US20170333898A1

US20170333898A1 - Self-flowing microfluidic analytical chip

Info

Publication number: US20170333898A1
Application number: US15/630,137
Authority: US
Inventors: Nedal Saleh; Waqas Khalid; Faisal Saleh
Original assignee: Plasmotica LLC
Current assignee: Plasmotica LLC
Priority date: 2016-05-19
Filing date: 2017-06-22
Publication date: 2017-11-23
Also published as: US20170333894A1; US20170333864A1; US20170338079A1; WO2017201505A2; WO2017201505A3; US10497541B2; US20170338080A1; US20170333897A1; US10832895B2

Abstract

A self-flowing microfluidic analytical chip may undergo spontaneous flow of a fluidic sample through microfluidic channels without an internal or external pump or corresponding pumping support hardware for fluid pumping. A self-flowing microfluidic analytical device includes sample preparation locations, sample analysis locations, and sample extraction locations connected by a network of microfluidic channels. Self-flowing characteristics of a microfluidic analytical chip result from maskless patterning of a substrate surface, where sequential passes of a patterning head preserve, rather than destroy, a pattern of surface functionalization. Self-flowing properties may be preserved by avoiding use of mask-removing solvents common to mask-removal steps in traditional microfluidic chip manufacturing processes.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present patent filing is a continuation of U.S. patent application Ser. No. 15/600,492, titled SELF-FLOWING MICROFLUIDIC ANALYTICAL CHIP, filed 19 May 2017, which claims the benefit of U.S. Provisional Patent Application 62/338,955, titled APPARATUS AND METHOD FOR PROGRAMMABLE SPATIALLY SELECTIVE NANOSCALE SURFACE FUNCTIONALIZATION, filed 19 May 2016; U.S. Provisional Patent Application 62/338,996, titled PUMP-FREE MICROFLUIDIC ANALYTICAL CHIP, filed 19 May 2016; U.S. Provisional Patent Application 62/339,002, titled PUMP-FREE MICROFLUIDIC ANALYTICAL SYSTEMS, filed 19 May 2016; and U.S. Provisional Patent Application 62/339,008, titled STAND ALONE PUMP-FREE MICROFLUIDIC ANALYTICAL CHIP DEVICE, filed 19 May 2016. The content of each of these earlier filed patent applications is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present disclosure related generally to a microfluidic analytical chip (MAC) for testing fluids. Fluids may include biological fluids added to the microfluidic analytical chip for preparation, analysis, and processing. Biological fluid extraction and analysis may be utilized for medical diagnostics, identification, and testing. Conventional fluid extraction and analysis chips may be large and expensive. Self flowing microfluidic analytical chips may be less expensive to operate, more reliable, and provide greater availability of fluid analyte testing under some analysis conditions. Self flowing microfluidic analytical chips may be less expensive because self-flowing of a fluidic sample across the microfluidic chip means that external pumps, liquid supplies, gas supplies, and power supplies (for pumping) may be left out of a microfluidic chip use method, reducing cost and simplifying testing procedures. Microfluidic analytical chips may be used as part of an in vitro diagnostics process or a point of care diagnostics method to identify and resolve medical conditions, or to perform environmental testing for pathogens or other compounds.

BACKGROUND OF THE INVENTION

Microfluidic analytical chips may frequently be large and expensive to produce. Large size and greater expense may be associated with the use, in traditional MACs, of large sample sizes in order to have sufficient analyte for detection after sample preparation and processing. Reducing sample sizes while maintaining analytes within detectable concentration ranges of sensors compatible with a microfluidic analytical chip may reduce LOC complexity and reduce costs associated with manufacturing and employing MACs may be used in settings involving testing of fluidic samples, including medical samples and environmental samples.

SUMMARY OF THE INVENTION

The invention addressing these and other drawbacks relates to methods, apparatuses, and/or systems for prioritizing retrieval and/or processing of data over retrieval and/or processing of other data.
Disclosed herein are embodiments of a chip that provides low cost, portable bio-fluid diagnostics. The chip includes a first substrate having formed thereon microfluidic channels surface functionalized to promote self-flow of a fluid without any internal or external pumping. The chip further includes second substrate coupled to the first substrate, providing cover for the microfluidic channels. The microfluidic channels may couple a sample extraction location, a sample preparation location, and a sample analysis location. The sample extraction location enables the fluid to be inserted into the microfluidic channels.
The sample preparation location may include one or more preparation chambers, such as a reagent chamber for chemical reagent, membrane chambers, a filters chamber, a micro heaters chamber, a fluid mixing chamber, a fluid separation chamber, and a waste collection chamber.
The sample analysis location may include one or more analysis chambers, such as an electrochemical analyte detection chamber utilizing electrochemical analysis techniques, an optical analyte detection chamber utilizing optical/florescence techniques, an enzyme analyte detection chamber utilizing enzyme-based detection, a column chromatography analyte detection chamber utilizing column chromatography in the microfluidic channels, and a spectrophotometry analyte detection chamber utilizing fluorescent tagging.
Disclosed herein are embodiments of a microfluidic analytical chip having substrate with a pattern of surface functionalization with at least two different types of surface functionalization therein, the surface functionalization being configured to manipulate self flow of a fluid across the surface of the substrate, and the pattern of surface functionalization being formed by at least one maskless surface functionalization process.
Also disclosed herein are embodiments of microfluidic analytical chip configured to analyze biological fluids or environmental samples.
These and other features of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and in the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. In addition, as used in the specification and the claims, the term “or” means “and/or” unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawing and in which like reference numerals refer to similar elements.

FIG. 1 illustrates an embodiment of a first substrate 100.

FIG. 2 illustrates an embodiment of microfluidic analytical chip having a second substrate 200.

FIG. 3 illustrates an embodiment of sample preparation location 300.

FIG. 4 illustrates an embodiment of a testing device 400 configured to receive a microfluidic analytical chip.

FIG. 5 illustrates an implementation of a method of analyzing a fluid sample using device microfluidic analytical chip 500.

FIG. 6 illustrates an implementation of a method of making an embodiment of a microfluidic analytical chip 600.

DETAILED DESCRIPTION OF THE INVENTION

Disclosed herein are embodiments of microfluidic analytical chip that comprise fluidic sample extraction, processing, and analysis. Fluidic samples may include bodily fluids such as blood, saliva, sputum, and urine or environmental samples. Sample extraction may be accomplished using prick-free, touch based methods. Sample extraction may involve use of capillary action to draw a portion of a fluid (a fluid sample, or sample) into a sample extraction chamber prior to sample preparation or sample analysis. Sample preparation may involve mixing reagents with the sample, passing the combination of reagents and sample through filters and membranes, heating the samples, separating blood cells and plasma, and other steps. Sample analysis may involve detection of various biomarkers by methods including electrochemical analysis of blood composition (e.g., plasma vs serum), biomaterial detection using optical/florescence techniques, column chromatography in micro channels, flow cytometry, spectrophotometry using fluorescent tagging, and potentially other techniques as well. Biomarkers may include antibodies, antigens, or other compounds associated with cellular metabolism or an immune response in an organism. Biological compounds detectable by a microfluidic analytical chip may include components of pathogens that cause illness, or components of cells indicative of illness of an organism.
Referring to FIG. 1, a first substrate 100 of a microfluidic analytical chip comprises first substrate first face 102, microfluidic channels 104, sample extraction location 106, and sample analysis location 108. The first substrate 100 may be operated in accordance with the processes described in FIG. 5 and FIG. 6.
In some embodiments, microfluidic channels 104 connect the sample extraction location 106 and the sample analysis location 108. The microfluidic channels 104 may be etched or embossed into the first substrate first face 102 or into a flat surface treated with functional groups, i.e., chemical moieties or specific groups of atoms or bonds within molecules that are responsible for the characteristic chemical reactions of those molecules. In embodiments in which the microfluidic channels 104 are recessed below a major surface of the first substrate first face 102, the microfluidic channels 104 may be formed by etching or embossing the first substrate first surface 102. Microfluidic channels in first substrate first face may have a channel width ranging from about 1000 micrometers (μm) down to about 100,000 micrometers (μm). A channel length of microfluidic channels may range from about 10 centimeter (cm) to about 1,000 nm. A depth of a microfluidic channel may range from about 10 millimeters (mm) to about 5 Angstroms (Å), according to embodiments. The channel height may arise from raised material artifacts of the embossing process. In an embodiment, the microfluidic channels may be activated by adding a lyophilized compound to a substrate first surface. Lyophilization may include rendering a reagent into a powdered form prior to application of the lyophilized material to a substrate surface. In an embodiment, lyophilized chemical reagent may be applied directly to an analyte detection surface in an analyte detection chamber. In an embodiment, a microfluidic pathway between locations may be functionalized by reacting a lyophilized material with a plasma-processed surface of a microfluidic analytical chip.
In an embodiment, microfluidic channels may be differently-functionalized regions of a surface, rather than regions that extend above or below a major surface of a substrate surface. A differently functionalized portion of a major surface of a substrate surface may have a different degree of hydrophilicity than an unmodified portion of the substrate surface. In some embodiments, the first portion of the pattern may have greater degree of hydrophilicity than an unmodified portion of the first substrate first surface. In some embodiments, the first portion of the pattern may have greater degree of hydrophobicity than an unmodified portion of the first substrate first surface. The different functionalization of the patterned portion of the surface may induce fluids to move across the surface without pumping or pressurization to induce fluid motion across the surface. Capillary action, or a reduction of the surface tension of the fluid upon movement of the fluid to an uncovered portion of the differently functionalized portion of the first substrate first surface, may draw a fluid across a first substrate first surface, through openings in a substrate to a different level of a substrate, up conductive paths that extend above a first substrate first surface, and onto a second substrate first surface.
The flow of fluid through the microfluidic channels 104 may be regulated by control geometries on a substrate surface. Control geometries may include breaks, or discontinuities, in the microfluidic channels 104 to reduce the speed of fluid flow. Control geometries may include perforated sections to control the speed of the fluid flow. Control geometries may also include achieve metering of fluid flow by allowing fluid to accumulate at an “island” or “reservoir” before fluid proceeds through a microfluidic channel. Fluid may flow uniformly, or with a stepwise change in flow rate, according to an embodiment. In a stepwise flow scenario, fluid may proceed non-uniformly using flow control geometries to slow or to accelerate fluid flow through a circuit.
The microfluidic channels 104 may comprise mixing geometries to mix various fluids. The mixing geometries may comprise a series of S-shaped curves in microfluidic channels 104, circular chambers with their inlet axis and outlet axis offset to allow eddies to form, and perforated channels to allow fluid to accumulate at an “island” and, once a specified amount of fluid is collected, it may jump or hop to the next segment of the microfluidic channels 104.
The microfluidic channels 104 may be surface functionalized to deter evaporation of liquid from the microfluidic channels 104. The surface may be functionalized by coupling substrate material with functional groups configured to interact with components of a fluid flow. Functionalization of a substrate material may include addition of functional groups to microfluidic channels to reduce an energy state of the liquid compared to an energy state of the liquid on a surface without the functional groups, or a liquid separated from the substrate surface. A reduced energy state of a fluid may be associated with a greater attraction of the surface to the fluid, or to components of the fluid. Increased attraction may increase the energy associated with evaporation of the fluid from the substrate surface, deterring a rate of evaporation of fluid from the surface.
In some implementations of microfluidic channels, a channel, or segments of a microfluidic channel, may have a varied channel dimension. The varied channel dimension may include channel height (or, depth), channel length, or channel width. The varied channel size may separate the components in the fluid or filtering materials of a mixture in the fluid by utilizing the momentum difference among the components in the fluid.
The sample extraction location 106 may comprise a port to allow insertion of fluid into the microfluidic channels 104. The sample extraction location 106 may comprise one or more needles. The port may for example be formed from various materials, such as plastics, polymers or oxides. The port may be for example cylindrical, disc, or square shape.
The sample extraction location 106 may comprise an array of micro needles to capture a fluidic sample from skin, tissues, or liquid samples. Micro needles may penetrate through a membrane to access a fluid, such as blood, lymph, or some other biological fluid. Micro needles may penetrate a surface of a fluid to reduce surface tension of the fluid and to promote entry of the fluid into sample extraction location. The array of micro needles may be formed from various materials, such as silicon, oxides, crystalline materials, or composite materials.
The sample analysis location 108 may comprise a combination of one or more analysis chambers, including but not limited to multiple chambers of the same type. The sample analysis location 108 may in some cases comprise an electrochemical analyte detection chamber. The electrochemical analyte detection chamber may detect analytes in fluids using electrochemical analysis techniques. The electrochemical analyte detection chamber may comprise a first set of at least two electrodes. The first set of at least two electrodes may be printed or functionalized onto the first substrate first face 102 or onto the second substrate 200. In an embodiment, an electrode, or a pair of electrodes, may be formed at a surface of an electrochemical analyte detection chamber in order to measure an a flow of electrical current through the fluidic sample In an embodiment, an electrode may interconnect through a body of a substrate, to a conductive pad at a remove form an electrochemical analyte detection chamber in order to promote an electrical connection between the electrode and a signal recording element configured to receive and analyze a signal from the electrode.
The sample analysis location 108 may comprise an optical analyte detection chamber. The optical analyte detection chamber may detect analytes in fluids using an optical/florescence technique. The optical analyte detection chamber may use light transmitted through the first substrate or the second substrate as either the first substrate or the second substrate may be formed from materials that may transmit light.
The sample analysis location 108 may comprise a biomaterial analyte detection chamber. The biomaterial analyte detection chamber may detect analytes in fluids using enzyme-based detection techniques or other techniques using biomaterials to trigger chemical changes in a fluidic sample. In an embodiment, biomaterials may trigger a signal by changing a color of a solution, by consuming an analyte to produce a detectable reaction product, or to produce a compound configured to adhere to an electrode surface and modify a signal from an analyte chamber. In an embodiment, biomaterials may be functionalized onto the surface of the first substrate or the second substrate to promote a chemical change that may be subsequently detected. In an embodiment, detection of a chemical change may include optical detection of a product of a chemical reaction.
The sample analysis location 108 may comprise a column chromatography analyte detection chamber. The column chromatography analyte detection chamber may detect analytes in fluids using column chromatography in the microfluidic channels 104. Chromatographic material may be functionalized onto the first substrate first face, or onto the second substrate in order to retain components of the fluidic sample during passage through fluidic channel. An analyte detection chamber may be configured to respond to a functional group on an analyte by binding the analyte and modifying a voltage of an electrode, or by binding an analyte and modifying a fluorescent taggant functionalized to the analyte detection chamber surface, or some other method of selecting among analyte fractions following a chromatographic process.
The sample analysis location 108 may comprise a spectrophotometry analyte detection chamber. The spectrophotometry analyte detection chamber may detect analytes in fluids using spectrophotometry, for example, by fluorescent tagging. The spectrophotometry analyte detection chamber may utilize light transmitted through the first substrate or the second substrate.
FIG. 2 depicts a microfluidic analytical chip 200 having a second substrate 201 comprising a second substrate first face 202. The microfluidic analytical chip 200 may be operated in accordance with the processes described in FIG. 5 and FIG. 6.
The second substrate 200 may further interact with first substrate 100, first substrate first face 102, and microfluidic channels 104. In some embodiments, the second substrate 201 with second substrate first face 202 may be placed on first substrate first face 102 of first substrate 100 to provide a cover for microfluidic channels 104. The second substrate first face 202 may be located between the first substrate first face 102 and the body of the second substrate. According to an embodiment, the second substrate comprises a material having a low degree of autofluorescence. In an embodiment with low autofluorescence second substrate material, optical signals form analytes passing through optical detection chambers may be detected at lower concentrations of analyte than in embodiments with second substrates having larger degrees of autofluorescence. A determination between a low-autofluorescence or a high-autofluorescence second substrate may relate to a cost of manufacturing device microfluidic analytical chip, an array of analyte testing chambers configured on a first substrate, and an anticipated amount of signal for an analyte according to a predicted usage scenario of a microfluidic analytical chip.
The first substrate 100 may have a first substrate material wherein the degree of hydrophilicity (or, hydrophobicity) of the surface may be modified by plasma-based surface functionalization. The first substrate may have a first substrate first surface made of a plastic material, a polymer, an inorganic oxide, such as silicon dioxide, polydimethylsiloxane (PDMS), or glass, inter alia. The second substrate 201 may have a plastic material, a polymer, an inorganic oxide, such as silicon dioxide, polydimethylsiloxane (PDMS), or glass, inter alia. The first substrate 100 and the second substrate 200 may be formed from the same material. Alternatively, the first substrate 100 may be formed from a different material than the second substrate 201.
Referring to FIG. 3, the sample preparation location 300 may comprise reagent chamber 302, membrane chambers 304, filters chamber 306, micro heaters chamber 308, electrodes chamber 310, fluid mixing chamber 312, fluid separation chamber 314, and waste collection chamber 316. The sample preparation location 300 may be operated in accordance with the processes described in FIG. 5 and FIG. 6.
In some embodiments, sample preparation location 300 is located on the first substrate 100. The sample preparation location 300 may be coupled to the sample extraction location 106 and the sample analysis location 108 via the microfluidic channels 104. The sample preparation location 300 may comprise a combination of one or more preparation chambers. The sample preparation location 300 may comprise multiple chambers of the same type. Sample preparation location may comprise multiple chambers with different types. Chambers of the sample preparation location may be located, with respect to each other, in series, in parallel, or in combinations of series and parallel arrangements, in order to provide reagents to a fluid stream during sample preparation and prior to sample analysis.
The reagent chamber 302 may store a reagent, for example, a chemical reagent. The reagent may be stored or delivered through the microfluidic analytical chip using passive valves. Passive valves may allow or delay flow of a fluid by virtue of the geometry of the passive valve and the pattern of surface functionalization through a portion of the channels of the microfluidic analytical chip. by way of at least one flow regulating valve, or shot valve. The at least one passive flow regulating valve may be located on the first substrate first face or on the second substrate. The at least one passive flow regulating valve may disrupt the microfluidic channels 104. Fluid may also be retained in a chamber by special functionalization of the walls of the chamber, wherein the special functionalization is configured to reduce a surface tension of the fluid within the chamber and to retain a portion of fluid within a chamber against a portion of a functionalized surface within the chamber. Special functionalization may include polar functional groups connected to a chamber wall, wherein the polar groups of the special functionalization may attract and retain water put in proximity to the walls.
Substrate services may be functionalized using a pattern to protect a first portion of a substrate surface while a second portion of substrate surface is exposed to functional icing conditions. In traditional masking processes, layer of photoresist may be deposited on a substrate top surface, and layer of photoresist may be patterned, such as by ultraviolet light, and developed in order to generate regions of the masking layer where the substrate surface is exposed. In a non-limiting embodiment, a polymethylmethacrylate (PMMA) substrate may be coated with a layer of photoresist. The photoresist may be patterned by exposing the photoresist to ultraviolet light, followed by a developing step to rinse a portion of the photoresist layer off of the substrate surface. The exposed portion of the substrate service may be functionalized by exposing the exposed portion to a plasma may modify his chemistry substrate in the exposed area, resulting in a modified chemical or physical characteristic of the substrate in the exposed portion. However, in order to remove the patterned photoresist from the substrate top surface, chemical treatments such as isopropyl alcohol (IPA), acetone, or alcohols may, while removing the photoresist, also remove some or all of the functionalization formed on the substrate surface. Thus, the functionalized chemistry may be incompatible with solvents or the chemical makeup of a functionalized surface after a plasma processing step to functionalize a substrate.
Functionalizing chemistry may include radical species or non-radical species that result in the addition of oxygen to a substrate surface. A representative sample of compounds that may generate an oxygen-modified surface may include a substrate
According to an embodiment, a supply of fluid (a gas or a liquid) to the working volume during surface modification may adjust the chemical composition of the substrate top surface during the surface modification process. According to an embodiment, a fluid mixture may include one or more gaseous species, or may include a volatilized (or aerosolized) liquid that, upon evaporation, provides a gaseous component for the gas mixture.
Chemical species that may be used for surface functionalization include compounds for increasing a concentration of surface oxygen on a substrate surface, compounds for increasing a concentration of a halogen on a substrate surface, and compounds for increasing a concentration of nitrogen on a substrate surface. Chemical species that functionalize a surface may be radicals or nonradicals. Chemical species that may promote functionalization of a surface with halogen atoms, including chlorine or bromine, may include atomic chlorine or atomic bromine, or non-radical species such as: hypochlorous acid (HOCl), nitryl chloride (NO₂Cl), chloramines, chlorine gas (Cl₂), bromine chloride (BrCl), chlorine dioxide (ClO₂), hypobromous acid (HOBr), or bromine gas (Br₂). Chemical species related to addition of oxygen to a substrate surface may include radicals or non-radical species, such as: superoxide (O₂ ⁻), hydroxyl radicals (HO.), hydroperoxyl radical (HO₂.), carbonate (CO₃.⁻), peroxyl radicals (RO₂.), where R is a carbon or other atom, and alkolxyl radicals (RO.), where R is a carbon or other atom, as well as nonradical species such as hydrogen peroxide, hypobromous acid (HOBr), hypochlorous acid (HOCl), ozone (O₃), organic peroxides (ROOH), where R=C, poroxynitrite (ONOO⁻), or peroxynitrous acid (ONOOH). Chemical species related to addition of nitrogen to a substrate surface may include species such as nitric oxide NO., nitrogen dioxide NO₂., nitrate radical (NO₃.), nitrous acid (HNO₂), dinitrogen tetroxide (N₂O₄), dinitrogen trioxide (N₂O₃), peroxynitrite (ONOO⁻), peroxynitrous acid (ONOOH), or nitryl chloride (NO₂Cl).
The membrane chambers 304 may be coupled to the first substrate first face 102, for example, by functionalizing the surface with membrane-binding chemistries to couple membrane materials to the first substrate 100. The membrane chambers may also be coupled to the second substrate 200, for example, by functionalizing the surface with membrane-binding chemistries to couple membrane materials to the second substrate 200. The filters chamber 306 may comprise filters. The filters may be coupled to the first substrate first face 102 by functionalizing the surface with filter-binding chemistries that allows binding of the filters to the first substrate 100. The filters chamber 306 may also be coupled to the second substrate 200, for example, by functionalizing the surface with filter-binding chemistries that allows binding of the filters to the second substrate 200.
Binding chemistries for filters or membranes of a microfluidic device analytical chip may include chemical moieties that attract a portion of a membrane or a filter to an activated portion of a substrate face. In an embodiment, a filter or membrane may be retained in a chamber of the microfluidic analytical chip by a fluid flow, or by an adhesive. In some embodiments, chemical moieties may be reversibly binding. In some embodiments, chemical moieties may be permanently binding, such that a filter or membrane is permanently attached to the substrate face.
According to an embodiment, a reversible binding chemistry may include formation of complexes or intermolecular clusters. In an embodiment, binding chemistry may include one or more sets of deoxyribonucleic acid (DNA) base pairs configured, by inclusion of one nucleobase of a DNA base pair, to attract and retain a portion of a filter or a membrane to an activated portion of a substrate face (e.g., having the other, complimentary nucleobase, of the DNA base pair). Pairs of nucleobases may form hydrogen bonds that retain one nucleobase against another nucleobase. In an embodiment, a rectangular membrane material may be configured with the nucleobase adenine on a first edge of the membrane material, and with guanine on a second edge of the membrane material, the second edge being opposite the first edge. A first substrate may have an activated region with the nucleobase thymine at a position in the microfluidic circuit where the membrane should attach to perform a filtering function, and a second substrate may have the nucleobase cytosine at a position in the microfluidic circuit where the membrane should attach. In an embodiment, the functionalization of substrate faces may be performed such that the membrane is bound to a single substrate face, with complimenting base pair interactions occurring at the sides of a microfluidic channel wherein the membrane is positioned. In an embodiment, a pattern of nucleobase activation (functionalization) on a substrate face may be configured to orient a membrane with a first orientation to present a first membrane face in an upstream orientation (i.e., toward a source for a fluid that traverses the microfluidic channel during operation of the microfluidic device).
In an embodiment, a permanent binding chemistry may include a dehydration reaction, or a condensation reaction between two reactants functionalized onto a substrate face and a membrane or filter material for a microfluidic circuit. In an embodiment, a condensation reaction configured to bind a membrane or a filter material within a channel of a microfluidic device or an integrated testing device may include [1] condensation of amino acids to form peptide bonds, or [2] a condensation reaction between a carboxylic acid and an alcohol to form an ester. Other examples of functionalization appropriate for binding chemistries of membranes or filters may be known to a practitioner of reasonable skill in the arts. A low-power plasma processing method that can activate, in a non-destructive manner, a surface of a material for functionalization, may allow configuration of membrane or filter materials with customizable reversible or permanent binding chemistries to retain membranes or filters, including both synthetic and naturally-occurring membrane or filter materials, in microfluidic channels.
In an embodiment, a filter may be configured to trap particles or components of a fluid that exceed a threshold size of a filter opening. In an embodiment, a plurality of filters may be used, in series, or in parallel, or in pluralities of filtering chambers, to fractionate a fluid during an analysis process.
The micro heaters chamber 308 may comprise micro heaters. The micro heaters may be located on the first substrate 100, or may be located on the second substrate 200. A micro heater chamber may be located in a substrate body to regulate a temperature of a microfluidic channel during analysis of a fluid.
The electrodes chamber 310 may comprise electrodes that may perform an electrochemical process. The electrodes may be printed on one or more of the first substrate 100 and the second substrate 200 by an electrode-printing technique. A combination of electrodes on one or more of the first and second substrates may allow for improved detection of analytes in an analytic chip or integrated testing device.
The fluid mixing chamber 312 may mix fluids, and may have a chamber geometry to help develop eddy currents to mix fluid mixing chamber fluids. Mixing of fluids in a microfluidic device may include, according to some embodiments, chambers with asymmetric entry and exit locations with regard to a center of the mixing chamber. An asymmetric fluid path through a mixing chamber may induce an eddy current, or rotational motion of the fluid around a center of the mixing chamber, wherein such eddy currents or rotational motion cause blending between one or more components of the fluid stream into the mixing chamber. In an embodiment, mixing of a fluid stream may serve to promote uniform distribution of solutes through the fluid stream. In an embodiment, mixing of a fluid stream may serve to promote a uniform distribution of a suspended material in the fluid stream.
The fluid separation chamber 314 may comprise separation channels configured to separate components a fluidic mixture. The separation channels may have an alterable channel width to regulate a flow velocity through the separation channel. Varying a flow velocity of the fluid through the separation channel may separate the fluidic mixture into fluidic mixture components. In an embodiment, a flow rate of a fluid through a narrow portion of the separation channel may be greater than a fluid flow rate through a wider portion of the separation channel. A reduction in fluid flow rate may be associated with fluid components having a larger mass or molecular weight moving along the separation channel more slowly than lower mass, or smaller molecular weight, fluid components.
The waste collection chamber 316 may allow the flow of fluids in the network of microfluidic channels 104. In some embodiments, one or more waste collection chambers are sized to receive a flow of fluid through microfluidic channels through a testing and analysis process, wherein, when one waste collection chamber fills with fluid, a second waste collection chamber may continue to fill with fluid to promote continuous and even fluid flow throughout a fluid preparation and analysis process.
FIG. 4 depicts a testing device 400 configured to receive a microfluidic analytical chip. The analytical chip may comprise a sample extraction location 106, a sample analysis location 108, a sample preparation location 300, and a sample data process and transmission 402. The fluid analytical device 400 may be manufactured and operated in accordance with the processes described in FIG. 5 and FIG. 6 and be configured to analyze, inter alia, components of a biological fluid or suspension. In an embodiment, fluidic analytical device 400 may include One embodiment of an analytical device may include a plurality of microfluidic channels configured to separate and analyze blood serum or blood plasma. One embodiment of an analytical device may include a plurality of microfluidic channels configured to separate and analyze components of environmental samples for contamination or biological activity. One embodiment of an analytical device may include a plurality of microfluidic channels configured to separate and analyze pathogens or biomarkers of disease.
In some embodiments, an fluid analytical device 400 may comprise a combination of at least two locations, the at least two locations chosen from the sample extraction location, the sample preparation location, and the sample analysis location. The sample data process and transmission 402 may be electronically coupled to the sample analysis location 108 and receive signals from the sample analysis location 108. The received signal may comprise analysis information obtained from the fluid analyzed in the sample analysis location 108. The sample data process and transmission 402 may transmit the signals to one or more machines. The transmission may occur via a wired or wireless connection to the one or more machines, for example via a machine data network.
FIG. 5 depicts an implementation of a method of analyzing a fluid sample using device microfluidic analytical chip 500 to identify a component of the fluidic sample. Method 500 includes an operation 502 wherein a fluid (fluidic sample) is extracted from a fluid source to the sample extraction location prior to manipulation of the fluid through the integrated testing device.
Method 500 includes an operation 504, wherein a flow of the fluid is directed from the sample extraction location to a sample preparation location. Method 500 includes an operation 506, the fluidic sample is prepared in the sample preparation location. Sample preparation locations in an integrated testing device may include a reagent chamber for a chemical reagent, a membrane chamber, a filters chamber, a micro heater chamber, a fluid mixing chamber, a fluid separation chamber, and a waste collection chamber. Sample preparation may include, for one volume of a fluidic sample prepared by the integrated testing device, preparation in at least one of the sample preparation chambers listed hereinabove. In some embodiments, a volume of a fluidic sample may be processed through multiple sample preparation chambers in order to prepare the sample for analysis.
Method 500 includes an operation 508, the flow of the fluidic sample is directed from the sample preparation location to a sample analysis location. Method 500 includes an operation 510, the fluidic sample is analyzed at the sample analysis location. Analysis of a sample may include direction of a volume of fluidic sample toward, and observation of the fluidic sample within, at least one of an electrochemical analyte detection chamber, the electrochemical analyte detection chamber using electrochemical analysis techniques; an optical analyte detection chamber, the optical analyte detection chamber using optical/florescence techniques; an enzyme analyte detection chamber, the enzyme analyte detection chamber using enzyme-based detection; a column chromatography analyte detection chamber, the column chromatography analyte detection chamber using column chromatography in the microfluidic channels; and an spectrophotometry analyte detection chamber, the spectrophotometry analyte detection chamber using fluorescent tagging.
Method 500 includes an operation 512, a signal is transmitted from the sample analysis location to a sample data process and transmission stage. Method 500 includes an operation 514, the signal from the sample data process and transmission stage is transmitted to one or more machines. In some embodiments, the flow of the fluidic sample is directed by microfluidic channels 104.
In a representative, non-limiting embodiment of the method of analyzing a fluid using an integrated testing device, a fluidic sample may be extracted from a fluid source and introduced into a sample extraction location, wherein the fluidic sample is a volume of blood plasma taken from a patient with an infection. According to the non-limiting embodiment of the method 500, the volume of blood plasma may be directed to a sample preparation location wherein the fluidic sample may be prepared by perform a series of preparation operations thereon, including, for example, filtering of a volume of the fluidic sample to isolate a pathogen. Sample filtration may be performed by passing the volume of the fluid sample through a membrane having openings with a threshold size, allowing some components of the fluidic sample to pass through, while retaining other components of the fluidic sample behind the membrane. A membrane of the integrated testing device wherein the non-limiting embodiment of the method may be may be configured such that blood cells of the fluidic sample are retained at the membrane, while pathogens non-cellular components of the fluidic sample pass through the membrane. Sample preparation may further include a processing step wherein a chemical reagent, including a first type of fluorescent dye molecule, with a first type of chemical binding component, may be introduced to the volume of fluidic sample, mixing the fluorescent dye molecule with the pathogen. Of a plurality of pathogen-binding chemical binding components of the sample preparation location, the first type of fluorescent dye molecule may label pathogens having a binding site corresponding with the first type of chemical binding component.
The labeled pathogens of the volume of fluidic sample may be further directed toward a sample analysis location. Sample analysis locations may include least one of an electrochemical analyte detection chamber, the electrochemical analyte detection chamber using electrochemical analysis techniques; an optical analyte detection chamber, the optical analyte detection chamber using optical/florescence techniques; an enzyme analyte detection chamber, the enzyme analyte detection chamber using enzyme-based detection; a column chromatography analyte detection chamber, the column chromatography analyte detection chamber using column chromatography in the microfluidic channels; and an spectrophotometry analyte detection chamber, the spectrophotometry analyte detection chamber using fluorescent tagging. Volumes of fluidic sample having been processed with fluorescent dye molecules, may be directed to, e.g., a spectrophotometry analyte detection chamber for optical testing. The volumes of fluidic samples may be exposed to an illumination source configured to promote fluorescence of molecules bound to pathogens or to components of pathogens. Light emitted during fluorescence of bound pathogens and/or bound pathogenic components may be detected by an optical detection bench and a signal transmitted to a data analysis component of the integrated testing device.
In a further representative, non-limiting embodiment of the present disclosure, a fluid sample may include a population of cells carrying a genetic marker or a genetic mutation indicative of an illness. A sample preparation operation may include filtering the fluid to collect the population of cells carrying the genetic marker or genetic mutation, cleaving cell walls to expose an interior of the cells having the genetic marker or mutation, and blending the cleaved cells with a solution containing mixture of chemicals, such as nucleobases and PCR, configured to amplify a number of strands of DNA. Sample preparation may also include treatment of the fluidic solution, or the ruptured cells within the fluidic solution, with a mixture of compounds configured to unzip DNA or to cleave DNA into fragments for testing purposes. According to an embodiment, a sample analysis operation may include, subsequent to binding fluorescent taggant molecules to DNA strands or fragments containing the genetic marker or genetic mutation, performing an optical analytical process (e.g., fluorescence spectrophotometry) to determine a number of bound DNA fragments having the genetic marker or genetic mutation (or, e.g., a presence of the genetic marker or genetic mutation in the fluidic sample after the sample preparation operation.
FIG. 6 depicts an implementation of a method of making an embodiment of a microfluidic analytical chip 600. Method 600 includes operation 602, a sample extraction location is formed on a first substrate. In operation 604, a sample preparation location is also formed on the first substrate. In operation 606, the sample preparation location is coupled to the sample extraction location. In operation 608, a sample analysis location is formed on the first substrate. In operation 610, the sample analysis location is coupled to the sample preparation location. In operation 612, a sample data process and transmission stage is coupled to the sample analysis location. In operation 614, a second substrate may be combined with the first substrate to form a cover for microfluidic channels in an analytic chip or integrated testing device. Inclusion of a second substrate may reduce evaporation of a sample during analysis, provide optical windows for sample analysis, and maintain sterility or cleanliness of the microfluidic channels prior to introduction of a fluidic sample to the microfluidic channels. In done operation 616, the method 600 ends.
The microfluidic channels may be etched into the first substrate, or embedded into the first substrate. The microfluidic channels may be utilized to couple the sample extraction location, the sample preparation location, and the sample analysis location.
In embodiments utilizing etching, the microfluidic channels may have a channel width ranging from 1000 microns to 100 nanometers, a channel length ranging from 10 centimeter to 100 nanometers, and a channel depth ranging from 1 millimeter to 5 angstroms. In embodiments utilizing embossing, the microfluidic channels may a channel width ranging from 1000 microns to 100 nanometers, a channel length ranging from 10 centimeter to 100 nanometers, a channel depth ranging from 1 millimeter to 5 angstroms, and a channel height ranging from 1 millimeter to 5 angstroms.
The microfluidic channels may be formed with control geometries (e.g., breaks and dotted sections) to control a flow of the fluid. The microfluidic channels may be formed with mixing geometries to mix various fluids, for example serpentine structures, offset inlets in a circular location to allow swirling, and dotted channels. The microfluidic channels may be surface functionalized to deter evaporation of liquid from the microfluidic channels, so that liquid in the microfluidic channels has a lower energy state than in an evaporated state in air. The microfluidic channels may be formed with a varied channel size to separate components in the fluid or filtering materials of a mixture in the fluid.
The sample extraction location may be formed with a needle insertion port to allow insertion of liquids, the needle insertion port composed of plastics, polymers, or oxides and cylindrical, disc or square shape. The sample extraction location may be formed with an array of micro needles to capture fluidic sample from skin or tissues or liquid containing features, for example from oxides, crystalline materials like silicon or oxides or composite materials like polymer and nano materials.
The reagent chamber may be formed to include least one shot valve or a specific functionalization of reagents on the first substrate first face or valves created by disrupting the microfluidic channels or the second substrate. The membrane chambers may be coupled to the first substrate first face by functionalizing the surface with membrane-binding chemistries to couple membrane materials to the first substrate or the second substrate. The filters chamber may be formed to include filters coupled to the first substrate first face by functionalizing the surface with filter-binding chemistries that allows binding of the filters to the first substrate or the second substrate. The micro heaters chamber may be formed to include micro heaters located in the first substrate or the second substrate. The electrodes chamber may be formed to include electrodes printed on the first substrate or the second substrate by an electrode-printing functionalization technique. The fluid mixing chamber may be formed to include fluid mixing geometries to develop eddy currents to mix fluid mixing chamber fluids, and the fluid separation chamber may be formed with separation channels having a fluidic mixture, the size of the separation channels alterable to separate the fluidic mixture into fluidic mixture components.
The electrochemical analyte detection chamber may be formed with a first set of at least two electrodes printed or functionalized on the first substrate first face or the second substrate. The optical analyte detection chamber may be formed to utilize light transmitted through the first substrate or the second substrate, and the enzyme analyte detection chamber may be formed with enzymes functionalized on the surface of the first substrate or the second substrate. The column chromatography analyte detection chamber may be formed from a chromatographic material functionalized onto the first substrate first face or the second substrate. The spectrophotometry analyte detection chamber may be formed to utilize light transmitted through the first substrate or the second substrate.
A combination of at least two locations chosen from the sample extraction location, the sample preparation location, and the sample analysis location may form the fluid analytical device.
In some embodiments, the analytical chip described herein may be manufactured with a patterning device like that described in a U.S. patent application titled APPARATUS AND METHOD FOR PROGRAMMABLE SPATIALLY SELECTIVE NANOSCALE SURFACE FUNCTIONALIZATION filed on the same day as this patent filing, the contents of which are incorporated by reference. In some embodiments, the analytical chip may be analyzed with a self-flowing microfluidic analytical system described in a U.S. patent application tiled STAND ALONE MICROFLUIDIC ANALYTICAL CHIP DEVICE, filed on the same day as the present patent filing, the contents of which are incorporated by reference.

Claims

What is claimed is:

1. A device comprising a first substrate having:

a first substrate first face;

a plurality of microfluidic channels on the first substrate first face and being surface functionalized for self-flowing fluid manipulation, and being connected to:

a sample extraction location,

a sample preparation location, and

a sample analysis location; wherein

the sample extraction location being configured to direct a fluid, received at the sample extraction location, into the plurality of microfluidic channels;

the sample preparation location having one or more preparation chambers comprising at least one of

a reagent chamber for a chemical reagent,

a membrane chamber,

a filters chamber,

a micro heater chamber,

a fluid mixing chamber,

a fluid separation chamber, and

an optical fluorescence chamber, and

a waste collection chamber; and

the sample analysis location having one or more analysis chambers including at least one of:

an electrochemical analyte detection chamber, the electrochemical analyte detection chamber using electrochemical analysis techniques;

an optical analyte detection chamber, the optical analyte detection chamber using optical/florescence techniques;

a biomaterial analyte detection chamber, the biomaterial analyte detection chamber using biomaterial-based detection;

a column chromatography analyte detection chamber, the column chromatography analyte detection chamber using column chromatography in the microfluidic channels; and

a spectrophotometry analyte detection chamber, the spectrophotometry analyte detection chamber using fluorescent tagging.

2. The device of claim 1, further comprising a second substrate having a second substrate first face and a second substrate body, the second substrate providing a cover for the microfluidic channels, the second substrate first face being between the first substrate first face and the second substrate body.

3. The device of claim 2, wherein:

the first substrate comprises a first substrate material, the first substrate material made of a first polymer, a first plastic, or a first inorganic oxide; and wherein

the second substrate comprises a second substrate material, the second substrate material made of a second polymer, a second plastic, or a second inorganic oxide.

4. The device of claim 1, wherein: the plurality of microfluidic channels are recessed channels below a major surface of the first substrate first face, wherein individual microfluidic channels of the plurality of microfluidic channels have:

a channel width of at least 100 nanometers and not greater than 100,000 micrometers;

a channel length of at least 100 nanometers and not greater than 1,000 centimeters; and

a channel depth of at least 5 angstroms and not greater than 10 millimeter.

5. The device of claim 4, wherein the plurality of microfluidic channels are recessed below a major surface of the first face of the first substrate by etching or embossing the major surface of first substrate first face.

6. The device of claim 1, wherein the plurality of microfluidic channels comprise control geometries to control a flow of the fluid, the control geometries comprising breaks and dotted sections.

7. The device of claim 1, wherein the plurality of microfluidic channels comprise mixing geometries to mix various fluids, the mixing geometries comprising at least serpentine structures, offset inlets in a circular location to allow swirling, and dotted channels.

8. The device of claim 1, wherein the plurality of microfluidic channels are further surface functionalized to deter evaporation of liquid from the microfluidic channels, the liquid in the microfluidic channels having a lower energy state than in an evaporated state in air.

9. The device of claim 1, wherein at least one microfluidic channel has a varied channel size configured to separate at least two component of the fluid.

10. The device of claim 1, wherein the sample extraction location further comprises a needle insertion port comprising a polymer, a plastic, or an oxide.

11. The device of claim 1, wherein the sample extraction location further comprises an array of micro needles to receive fluid from skin or a fluid-filled feature, the array of micro needles comprising composite materials such as polymers and nano materials, or crystalline materials such as silicon and an inorganic oxide.

12. The device of claim 1, wherein:

the chemical reagent is retained in the reagent chamber by at least passive valve or a specific functionalization of reagents on the first substrate first face or valves created by disrupting the microfluidic channels or the second substrate first surface;

the membrane chambers are coupled to the first substrate first face by functionalizing the surface with membrane-binding chemistries to couple membrane materials to at least one of the first substrate or the second substrate;

the filters chamber comprise filters, the filters coupled to the first substrate first face by functionalizing the surface with filter-binding chemistries that allows binding of the filters to at least one of the first substrate or the second substrate;

the micro heaters chamber comprise micro heaters, the micro heaters located in the first substrate or the second substrate;

the electrodes chamber comprising electrodes, the electrodes printed on the first substrate or the second substrate by an electrode-printing functionalization technique;

the fluid mixing chamber comprising fluid mixing geometries to develop eddy currents to mix fluid mixing chamber fluids; and

the fluid separation chamber comprises separation channels, the separation channels containing a fluidic mixture, the size of the separation channels alterable to separate the fluidic mixture into fluidic mixture components.

13. The device of claim 1, wherein:

the electrochemical analyte detection chamber comprises a first set of at least two electrodes printed or functionalized on the face of one or more of the first substrate and the second substrate;

the optical analyte detection chamber uses light transmitted light through the first substrate or the second substrate;

the enzyme analyte detection chamber comprises enzymes functionalized on the surface of the the first substrate or the second substrate;

the column chromatography analyte detection chamber comprises a chromatographic material, the chromatographic material functionalized onto the first substrate first face or the second substrate; and

the spectrophotometry analyte detection chamber uses light transmitted through the first substrate or the second substrate.

14. The device of claim 1, wherein a combination of at least two locations comprises a fluid analytical device, the at least two locations chosen from the sample extraction location, the sample preparation location, and the sample analysis location.

15. A microfluidic device comprising:

a substrate having a first substrate face, the first substrate face having an unmodified area and a patterned area, the unmodified area having an unmodified surface functionalization and the patterned area having at least one other type of surface functionalization configured to promote self flow of a fluid, without pumping, across the first substrate first surface, wherein at least one of the first portion of the patterned area, having a first type of surface functionalization, and a second portion of the patterned area, having a second type of surface functionalization, is formed by at least one maskless surface functionalization process.

16. The microfluidic device of claim 15, wherein at least one of the first type of surface functionalization and the second type of surface functionalization is a type of functionalization that is removed from a surface when a mask material is removed.

17. The microfluidic analytical chip of claim 15, wherein at least some of the patterned area further comprises lyophilized chemical pathways.

18. A arrangement comprising a first substrate having: