Micro-channel device and fine particle measuring system

Abstract

To provide a pore device that can improve measurement accuracy.SOLUTION: A micro-channel device 400 comprises a micro-channel chip 410. The micro-channel chip 410 has a channel 412 formed in its in-plane direction. The micro-channel 412 has a gate part 414 with a narrow width, and a first portion 420 and a second portion 422 partitioned from each other by the gate part 414. When a length of the gate part 414 is defined as L, and a width of the gate part 414 is defined as W, a relation of 1≤L / W<2 is satisfied.SELECTED DRAWING: Figure 7A

Description

[Technical field]

[0001] The present disclosure relates to a microfluidic device. [Background technology]

[0002] A particle size distribution measurement method called the electrical sensing zone method (Coulter principle) is known. In this measurement method, an electrolyte containing particles is passed through a fine hole called a nanopore. When a particle passes through the pore, the electrolyte in the pore decreases by an amount equivalent to the volume of the particle, increasing the electrical resistance of the pore. Therefore, the volume of the particle (i.e., the particle size) can be measured by measuring the electrical resistance of the pore.

[0003] 1 is a block diagram of a particle measurement system 1R using an electrical sensing zone method. The particle measurement system 1R includes a pore device 100R, a measuring apparatus 200R, and a data processing apparatus 300.

[0004] The inside of the pore device 100R is filled with an electrolyte 2 containing particles 4 to be detected. The inside of the pore device 100R is separated into two spaces by a pore chip 102, and electrodes 106 and 108 are provided in the two spaces. A fine hole (pore) 104 is provided in the pore chip 102. When a potential difference is generated between the electrodes 106 and 108, an ionic current flows between the electrodes, and the particles 4 move from one space to the other space via the fine hole 104 by electrophoresis.

[0005] The measurement device 200R generates a potential difference between the electrode pair 106, 108, and acquires information correlated with the resistance value Rp between the electrode pair. The measurement device 200R includes a transimpedance amplifier 210, a voltage source 220, and a digitizer 230. The voltage source 220 generates a potential difference Vb between the electrode pair 106, 108. This potential difference Vb serves as a driving source for electrophoresis and also as a bias signal for measuring the resistance value Rp.

[0006] A minute current Is that is inversely proportional to the resistance of the pore 104 flows between the electrode pair 106 and 108 . Is = Vb / Rp … (1)

[0007] The transimpedance amplifier 210 converts the minute current Is into a voltage signal Vs. When the conversion gain is r, the following equation holds: Vs = -r × Is … (2) Substituting equation (1) into equation (2), we obtain equation (3). Vs = -Vb × r / Rp … (3) The digitizer 230 converts the voltage signal Vs into digital data Ds. In this manner, the voltage signal Vs that is inversely proportional to the resistance value Rp of the pore 104 can be obtained by the measurement device 200R.

[0008] 2 is a waveform diagram of an exemplary minute current Is measured by the measuring device 200R. Note that the vertical and horizontal axes of the waveform diagrams and time charts referred to in this specification are appropriately enlarged or reduced for ease of understanding, and each waveform shown is simplified, exaggerated, or emphasized for ease of understanding.

[0009] During the short period when the particle passes through, the resistance value Rp of the pore 104 increases. Therefore, the current Is decreases in a pulsed manner each time a particle passes through. The amplitude of each pulse current correlates with the particle size. The data processing device 300 processes the digital data Ds and analyzes the number and particle size distribution of the particles 4 contained in the electrolyte 2. Part of the data processing device 300 may be a server or a cloud. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2017-016881 A [Patent Document 2] JP 2014-219235 A [Patent Document 3] JP 2018-054594 A

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0011] The conventional pore chip 104 has a structure in which openings (pores) are formed in a membrane, and the thickness t was sufficiently smaller than the pore diameter (opening diameter) d (t < d). The present inventors have studied such a low aspect ratio pore device and have come to recognize the following problems.

[0012] In a low aspect ratio pore device, the electric field strength in the pore has a large dependence in the diameter direction. Therefore, different signals will be measured when the particle passes through the center of the pore and when it passes through the outer periphery of the pore, resulting in a decrease in measurement accuracy.

[0013] The present disclosure has been made in such circumstances, and one of the exemplary purposes of one aspect thereof is to provide a device capable of improving measurement accuracy.

Means for Solving the Problems

[0014] A microchannel device according to an aspect of the present disclosure includes a microchannel chip. The microchannel chip has a channel formed in the in-plane direction of the microchannel chip. The channel has a narrow gate portion, and a first portion and a second portion separated by the gate portion. When the length of the gate portion is L and the width of the gate portion is W, the relationship 1 ≦ L / W < 2 is satisfied.

[0015] In addition, combinations of the above components arbitrarily, and components and expressions mutually replaced between methods, devices, systems, etc. are also effective as aspects of the present invention or the present disclosure. Furthermore, the description of this item (means for solving the problems) does not explain all the essential features of the present invention. Therefore, sub-combinations of these described features can also be the present invention. Effect of the Invention

[0016] According to certain aspects of the present disclosure, measurement accuracy can be improved. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a block diagram of a particle measurement system using an electrical sensing zone method. [Diagram 2] FIG. 13 is a waveform diagram of an exemplary minute current Is measured by a measuring device. [Diagram 3] FIG. 1 is a cross-sectional view of a conventional pore tip. [Figure 4] FIG. 1 shows a histogram generated when measuring standard particles using a conventional pore tip. [Diagram 5] FIG. 1 is a schematic diagram illustrating a cause of a histogram split in the prior art. [Figure 6] FIG. 1 is a perspective view of a microchannel device according to a first embodiment. [Figure 7A] FIG. 2 is a plan view of the microfluidic device. [Figure 7B] 7B is a cross-sectional view of the microfluidic device shown in FIG. 7A taken along the line AA'. [Figure 8] FIG. 2 is an enlarged view of the periphery of a gate portion of the micro-channel chip. [Figure 9] FIG. 1 is a diagram showing a particle measurement system including a microfluidic device. [Figure 10] FIG. 2 is a diagram showing the potentials at a gate portion of a microchannel device and its periphery. [Figure 11] FIG. 2 is a diagram showing an electric field at a gate portion of a microchannel device and its periphery. [Figure 12] FIG. 13 is a diagram showing the electric field distribution in a micro-channel chip with W=H=L=3 μm. [Figure 13] FIG. 13 is a diagram showing the electric field distribution in a micro-channel chip with W=H=3 μm and L=50 nm. [Figure 14] FIG. 13 is a diagram showing the aspect ratio dependence of the electric field strength distribution in the y direction. [Figure 15]FIG. 4 is a cross-sectional view of a microchannel device according to Modification 1. [Figure 16] FIG. 11 is a perspective view of a microchannel device according to Modification 2. [Figure 17A] FIG. 17 is a plan view of the microfluidic device of FIG. [Figure 17B] 17B is a cross-sectional view of the microchannel device of FIG. 17A taken along the line AA'. FIG. [Figure 18] FIG. 11 is an enlarged view of the periphery of a gate portion of the micro-channel chip according to Modification 3. [Figure 19] FIG. 11 is a cross-sectional view of a microchannel device according to Modification 4. [Figure 20] FIG. 11 is a plan view of a microchannel device according to a second embodiment. [Figure 21] FIG. 21 is a plan view of the microfluidic device of FIG. 20. [Figure 22] 22 is a plan view and a cross-sectional view taken along line AA of the microfluidic device of FIG. 21. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] (Overview of the embodiment) A summary of some exemplary embodiments of the present disclosure will be described. This summary is intended to provide a simplified overview of some concepts of one or more embodiments for a basic understanding of the embodiments as a prelude to the detailed description that follows, and is not intended to limit the scope of the invention or disclosure. This summary is not intended to be an exhaustive overview of all possible embodiments, nor is it intended to identify key elements of all embodiments or to delineate the scope of some or all aspects. For convenience, the term "one embodiment" may be used to refer to one embodiment (example or variant) or multiple embodiments (examples or variants) disclosed in this specification.

[0019] A micro-channel chip according to one embodiment includes a micro-channel chip. The micro-channel chip has a channel formed in the in-plane direction of the micro-channel chip. The channel has a narrow gate portion, and a first portion and a second portion separated by the gate portion. When the length of the gate portion is L and the width of the gate portion is W, the relationship 1≦L / W<2 is satisfied.

[0020] According to this configuration, a substantially uniform electric field can be generated in the width and height directions within the gate section, so that when a particle passes through the gate section, an electric signal of the same intensity is generated regardless of the path the particle takes, improving measurement accuracy.

[0021] In one embodiment, the cross section of the gate portion may be rectangular.

[0022] In one embodiment, the cross-sectional width and height of the gate portion may be substantially equal.

[0023] In one embodiment, the material of the microchannel chip may be polydimethylsiloxane. Polydimethylsiloxane is a material that has advantages over other materials in terms of processability and cost. Alternatively, the material of the microchannel chip may be a cyclic olefin-based resin such as COP (cyclic olefin copolymer) or COC (cyclic olefin copolymer).

[0024] In one embodiment, the micro-channel chip may have an inlet that connects the outside of the micro-channel chip to the first portion, and an outlet that connects the outside of the micro-channel chip to the second portion.

[0025] In one embodiment, the micro-channel chip may have a first inlet connecting the outside of the micro-channel chip to the first portion, a second inlet connecting the outside of the micro-channel chip to the second portion, a first outlet connecting the outside of the micro-channel chip to the first portion, and a second outlet connecting the outside of the micro-channel chip to the second portion.

[0026] The micro-channel chip may further have a first electrode opening that communicates the bottom surface of the micro-channel chip with the first portion, and a second electrode opening that communicates the bottom surface of the micro-channel chip with the second portion. The micro-channel device may further include an electrode sheet having the micro-channel chip laminated on a surface thereof. The electrode sheet may include a first electrode drawn out from the first electrode opening formed on the surface thereof, and a second electrode drawn out from the second electrode opening.

[0027] A particle measurement system according to one embodiment may include any of the micro flow channel devices described above, and a measurement device connected to the micro flow channel device and configured to measure an electrical signal.

[0028] (Embodiment) Hereinafter, preferred embodiments will be described with reference to the drawings. The same or equivalent components, parts, and processes shown in each drawing will be given the same reference numerals, and duplicated descriptions will be omitted as appropriate. In addition, the embodiments are illustrative and do not limit the disclosure and invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the disclosure and invention.

[0029] In addition, the dimensions (thickness, length, width, etc.) of each component shown in the drawings may be enlarged or reduced as appropriate for ease of understanding. Furthermore, the dimensions of multiple components do not necessarily represent their relative sizes, and even if a component A is drawn thicker than another component B on the drawings, component A may actually be thinner than component B.

[0030] In this specification, "a state in which component A is connected to component B" includes not only a case in which component A and component B are directly physically connected to each other, but also a case in which component A and component B are indirectly connected to each other via other components that do not substantially affect the electrical connection state between them or that do not impair the function or effect achieved by their combination.

[0031] Similarly, "a state in which component C is connected (provided) between components A and B" includes not only the case in which components A and C, or components B and C, are directly connected to each other, but also the case in which they are indirectly connected to each other via other components that do not substantially affect the electrical connection between them or that do not impair the functions or effects achieved by their combination.

[0032] In addition, in this specification, symbols attached to electrical signals such as voltage signals and current signals, or circuit elements such as resistors, capacitors, and inductors represent the respective voltage values, current values, or circuit constants (resistance values, capacitance values, inductances) as necessary.

[0033] Before describing the microfluidic device 400 according to the embodiment, a conventional pore chip and problems associated with the same will be described.

[0034] 3 is a cross-sectional view of a conventional pore chip 800. The pore chip 800 includes a membrane 810, and a pore (opening) 812 is formed in the membrane 810. In the conventional pore chip 800, the membrane 810 has a thickness t of several tens of nm. This is because (i) by reducing the thickness t, a film with high crystallinity can be formed and the film formation time can be shortened, (ii) procurement is easy, i.e., a thin film is less expensive and has a short delivery time, and (iii) the film processability is good, i.e., it is convenient when processing it later by dry etching or the like.

[0035] In this way, when using a membrane 810 having a thickness t of several tens of nm, the following relationship exists between the diameter d of the pore 812 (called the pore diameter) and the thickness t of the membrane 810: d>t If the aspect ratio of the pore is defined as t / d, it can be said that the conventional pore chip 800 has a low aspect ratio.

[0036] FIG. 4 shows a histogram generated when a standard particle is measured using a conventional pore chip 800. The pore chip 800 used in the experiment has d=3 μm and an aspect ratio of 0.017 (t=0.050 μm). The diameter of the standard particle is 0.9 μm. The horizontal axis of the histogram represents the particle size estimated from the current measured when the particle passes through the pore, and the vertical axis represents the number of particles.

[0037] Ideally, the histogram should be unimodal because standard particles with the same diameter are being measured, but the measurement results show that the histogram splits into two and shows strong bimodality. When the histogram has a bimodality, it becomes difficult to estimate the particle diameter, and the measurement accuracy decreases.

[0038] The present inventors focused on the electric field intensity within the pores 812 as the reason why biphasic phenomenon occurred when the conventional pore chip 800 was used.

[0039] FIG. 5 is a schematic diagram for explaining the cause of the split of the histogram in the conventional technology. The pore chip 800 is accommodated in the case 900. The case 900 is divided into two chambers 902, 904 by the pore chip 800. The chambers 902, 904 are filled with an electrolyte 2 containing particles 4. The particles 4 can take different paths when passing through the pore 812. Two paths (i) and (ii) are representatively shown in FIG. 5. If the electric field strength in the pore 812 is uniform, a signal of the same intensity will be measured regardless of the passing path. However, if the electric field strength in the pore 812 is non-uniform, when particles 4 having the same particle size pass through, signals of different intensities will be measured depending on the passing path. This causes the histogram to be split.

[0040] The above are problems that occur in the conventional technology. In the following, a microchannel device 400 according to an embodiment that can solve these problems will be described.

[0041] (Embodiment 1) Fig. 6 is a perspective view of the microfluidic device 400 according to embodiment 1. Fig. 7A is a plan view of the microfluidic device 400. Fig. 7B is a cross-sectional view of the microfluidic device 400 of Fig. 7A taken along line AA'.

[0042] The microchannel device 400 has a laminated structure of a microchannel chip 410, an electrode sheet 440, and a support substrate 460. A microchannel 412 is formed in the chip surface (xy plane) in the microchannel chip 410. The microchannel 412 may have dimensions (channel width of several μm to several hundred μm) classified as a so-called microchannel, but as described later, the width at the gate portion is designed based on the particles to be measured, and therefore may locally have a width on the order of submicrons or nanometers.

[0043] The material of the micro-channel chip 410 may be polydimethylsiloxane. Alternatively, the material of the micro-channel chip 410 may be a cyclic olefin resin such as COP (cyclic olefin copolymer) or COC (cyclic olefin copolymer). The method of forming the micro-channel 412 is not particularly limited, and a known technology or a technology that will be available in the future may be used.

[0044] The microchannel 412 extends in the x-direction, with one end connected to an inlet 424 and the other end connected to an outlet 426. One of the inlet 424 and the outlet 426 can be used as an inlet for an electrolyte solution containing fine particles, and the other can be used for venting air.

[0045] The inlet 424 communicates between the first space 420 and the upper surface of the micro-channel chip 410 , and the outlet 426 communicates between the second space 422 and the upper surface of the micro-channel chip 410 .

[0046] The first electrode opening 428 communicates between the first space 420 and the bottom surface of the micro-channel chip 410. The second electrode opening 430 communicates between the second space 422 and the bottom surface of the micro-channel chip 410.

[0047] A first electrode E1 and a second electrode E2 are formed on the electrode sheet 440. The first electrode E1 is drawn outward from the first electrode opening 428, and the second electrode E2 is drawn outward from the second electrode opening 430.

[0048] The first electrode E1 includes a first flow path side electrode 442, a first connection wiring 444, and a first measurement instrument side electrode 446. The first measurement instrument side electrode 446 is formed in a position that does not overlap with the micro-flow path chip 410. The first flow path side electrode 442 is formed in a position that overlaps with the first electrode opening 428, and is exposed to the first space 420. The first connection wiring 444 connects the first flow path side electrode 442 and the first measurement instrument side electrode 446.

[0049] Similarly, the second electrode E2 includes a second flow path side electrode 448, a second connection wiring 450, and a second measurement instrument side electrode 452. The second measurement instrument side electrode 452 is formed in a location that does not overlap with the micro-flow path chip 410. The second flow path side electrode 448 is formed in a location that overlaps with the second electrode opening 430, and is exposed to the second space 422. The second connection wiring 450 connects the second flow path side electrode 448 and the second measurement instrument side electrode 452.

[0050] The first electrode E1 and the second electrode E2 are capable of being electrically connected to a measuring instrument (not shown) at a first measuring instrument side electrode 446 and a second measuring instrument side electrode 452, respectively.

[0051] 8 is an enlarged view of the periphery of the gate portion 414 of the micro-channel chip 410. The side walls S1 and S2 of the micro-channel 412 protrude toward the center at the gate portion 414, forming a partition wall 416. The portion sandwiched between the two partition walls 416 becomes the gate portion 414 with a narrow width (length in the y direction). At the gate portion 414, the micro-channel 412 is separated into a first space 420 and a second space 422. The gate portion 414 is also referred to as a narrow portion. In this embodiment, the cross section of the gate portion 414 is a rectangle with a width W and a height H.

[0052] When the length of the gate portion 414 is L, the relationship 1≦L / W<2 is satisfied. Similarly, the relationship 1≦L / H<2 is satisfied. The width W and the height H may be substantially equal or different. L / W is referred to as the aspect ratio.

[0053] The above is the configuration of the micro fluidic device 400. Next, particle measurement using the micro fluidic device 400 will be described.

[0054] 9 is a diagram showing a particle measurement system 1 including a micro flow channel device 400. The particle measurement system 1 includes a measurement device 200, a data processing device 300, and the micro flow channel device 400.

[0055] The configuration of the measurement device 200 is similar to that of the measurement device 200R of FIG. 1, and includes a voltage source 220, a transimpedance amplifier 210, and a digitizer 230. The voltage source 220 applies a bias voltage Vb between the first electrode E1 and the second electrode E2 of the micro-channel device 400. The inside of the micro-channel 412 of the micro-channel chip 410 is filled with an electrolyte solution containing particles 2. By applying the bias voltage Vb, a current Is flows from the first electrode E1 to the second electrode E2. The transimpedance amplifier 210 converts the current Is into a voltage signal Vs. The digitizer 230 converts the voltage signal Vs into a digital value Ds.

[0056] The current Is flowing from the first electrode E1 to the second electrode E2 is inversely proportional to the impedance Z between the first electrode E1 and the second electrode E2. The particles 2 are positively or negatively charged and move due to the electric field generated between the first electrode E1 and the second electrode E2 (electrophoresis). When the particles 2 pass through the gate portion 414, the impedance Z between the first electrode E1 and the second electrode E2 increases, so the current Is decreases. That is, in the microchannel device 400, the gate portion 414 plays the role of the pore 104 in the conventional pore device 100R.

[0057] In order to verify the superiority of the microchannel device 400, an electromagnetic field simulation was performed and the results will be described.

[0058] 10 is a diagram showing the potential at the gate portion 414 and its periphery of the microchannel device 400. In the simulation, the dimensions of the gate portion 414 were set to W=H=L=3 μm.

[0059] FIG. 11 is a diagram showing the gate portion 414 of the microfluidic device 400 and the electric field around it.

[0060] 12 is a diagram showing the electric field distribution in micro-channel chip 410 with W=H=L=3 μm. The horizontal axis indicates the position in the length direction (x-axis) of micro-channel 412, where x=0 is the center of gate section 414. The vertical axis indicates the position in the width direction (y-axis) of micro-channel 412, where y=0 is the center of gate section 414. Shading indicates electric field intensity, and arrows indicate the direction of the electric field.

[0061] In a device with an aspect ratio L / W=1, it can be seen that inside gate portion 414, the electric field vectors are parallel and have no component in the y-axis direction, resulting in a uniform electric field distribution.

[0062] For comparison, a similar simulation was performed with the length L of the gate portion 414 set to 50 nm.

[0063] 13 is a diagram showing the electric field distribution in micro-channel chip 410 with W=H=3 μm and L=50 nm. When L=50 nm, the aspect ratio L / W=0.017, which does not satisfy the relationship 1≦L / W<2. In this case, it can be seen that the electric field vector has a component in the y-axis direction at the end of gate portion 414, and the electric field distribution is not uniform.

[0064] FIG. 14 is a diagram showing the aspect ratio dependence of the electric field strength distribution in the y direction. The horizontal axis represents the position in the width direction (y direction), and the vertical axis represents the electric field strength. As the aspect ratio L / W decreases, that is, as the distance from the center increases, or in other words, as the side wall is approached, the electric field strength increases. That is, in a device with a low aspect ratio, the electric field concentrates at the end of the gate portion 414. On the other hand, it can be seen that a uniform electric field strength distribution can be obtained in the range where the aspect ratio L / W is 1 or more.

[0065] According to the present embodiment, by setting the aspect ratio L / W to 1 or more, a uniform electric field distribution can be obtained in the gate portion 414. As a result, signals of the same intensity can be measured regardless of the passage path of the particles. Thereby, splitting of the histogram can be prevented, and a histogram with high unimodality can be obtained. As a result, the detection accuracy of the particle diameter and the type of particles can be improved.

[0066] Note that when the aspect ratio L / W is increased, that is, when the length L of the gate portion 414 is increased, clogging is likely to occur, and the probability that a plurality of particles simultaneously exist inside the gate portion 414 increases, and the measurement accuracy of the particle size distribution decreases. If the diameter of the particle is φ, if L < 2×φ holds, the number of particles simultaneously existing in the gate portion 414 can be regarded as 1. Here, the diameter φ of the particle that can pass through the gate portion 414 is limited by the width W of the gate portion 414, and the relationship φ < W holds. Therefore, if L < 2×W, that is, L / W < 2 holds, the probability that a plurality of particles simultaneously exist inside the gate portion 414 can be reduced, and the measurement accuracy can be improved. Similarly, since the relationship φ < H holds, if L < 2×H, that is, L / H < 2 holds, the probability that a plurality of particles simultaneously exist inside the gate portion 414 can be reduced, and the measurement accuracy can be improved.

[0067] Subsequently, a modified example of the microchannel device 400 according to Embodiment 1 will be described.

[0068] 15 is a cross-sectional view of a microchannel device 400A according to Modification 1. In this modification, the heights of the first space 420 and the second space 422 gradually decrease as they approach the gate portion 414. This makes it easier to fill the insides of the first space 420 and the second space 422 with an electrolyte solution containing particles before measurement. In addition, the particles are more likely to reach the gate portion 414 during measurement.

[0069] Fig. 16 is a perspective view of a micro-channel device 400B according to Modification 2. Fig. 17A is a plan view of the micro-channel device 400B of Fig. 16. Fig. 17B is a cross-sectional view of the micro-channel device 400B of Fig. 17A along line A-A'. In this modification, a first electrode opening 428 is provided at the same position as the inlet 424, and a second electrode opening 430 is provided at the same position as the outlet 426.

[0070] Moreover, the height of the first space 420 and the second space 422 gradually decreases as they approach the gate portion 414 .

[0071] Fig. 18 is an enlarged view of the periphery of the gate portion 414 of the micro-channel chip 410C according to Modification 3. In this modification, the shape of the partition wall 416C is different from that of the partition wall 416 in Fig. 8. Specifically, the partition wall 416C is formed so that the width of the first space 420 and the width of the gate portion 414 change continuously.

[0072] 19 is a cross-sectional view of a micro-channel device 400D according to Modification 4. The electrode sheet 440 is omitted from the micro-channel device 400D. The micro-channel chip 410D is also omitted from the first electrode opening 428 and the second electrode opening 430. A rod-shaped first electrode E1 and a rod-shaped second electrode L2 can be inserted from the inlet 424 and the outlet 426.

[0073] In the microchannel device 400 described in the first embodiment, when the width W (and / or height H) of the gate portion 414 is approximately several microns (e.g., 3 μm), the first space 420, the gate portion 414, and the second space 422 can be filled with liquid by injecting the liquid from the inlet 424. However, when the width W of the gate portion 414 is narrower than 3 μm, the liquid injected from the inlet 424 becomes difficult to enter the gate portion 414.

[0074] In the second embodiment described below, a microchannel device in which the cross-sectional area of ​​the gate portion 414 is small and which is suitable for detecting smaller particles will be described.

[0075] (Embodiment 2) 20 is a plan view of a microchannel device 400E according to embodiment 2. In embodiment 2, the first space 420E and the second space 422E are U-shaped. The shapes of the first space 420E and the second space 422E are not particularly limited, and may be V-shaped, J-shaped, or horseshoe-shaped.

[0076] A first inlet 431 and a first outlet 432 are provided on the first space 420E side. The first inlet 431 communicates one end of the first space 420E with the upper surface of the micro-channel chip 410E. The first outlet 432 communicates the other end of the first space 420E with the upper surface of the micro-channel chip 410E.

[0077] Similarly, a second inlet 433 and a second outlet 434 are provided on the second space 422E side. The second inlet 433 communicates one end of the second space 422E with the upper surface of the micro-channel chip 410E. The second outlet 434 communicates the other end of the second space 422E with the upper surface of the micro-channel chip 410E.

[0078] The first space 420E and the second space 422E are connected via a gate portion 414E.

[0079] FIG. 21 is a plan view of the microfluidic device 400E of FIG.

[0080] Prior to measurement, liquid is injected into first space 420E from first inlet 431, and the liquid fills the inside from first inlet 431 toward first outlet 432. Similarly, liquid is injected into second space 422E from second inlet 433, and the liquid fills the inside from second inlet 433 toward second outlet 434. When the liquid reaches gate portion 414E on the first space 420E side and second space 422E side, the inside of gate portion 414E is also filled with liquid due to capillary action.

[0081] In the second embodiment as well, the internal heights of the first space 420E and the second space 422E can be changed in stages.

[0082] Fig. 22 shows a plan view and a cross-sectional view along line AA of the microchannel device 400E of Fig. 21. The first space 420E and the second space 422E are each higher at the inner circumference of the U-shape, and the height decreases toward the outer circumference, i.e., toward the gate portion 414E. For example, the width of the first space 420E and the second space 422E may be 1 mm, and the depth may change in three steps of 200 μm, 50 μm, and 20 μm. The height of the gate portion 414E is about 3 μm.

[0083] The modified examples described in embodiment 1 can also be applied to embodiment 2. For example, in embodiment 2, the first electrode opening 428 and the second electrode opening 430 may not be provided, and the rod-shaped first electrode E1 and second electrode E2 may be inserted into the first inlet 431 and the second inlet 433.

[0084] The present invention has been described based on the embodiments, but the embodiments merely illustrate the principles and applications of the present invention, and many modifications and changes in arrangement are permitted to the embodiments without departing from the spirit of the present invention as defined in the claims. [Explanation of symbols]

[0085] 1. Particle measurement system 2 Electrolyte 4 particles 200 Measuring Equipment 210 Transimpedance Amplifier 220 Voltage Source 230 Digitizer 100 pore device 102 Pore Tip 104 Pore 106,108 electrode 400 Microfluidic Device 410 Microfluidic Chip 412 Microchannel 414 Gate 420 1st space 422 2nd space 424 Inlet 426 Outlet 428 Opening for first electrode 430 Second electrode opening 431 First Inlet 432 1st Outlet 433 Second Inlet 434 2nd Outlet 440 Electrode Sheet E1 1st electrode 442 First flow path side electrode 444 1st connection wiring 446 First Measuring Instrument Electrode E2 2nd electrode 448 Second flow path side electrode 450 Second connection wiring 452 Second Measuring Instrument Side Electrode 460 Support Substrate 300 Data processing device

Claims

1. A microfluidic chip is provided. the micro-channel chip has a channel formed in an in-plane direction of the micro-channel chip, The flow path has a narrow gate portion and a first portion and a second portion separated by the narrow gate portion, A microchannel device, characterized in that, when the length of the gate portion is L and the width of the gate portion is W, the relationship of 1≦L / W<2 is satisfied.

2. 2. The microchannel device according to claim 1, wherein the gate portion has a rectangular cross section.

3. The microfluidic device according to claim 2 , wherein the width and height of the cross section of the gate portion are substantially equal to each other.

4. 4. The micro-channel device according to claim 1, wherein the micro-channel chip is made of polydimethylsiloxane.

5. The microchannel chip comprises: an inlet communicating the outside of the micro-channel chip with the first portion; an outlet that communicates the outside of the micro-channel chip with the second portion; 4. The microchannel device according to claim 1, further comprising:

6. The microchannel chip comprises: a first inlet communicating an outside of the micro-channel chip with the first portion; a second inlet communicating the outside of the micro-channel chip with the second portion; a first outlet that communicates the outside of the micro-channel chip with the first portion; a second outlet port communicating the outside of the micro-channel chip with the second portion; 4. The microchannel device according to claim 1, further comprising:

7. The microchannel chip comprises: a first electrode opening that communicates a bottom surface of the micro-channel chip with the first portion; a second electrode opening that communicates between a bottom surface of the micro-channel chip and the second portion; and The microchannel device further includes an electrode sheet having the microchannel chip laminated on a surface thereof, 4. The micro-channel device according to claim 1, wherein the electrode sheet includes a first electrode extended from the opening for the first electrode formed on its surface, and a second electrode extended from the opening for the second electrode.

8. The microfluidic device according to claim 1 , a measuring device connected to the microfluidic device and measuring an electrical signal; A particle measurement system comprising:

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