KR20160064768A - Apparatus and method for microfluidic chip filtration using spiral branch channel - Google Patents

Abstract

A device for filtering a microfluidic chip according to the present invention comprises: a main channel formed to flow a sample solution including particles; a side channel connected with the main channel and making a solvent liquid flowed so as to make the sample solution focused toward a wall surface of the main channel in the opposite side of the side channel; and one or more branch channels connected with the main channel, and formed to receive the particles from the main channel. Each of the branch channels is formed in a spiral shape having an inner surface and an outer surface on the basis of a radius curvature and includes two or more exits for discharging the particles therefrom. The device for filtering a microfluidic chip may generate a Dean flow in a spiral branch channel, so particles or cells may be separated and analyzed by size. Also, gravity concentration is applied, so separation efficiency may be improved. A designing procedure therefor is simple compared to a conventional multimodal linear branch channel.

Description

TECHNICAL FIELD The present invention relates to a microfluid chip filtering apparatus and method using a spiral branch channel,

Embodiments relate to a microfluidic chip filtering apparatus and method using a spiral branch channel, and more particularly, to a microfluidic chip filtering apparatus and method using a microfluidic chip filtration apparatus using a spiral branch channel, Chip filtering apparatus and method.

There is a method of hydrolytic filtration and separation by inertial force as a method of manipulating and separating particles and cells by hydrodynamic effects in a channel flow without voluntary introduction of external fields such as magnetic field, dielectrophoresis, and optical techniques . Hydraulic filtration is based on the flow resistance to laminar flow and the flow fraction at any channel point. Numerous studies and developments have been made on various types of cells for hydrodynamic filtration. For example, in Japanese Patent Laid-Open Publication No. 2012-076016, entitled " Apparatus and Method for Continuous Two- .

1 is a plan view of a simple device for illustrating the principle of a conventional hydrodynamic filtration device.

Referring to FIG. 1, in the conventional hydrodynamic filtration apparatus, when a sample solution in which particles or cells are dispersed is continuously introduced into the main channel 10 and flows, the flow fraction in each branch channel 30 Separation occurs by selective exclusion of the streamline as determined by. In FIG. 1, the branch channel 30 is shown as a single channel, but in practice it is a multiple linear channel with a plurality of channels. A solvent solution is continuously introduced into the side channel 20 connected to the side surface of the main channel 10 to increase the flow fractionation effect by continuously introducing the sample solution into the main channel 10 ) To the wall surface. The stream line near the wall surface where the branch channel 30 is formed in the main channel 10 falls into the branch channel 30. At this time, the particles whose center is located in the stream line also fall into the branch channel 30. [ The flow rate exiting the branch channel 30 is determined from the flow distribution between the main channel 10 and the branch channel 30 in relation to the flow resistance in the channel network.

, 측면채널(20) 입구에서의 유량을

라 할 경우, W/2-W_C=X를 만족하는 X에 대해 -X≤x≤0 (혹은 대칭에 의해, 0≤x≤X) 범위에 대한 유량을 Q_X 라고 하면,

+

= Q와

+ Q_X = Q/2인 관계가 성립한다. 따라서, 주채널(10)에서 분지채널(30)이 분지되는 분지점 S_b에서 유량비는 하기 수학식 1로 정해진다. In FIG. 1, W _C is a cut-off thickness formed by this flow distribution, and it is determined whether or not the particle falls into the branch channel 30 according to the size of W _C and the radius of the particle. The width of the main channel 10 is W, the flow rate at the inlet of the main channel 10 is

, The flow rate at the inlet of the side channel (20)

, The flow rate for the range satisfying W / 2-W _C = X with respect to the range of -X? X? 0 (or symmetry, 0? _X ? _X )

+

= Q and

+ Q _X = Q / 2. Therefore, the flow ratio at the branching point S _b at which the branch channel 30 branches from the main channel 10 is determined by the following equation (1).

Here, the flow rate is obtained by integrating the velocity distribution obtained by the equation of motion and the boundary condition for the channel section in a normal state and laminar Newtonian fluid in a quadrangular square channel section.

In the hydrodynamic filtration method, the branch channels are generally formed in a number of tens or more in order to enhance the flow focusing effect, and they are collected at the outlet portion and discharged to the outside. Here, the outlet is designed to be installed as many as the number of aliquots to be separated by a specific size in a sample solution in which particles or cells are mixed in various sizes. The flow rate ratio between the branch channel and the main channel at the branch point to any j-th branch channel among the channel networks having dozens of branch channels can be summarized as shown in Equation (2).

=tanh(npW/2H),

=cosh(npW/2H),

=sinh(npX/H) 이며, W와 H는 각각 주채널의 폭과 높이를 나타낸다. 위의 수학식 2와 각 분지점에서의 압력강하 관계로부터, 목적하는 입자나 세포의 분리를 위해 설정한 W_C 값과 각 채널의 폭, 높이, 길이, 그리고 분지채널 개수, 분지채널간의 간격, 출구 개수 등의 제반 설계값들을 결정하기 위해서는, 복잡한 반복 계산이 수행되어야만 한다. In the above Equation 2,

= tanh (npW / 2H),

= cosh (npW / 2H),

= sinh (npX / H), and W and H indicate the width and height of the main channel, respectively. From the relationship between the pressure drop at each point and the above equation (2), the W _C value set for separating the desired particles or cells and the width, height, length, and number of branch channels of each channel, In order to determine all design values such as the number of outlets, complex iterations must be performed.

That is, in the conventional hydrodynamic filtration method, branch channels as many as the number of normally installed outlets are required to improve flow concentration, and each branch channel is composed of several to several tens of linear channels, A straight branch channel was required. In order to design a microfluidic chip having such a complicated channel network, a very large amount of calculation was required.

Japanese Laid-Open Patent Publication No. 2012-076016 United States Patent No. 8,186,913 U.S. Patent No. 8,361,415

According to an aspect of the present invention, a dean flow generated in a spiral channel is applied to hydrodynamic filtration to increase the separation efficiency in separating and analyzing particles or cells by size, It is possible to provide a new microfluidic chip filtering apparatus and method which are easy to use.

A microfluidic chip filtering apparatus according to an embodiment includes a main channel configured to flow a sample solution containing particles; A side channel connected to the main channel and allowing the solvent solution to flow to focus the sample solution toward the main channel wall surface opposite to the side channel; And one or more branch channels connected to the main channel and configured to receive the particles from the main channel. Each of the one or more branch channels is helically shaped with an inner side and an outer side relative to a radius of curvature and includes two or more outlets for the particles to escape from the branch channel.

In one embodiment, each of the one or more branch channels includes a first outlet located relatively adjacent to the inner surface and a second outlet located relatively adjacent to the outer surface.

In one embodiment, the at least one branch channel is connected to the main channel from a direction parallel to the longitudinal direction of the main channel and / or a branch channel connected to a side of the main channel from a direction different from the longitudinal direction of the main channel Branch channels.

In one embodiment, each of the main channel and the at least one branch channel has a shape in which the width of the channel is larger than the height (i.e., the aspect ratio of the channel cross section is small).

In one embodiment, the sample solution comprises a plurality of types of particles of different sizes, wherein the at least one branch channel comprises a greater number of outlets than the number of types of particles.

In one embodiment, when the diameter of the particle is denoted by D, the width of the branch channel is denoted by W _B , and the height of the branch channel is denoted by H, the following equation is satisfied: D (W _B + H) / 2 W _B H> 0.07 The microfluidic chip filtering device is constructed.

In one embodiment, when the diameter of the particle is D, the radius of curvature of the branch channel is R _C , and the height of the branch channel is H, 0.08? 2D ² R _C / H ³ <20 The microfluidic chip filtering device is constituted.

A microfluidic chip according to an embodiment includes a channel substrate; A main channel formed on the channel substrate and configured to flow a sample solution containing particles, a side channel connected to the main channel and concentrating the sample solution toward the main channel wall side opposite to the side channel, And at least one branch channel connected to the main channel and adapted to receive the particles from the main channel. Each of the one or more branch channels is helically shaped with an inner side and an outer side relative to a radius of curvature and includes two or more outlets for the particles to escape from the branch channel.

The microfluidic chip filtering method according to an embodiment includes injecting a sample solution containing particles into a main channel; Injecting a solvent liquid into a side channel connected to the main channel; Moving the particles from the main channel to a spirally branched channel connected to the main channel and having an inner side surface and an outer side surface with respect to a radius of curvature; Separating the particles in size by an inertial lift force and a dean drag force in the branch channel; And discharging the particles from the branch channel through two or more outlets of the branch channel.

In one embodiment, separating the particles by size comprises concentrating the particles in the direction of the inner side of the branch channel by inertial lift and drag forces.

In one embodiment, the sample solution comprises a first particle and a second particle smaller than the first particle. Wherein the step of discharging the particles comprises: discharging the first particles through a first outlet located relatively adjacent to the inner side of the branch channel; And discharging the second particles through a second outlet located relatively adjacent to the outer surface of the branch channel.

In one embodiment, the microfluidic chip filtering method further comprises moving the particles remaining in the main channel without moving to the branch channel to another branch channel located behind the branch channel along the flow direction of the sample solution step; Separating said particles by size by inertial lifting and dragging forces in said another branch channel; And discharging the particles from the further branch channel through two or more outlets of the further branch channel.

In accordance with one aspect of the present invention, a microfluidic chip filtration apparatus and method includes: connecting one or more helical branch channels to a main channel to enhance flow focusing effect; , A Dean flow can be generated in the spiral branch channel. Using this, it is possible to separate and analyze the particles or cells by size, and it is possible to increase the separation efficiency compared to the conventional multi-channel linear branch channel in which the inertial concentration is added and only the hydrodynamic filtering is performed, The design process can be simplified because there is no need to introduce dozens of branch channels designed. The filtration apparatus and method can be implemented in the form of a microfluidic chip. The filtration apparatus and method can be implemented in the form of a microfluidic chip, and can be classified into various types such as sorting of red blood cells, white blood cells, hepatocytes, stem cells, (micro total analysis system), such as counting and specific size fractionation.

1 is a plan view of a simple device for illustrating the principle of a conventional hydrodynamic filtration device.
2 is a plan view of a microfluidic chip filtering apparatus according to an embodiment.
3 is a conceptual diagram for explaining a pressure gradient due to the occurrence of Dean flow in a curved channel and fluid inertia due to centrifugal force.
FIG. 4 is a conceptual diagram for explaining the concentration of particles when there is only an inertial lift force and an inertial lifting force at the same time in the curved channel.
5 is a view illustrating the structure of a spiral branch channel in a microfluidic chip filtering apparatus according to an embodiment.
6A to 6C are views showing a comparison between a conventional apparatus and a device according to an embodiment in a hydrodynamic filtration structure for separation analysis of a bi-dispersible particle sample or a bimodal cell sample.
FIGS. 7A to 7C are views showing a comparison between a conventional apparatus and an apparatus according to an embodiment in a hydrodynamic filtration structure for separation analysis of a tridisperse particle sample or a trimodal cell sample. FIG.
FIG. 8 is a schematic view of a microfluidic chip for separating three dispersed particles by size using a microfluidic chip filtering apparatus according to an embodiment.
FIG. 9A is a graph showing recovery rates obtained by size-based separation of three dispersed particles by a conventional hydraulic filtration structure. FIG.
FIG. 9B is a graph showing the purity obtained for the size-based separation of three dispersed particles by the conventional hydrodynamic filtration structure. FIG.
FIG. 10A is a graph showing recovery rates obtained by size-based separation of three dispersed particles using a microfluidic chip filtration apparatus according to an embodiment. FIG.
FIG. 10B is a graph showing the purity obtained for the size-based separation of three dispersed particles using the microfluidic chip filtering apparatus according to one embodiment.

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

2 is a plan view of a microfluidic chip filtering apparatus according to an embodiment.

Referring to FIG. 2, the microfluidic chip filtering apparatus according to the present embodiment includes a main channel 10 and one or more branch channels 40 connected to the main channel 10. In one embodiment, the microfluidic chip filtering device further comprises a side channel 20 connected to one side of the main channel 10. Although each channel 10, 20, 40 is shown in the drawings herein as being a component having a predetermined shape, each channel 10, 20, (Not shown), and each channel 10, 20, 40 shown in the figures is intended to represent the shape of such a space. The support such as the substrate may be made of polydimethylsiloxane (PDMS), which is easy to process a channel having a desired shape, but is not limited thereto.

The main channel 10 is a space through which a sample solution containing particles to be filtered flows. Particles are intended to encompass cells such as deformable soft red blood cells, white blood cells, hepatocytes, stem cells, cancer cells as well as hard objects that are not deformed like nanoparticles, It is not limited to a specific kind. The sample solution flowing in the main channel 10 may include one or more kinds of particles 100 and 200 having different sizes and a part or all of the particles 100 and 200 may be supplied from the main channel 10 to the branch channel 40, So that the particles can be filtered through the branch channel 40.

The side channel 20 is connected to one side of the main channel 10 and serves to concentrate the particles toward the wall opposite to the side channel 20 by continuously introducing a solvent medium. The side channel 20 may be connected to the main channel 10 at an angle of 60 degrees with the main channel 10. At least one branch channel 40 may be connected to a wall surface opposite the side channel 20 in the main channel 10.

The branch channel 40 has a spiral shape that curves with a curvature. The width W _B of the branch channel 40 is equal to or greater than the width W of the main channel 10. The shape of the branch channel 40 shown in Fig. 2 is merely exemplary, and the specific spiral shape of the branch channel 40 will be described in detail later. The streamlines near the wall where the branch channel 40 is formed in the main channel 10 fall into the branch channel 40 where the particles 100 and 200 whose center is located in the streamline are also connected to the branch channel 40 It will fall out. The flow rate exiting the branch channel 40 is determined from the flow distribution between the main channel 10 and the branch channel 40 in relation to the flow resistance in the channel network and is determined by the cut- It is determined whether or not the particles 100 and 200 fall into the branch channel 40 at the branch point S _b according to the thickness W _C and the size of the radius of the particles 100 and 200. The number of branch channels 40 is determined by the number of aliquots to be separated by a specific size in a sample solution in which particles are mixed in various sizes.

In one embodiment, each of the main channel 10 and the at least one branch channel 40 has a shape in which the width of each channel is larger than the height, that is, the aspect ratio of the channel cross-section is small.

In the embodiment shown in FIG. 2, two kinds of particles 100 and 200 of different sizes are shown to illustrate the process of separating two particles of bidisperse. However, this is an illustrative example, and there may be more kinds of particles included in the sample solution to be filtered by the microfluidic chip filtration apparatus according to the embodiments. It should also be understood that the shape and size of each channel 10, 20, 40 shown in Fig. 2 is merely exemplary and does not limit the actual shape and size of each channel.

In embodiments of the present invention, the branch channel 40 is helical and thus includes an inner surface 410 having a relatively small radius of curvature and an outer surface 420 having a relatively large radius of curvature. At this time, in the sample solution flowing in the branch channel 40, separation of the particles 100 and 200 occurs due to Dean flow. As a result, the relatively large particles 100 are moved in the direction of the inner side 410 of the branch channel 40 and the relatively small particles 200 are moved along the outer side 420 of the branch channel 40 ) Direction. This will be described in detail with reference to FIG. 3 and FIG.

3 is a conceptual diagram for explaining a pressure gradient due to the generation of the dean flow in the curved channel and fluid inertia due to the centrifugal force.

Referring to FIG. 3, when a fluid flows through the curved channel, a local velocity varies depending on a length difference between an outer side surface and an inner side surface of the channel, thereby causing a pressure gradient in a spanwise direction of the channel. In addition, due to the centrifugal force due to the curvature of the channel, fluid inertia occurs in the direction opposite to the pressure gradient. Depending on the magnitude difference between the pressure gradient and the fluid inertia, a secondary flow field is formed in the lateral direction, which is called the dehydration flow.

The size of a Dean flow is determined by the dimensionless number Dean number (Dean number) (De = Re (W B / R C) 1/2), where Re is the Reynolds number that represents the intensity of the flow (Reynolds number), W _B is the width of the channel, and R _C is the radius of curvature at which the channel is bent. That is, the larger the Reynolds number (Re), the radius of curvature (R _c) more is less, and the larger the ratio W _B / H of the width (W _B) and height (H) of the channel (that is, the more shallow channel) strong Dean Due to the drag due to the flow, a more unidirectional axial velocity distribution is obtained. As for this, M.-S. Chun, "Electrokinetic secondary-flow behavior in a curved microchannel under dissimilar surface conditions", Phys. Rev. E, 83, 036312, 2011, etc., so that detailed description is omitted. When the Dean number (De) is much smaller than 0.1, the pressure gradient is larger than the fluid inertia so that the axial velocity distribution (inwardly inclined) deviated in the inner side direction of the channel is formed. However, when the Dean number De becomes about 0.1 or more An axial velocity distribution (outward slope) deviated in the outer surface direction of the channel is formed.

The Dino Di Carlo research group applied this Dean flow to particle manipulation and separation. Such studies are known from U.S. Patent No. 8,186,913 and U.S. Patent No. 8,361,415, and include content of particle concentration and inertial concentration at particle concentration by adding inertial concentration and drag in curved or spiral channels .

FIG. 4 is a conceptual diagram for explaining the concentration of particles when there is only an inertial lift force and an inertial lifting force at the same time in the curved channel.

Referring to FIG. 4, v _z represents the flow direction of the fluid in the channel, and when a dehydrated flow is generated in the curved channel in the lateral direction, vortices are formed vertically symmetrically on the channel cross section. Dean vortex vortex is known to be counterclockwise at the top and clockwise at the bottom. The shape of the dean flow is the direction opposite to the direction in which the channel is bent (that is, in the inner side direction from the outer side of the channel) in the vicinity of the upper and lower walls of the channel, Direction).

Without considering the dean flow, the inertial lift on the particles is due to the shear-induced inertial lift due to the strong shear flow near the channel center and the inertial lift due to the channel wall in the opposite direction Particles are concentrated at the equilibrium point of the portion (that is, up, down, left, and right of the channel section). When the drag force due to the dean flow is applied, the particles in the vicinity of the channel upper and lower walls move inward (that is, inward from the channel outer side) due to the influence of the strong drag force. Particles in the vicinity of the channel outer side receive the drag force in the same direction as the lift force and move in the lateral direction of the channel along the din vortex. However, the particles in the inner side of the channel receive the drag in opposite direction to the lift force, . As a result, the particles are concentrated near the inner side of the channel.

Referring again to FIG. 2, the particles flowing in the branch channel 40 are separated due to the size of the particles 100 and 200 while moving due to the influence of the inertial lifting force and the drag force described above. The inertial lifting force F _L acts from the inner side surface 410 of the branch channel 40 toward the outer side surface 420 and the drag force F _D acts in the opposite direction. Where D is the diameter of the particle, F _L is the function of D ⁴ , and F _D is the function of D. Therefore, as the particle size is larger, the F _L / F _D value becomes larger. Therefore, the particle 100 having a relatively larger size moves toward the inner surface 410 of the branch channel 40, The separation of the small particles 200 occurs.

Specifically, it is known that when the particle having the diameter D flows through the channel having the hydraulic diameter D _H , it is known that the conditions of the following formula (3) must be satisfied in order for the particles to be concentrated by the inertial lift: have.

Since the hydraulic diameter D _H of the width and height of the channel W _B and a branch channel (40) H, respectively, _{2W B H / (W B +} H), equation (3) _{D (W B + H) /} 2W B H > 0.07. Here, the height H refers to the vertical length of the channel cross-section with respect to the bottom surface of the channel, and may also be referred to as the depth when the upper surface of the channel is referred to. Further, in order to smoothly achieve separation according to the size of the particles in the curved and spiral channels, the ratio of the inertia lift to the drag force (i.e., F _L / F _D = 2D ² R _C / H ³ ) It is 20 or less in the embodiment, which can be summarized as shown in Equation (4) below.

Accordingly, the shape of the spiral branch channel in the microfluidic chip filtering apparatus according to one embodiment can be determined based on the above-described Equation (3) and Equation (4) as design conditions.

The particles 100 and 200 can be separated by size by appropriately configuring the outlet 430 through which the particles 100 and 200 exit from the branch channel 40 in the branch channel 40 satisfying the above condition. For example, outlet 430 may comprise two or more separate outlets configured to allow each particle 100, 200 to exit.

5 is a view illustrating a structure of a spiral branch channel in a microfluidic chip filtering apparatus according to an embodiment.

Referring to FIG. 5, the number of turns of the branch channel 40 is N, which is an arbitrary natural number, and the first spiral space 400 located innermost can be formed with the outlets 431 and 432 in which the tubing is installed. In order for 1/16 inch tubing having a diameter of 1.59 mm to be installed in each of the outlets 431 and 432, the diameter of the initial helical space 400 should be about 3.1 mm or more. Also, the width W _B of the branch channel 40 may be 120 micrometers (μm). The outlet 431 extends adjacent the inner side 410 of the branch channel 40 and the outlet 432 extends adjacent the outer side 420 of the branch channel 40. Each of the outlets 431 and 432 may be connected to the branch channel 40 through branch pipes 435 connected to the corresponding connection pipes 433 and 434 and the connection pipes 433 and 434. The branch pipe 435 is installed such that the particles moved through the branch channel 40 are not changed in the course of entering the two connection pipes 433 and 434, May be 1.2 to 1.5 times the width of the branch channel (40). In addition, the width of each of the connectors 433 and 434 may be 0.6 to 0.75 times the width of the branch channel 40. [ However, this is merely an example, and the width of each part and the relationship therebetween are not limited to those described above.

The number of spirals constituting the branch channel 40 can be determined in a variety of ways, and thus the radius of curvature of the branch channel 40 is different. Table 1 below summarizes the radius of curvature (R _C ) from the rotation center of the branch channel 40 to the center of the channel with respect to each spiral rotation speed. However, the shape of the branch channel in the microfluidic chip filtering apparatus according to the embodiments is not limited by the numerical values shown in Table 1 below.

Spiral rotation speed (n) One 2 3 N Interval between channels (W _S ) (μm) 3200 240 200 200 Channel width (W _B ) (μm) 120 120 120 120 Curvature radius (R _C ) (μm) 3260 3620 3940 ? W _S + W (N-0.5)

6A to 6C are views showing a comparison between a conventional apparatus and an apparatus according to an embodiment in a hydrodynamic filtration structure for the separation analysis of a two-dispersed particle sample.

Figure 6a shows the construction of a bifurcated particle sample composed of a relatively small particle D _s and a relatively large particle D _L , and Figure 6b shows a conventional hydrodynamic filtration device for its separation analysis. As shown in FIG. 6B, in the conventional apparatus, the main channel 10 is connected to the multi-branch straight branch channel 31 made up of a plurality of branch channels 31. A sample solution may be injected into the inlet 110 of the main channel 10. [ A side channel 20 to which a solvent liquid is injected may be connected to one side of the main channel 10. In the illustrated device, than the radius of the relatively small size particles D _S W _C branch channel formed in the first part that is designed to be larger D _S The particles move from the main channel 10 to the branch channel 31 and as a result are separated at the outlet 310 of the branch channel 31. On the other hand, the relatively large D _L particles travel along the main channel 10 and are collected at the outlet 120 of the main channel 10.

On the other hand, FIG. 6C shows a microfluidic chip filtering apparatus according to one embodiment for separation analysis of a sample containing two dispersed particles. 6C, the microfluidic chip filtering apparatus according to the present embodiment includes a main channel 10 and a spiral branch channel 40 connected thereto, and the spiral branch channel 40 includes two or more outlets 431 and 432 ). The relatively large particles in the spiral branch channel 40 are concentrated in the channel side by the dean flow so that an outlet 431 adjacent to the inner side of the branch channel 40 has a portion D _L And the outlet 432 adjacent to the outer surface of the branch channel 40 is D _{S &lt; RTI} ID = _0.0 &gt; Particles are collected. The remaining D _L particles are also collected at the outlet 120 of the main channel 10.

Accordingly, the microfluidic chip filtering apparatus according to the present embodiment can be used to separate two kinds of particles having different sizes. This microfluidic chip filter can be applied to bimodal cell samples distributed in Gaussian form with small particle part (D _S ± σ _S ) and large particle part (D _L ± σ _L ). Here, σ _S and σ _L represent the standard deviation of the size of each particle.

7a to 7c are diagrams comparing a conventional apparatus and an apparatus according to an embodiment in a hydrodynamic filtration structure for separation analysis of tridisperse particle samples.

Figure 7a shows the construction of a three-dispersed particle sample composed of a relatively small particle D _S , a middle particle D _M and a relatively large particle D _L , and Figure 7b shows a conventional hydrodynamic filtration device for its separation analysis . Compared with the apparatus described above with reference to FIG. 6B, the conventional apparatus shown in FIG. 7B is configured to separate particles of different sizes using two kinds of multi-branch channels 31 and 32. FIG. Although the branch channels 31 and 32 are shown as several channels for the sake of convenience of description, in practice, they are made up of several to several tens of branch channels. Thus, adding one kind of multi-branch channels requires several tens or more branch channels To increase the design burden.

Meanwhile, FIG. 7C shows a microfluidic chip filtering apparatus according to an embodiment for separation analysis of a sample containing three dispersed particles. 6C, the microfluidic chip filtering apparatus according to the present embodiment includes a main channel 10, a first helical branch channel 40 connected to the main channel 10, and a second helical branch channel 40 connected to the main channel 10, Channel &lt; / RTI &gt; The first branch channel 40 is connected to the side of the main channel 10 from a direction different from the longitudinal direction of the main channel 10 and the second branch channel 50 is connected to the side of the main channel 10 parallel to the longitudinal direction of the main channel 10 To the main channel (10). The first spiral branch channel 40 includes outlets 431 and 432 and the second spiral branch channel 50 includes outlets 531 and 532. [

The shape of the main channel 10 and each of the branch channels 40 and 50 is determined so that the radius or area of the particle or cell to be firstly separated is smaller than the first cutoff thickness W _C of the main channel. As a result, only the D _S particles and some D _M particles fall into the branch channel 40 at the points of the main channel 10 and the first spiral branch channel 40, and the remaining D _M and D _L particles continue to flow into the main channel Moves along the channel (10). Some of the D _M particles missing in the branch channel 40 are collected at the outlet 431 adjacent to the inner side of the branch channel 40 because relatively large particles are concentrated in the spiral branch channel 40, the outlet 432 is adjacent the outer surface of (40) D _S Particles are collected. The same process occurs in the second spiral branch channel 50 and at the exit 531 adjacent to the inner side of the branch channel 50 in the second branch channel 50 D _L particles are collected and the At the outlet 532 adjacent the outer surface, D _M particles are collected.

Therefore, it is possible to separate three kinds of particles having different sizes by using the apparatus according to this embodiment. The microfluidic chip filter is distributed in Gaussian form with relatively small particle parts (D _S ± σ _S ), middle particle parts (D _M ± σ _M ), and relatively large particle parts (D _L ± σ _L ) Gt; (trimodal) &lt; / RTI &gt; Here, σ _S , σ _M and σ _L represent the standard deviation of the size of each particle.

6C and 7C show a microfluidic chip filtering apparatus according to an embodiment for filtering two dispersed and three dispersed particle samples, respectively. The microfluidic chip filtering apparatus of FIG. 6C includes one spiral branch channel 40 And the microfluidic chip filtration device of Figure 7c includes two spiral branch channels 40,50. However, this is merely an example, and the form of the microfluidic chip filtering apparatus according to the present invention is not limited to the above. That is, the microfluidic chip filtering apparatus according to the embodiments may include an appropriate number of spiral branch channels depending on the type of the sample to be analyzed, and one or a plurality of spiral branch channels may be arranged in the longitudinal direction of the main channel and / It can be connected to the main channel in the lateral direction of the main channel to form a microfluidic chip filtering device.

In the microfluidic chip filtering apparatus according to the embodiments, the average flow rate of the sample, the size of the main channel and the branch channel cross section, the width of the main channel and the branch channel, the radius of curvature of the branch channel, The number of outlets and the like can be appropriately determined based on the radius or area of the particle to be separated. For example, the microfluidic chip filtration device may comprise a plurality of spiral branch channels arranged on the side of the main channel along the flow direction of the sample. At this time, the radius or area of the particle to be separated first becomes smaller than the first cutoff thickness W _C of the main channel, causing the particles to fall into the first branch channel along the flow direction of the sample, The radius or area of the particles may be made smaller than the second cutoff thickness W _C of the main channel so that the particles fall into the branch channel located second along the flow direction of the sample. By repeating the above procedure for each branch channel, the particles can be separated by size in each branch channel.

FIG. 8 is a schematic view of a microfluidic chip for separating three dispersed particles by size using a microfluidic chip filtering apparatus according to an embodiment.

Referring to FIG. 8, the microfluidic chip filtering apparatus 1 according to the present embodiment may be formed on a substrate 2 to form a microfluidic chip. For example, a channel having a channel depth or channel height of about 60 micrometers may be formed in a PDMS channel substrate 2 using a MEMS (Micro Electro Machining System) process, (20), and an inner side outlet and an outer side outlet of each branch channel (40) can be formed by passing through the channel substrate (2) with a round knife. The diameter of each inlet and outlet can be 1/16 inch to allow installation of 1/16 inch tubing. The thickness of the channel substrate 2 is preferably 1.5 to 2.5 millimeters and the channel width of the main channel 10 and the side channel 20 is 70 to 100 micrometers. The channel width is preferably 100 to 150 mu m. Further, the channel substrate 2 can be bonded to a glass substrate (not shown). The glass substrate may be wider than the channel substrate 2 and may have a thickness of 1.0 to 1.5 mm and may be joined to the channeled surface in the channel substrate 2 using an oxygen plasma bonding method or other suitable method.

It should be understood, however, that the above-described methods of working the channel, and the respective numerical values associated with the channel and the substrate are merely exemplary and are not intended to limit the method or form of manufacture of the microfluidic chip filtering device according to the embodiments.

의 유량으로 여과하고자 하는 입자가 포함된 시료용액을 주입하고, 또 다른 실린지 펌프(4)에 의해 용매액을 설치된 튜빙을 통해 측면채널(20) 입구로

의 유량으로 주입할 수 있다. 여기서,

/

는 6이상을 유지하여 시료용액이 주채널(10)에서 분지채널(40)이 형성된 벽면 부근에 충분히 집중하여 컷오프 두께 W_C 가 형성되도록 할 수 있다. 각 분지채널(40) 출구에서 나오는 크기 별로 분리된 시료는 별도의 용기(5, 6, 7)에 취합할 수 있다. Next, the tubing is installed at each inlet and outlet of the channels 10, 20, 40, and the sample solution to be separated at a constant pressure by the syringe pump can be injected through the installed tubing. By using the syringe pump 3,

The sample solution containing the particles to be filtered is injected at a flow rate of the sludge into the side channel 20 through the tubing provided with the solvent solution by another syringe pump 4

Of the flow rate. here,

/

Can be maintained at 6 or more so that the sample solution is sufficiently concentrated in the vicinity of the wall surface where the branch channel 40 is formed in the main channel 10 so that the cut-off thickness W _C is formed. Samples separated in size from the outlet of each branch channel 40 can be collected in separate containers 5, 6 and 7.

9A and 9B are graphs respectively showing the recovery and the purity obtained for the size-based separation of three dispersed particles by the conventional hydraulic filtration structure.

The present inventors have found that when three kinds of polystyrene latex particles having a diameter of 6, 11 and 18 μm and each having a completely spherical shape are dispersed in a solution prepared with a Triton X-100 surfactant at a concentration of 0.2% (w / v) They were dispersed by the same number. Surfactants serve to prevent adsorption between particles and particles, and between particles and channel walls. The hydrodynamic filtration apparatus shown in FIG. 6B was constructed using the sample constructed as described above, and the particles were separated by fabricating it as a microfluidic chip as shown in FIG. As a result, the particles discharged to the outlet formed on the microfluid chip were received in each container, and a certain volume of the particles was taken, and the number of the three kinds of particles contained therein was calculated by a fluorescence microscope and an imaging program.

9A and 9B show recovery rates and purity calculated as above, respectively, and the recovery rate and purity are measures for quantitatively determining the separation efficiency or separation performance. The recovery rate is defined as [the number of particles to be separated at the particular outlet] / [the total number of particles to be separated in the sample collected at all the outlets]. The purity is also defined as [number of particles to be separated] / [total number of particles in the sample collected at each exit].

FIGS. 10A and 10B are graphs respectively showing recovery rates and purity values obtained by size-based separation of three dispersed particles using the microfluidic chip filtration apparatus according to one embodiment.

The three dispersed particle samples prepared as described above with reference to FIGS. 9a and 9b were used and a spiral branch channel was constructed according to the embodiment shown in FIG. 7c, which was fabricated as a microfluidic chip as shown in FIG. 8 Separation of the particles was carried out. Except that the outlet 431 and the outlet 532 were connected to the same vessel among the particles discharged to the respective outlets 431, 432, 531 and 532 (FIG. 7C) of the spiral branch channel, Is the same as that described above with reference to Figs. 9A and 9B.

Comparing the recovery rates shown in Figs. 9A and 10A with each other and comparing the recovery rates shown in Figs. 9B and 10B with each other, both the recovery rate and the purity obtained using the microfluidic chip filtering apparatus according to the embodiment of the present invention It can be confirmed that it is improved as compared with the case of using the conventional hydrodynamic filtration apparatus.

While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. However, it should be understood that such modifications are within the technical scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (13)

A main channel configured to flow a sample solution containing particles; And
A side channel connected to the main channel and concentrating the sample solution toward the main channel wall side opposite to the side channel so that the solvent solution flows; And
And at least one branch channel connected to the main channel and configured to receive the particles from the main channel,
Wherein each of the at least one branch channel is helically shaped with an inner side and an outer side and includes at least two outlets for the particles to escape from the branch channel.
The method according to claim 1,
Wherein each of the one or more branch channels includes a first outlet located relatively adjacent to the inner surface and a second outlet located relatively adjacent to the outer surface.
The method according to claim 1,
Wherein the at least one branch channel comprises a branch channel connected to a side of the main channel from a direction different from the longitudinal direction of the main channel.
The method according to claim 1,
Wherein the at least one branch channel comprises a branch channel connected to the main channel from a direction parallel to the longitudinal direction of the main channel.
The method according to claim 1,
Wherein each of the main channel and the at least one branch channel has a shape in which the width of the channel is larger than the height.
The method according to claim 1,
The sample solution includes a plurality of kinds of particles having different sizes,
Wherein the at least one branch channel comprises a greater number of outlets than the number of types of particles.
The method according to claim 1,
(W _B + H) / 2W _B H > 0.07 when the diameter of the particle is D, the width of the branch channel is W _B , and the height of the branch channel is H, Device.
The method according to claim 1,
When referring to the radius of curvature of the diameter of the particles D, the branch channel the height of the R _C, wherein the branch channel to _{^{H, 0.08 ≤ 2D 2 R C}} / H 3 < microfluidic chip filtration device that satisfies Equation 20 .
A channel substrate; And
A main channel formed on the channel substrate and configured to flow a sample solution containing particles, a side channel connected to the main channel, the side channel concentrating the sample solution toward the main channel wall opposite to the side channel, and And a microfluidic chip filtration device coupled to the main channel and including at least one branch channel configured to receive the particles from the main channel,
Wherein each of the one or more branch channels is helically shaped with an inner side and an outer side relative to a radius of curvature and comprises at least two outlets for the particles to escape from the branch channel.
Injecting a sample solution containing particles into the main channel;
Injecting a solvent liquid into a side channel connected to the main channel;
Moving the particles from the main channel to a spirally branched channel connected to the main channel and having an inner side surface and an outer side surface with respect to a radius of curvature;
Separating the particles by size by inertial lift and Dean drag in the branch channel; And
And discharging the particles from the branch channel through two or more outlets of the branch channel.
11. The method of claim 10,
The step of separating the particles by size comprises concentrating the particles in the direction of the inner side of the branch channel by an inertial lift and drag force.
11. The method of claim 10,
Wherein the sample solution includes a first particle and a second particle smaller in size than the first particle,
Discharging the first particles through a first outlet located relatively adjacent to the inner side of the branch channel; And
And discharging the second particles through a second outlet located relatively adjacent to the outer surface of the branch channel.
11. The method of claim 10,
Moving particles remaining in the main channel without moving to the branch channel into another branch channel located behind the branch channel along the flow direction of the sample solution;
Separating said particles by size by inertial lifting and dragging forces in said another branch channel; And
Further comprising ejecting said particles from said another branch channel through two or more outlets of said another branch channel.

Images