wherein at least one surface of the meandering channel is transparent. ### Claim 62 (depends on 60) A device as in claim 60, wherein at least a portion of the meandering region is formed in poly(dimethylsiloxane). ### Claim 63 (depends on 60) A device as in claim 60, wherein at least a portion of the meandering region is formed in polystyrene. ### Claim 64 (depends on 60) A device as in claim 60, wherein at least a portion of the meandering region is formed in polycarbonate. ### Claim 65 (depends on 60) A device as in claim 60, wherein at least a portion of the meandering region is formed in a cyclo-olefin copolymer. ### Claim 66 (depends on 60) A device as in claim 60, wherein an antibody or antigen is associated with a portion of a meandering region surface. ### Claim 67 (depends on 60) A device as in claim 60, wherein a metal colloid is associated with a portion of a meandering region surface. ### Claim 68 (depends on 60) A device as in claim 60, wherein a precipitating dye is associated with a portion of a meandering region surface. ### Claim 69 (depends on 60) A method as in claim 60, wherein a chemiluminescent species is associated with a portion of a meandering region surface. ### Claim 70 (depends on 60) A device as in claim 60, wherein a first segment of the meandering channel is spaced apart from a second adjacent segment of the channel by a distance of less than 0.5 times the width of the meandering channel. ### Claim 71 (depends on 60) A device as in claim 60, wherein a first segment of the meandering channel is spaced apart from a second adjacent segment of the channel by a distance of less than the width of the meandering channel. ### Claim 72 (depends on 60) A device as in claim 60, wherein a first segment of the meandering channel is spaced apart from a second adjacent segment of the channel by a distance of less than 2 times the width of the meandering channel. ### Claim 73 (depends on 60) A device as in claim 60, wherein the width of the meandering channel is greater than or equal to 75 microns wide. ### Claim 74 (depends on 60) A device as in claim 60, wherein the meandering region is defined by an area of greater than or equal to 2 mm2. ### Claim 75 (depends on 60) A device as in claim 60, wherein the meandering region is defined by an area of greater than or equal to 4 mm2. ### Claim 76 (depends on 60) A device as in claim 60, wherein the meandering region is serpentine. ### Claim 77 (depends on 60) A device as in claim 60, wherein a first segment of the meandering channel is parallel to a second segment of the meandering channel. ### Claim 78 (depends on 60) A device as in claim 60, wherein the meandering channel comprises a plurality of parallel segments. ### Claim 79 (depends on 60) A device as in claim 60, wherein the meandering channel comprises at least 5 parallel segments. ### Claim 80 (depends on 60) A device as in claim 60, wherein the meandering channel comprises at least 10 parallel segments. ### Claim 81 (depends on 60) A device as in claim 60, wherein the meandering channel comprises at least 20 parallel segments. ### Claim 82 (depends on 60) A device as in claim 60, wherein the meandering channel comprises a plurality of turns. ### Claim 83 (depends on 60) A device as in claim 60, wherein the meandering channel comprises at least 10 turns. ### Claim 84 (depends on 60) A device as in claim 60, wherein the meandering channel comprises at least 20 turns. ### Claim 85 (depends on 60) A device as in claim 60, wherein the meandering channel comprises at least 30 turns. ### Claim 86 A method comprising: carrying out a chemical and/or biological reaction in a meandering microfluidic channel; exposing the meandering microfluidic channel defined by an area of at least 0.5 mm2 to light; and measuring a single signal over a measurement area comprising more than one adjacent segments of the meandering channel. ### Claim 87 (depends on 86) A method as in claim 86, wherein determining the signal comprises detection with an unaided eye. ### Claim 88 (depends on 86) A method as in claim 86, wherein the signal is a light transmittance signal. ### Claim 89 (depends on 86) A method as in claim 86, wherein determining the signal comprises using an optical system that does not comprise an optical magnifying component. ### Claim 90 (depends on 86) A method as in claim 86, wherein a first portion of the signal, measured from a first segment of the meandering channel, is similar to a second portion of the signal, measured from a second adjacent segment of the meandering channel. ### Claim 91 (depends on 86) A method as in claim 86, wherein a portion of the signal, measured from a first segment of the meandering channel, is similar to portions of the signal measured from at least 5 adjacent segments of the meandering channel. ### Claim 92 (depends on 86) A method as in claim 86, wherein the measurement area is at least 2 mm2. ### Claim 93 (depends on 86) A method as in claim 86, wherein the measurement area is at least 4 mm2. ### Claim 94 A device comprising: a microfluidic channel comprising a meandering region, wherein at least a portion of the area of the meandering region comprises an optical detection pathway, and wherein at least a portion of the microfluidic channel in the meandering region has a cross-section that is completely enclosed; and a detector aligned with the optical detection pathway, the detector able to detect a signal within at least a portion of the area of the meandering region and through more than one segment of the meandering region such that a first portion of the signal, measured from a first segment of the meandering region, is similar to a second portion of the signal, measured from a second segment of the meandering region. ### Claim 95 (depends on 94) A device as in claim 94, wherein the detector does not comprise an optical magnifying component. ### Claim 96 (depends on 94) A device as in claim 94, wherein the optical detection pathway comprises an area of at least 2 mm2. ### Claim 97 (depends on 94) A method as in claim 94, wherein a chemiluminescent species is associated with a portion of the meandering region. ### Claim 98 A method comprising: accumulating an opaque material on a meandering region of a microfluidic channel; exposing at least a portion of an area of the meandering region to light; and determining the transmission of light through the opaque material and through at least a portion of the area of the meandering region. ### Claim 99 (depends on 98) A method as in claim 98, wherein the opaque material is electrolessly deposited on a metal colloid. ### Claim 100 (depends on 99) A method as in claim 99, wherein the metal colloid comprises a gold-conjugated antibody. ### Claim 101 (depends on 98) A method as in claim 98, comprising exposing the opaque material to light of a first wavelength and detecting transmission of light of the first wavelength. ### Claim 102 (depends on 101) A method as in claim 101, wherein the light is pulse modulated. ### Claim 103 (depends on 98) A method as in claim 98, wherein the transmittance is determined in the absence of a photomultiplier or an avalanche photodiode. ### Claim 104 (depends on 98) A method as in claim 98, wherein the transmission of light through the opaque material is determined through at least 25% of the area of the meandering region. ### Claim 105 (depends on 98) A method as in claim 98, wherein the opaque material is a precipitating dye. ### Claim 106 A method comprising: passing a fluid over a surface of a meandering region of a microfluidic channel; allowing a sample component to bind with a binding partner disposed on the surface; allowing a metal colloid to associate with a sample component; and flowing a metal solution over the surface to form a metallic layer. ### Claim 107 (depends on 106) A method as in claim 106, wherein a single signal is measured through more than one adjacent segments of the meandering channel. ### Claim 108 (depends on 107) A method as in claim 107, wherein the signal is a transmittance signal. ### Claim 109 (depends on 107) A method as in claim 107, wherein the signal is measured without using magnifying optics. ### Claim 110 (depends on 106) A method as in claim 106, wherein the metal colloid comprises gold. ### Claim 111 (depends on 106) A method as in claim 106, wherein the metal colloid comprises a gold-conjugated antibody. ### Claim 112 (depends on 106) A method as in claim 106, wherein the metal solution comprises silver. ### Claim 113 (depends on 106) A method as in claim 106, further comprising measuring conductivity of the metal layer. ### Claim 114 A method comprising: passing a fluid over a surface of a microfluidic channel having a width of at least 0.5 mm, wherein the channel comprises an upper surface and a lower surface; allowing a sample component to bind with a binding partner disposed on at least one of the upper and lower surfaces; allowing a metal colloid to associate with a sample component; and flowing a metal solution over the surface to form a metallic layer. ### Claim 115 (depends on 114) A method of claim 114, wherein the channel comprises at least one support extending from the lower surface to the upper surface is positioned within the pathway. ### Claim 116 (depends on 114) A method of claim 114, wherein the channel has a width of greater than 1.5 mm. ### Claim 117 A device comprising: accumulating an opaque material on a region of a microfluidic pathway for fluid flow, wherein the pathway is defined in part by an upper surface and a lower surface, the pathway having a width, a length, and a height, at least a portion of the width being at least about 1 mm, at least a portion of the length being at least about 1 mm, and at least a portion of the height being less than or equal to about 500 μm; exposing the region to light; and determining the transmission of light through the opaque material. ### Claim 118 (depends on 117) A device of claim 117, comprising at least one support extending from the lower surface to the upper surface is positioned within the pathway. ### Claim 119 (depends on 60) A device as in claim 60, further comprising a second optical detection pathway. ### Claim 120 (depends on 119) A device as in claim 119, wherein the second optical detection pathway is aligned with a second meandering region. ### Claim 121 (depends on 60) A device as in claim 60, wherein at least 25% of the area of the meandering region comprises an optical detection pathway. ### Claim 122 (depends on 60) A device as in claim 60, wherein the optical detection pathway is aligned with a portion, but not all, of the meandering region. ### Claim 123 (depends on 122) A device as in claim 122, wherein the optical detection pathway is aligned over a series of segments of the meandering region, but not all of the meandering region. ### Claim 124 (depends on 60) A device as in claim 60, wherein the detector does not comprise an optical magnifying component.