KR101087191B1 - Apparatus and method for analysis of microfluidic aqueous samples and microparticles using pyklinophoresis - Google Patents

Abstract

The present invention relates to a microfluidic control device and a microfluidic analysis method, by analyzing the movement and position of microparticles moving according to a density gradient in a microchannel using a newly identified physical phenomenon called pyklinophoresis. The present invention relates to a microfluidic control device capable of continuously analyzing the density of the injected fluid or the size of the microparticles and separating the microparticles by the size and a method thereof.

Density Difference, Fluid Density, Microparticles, Microfluidics, Lab-on-a-Chip

Description

{Apparatus and method for analysis of microfluidic aqueous samples and microparticles using pyklinophoresis}

The present invention relates to a microfluidic control device and a microfluidic analysis method, by analyzing the movement and position of microparticles moving according to a density gradient in a microchannel using a newly identified physical phenomenon called pyklinophoresis. The present invention relates to a microfluidic control device capable of continuously analyzing the density of the injected fluid or the size of the microparticles and separating the microparticles by the size and a method thereof.

The rapidly increasing bioinformation is difficult to process quickly with the existing laboratory analysis system. In line with these trends, biological detection systems for the identification of life phenomena, drug development and diagnostics are based on microfluidics. -TAS is developing in the form of micro-Total Analysis System) and lab-on-a-chip. Since most of the biochemical samples to be analyzed exist in solution, the technique of delivering a liquid sample is the most important factor.

Microfluidics is a research field that controls the flow of microfluids, and researches and develops core technologies based on the commercialization of the micro-composite analysis system and lab-on-a-chip. The micro-combination analysis system is a system that comprehensively implements chemical and biological experiments and analyzes undergoing a plurality of experimental steps and reactions on one unit existing on one bench. This micro-analysis system consists of a sampling area, a microfluidic circuit, a detector and a controller for controlling them.

In addition, the lab-on-a-chip means 'laboratory on chip' or 'laboratory on chip', which is usually made of a material such as plastic, glass, silicon, or the like to make microchannels of less than nanoliters, through which several nanoliters By moving only a small amount of liquid samples, it is possible to quickly perform existing experiments or research processes. Implementation of the micro-analytical analysis system or lab-on-a-chip that can rapidly analyze the rapidly increasing bio-information can be effectively accomplished by combining with appropriate biomolecular analysis methods.

Recently, various methods and devices for analyzing microfluidics have been developed. Density among the intrinsic properties of a material is a physical constant that can indirectly identify the reaction, state change, temperature, etc. of a material by analyzing its properties with a simple analysis method. Various attempts have been made to analyze these densities in microfluidic devices, but they have limitations that cannot be widely used for complex design, fabrication and operation methods.

Prior art (US Pat. No. 6,477,901, 2002) uses a Coriolis effect to change the movement of a channel according to the density and viscosity of the fluid flowing inside the channel when the microfluidic channel produced by the microprocessing technique causes resonance. It is a method of density analysis by measuring. However, the construction of the prior art requires a complicated process step for producing a microfluidic channel causing resonance vibration in the air, and there is a limit that can be an obstacle to integration with other microfluidic devices.

The first problem to be solved by the present invention is to provide a microfluidic control device that can analyze the density of the microfluid or the size of the microparticles to a very small amount of several nanoliters by using a density difference phenomenon.

The second problem to be solved by the present invention is to provide a microfluidic chip that can continuously separate and analyze the size of the microparticles by using a density difference phenomenon.

The third problem to be solved by the present invention is to provide a method for analyzing the density of the microfluidic or the size of the microparticles using the microfluidic control device.

The fourth problem to be solved by the present invention is to provide a method for separating the microparticles by size using a density difference phenomenon.

In order to solve the first problem, the present invention includes a first inlet and a second inlet in which a first fluid and a second fluid having different densities are injected; A third injection hole into which the fine particles moved by the first fluid and the second fluid are injected; A microfluidic channel in which the injected first and second fluids and the injected microparticles cross and move; And a discharge port through which the microparticles having passed through the microfluidic channel are discharged, wherein the injected first fluid and the second fluid form a density gradient within the microfluidic channel, and the microparticles are formed by the fluids. It provides a microfluidic control device using a density difference phenomena, characterized in that moving according to the formed density gradient.

According to an embodiment of the present invention, the first inlet and the second inlet may be configured to be vertically or symmetrically, and the third inlet may be configured to have a predetermined angle with the first inlet or the second inlet.

In addition, according to another embodiment of the present invention, the first fluid, the second fluid and the microparticles may be injected at the same time, it is preferable that the microparticles are dispersed and injected into the fluid.

In the present invention, the first fluid, the second fluid and the microparticles are aligned by flowing to the center or a specific portion of the microfluidic channel is moved by the density difference.

According to another embodiment of the present invention, it is preferable that the discharge portion is wider than the microfluidic channel so that the microparticles whose path is changed by the density difference motion are discharged from the microfluidic channel. The location is measured to analyze the density of the microfluidics or the size of the microparticles.

The present invention to solve the second problem is a polymer substrate comprising a microfluidic control device using the density difference phenomenon according to claim 1; And it provides a microfluidic chip comprising a glass substrate formed on the lower portion of the polymer substrate.

According to one embodiment of the present invention, the polymer substrate is made of polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), polyacrylate, polycarbonate, polycyclic olefin, polyimide and polyurethane. It may consist of one or more polymers selected from the group consisting of.

In order to solve the third problem, the present invention is a method for analyzing microfluids and microparticles using a microfluidic control device using a density difference phenomenon, the first fluid and the second fluid having different densities are microfluidics Implanting into the channel to form a density gradient in the microfluidic channel; Injecting microparticles into the microfluidic channel; Flowing the microfluidic channel by crossing the injected microfluids and microparticles; Changing the path of the injected fine particles in a low density direction by a density gradient of the microfluid; It provides a microfluidic analysis method using a density difference phenomenon characterized in that it comprises the step of measuring the position of the microparticles passing through the microfluidic channel to the discharge portion.

According to one embodiment of the present invention, after the position measuring step may further comprise the step of analyzing the density of the microfluidic or the size of the microparticles using the position data.

According to one embodiment of the present invention, the first inlet and the second inlet in the microfluidic analysis method using the density difference phenomena may be configured up-down or left-right symmetry. In addition, the third inlet may be configured to be inclined to have a predetermined angle with the first inlet or the second inlet, for example, may be connected in a vertical direction.

In addition, according to another embodiment of the present invention, the first fluid, the second fluid and the microparticles may be injected at the same time in the microfluidic analysis method using a density difference phenomenon, it is preferable that the microparticles are dispersed and injected into the fluid Do.

In the present invention, the first fluid, the second fluid and the microparticles are aligned by flowing to the center or a specific portion of the microfluidic channel is moved by the density difference.

According to another embodiment of the present invention, it is preferable that the discharge portion is wider than the microfluidic channel so that the microparticles whose path is changed by the density difference motion are discharged from the microfluidic channel. The location is measured to analyze the density of the microfluidics or the size of the microparticles. At this time, the analysis of the density of the microfluidic or the size of the microparticles can be carried out continuously.

In addition, in order to solve the fourth problem, the present invention is a method for separating the microparticles using a microfluidic control device using a density differential phenomena phenomenon, the first fluid and the second fluid having different densities in the microfluidic channel Implanted to form a density gradient in the microfluidic channel; Injecting microparticles into the microfluidic channel; Flowing the microfluidic channel by crossing the injected microfluids and microparticles; Changing the path of the injected fine particles in a low density direction by a density gradient of the microfluid; The present invention provides a method for separating fine particles using a density difference phenomena, characterized in that the fine particles discharged through the microfluidic channel to the discharge part are separated by sizes.

The microfluidic control device using the density difference phenomena according to the present invention and the method for separating and analyzing the density of the microfluid or the size of the microparticles using the control device more accurately analyze the trace amount than the conventional fluid density measurement method. It does not require a complicated structure like the conventional microparticle analysis apparatus. In addition, the manufacturing process of the control element is simple, very fast and simple to separate and analyze the microparticles. In addition, the microfluidic chip according to the present invention is very useful because it is easy to integrate and easy to carry.

Hereinafter, the present invention will be described in detail with reference to the drawings.

First, Figure 1 is a cross-sectional view of a microfluidic control device using a density difference phenomenon according to an embodiment of the present invention. Specifically, the microfluidic density measuring and microparticle analyzing apparatus of the present invention includes a first inlet 101 through which a fluid having a high density value is injected, a second inlet 102 through a fluid having a low density value, and a microparticle injection port. It comprises a 103, a microfluidic channel 105, and the discharge section 106, the microfluidic channel 105 includes an intersection 104, the microfluid and microparticles intersect therein.

The present invention is characterized by having a configuration for injecting fluid having two or more different density values through different inlets. As shown in Fig. 1, a fluid having a high density value is injected from the upper direction, and a fluid having a low density value is injected from the lower direction. Injected fluids having different density values meet microparticles injected from the microparticle inlet 103 at the microfluidic channel intersection 104, and have different densities from those of the microparticles encountered at the intersection 104. Fluid flows along the microfluidic channel 105. The point where the microparticles and the microfluid meet at the intersection 104 may be a center line or a specific portion of the microfluidic channel 105, which is determined depending on whether the fluid is injected at the same pressure from the upper and lower directions or at different pressures. It is adjustable and any fluid element can also be used to control the fluid flow. For example, devices and devices such as a syringe pump, a peristatic pump, an electroosmotic flow pump, etc. may be used to control the flow of the fluid.

Microfluidic channel 105 is a conduit for passing injected sample fluids and microparticles to outlet 106 and is formed of a kind of polymer substrate. In the microfluidic channel 105, fluids having different density values form a density gradient by diffusion phenomenon, and the microparticles are subjected to hydraulic pressure by the density of the surrounding fluid and by the density gradient. When a pressure difference occurs around the fine particles, the flow flows by changing the path in a lower density direction.

This density difference phenomenon is that the pressure received by the object while the object is immersed in the fluid is proportional to the density of the surrounding fluid, the distance the object is located from the water surface, and is proportional to the area of the object. Therefore, the microparticles flowing along the microfluidic channel under the density gradient show a difference in the path change depending on the degree of density difference formed in the surroundings, and the larger the size of the microparticles causes the larger path change and exits to the discharge part 106. do.

The discharge part 106 is a region for trapping the microfluids and the microfluids whose path is deflected through the microfluidic channel 105 and is formed to have a width wider than that of the microfluidic channel 105.

Microfluidic chip for microfluidic and microparticle analysis according to the present invention will be described with reference to FIG. Referring to FIG. 2, the microfluidic chip of the present invention includes a polymer substrate 201 including the microfluidic channel and a glass substrate 202 constituting the bottom surface of the microfluidic channel. The polymer substrate 201 may be manufactured by a conventional method such as patterning. The polymer substrate 201 and the glass substrate 202 can be manufactured by a conventional method such as micro molding.

The method of analyzing the density of the fluid and analyzing the microparticles using the microfluidic control device of the present invention will be described with reference to FIG. 1. First, fluids having different density values are injected into the microfluidic channel through the inlet to form a density gradient in the microfluidic channel. Fluids are injected in the upper direction and the lower direction of the microfluidic channel 105 by the difference in density values, move along the center or a specific portion of the channel, and form a density gradient inside the microfluidic channel. In addition, the microparticles are injected through the microparticle injection port 103, the microfluid and the microparticles may be injected at the same time.

Thereafter, the injected microfluids and the microparticles meet at the intersection and flow through the microfluidic channel. At this time, the injected microparticles flow along the channel by changing the path in the direction of low density by the density difference gradient of the microfluid. The microparticles separated through the microfluidic channel are trapped at the end of the microfluidic channel or trapped at the outlet with an expansion channel for measuring the position of the particles. By measuring the position of the fine particles discharged to the discharge portion to analyze the density of the microfluidic or the size of the microparticles, at this time, the density or size analysis can be performed continuously.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are illustrative of the present invention, and the scope of the present invention is not limited by the examples.

Example 1 Fabrication of Microfluidic Devices According to the Present Invention

The microfluidic control device for density analysis and microparticle-based microfluidic analysis according to the present invention was fabricated as follows using a micromolding technique using polydimethylsiloxane (PDMS).

First, a mold, which is a microstructure having a width of 100 μm and a height of 20 μm, was fabricated by using SU-8 as a photosensitive material on a silicon wafer substrate. The prepared mold was poured into a mixture of a curing agent and a prepolymer of PDMS 10: 1 and cured at 80 ° C. for 2 hours to prepare a PDMS substrate. After the curing process, a hole was formed in the PDMS substrate to prepare a sample inlet and an outlet. Thereafter, the PDMS substrate was oxidized using an air plasma, and the microfluidic device was completed by stacking the ferromagnetic microstructure together on the slide glass substrate. A plan view and a cross-sectional view of the microfluidic device thus manufactured are shown in FIGS. 1 and 2, respectively.

In this embodiment, polydimethylsiloxane (PDMS) was used as the material of the polymer substrate. In addition, polymethyl methacrylate (PMMA), polyacrylate, polycarbonylate, polycyclic olefin, polyimide, poly Polymeric materials, such as urethane, can also be used.

Experimental Example 1 Analysis of Density or Concentration of Microfluidics

The experiment to measure the density and concentration of the microfluid having an unknown density in the density-differentiation-based microfluidic device prepared in the above embodiment was performed as follows.

Sucrose solutions with concentrations of 0%, 3%, 6%, 10%, 12%, 16% are prepared for density analysis of sucrose solutions with unknown density values. A 10% sucrose solution was injected into the upper inlet 101 of the microfluidic device manufactured in Example 1 above. Then, 15 μm diameter microparticles contained in a 10% solution of sucrose were injected into the fine particle inlet 103, and 0%, 3%, 6%, 10%, 12% and 16 were respectively injected into the lower inlet 102. While injecting the sucrose solution of the concentration of%, the position of the fine particles at each concentration in the discharge unit 106 was measured. At this time, the position of the microparticles was measured from the bottom wall of the discharge unit 106, the distance is measured, the position of the microparticles measured in the discharge unit 106 is shown in FIG.

Thereafter, a sample having an unknown concentration is injected into the lower injecting unit 102, and the conditions of the remaining injecting unit are controlled by the position of the fine particles measured at the discharge unit 106 when the experiment is conducted under the same situation. The density can be measured. In addition, the measured density value may be calculated as a concentration value by converting it through a correlation graph between density and concentration.

Experimental Example 2: Analysis of the Size of Fine Particles

Using the microfluidic control device according to the present invention to analyze the size of the microparticles, the following experiment was performed to continuously separate.

First, microparticles having diameters of about 10 μm, 11 μm, 12 μm, 14 μm, and 15 μm were prepared. Since a graph showing the correlation between the size of each particle and its position should be obtained, the variation of each particle size should be within 0.1%. A 10% sucrose solution was injected into the upper inlet 101 of the microfluidic device manufactured in Example 1 above. In addition, the fine particle inlet 103 is sequentially injected into the microparticles having a diameter of 10 μm, 11 μm, 12 μm, 14 μm, 15 μm contained in a 10% sucrose solution by size, to the lower inlet 102 While injecting a distilled water solution, which is a sucrose solution of 0% concentration, the position of the microparticles was measured by the size of each microparticle in the discharge unit 106. At this time, the position of the fine particles was measured from the bottom wall of the discharge portion 106, the position of the fine particles measured in the discharge portion 106 is shown in FIG.

A sample having an unknown microparticle size is injected into the microparticle injecting unit 103, and the conditions of the remaining injecting unit are changed to an unknown sample through the position of the microparticles measured at the discharge unit 106 when the experiment is performed in the same situation. The size of the included microparticles can be measured. At this time, the size of the microparticles to be measured should be within the size range of the obtained microparticles.

1 is a plan view (conceptual diagram) of a microfluidic control device using a density difference phenomenon according to the present invention.

2 is a cross-sectional view of the microfluidic chip according to the present invention.

Figure 3 is a graph showing the results of analyzing the density of the microfluid by the density difference electrophoresis method using the microfluidic control device according to the present invention.

Figure 4 is a graph analyzing the results of the separation of the microparticles by size by the density difference method using the microfluidic control device according to the present invention.

<Explanation of symbols for the main parts of the drawings>

101: first fluid inlet 201: polymer substrate

102: second fluid inlet 202: glass substrate

103: microparticle injection hole 203: cross section of the microfluidic channel

104: intersection

105: microfluidic channel

106: discharge part

Claims (21)

A first inlet and a second inlet through which the first microfluid and the second microfluid have different densities; A third inlet hole into which fine particles are moved by the first microfluidic fluid and the second microfluidic fluid; A microfluidic channel in which the injected first and second microfluids and the injected microparticles cross and move; And And a discharge part through which the fine particles passing through the microfluidic channel are discharged. The injected first microfluidic fluid and the second microfluidic fluid form a density gradient within the microfluidic channel, The microfluidic control device using a density difference phenomenon characterized in that the microparticles are moved in accordance with the density gradient formed by the fluids. The microfluidic control device according to claim 1, wherein the first inlet and the second inlet are configured to be symmetrical in the vertical direction. The microfluidic control device of claim 1, wherein the third inlet is configured to have a predetermined angle with the first inlet or the second inlet. Claim 4 was abandoned when the registration fee was paid. The microfluidic control device of claim 1, wherein the first microfluidic fluid, the second microfluidic fluid, and the microparticles are injected at the same time. The microfluidic control device according to claim 1, wherein the microparticles are dispersed and injected into the microfluid injected into the third inlet. Claim 6 was abandoned when the registration fee was paid. The microfluidic control of claim 1, wherein the first microfluid, the second microfluid, and the microparticles to be injected flow in a central portion or a specific portion of the microfluidic channel and are moved by density differential motion. device. The microfluidic control device according to claim 1, wherein the discharge part is wider than the microfluidic channel so that the microparticles whose path is changed due to density differential motion are discharged from the microfluidic channel. The microfluidic control device according to claim 1, wherein the location of the microfluid discharged from the discharge unit is measured to analyze the density of the microfluid or the size of the microparticles. A polymer substrate comprising a microfluidic control device using the density difference phenomenon according to claim 1; And a glass substrate formed under the polymer substrate. The polymer substrate is at least one polymer selected from the group consisting of polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), polyacrylate, polycarbonylate, polycyclic olefin, polyimide and polyurethane Microfluidic chip, characterized in that consisting of. delete A method for analyzing microfluids and microparticles using a microfluidic control device using the density differential phenomena according to claim 1, A first microfluid and a second microfluid having different densities are injected into the microfluidic channel to form a density gradient in the microfluidic channel; Injecting microparticles into the microfluidic channel; Flowing the microfluidic channel by crossing the injected microfluids and microparticles; Changing the path of the injected fine particles in a low density direction by a density gradient of the microfluid; And Measuring the positions of the microparticles passing through the microfluidic channel and discharged to the discharge unit; And The relative density difference between the first microfluid and the second microfluid is analyzed in proportion to the degree of the position of the particle measured in the step deviating from the center of the microchannel, or the position of the measured particle is departed from the center of the microchannel. And analyzing the relative size of the microparticles injected through the third inlet in proportion to the degree. delete Claim 13 was abandoned upon payment of a registration fee. 12. The method of claim 11, wherein the first inlet and the second inlet are configured to be vertically or symmetrical. Claim 14 was abandoned when the registration fee was paid. 12. The method of claim 11, wherein the third inlet is configured to have a predetermined angle with the first inlet or the second inlet. Claim 15 was abandoned upon payment of a registration fee. 12. The method of claim 11, wherein the first microfluid and the second microfluid and the microparticles are injected at the same time. Claim 16 was abandoned upon payment of a setup registration fee. 12. The method of claim 11, wherein the microparticles are dispersed and injected into the microfluid injected into the third inlet. Claim 17 has been abandoned due to the setting registration fee. The microfluidic analysis of claim 11, wherein the injected first microfluidic fluid, the second microfluidic fluid, and the microparticles flow in alignment with a central portion or a specific portion of the microfluidic channel and are moved by density differential motion. Way. Claim 18 was abandoned upon payment of a set-up fee. 12. The method of claim 11, wherein the discharge unit is wider than the microfluidic channel so that the microparticles whose path is changed due to density differential motion are discharged from the microfluidic channel. Claim 19 was abandoned upon payment of a registration fee. 12. The method of claim 11, wherein the location of the microfluid discharged from the discharge unit is measured to analyze the density of the microfluid or the size of the microparticles. Claim 20 was abandoned upon payment of a registration fee. 12. The method of claim 11, wherein the analysis of the density of the microfluidics or the size of the microparticles is carried out continuously. A method for separating microparticles using a microfluidic control device using the density difference phenomenon according to claim 1, A first microfluid and a second microfluid having different densities are injected into the microfluidic channel through the first inlet and the second inlet, respectively, to form a density gradient in the microfluidic channel; Injecting microparticles into the microfluidic channel; Flowing the microfluidic channel by crossing the injected first microfluid and second microfluids with the microparticles injected through the third inlet; Changing the path of the injected fine particles in a low density direction by a density gradient of the microfluid; The fine particle separation method using a density difference phenomenon characterized in that the fine particles discharged through the microfluidic channel and discharged to the discharge unit by size.

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