Microchannel device and microparticle measurement system

Abstract

Provided is a void device capable of improving measurement accuracy. A microchannel device (400) is provided with a microchannel chip (410). The microchannel chip (410) has a channel (412) formed in the in-plane direction thereof. The microchannel (412) has a channel portion (414) having a narrow width, and a first portion (420) and a second portion (422) separated by the channel portion (414). When the length of the channel part (414) is set to be L and the width of the channel part (414) is set to be W, the relationship of 1 < = L / W < 2 is satisfied.

Description

Technical Field

[0001] The present invention relates to a micro-flow channel device. Background Art

[0002] A particle size distribution measurement method known as the inductive strip method (Coulter principle) is known. In this method, an electrolyte containing particles is passed through a pore called a nanopore. As the particle passes through the pore, the electrolyte in the pore decreases by an amount corresponding to the particle's volume, increasing the pore's resistance. Therefore, by measuring the pore's resistance, the particle's volume (i.e., particle size) can be determined.

[0003] Figure 1 1 is a block diagram of a particle measurement system 1R using the inductive strip method. The particle measurement system 1R includes a pore device 100R, a measurement device 200R, and a data processing device 300 .

[0004] The interior of the pore device 100R is filled with an electrolyte solution 2 containing particles 4 to be detected. The interior of the pore device 100R is divided into two compartments by a pore chip 102, each of which contains an electrode 106 and an electrode 108. The pore chip 102 is provided with pores (apertures) 104. When a potential difference is generated between electrodes 106 and 108, an ionic current flows between the electrodes, and particles 4 migrate from one compartment to the other through the pores 104 by electrophoresis.

[0005] Measuring device 200R generates a potential difference between electrode pair 106 and 108 and acquires information related to resistance value Rp between the electrode pair. Measuring device 200R includes a transimpedance amplifier 210, a voltage source 220, and a digital converter 230. Voltage source 220 generates a potential difference Vb between electrode pair 106 and 108. This potential difference Vb is the driving source for electrophoresis and serves as a bias signal for measuring resistance value Rp.

[0006] A minute current Is inversely proportional to the resistance of the pore 104 flows between the electrode pair 106 and 108 .

[0007] Is=Vb / Rp…(1)

[0008] The trans-impedance amplifier 210 converts the minute current Is into a voltage signal Vs. When the conversion gain is set to r, the following equation holds.

[0009] Vs=-r×Is…(2)

[0010] When equation (1) is substituted into equation (2), equation (3) is obtained.

[0011] Vs=-Vb×r / Rp…(3)

[0012] The digital converter 230 converts the voltage signal Vs into digital data Ds. In this way, the measuring device 200R can obtain a voltage signal Vs that is inversely proportional to the resistance value Rp of the pore 104 .

[0013] Figure 2 This is a waveform diagram of an exemplary minute current Is measured by the measuring device 200R. It should be noted that the vertical and horizontal axes of the waveform diagrams and timing charts referenced in this specification are appropriately enlarged or reduced for ease of understanding, and the waveforms shown are also simplified, exaggerated, or emphasized for ease of understanding.

[0014] During the short period of particle passage, the resistance Rp of pore 104 increases. Consequently, each time a particle passes, the current Is decreases in a pulsed pattern. The amplitude of each pulse current is correlated with the particle size. Data processing device 300 processes digital data Ds to analyze information such as the number and particle size distribution of particles 4 contained in electrolyte solution 2. Part of data processing device 300 may also be a server or cloud.

[0015] Prior art literature

[0016] Patent Literature

[0017] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-014702

[0018] Patent Document 2: Japanese Patent Application Laid-Open No. 2017-120257 Summary of the Invention

[0019] Problems to be solved by the invention

[0020] The conventional pore chip 104 has a structure in which openings (pores) are formed in a membrane, and the thickness t is sufficiently small relative to the pore diameter (opening diameter) d (t<d). The present inventors have studied such low aspect ratio pore devices and have recognized the following problems.

[0021] In devices with low-aspect-ratio pores, the electric field strength within the pore is highly dependent on the diameter. Therefore, different signals are measured when a particle passes through the center of the pore versus the periphery, reducing measurement accuracy.

[0022] The present invention has been made under the above circumstances, and one of the exemplary objects of one embodiment thereof is to provide a device capable of improving measurement accuracy.

[0023] Solutions for solving problems

[0024] A micro-flow path device according to one embodiment of the present invention includes a micro-flow path chip. The micro-flow path chip has a flow path formed in the in-plane direction of the micro-flow path chip. The flow path includes a narrow channel portion, and a first portion and a second portion separated by the channel portion. When the length of the channel portion is L and the width of the channel portion is W, the relationship 1 ≤ L / W < 2 is satisfied.

[0025] It should be noted that any combination of the above components, or any substitution of components or expressions between methods, devices, systems, etc., are valid as the present invention or the solution disclosed herein. Furthermore, the description of this item (solution to the problem) does not necessarily describe all the essential features of the present invention; therefore, any subcombination of these features may also constitute the present invention.

[0026] Effects of the Invention

[0027] According to one aspect of the present invention, measurement accuracy can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a block diagram of a microparticle measurement system using the inductive strip method.

[0029] Figure 2 This is a waveform diagram of an exemplary minute current Is measured by a measuring device.

[0030] Figure 3 is a cross-sectional view of a conventional aperture chip.

[0031] Figure 4 This figure shows a histogram generated when standard particles are measured using a conventional aperture chip.

[0032] Figure 5 It is a schematic diagram explaining the cause of the splitting of the histogram in the conventional technology.

[0033] Figure 6 This is a perspective view of the micro-channel device according to the first embodiment.

[0034] Figure 7A This is a top view of the micro-flow channel device.

[0035] Figure 7B yes Figure 7A AA' line cross-sectional view of the micro-flow channel device.

[0036] Figure 8 This is an enlarged view of the gate area of ​​the micro-flow channel chip.

[0037] Figure 9 This is a diagram showing a microparticle measurement system including a micro-channel device.

[0038] Figure 10 This is a diagram showing the potential of the channel portion of a micro-channel device and its surrounding area.

[0039] Figure 11 This is a diagram showing the electric field in the channel portion of a micro-channel device and its surroundings.

[0040] Figure 12 This is a diagram showing the electric field distribution of a micro-channel chip with W=H=L=3 μm.

[0041] Figure 13 This is a diagram showing the electric field distribution of a micro-channel chip with W=H=3 μm and L=50 nm.

[0042] Figure 14 Graph showing the aspect ratio dependence of the electric field intensity distribution in the y direction.

[0043] Figure 15 This is a cross-sectional view of a micro-channel device according to Modification 1.

[0044] Figure 16 This is a perspective view of a micro-channel device according to Modification 2.

[0045] Figure 17A yes Figure 16 Top view of the micro-flow channel device.

[0046] Figure 17B yes Figure 17A AA' line cross-sectional view of the micro-flow channel device.

[0047] Figure 18 This is an enlarged view of the channel portion and its surroundings of the micro-flow channel chip according to Modification 3.

[0048] Figure 19 This is a cross-sectional view of a micro-channel device according to Modification 4.

[0049] Figure 20 This is a top view of the micro-channel device according to the second embodiment.

[0050] Figure 21 yes Figure 20 Top view of the micro-flow channel device.

[0051] Figure 22 yes Figure 21 Top view and AA line cross-sectional view of the micro-flow channel device.

[0052] Description of Reference Numerals

[0053] 1. Particle measurement system, 2. Electrolyte, 4. Particles, 200. Measuring device, 210. Transimpedance amplifier, 220. Voltage source, 230. Digital converter, 100. Pore device, 102. Pore chip, 104. Pore, 106. 108. Electrodes, 400. Microchannel device, 410. Microchannel chip, 412. Microchannel, 414. Channel portion, 420. First space, 422. Second space, 424. Inlet, 426. Outlet, 428. First electrode opening, 430. Second electrode opening, 431. First inlet, 432. First outlet, 433. Second inlet, 434. Second outlet, 440. Electrode sheet, E1. First electrode, 442. First channel-side electrode, 444. First connecting wiring, 446. First measuring device-side electrode, E2. Second electrode, 448. Second channel-side electrode, 450. Second connecting wiring, 452. Second measuring device-side electrode, 460. Support substrate, 300. Data processing device. DETAILED DESCRIPTION

[0054] (Overview of Embodiments)

[0055] The following describes an overview of several exemplary embodiments of the present invention. This overview serves as a prelude to the detailed description that will be described later. It is intended to provide a basic understanding of the embodiments and to simplify several concepts of one or more embodiments without limiting the breadth of the invention or disclosure. This overview is not an inclusive overview of all embodiments considered and is not intended to identify the important elements of all embodiments or to divide the scope of some or all schemes. For convenience, "one embodiment" is sometimes used to represent one embodiment (embodiment or variation) or multiple embodiments (embodiment or variation) disclosed in this specification.

[0056] A microchannel device according to one embodiment includes a microchannel chip. The microchannel chip has a channel formed in the in-plane direction of the microchannel chip. The channel includes a narrow gate portion, and a first portion and a second portion separated by the gate portion. When the gate portion has a length L and a width W, the relationship 1 ≤ L / W < 2 is satisfied.

[0057] This structure can generate a substantially uniform electric field in the width and height directions within the channel portion. Therefore, when a particle passes through the channel portion, an electric signal of the same intensity is generated regardless of the path it passes through, thereby improving measurement accuracy.

[0058] In one embodiment, the cross section of the channel portion may also be rectangular.

[0059] In one embodiment, the width and height of the cross section of the channel portion may be substantially equal.

[0060] In one embodiment, the microchannel chip can be made of polydimethylsiloxane. Polydimethylsiloxane offers advantages over other materials in terms of processability and cost. Alternatively, the microchannel chip can be made of a cyclic olefin resin such as COP (cyclic olefin copolymer) or COC (cyclic olefin copolymer).

[0061] In one embodiment, the micro-flow channel chip may include an inlet (Inlet) communicating with the outside of the micro-flow channel chip and the first portion, and an outlet (Outlet) communicating with the outside of the micro-flow channel chip and the second portion.

[0062] In one embodiment, the micro-flow path chip may also have a first inlet connecting the outside of the micro-flow path chip with the first part, a second inlet connecting the outside of the micro-flow path chip with the second part, a first outlet connecting the outside of the micro-flow path chip with the first part, and a second outlet connecting the outside of the micro-flow path chip with the second part.

[0063] The micro-channel chip may also include a first electrode opening connecting the bottom surface of the micro-channel chip to the first portion, and a second electrode opening connecting the bottom surface of the micro-channel chip to the second portion. The micro-channel device may also include an electrode sheet, on the surface of which the micro-channel chip is laminated. The electrode sheet may also include a first electrode extending from the first electrode opening formed on its surface, and a second electrode extending from the second electrode opening.

[0064] A particle counting system according to one embodiment may include any one of the above-described micro-channel devices, and a measuring device that is connected to the micro-channel device and measures an electrical signal.

[0065] (Implementation Method)

[0066] The following describes preferred embodiments with reference to the accompanying drawings. Identical or equivalent components, members, and processes shown in the various figures are denoted by the same reference numerals, and duplicate descriptions are omitted as appropriate. Furthermore, the embodiments do not limit the disclosure and invention, but are merely illustrative. Not all features or combinations thereof described in the embodiments are necessarily essential to the disclosure and invention.

[0067] In addition, the dimensions (thickness, length, width, etc.) of each component described in the drawings may be appropriately exaggerated or reduced for ease of understanding. Furthermore, the dimensions of multiple components do not necessarily indicate their size relationships. Even if a component A is depicted as thicker than another component B in the drawings, component A may still be thinner than component B.

[0068] In this specification, "the state in which component A and component B are connected" includes not only the case in which component A and component B are directly physically connected, but also the case in which component A and component B are indirectly connected via other components that do not have a substantial impact on their electrical connection state or do not damage the function or effect achieved through their coupling.

[0069] Similarly, "the state in which component C is connected (set) between component A and component B" includes not only the situation in which component A and component C or component B and component C are directly connected, but also the situation in which they are indirectly connected via other components that do not have a substantial impact on their electrical connection state or do not damage the functions or effects achieved through their coupling.

[0070] In addition, in this specification, the symbols marked in electrical signals such as voltage signals and current signals or circuit elements such as resistors, capacitors, and inductors represent their respective voltage values, current values, or circuit constants (resistance values, capacitance values, inductance) as needed.

[0071] Before describing the micro-channel device 400 according to the embodiment, a conventional pore chip and problems associated therewith will be described.

[0072] Figure 3 This is a cross-sectional view of a conventional pore chip 800. Pore chip 800 includes a membrane 810 having pores (openings) 812 formed therein. Conventional pore chip 800 utilizes a membrane 810 having a thickness t of several tens of nanometers. This is due to the following reasons: (i) reducing the membrane thickness t allows for the formation of a highly crystalline film and shortens the film formation time; (ii) improved supply, i.e., low film cost and short delivery times; and (iii) excellent film processability, i.e., ease of subsequent dry etching processing.

[0073] When the membrane 810 having a thickness t of several tens of nm is used as described above, between the diameter d of the pore 812 (referred to as the pore diameter) and the thickness t of the membrane 810,

[0074] d>t

[0075] When the aspect ratio of the pore is defined as t / d, the conventional pore chip 800 can be said to have a low aspect ratio.

[0076] Figure 4 This figure shows a histogram generated when measuring standard particles using a conventional pore chip 800. The pore chip 800 used in the experiment had a diameter of d = 3 μm and an aspect ratio of 0.017 (t = 0.050 μm). The diameter of the standard particle was 0.9 μm. The horizontal axis of the histogram represents the particle size estimated from the current measured when the particle passed through the pore, while the vertical axis represents the number of particles.

[0077] Since the measurement was performed on standard particles of the same diameter, the histogram should ideally be single-peaked. However, in the measurement results, the histogram split into two, showing a strong bimodal nature. When the histogram has a bimodal nature, it is difficult to estimate the particle diameter, and the measurement accuracy decreases.

[0078] The present inventors focused on the electric field intensity within the pores 812 as a cause of the occurrence of bimodality when using the conventional pore chip 800 .

[0079] Figure 5 This is a schematic diagram illustrating the reason for the splitting of the histogram in the prior art. A pore chip 800 is housed in a housing 900. Housing 900 is divided into two chambers 902 and 904 by pore chip 800. Chambers 902 and 904 are filled with electrolyte 2 containing particles 4. Particles 4 can take different paths when passing through pores 812. Figure 5 Two paths (i) and (ii) are representatively shown in FIG. If the electric field strength within pore 812 is uniform, signals of the same intensity are measured regardless of the path taken. However, if the electric field strength within pore 812 is non-uniform, particles 4 of the same particle size pass through, resulting in different signal intensities depending on the path taken. This causes the histogram to split.

[0080] The above are problems that occur in the conventional technology. Hereinafter, a micro-channel device 400 according to an embodiment that can solve these problems will be described.

[0081] (Implementation 1)

[0082] Figure 6 This is a perspective view of the micro-channel device 400 according to the first embodiment. Figure 7A It is a top view of the micro-channel device 400 . Figure 7B yes Figure 7A AA' line cross-sectional view of the micro-flow channel device 400.

[0083] The micro-channel device 400 has a stacked structure consisting of a micro-channel chip 410, an electrode sheet 440, and a support substrate 460. Within the micro-channel chip 410, a micro-channel 412 is formed within the chip surface (xy plane). The micro-channel 412 can have dimensions classified as a so-called micro-channel (channel widths ranging from several μm to several hundred μm). However, as described later, the width of the channel portion is designed based on the particles being measured, and therefore, it can have submicron or nanometer widths in certain areas.

[0084] The material of the microchannel chip 410 can be polydimethylsiloxane. Alternatively, the material of the microchannel chip 410 can be a cyclic olefin resin such as COP (cyclic olefin copolymer) or COC (cyclic olefin copolymer). The method for forming the microchannel 412 is not particularly limited and can use known techniques or future technologies.

[0085] Fine flow path 412 extends in the x direction, connected at one end to inlet 424 and at the other end to outlet 426. One of inlet 424 and outlet 426 can be used as an inlet for electrolyte containing microparticles, and the other can be used to exhaust air.

[0086] The inlet 424 connects the first space 420 with the upper surface of the micro-flow path chip 410 , and the outlet 426 connects the second space 422 with the upper surface of the micro-flow path chip 410 .

[0087] The first electrode opening 428 connects the first space 420 to the bottom surface of the micro-flow path chip 410 . The second electrode opening 430 connects the second space 422 to the bottom surface of the micro-flow path chip 410 .

[0088] The first electrode E1 and the second electrode E2 are formed on the electrode sheet 440. The first electrode E1 is led outward from the first electrode opening 428, and the second electrode E2 is led outward from the second electrode opening 430.

[0089] The first electrode E1 includes a first flow channel electrode 442, a first connecting wiring 444, and a first measuring device electrode 446. The first measuring device electrode 446 is formed in a portion that does not overlap with the micro-flow channel chip 410. The first flow channel 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 connecting wiring 444 connects the first flow channel electrode 442 to the first measuring device electrode 446.

[0090] Similarly, the second electrode E2 includes a second flow channel-side electrode 448, a second connecting wiring 450, and a second measuring device-side electrode 452. The second measuring device-side electrode 452 is formed in a portion that does not overlap with the micro-flow channel chip 410. The second flow channel-side electrode 448 is formed in a position that overlaps with the second electrode opening 430 and is exposed to the second space 422. The second connecting wiring 450 connects the second flow channel-side electrode 448 to the second measuring device-side electrode 452.

[0091] The first electrode E1 and the second electrode E2 can be electrically connected to a measuring device (not shown) in the first measuring device side electrode 446 and the second measuring device side electrode 452 , respectively.

[0092] Figure 8This is an enlarged view of the area surrounding the channel portion 414 of the micro-flow path chip 410. The side walls S1 and S2 of the micro-flow path 412 protrude toward the center of the channel portion 414 to form a partition wall 416. The portion sandwiched between the two partition walls 416 forms the channel portion 414 having a narrow width (length in the y direction). In the channel portion 414, the micro-flow path 412 is divided into a first space 420 and a second space 422. The channel portion 414 is also referred to as a narrow portion. In this embodiment, the cross-section of the channel portion 414 is a rectangle with a width W and a height H.

[0093] When the length of the channel 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.

[0094] The above is the structure of the micro-channel device 400. Next, the measurement of particles using the micro-channel device 400 will be described.

[0095] Figure 9 1 is a diagram showing a microparticle measurement system 1 including a micro-channel device 400 . The microparticle measurement system 1 includes a measurement device 200 , a data processing device 300 , and the micro-channel device 400 .

[0096] The structure of the measuring device 200 is Figure 1 The measuring device 200R is similar to the one described above and includes a voltage source 220, a transimpedance amplifier 210, and a digital converter 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 interior of the micro-channel 412 of the micro-channel chip 410 is filled with an electrolyte containing the microparticles 2. The application of the bias voltage Vb causes a current Is to flow from the first electrode E1 to the second electrode E2. The transimpedance amplifier 210 converts the current Is into a voltage signal Vs. The digital converter 230 converts the voltage signal Vs into a digital value Ds.

[0097] The current Is flowing from the first electrode E1 to the second electrode E2 is inversely proportional to the impedance Z between the first and second electrodes E1, E2. The particles 2 are positively or negatively charged and migrate (electrophoresis) due to the electric field generated between the first and second electrodes E1, E2. As the particles 2 pass through the channel portion 414, the impedance Z between the first and second electrodes E1, E2 increases, thereby decreasing the current Is. In other words, in the microchannel device 400, the channel portion 414 functions as the pore 104 in the conventional pore device 100R.

[0098] In order to verify the superiority of the micro-channel device 400 , the results of electromagnetic field simulation will be described.

[0099] Figure 101 is a diagram showing the potential of the channel portion 414 and its surroundings of the micro-channel device 400. In the simulation, the dimensions of the channel portion 414 were set to W=H=L=3 μm.

[0100] Figure 11 4 is a diagram showing the electric field in the channel portion 414 of the micro-channel device 400 and its surroundings.

[0101] Figure 12 This diagram shows the electric field distribution of a microchannel chip 410 with W=H=L=3μm. The horizontal axis represents the position in the longitudinal direction (x-axis) of the microchannel 412, with x=0 being the center of the channel 414. The vertical axis represents the position in the width direction (y-axis) of the microchannel 412, with y=0 being the center of the channel 414. Shading indicates electric field intensity, and arrows indicate the direction of the electric field.

[0102] In the device with an aspect ratio L / W=1, it can be seen that inside the channel portion 414, the electric field vectors are parallel and have no component in the y-axis direction, resulting in a uniform electric field distribution.

[0103] For comparison, the same simulation was performed except that the length L of the channel portion 414 was set to 50 nm.

[0104] Figure 13 This figure shows the electric field distribution of a 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 violates the relationship 1 ≤ L / W < 2. In this case, the electric field vector at the end of the channel portion 414 has a component in the y-axis direction, making the electric field distribution non-uniform.

[0105] Figure 14 This graph shows the aspect ratio dependence of the electric field intensity distribution in the y-direction. The horizontal axis represents position in the width direction (y-direction), and the vertical axis represents electric field intensity. As the aspect ratio L / W decreases, the electric field intensity increases as it moves away from the center, in other words, as it approaches the sidewalls. In other words, in devices with low aspect ratios, the electric field is concentrated at the ends of the channel portion 414. In contrast, a uniform electric field intensity distribution is achieved within the range where the aspect ratio L / W is greater than 1.

[0106] According to this embodiment, by setting the aspect ratio L / W to 1 or greater, a uniform electric field distribution can be obtained in the channel portion 414. This allows for the measurement of signals of the same intensity regardless of the particle's path. This prevents histogram splitting and allows for a highly unimodal histogram. Consequently, the accuracy of detecting particle diameters and particle types can be improved.

[0107] It should be noted that increasing the aspect ratio L / W, that is, when the length L of the channel portion 414 becomes longer, clogging is more likely to occur. In addition, the probability of multiple particles existing simultaneously inside the channel portion 414 increases, and the measurement accuracy of the particle size distribution decreases. When the diameter of the particle is set to φ, if L < 2×φ holds, the number of particles existing simultaneously inside the channel portion 414 can be considered to be 1. Here, the diameter φ of the particle that can pass through the channel portion 414 is limited by the width W of the channel portion 414, and the relationship φ < W holds. Therefore, if L < 2×W, ​​that is, L / W < 2 holds, the probability of multiple particles existing simultaneously inside the channel portion 414 can be reduced, and the measurement accuracy can be improved. Similarly, because the relationship φ < H holds, if L < 2×H, that is, L / H < 2 holds, the probability of multiple particles existing simultaneously inside the channel portion 414 can be reduced, and the measurement accuracy can be improved.

[0108] Next, a modification of the micro-channel device 400 of the first embodiment will be described.

[0109] Figure 15 This is a cross-sectional view of a micro-channel device 400A according to Modification 1. In this modification, the heights of the first and second spaces 420 and 422 gradually decrease as they approach the channel portion 414. This allows the interiors of the first and second spaces 420 and 422 to be easily filled with the electrolyte containing particles before measurement. Furthermore, during measurement, particles can more easily reach the channel portion 414.

[0110] Figure 16 This is a perspective view of a micro-channel device 400B according to Modification 2. Figure 17A yes Figure 16 A top view of the micro-channel device 400B. Figure 17B yes Figure 17A In this modification, the first electrode opening 428 is provided at the same position as the inlet 424 , and the second electrode opening 430 is provided at the same position as the outlet 426 .

[0111] In addition, the heights of the first space 420 and the second space 422 continuously and gradually decrease as approaching the channel portion 414 .

[0112] Figure 18 This is an enlarged view of the periphery of the channel portion 414 of the micro-channel chip 410C of Modification 3. In this modification, the shape of the partition wall 416C is similar to that of the micro-channel chip 410C. Figure 8 Specifically, the partition wall 416C is formed so that the width of the first space 420 and the width of the channel portion 414 continuously change.

[0113] Figure 19This 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. Furthermore, the first electrode opening 428 and the second electrode opening 430 are omitted from the micro-channel chip 410D. Furthermore, the rod-shaped first electrode E1 and the second electrode L2 can be inserted through the inlet 424 and the outlet 426.

[0114] In the micro-channel device 400 described in Embodiment 1, the width W (and / or height H) of the channel portion 414 is approximately several micrometers (e.g., 3 μm), and the first space 420, the channel portion 414, and the second space 422 can be filled with liquid by injecting liquid from the inlet 424. However, if the width W of the channel portion 414 is narrower than 3 μm, it is difficult for the liquid injected from the inlet 424 to enter the channel portion 414.

[0115] Embodiment 2 described below describes a micro-channel device in which the cross-sectional area of ​​the channel portion 414 is small and is suitable for detecting even smaller particles.

[0116] (Implementation Method 2)

[0117] Figure 20 This is a top view of a micro-channel 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.

[0118] The first space 420E is provided with a first inlet 431 and a first outlet 432. The first inlet 431 connects one end of the first space 420E to the upper surface of the micro-channel chip 410E. The first outlet 432 connects the other end of the first space 420E to the upper surface of the micro-channel chip 410E.

[0119] Similarly, a second inlet 433 and a second outlet 434 are provided on the second space 422E side. The second inlet 433 connects one end of the second space 422E to the upper surface of the micro-flow channel chip 410E. The second outlet 434 connects the other end of the second space 422E to the upper surface of the micro-flow channel chip 410E.

[0120] The first space 420E and the second space 422E are connected via the channel portion 414E.

[0121] Figure 21 yes Figure 20 A top view of the micro-channel device 400E.

[0122] Before measurement, liquid is injected from the first inlet 431 into the first space 420E, filling the interior of the space with liquid from the first inlet 431 toward the first outlet 432. Similarly, liquid is injected from the second inlet 433 into the second space 422E, filling the interior of the space with liquid from the second inlet 433 toward the second outlet 434. When the liquid from the first space 420E and the second space 422E reaches the channel portion 414E, the interior of the channel portion 414E is also filled with liquid due to capillary action.

[0123] In the second embodiment, the height inside the first space 420E and the second space 422E can also be changed in stages.

[0124] Figure 22 yes Figure 21 A top view and a cross-sectional view along line AA of the micro-channel device 400E are shown. The heights of the first space 420E and the second space 422E increase toward the inner periphery of the U-shape and decrease toward the outer periphery, that is, toward the channel portion 414E. For example, the widths of the first space 420E and the second space 422E may be 1 mm, and the depths may vary in three steps: 200 μm, 50 μm, and 20 μm. The height of the channel portion 414E is approximately 3 μm.

[0125] The modified example described in Embodiment 1 is also applicable 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 .

[0126] The present invention has been described based on the embodiments. However, the embodiments merely illustrate the principles and applications of the present invention, and many modifications and changes in configuration are permitted within the scope of the present invention defined by the claims.

Claims

1. A micro-channel device, characterized in that: The micro-channel device comprises a micro-channel chip, The micro-channel chip has channels formed in the in-plane direction of the micro-channel chip. The flow path includes a narrow channel portion, and a first portion and a second portion separated by the channel portion. When the length of the channel portion is L and the width of the channel portion is W, a relationship of 1≤L / W<2 is satisfied.

2. The micro-channel device according to claim 1, characterized in that: The cross section of the channel portion is rectangular.

3. The micro-channel device according to claim 2, characterized in that: The width and height of the cross section of the channel portion are substantially equal.

4. The micro-channel device according to any one of claims 1 to 3, characterized in that: The microchannel chip is made of polydimethylsiloxane.

5. The micro-channel device according to any one of claims 1 to 3, characterized in that: The micro-channel chip has: an inlet that connects the outside of the micro-flow channel chip with the first portion; and An outlet connects the outside of the micro-channel chip with the second portion.

6. The micro-channel device according to any one of claims 1 to 3, characterized in that: The micro-channel chip has: a first inlet connecting the outside of the micro-channel chip with the first portion; a second inlet connecting the outside of the micro-channel chip with the second portion; a first outlet connecting the outside of the micro-channel chip with the first portion; as well as A second outflow port connects the outside of the micro-flow channel chip and the second portion.

7. The micro-channel device according to any one of claims 1 to 3, characterized in that: The micro-channel chip also has: a first electrode opening that connects the bottom surface of the micro-channel chip with the first portion; and a second electrode opening that connects the bottom surface of the micro-channel chip with the second portion, The micro-channel device further comprises an electrode sheet, on the surface of which the micro-channel chip is stacked. The electrode sheet includes a first electrode led out from the first electrode opening formed on the surface thereof, and a second electrode led out from the second electrode opening.

8. A particle measurement system, characterized in that: The microparticle measurement system comprises: The micro-channel device according to any one of claims 1 to 3; and A measuring device is connected to the micro-channel device and measures the electrical signal.

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