Flow channel chip and separation system

Abstract

To provide a flow channel chip and a separation system capable of stabilizing the separation work of a specific kind of dielectric particles from a suspension.SOLUTION: A flow channel chip 10 includes: a substrate 10a having an inlet 21 into which a suspension L1 containing a plurality of kinds of dielectric particles P1, P2 including a specific kind of dielectric particles P1 is introduced and a flow channel 30 through which the suspension L1 introduced from the inlet 21 flows; a separation electrode 50 located in the flow channel 30 for generating a dielectrophoretic force for guiding the specific kind of dielectric particles P1 of the plurality of kinds of dielectric particles P1, P2 in a prescribed direction; and a sensor electrode 60 located in the flow channel 30 for measuring an electric resistance of the suspension L1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a channel chip and a separation system. [Background technology]

[0002] Dielectrophoresis is used as a particle control technology in microspaces such as microfluidic devices. In the biotechnology field, various research and development projects are being conducted on the characteristics analysis and separation and concentration of cells and microorganisms. Examples of these techniques include those described in Patent Document 1.

[0003] The separation device disclosed in Patent Document 1 comprises a flow path through which a sample liquid (suspension) containing circulating cancer cells (specific types of dielectric particles) flows in a predetermined direction (liquid flow direction), a replacement unit, an analysis unit, and a separation unit. The separation unit comprises a pair of electrodes, a power supply unit, and a collection unit. The power supply unit generates an AC voltage and supplies it between the pair of electrodes. This causes a positive dielectrophoretic force (attraction) to act on the cancer cells, causing them to be attracted to the pair of electrodes and flow through the flow path in the direction of extension of the pair of electrodes, and then be collected in the collection unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-134020 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a channel chip and a separation system that can stabilize the separation of specific types of dielectric particles from a suspension. [Means for solving the problem]

[0006] A channel chip according to one aspect of the present disclosure includes a substrate, a separation electrode, and a sensor electrode. The substrate has an inlet into which a suspension containing multiple types of dielectric particles, including a specific type of dielectric particles, is introduced, and a channel through which the multiple types of dielectric particles in the suspension introduced from the inlet flow. The separation electrode is located within the channel to generate a dielectrophoretic force that guides a specific type of dielectric particles among the multiple types of dielectric particles in a predetermined direction. The sensor electrode is located within the channel to measure the electrical resistance of the suspension.

[0007] A separation system according to one aspect of the present disclosure includes the above-described channel chip and a measurement device that measures the electrical resistance of the suspension based on an output from the sensor electrode. [Effects of the Invention]

[0008] According to aspects of the present disclosure, the separation of specific types of dielectric particles from a suspension can be stabilized. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram of a configuration example of a separation system including a channel chip according to a first embodiment; [Figure 2] Schematic plan view of the channel chip in Figure 1 [Figure 3] Graph showing the time variation of the resistance component and reactance component of the impedance determined by the sensor electrode [Figure 4] A double logarithmic graph showing the change in impedance with frequency due to differences in the area of the sensor electrode [Figure 5] A semi-logarithmic graph showing the change in measurement efficiency with frequency due to differences in the area of the sensor electrode. [Figure 6] Log-log graph showing the range of impedance change with frequency for small sensor electrode areas [Figure 7] A double logarithmic graph showing the range of impedance change with frequency for a large sensor electrode area. [Figure 8] 10 is a schematic plan view of a configuration example of a channel chip according to a second embodiment; [Figure 9]10 is a schematic plan view of a first configuration example of a channel chip according to a third embodiment; [Figure 10] 10 is a schematic plan view of a second configuration example of a channel chip according to a third embodiment; [Figure 11] 10 is a schematic plan view of a first configuration example of a channel chip according to a fourth embodiment; [Figure 12] 10 is a schematic plan view of a second configuration example of a channel chip according to a fourth embodiment; [Figure 13] 10 is a schematic plan view of a third configuration example of a channel chip according to a fourth embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0010] [1. Embodiment] 1.1 First Embodiment [1.1.1 Overview] FIG. 1 is a block diagram of a configuration example of a separation system 1 according to a first embodiment. The separation system 1 of FIG. 1 enables separation of a specific type of dielectric particles P1 from a suspension L1. The suspension L1 contains multiple types of dielectric particles including the specific type of dielectric particles P1. The separation system 1 of FIG. 1 separates the specific type of dielectric particles P1 from the multiple types of dielectric particles contained in the suspension L1 using the principle of dielectrophoresis. In this embodiment, the suspension L1 is blood. The multiple types of dielectric particles are, for example, cells contained in the blood. Examples of cells contained in the blood include cancer cells and white blood cells. In this embodiment, for ease of explanation, it is assumed that the suspension L1 contains two types of dielectric particles P1 and P2. The specific type of dielectric particles P1 are cancer cells, particularly circulating cancer cells (CTCs). The dielectric particles P2 are white blood cells. The separation system 1 of FIG. 1 is used to separate circulating cancer cells (specific type of dielectric particles P1) from blood (suspension L1).

[0011] The separation system 1 of FIG. 1 includes a channel chip 10 through which a suspension liquid L1 flows. The channel chip 10 of FIG. 1 includes a substrate 10a, a separation electrode 50, and a sensor electrode 60. The substrate 10a has an inlet 21 through which the suspension liquid L1 containing multiple types of dielectric particles P1 and P2, including a specific type of dielectric particle P1, is introduced, and a channel 30 through which the multiple types of dielectric particles P1 and P2 of the suspension liquid L1 introduced from the inlet 21 flow. The separation electrode 50 is located within the channel 30 to generate a dielectrophoretic force that guides the specific type of dielectric particles P1 of the multiple types of dielectric particles P1 and P2 in a predetermined direction. The sensor electrode 60 is located within the channel 30 to measure the electrical resistance of the suspension liquid L1.

[0012] In the flow channel chip 10 of FIG. 1, the separation electrode 50 generates a dielectrophoretic force, which allows the separation electrode 50 to guide a specific type of dielectric particle P1 from the multiple types of dielectric particles P1 and P2 in a predetermined direction, thereby enabling the separation of the specific type of dielectric particle P1 from the suspension L1. The magnitude of the dielectrophoretic force depends on the strength of the electric field generated in the suspension L1. The strength of the electric field generated in the suspension L1 is determined by the impedance (reactance and resistance) of the separation electrode 50 and the electrical resistance of the suspension L1. The influence of the electrical resistance of the suspension L1 is relatively large, and a change in the electrical resistance of the suspension L1 also changes the electric field strength, which leads to a change in the magnitude of the dielectrophoretic force. A change in the magnitude of the dielectrophoretic force may prevent successful separation of the specific type of dielectric particle P1 from the suspension L1. To address this situation, the flow channel chip 10 of FIG. 1 is equipped with a sensor electrode 60, which can measure the electrical resistance of the suspension L1. Therefore, the flow channel chip 10 can perform the separation of a specific type of dielectric particles P1 from the suspension L1, taking into account the electrical resistance of the suspension L1. For example, the voltage applied to the separation electrode 50 can be adjusted or the components of the suspension L1 supplied to the flow channel chip 10 can be adjusted in accordance with the electrical resistance of the suspension L1 measured by the sensor electrode 60. If the electrical resistance of the suspension L1 measured by the sensor electrode 60 is an abnormal value, the separation operation can be stopped. Therefore, the flow channel chip 10 can stabilize the separation of a specific type of dielectric particles P1 from the suspension L1.

[0013] [1.1.2 Details] The following further describes the channel chip 10 and separation system 1 of Embodiment 1. As shown in Figure 1, the separation system 1 includes a channel chip 10, a voltage control device 11, a measurement device 12, and an analysis device 13.

[0014] [1.1.2.1 Flow Channel Chip] The channel chip 10 forms a microchannel for separating a specific type of dielectric particles P1 from a suspension liquid L1. In the separation system 1, the suspension liquid L1 is flowed through the channel chip 10, and the specific type of dielectric particles P1 are separated from the suspension liquid L1 in the channel chip 10. In the separation system 1, the channel chip 10 is configured to be disposable from the viewpoint of preventing contamination.

[0015] Fig. 2 is a schematic plan view of the channel chip 10. The channel chip 10 in Fig. 2 includes a base 10a, a separated electrode 50, a sensor electrode 60, separated electrode pads 71 and 72, and sensor electrode pads 81 and .

[0016] The base 10a has an inlet 21, a flow channel 30, and a plurality of collecting units 40-1 and 40-2 (hereinafter collectively referred to as 40). The base 10a is a part that defines the outer shape of the flow channel chip 10. In this embodiment, the base 10a is a rectangular plate. The base 10a is formed using, for example, a substrate made of glass or silicone (e.g., polydimethylsiloxane (PDMS)). As an example, the base 10a may be configured by attaching a second substrate (e.g., a PDMS substrate) on its surface that has spaces corresponding to the inlet 21, the flow channel 30, and the plurality of collecting units 40-1 and 40-2, respectively, to a first substrate (e.g., a glass substrate) on its surface that has a separation electrode 50, a sensor electrode 60, separation electrode pads 71 and 72, and sensor electrode pads 81 and 82 formed thereon.

[0017] 1, the inlet 21 is a portion of the substrate 10a into which the suspension liquid L1 is introduced. The inlet 21 is connected to a supply source of the suspension liquid L1 by a tube, for example, and the suspension liquid L1 is supplied via the tube.

[0018] The flow path 30 is a portion of the substrate 10a through which multiple types of dielectric particles P1 and P2 flow in the suspension L1 introduced from the inlet 21. As shown in Fig. 2, the flow path 30 includes a main flow path 31 and multiple (two in the illustrated example) branch flow paths 32-1 and 32-2 (hereinafter collectively referred to as 32).

[0019] The main flow path 31 in FIG. 2 constitutes the main part of the flow path 30. The main flow path 31 is a portion for separating a specific type of dielectric particles P1 in the flow path 30. In this embodiment, the main flow path 31 is rectangular in plan view. A first end (left end in FIG. 2) in the length direction (left-right direction in FIG. 2) of the main flow path 31 is connected to the inlet 21. A second end (right end in FIG. 2) in the length direction of the main flow path 31 is connected to each branch flow path 32.

[0020] The branch flow paths 32-1 and 32-2 are portions of the flow path 30 that transport the dielectric particles P1 and P2 separated from each other in the main flow path 31 so as not to remix with each other. The branch flow paths 32-1 and 32-2 are located on the opposite side of the main flow path 31 from the inlet 21. Therefore, each branch flow path 32 is located downstream (on the right side in FIG. 2) with respect to the main flow path 31. The branch flow path 32-1 is connected to a first end 311 of the main flow path 31 in the width direction (the up-down direction in FIG. 2). As shown in FIG. 1, the branch flow path 32-1 is a portion through which the specific type of dielectric particles P1 separated in the main flow path 31 flows. The branch flow path 32-2 is connected to a second end 312 of the main flow path 31 in the width direction. As shown in FIG. 2, the branch flow path 32-1 is a portion through which the remaining dielectric particles P2, after the specific type of dielectric particles P1 have been separated from the multiple types of dielectric particles P1 and P2, flow.

[0021] The multiple collecting units 40 include a first collecting unit 40-1 and a second collecting unit 40-2. The first collecting unit 40-1 is connected to the first end 311 in the width direction of the main channel 31 via the branch channel 32-1. The first collecting unit 40-1 collects a specific type of dielectric particles P1 flowing through the branch channel 32-1. The first collecting unit 40-1 may have, for example, an outlet through which the solution S1 containing the specific type of dielectric particles P1 can be supplied from the channel chip 10 to the outside. The second collecting unit 40-2 is connected to the second end 312 in the width direction W1 of the main channel 31 via the branch channel 32-2. The second collecting unit 40-2 collects the dielectric particles P2 flowing through the branch channel 32-2. The second collecting unit 40-2 may have, for example, an outlet through which the solution S2 containing the dielectric particles P2 can be supplied from the channel chip 10 to the outside.

[0022] The separation electrode 50 is located within the flow channel 30 to generate a dielectrophoretic force that guides a specific type of dielectric particles P1, among the multiple types of dielectric particles P1 and P2 in the suspension L1, in a predetermined direction. In FIG. 2, only a portion of the separation electrode 50 is located within the flow channel 30. In this embodiment, the predetermined direction is a direction toward the first end 311 in the width direction of the main flow channel 31. In this embodiment, as shown in FIG. 2, the separation electrode 50 is located in the main flow channel 31. The separation electrode 50 is located on the bottom surface of the main flow channel 31. The separation electrode 50 may be formed, for example, of a relatively inexpensive planar electrode. As an example, the separation electrode 50 may include an electrode layer formed on the first substrate of the base 10a and a protective layer formed on the electrode layer. The electrode layer is made of a metal such as Al. The protective layer is made of silicon oxide, for example.

[0023] The separation electrode 50 is a comb-shaped electrode having a plurality of teeth 511, 521 arranged in a predetermined direction D1 on the bottom surface of the main channel 31. The predetermined direction D1 corresponds to the direction of the dielectrophoretic force acting on the dielectric particles P1. The predetermined direction D1 is, for example, a direction from the first end 311 to the second end 312 in the width direction of the channel 30 (a downward and rightward direction in FIG. 2) along the direction in which the suspension liquid L1 flows in the channel 30 (a rightward direction in FIG. 2). The plurality of teeth 511, 521 includes a plurality of first teeth 511 and a plurality of second teeth 521. The first teeth 511 and the second teeth 521 are arranged alternately. The plurality of first teeth 511 extend from the first end 311 to the second end 312 in the width direction of the main channel 31. The plurality of second teeth 521 extend from the second end 312 to the first end 311 in the width direction of the main channel 31.

[0024] 2 includes a pair of electrode patterns 51, 52. The electrode pattern 51 includes a plurality of first tooth portions 511 and a connecting portion 512 located on the first end 311 side in the width direction of the main channel 31 and connecting the base ends of the plurality of tooth portions 511. The connecting portion 512 is located outside the channel 30. The electrode pattern 52 includes a plurality of second tooth portions 521 and a connecting portion 522 located on the second end 312 side in the width direction of the main channel 31 and connecting the base ends of the plurality of second tooth portions 521. The connecting portion 522 is located outside the channel 30.

[0025] The sensor electrode 60 is an electrode separate from the separation electrode 50. The sensor electrode 60 is located on the opposite side of the separation electrode 50 from the inlet 21 of the flow path 30. In this embodiment, the sensor electrode 60 is provided across the multiple branch flow paths 32-1, 32-2. The sensor electrode 60 is located within the flow path 30 to measure the electrical resistance of the suspension L1. In FIG. 2, only a portion of the sensor electrode 60, but not all of it, is located within the flow path 30. In this embodiment, the electrical resistance of the suspension L1 includes at least one of impedance, resistance, and reactance.

[0026] The sensor electrode 60 is disposed on the bottom surface of the branch flow channel 32. The sensor electrode 60 may be formed, for example, of a relatively inexpensive planar electrode. As an example, the sensor electrode 60 may be configured to include an electrode layer formed on the first substrate of the base body 10a and a protective layer formed on the electrode layer. The material of the electrode layer is, for example, a metal such as Al. The protective layer is, for example, silicon oxide.

[0027] As shown in FIG. 2 , the sensor electrode 60 is a comb-shaped electrode having a plurality of teeth 611, 621 arranged on the bottom surface of the flow channel 30 along the length of the flow channel 30. In this embodiment, the plurality of teeth 611, 621 are arranged along the length of each branch flow channel 32 of the flow channel 30. The plurality of teeth 611, 621 include a plurality of first teeth 611 and a plurality of second teeth 621. The first teeth 611 and the second teeth 621 are arranged alternately. In the first branch flow channel 32-1, the plurality of first teeth 611 extend from the side of the first branch flow channel 32-1 opposite to the second branch flow channel 32-2 toward the second branch flow channel 32-2 side of the first branch flow channel 32-1. The plurality of second teeth 621 extend from the side of the first branch flow channel 32-1 opposite to the second branch flow channel 32-2 toward the side of the first branch flow channel 32-1 opposite to the second branch flow channel 32-2. In the second branch flow channel 32-2, the multiple first teeth 611 extend from the side of the second branch flow channel 32-2 opposite to the first branch flow channel 32-1 toward the first branch flow channel 32-1 side of the second branch flow channel 32-2. The multiple second teeth 621 extend from the side of the second branch flow channel 32-2 near the first branch flow channel 32-1 toward the side of the second branch flow channel 32-2 opposite to the first branch flow channel 32-1.

[0028] The sensor electrode 60 of FIG. 2 includes a first electrode pattern 61 and a second electrode pattern 62. The first electrode pattern 61 includes a plurality of first teeth 611 located in the first and second branch flow channels 32-1 and 32-2, a connecting portion 612 connecting the base ends of the plurality of first teeth 611 located in the first branch flow channel 32-1, a connecting portion 612 connecting the base ends of the plurality of first teeth 611 located in the second branch flow channel 32-2, and a connecting portion 613 connecting the connecting portions 612 to each other. Each connecting portion 612 is located outside the flow channel 30. The second electrode pattern 62 includes a plurality of second teeth 621 located in the first and second branch flow channels 32-1 and 32-2, and a connecting portion 622 located between the first and second branch flow channels 32-1 and 32-2 and connecting the base ends of the plurality of second teeth 621.

[0029] When measuring the electrical resistance of the suspension L1 using the sensor electrode 60, a measurement voltage is applied between the first and second electrode patterns 61 and 62 of the sensor electrode 60, and the current flowing through the suspension L1 between the first and second electrode patterns 61 and 62 of the sensor electrode 60 is measured. The measurement voltage is, for example, an AC voltage of a predetermined frequency. This makes it possible to measure the impedance between the first and second electrode patterns 61 and 62 of the sensor electrode 60. The impedance between the first and second electrode patterns 61 and 62 of the sensor electrode 60 includes a reactance component (imaginary part) and a resistance component (real part). The reactance component is mainly determined by the sensor electrode 60, and the resistance component is mainly determined by the electrical resistance of the suspension L1. More specifically, the resistance component includes the electrical resistance of the sensor electrode 60. Therefore, the electrical resistance of the suspension L1 can be calculated from the impedance between the first and second electrode patterns 61 and 62 of the sensor electrode 60 with respect to the measurement voltage. The predetermined frequency of the measurement voltage may be a specific frequency or a frequency band having a certain range. When the predetermined frequency of the measurement voltage is a frequency band having a certain range, measurement is performed using a sawtooth wave, a triangular wave, or the like.

[0030] FIG. 3 is a graph showing the time-dependent changes in the resistance component and reactance component of the impedance (the impedance between the first and second electrode patterns 61, 62 of the sensor electrode 60) determined by the sensor electrode 60. FIG. 3 shows the results of measuring the impedance for a predetermined time. The predetermined time is, for example, two hours. In FIG. 3, X represents the reactance component, and R represents the resistance component. As is clear from FIG. 3, the reactance component X hardly changes, but the resistance component R changes over time. In particular, in FIG. 3, the resistance component R decreases over time.

[0031] The separated electrode pads 71 and 72 are used to apply a predetermined voltage to the separated electrode 50. The separated electrode pads 71 and 72 are connected to the pair of electrode patterns 51 and 52 of the separated electrode 50, respectively, in order to apply a predetermined voltage between the pair of electrode patterns 51 and 52 of the separated electrode 50. The separated electrode pads 71 and 72 are connected to the pair of electrode patterns 51 and 52 of the separated electrode 50, respectively, by, for example, wiring patterns or the like. The separated electrode pads 71 and 72 are arranged to be located on the outer surface of the base 10a. The voltage of the separated electrode 50 can be controlled by controlling the voltage between the separated electrode pads 71 and 72.

[0032] The sensor electrode pads 81 and 82 are provided separately from the separated electrode pads 71 and 72. The sensor electrode pads 81 and 82 are used to apply a measurement voltage to the sensor electrode 60. The sensor electrode pads 81 and 82 are connected to the first and second electrode patterns 61 and 62 of the sensor electrode 60, respectively, to apply a measurement voltage between the first and second electrode patterns 61 and 62 of the sensor electrode 60. The sensor electrode pads 81 and 82 are connected to the pair of electrode patterns 61 and 62 of the sensor electrode 60, respectively, by, for example, a wiring pattern or the like. The sensor electrode pads 81 and 82 are arranged to be located on the outer surface of the base 10a. The voltage of the sensor electrode 60 can be controlled by controlling the voltage between the sensor electrode pads 81 and 82.

[0033] As shown in FIGS. 1 and 2 , the flow channel chip 10 includes a sensor electrode 60 for measuring the electrical resistance of the suspension L1. In the flow channel chip 10, the separation electrode 50 and the sensor electrode 60 are separate electrodes. Therefore, the separation electrode 50 and the sensor electrode 60 can be designed according to conditions suitable for their respective purposes. For example, when the separation electrode 50 is used as the sensor electrode 60, the configuration is limited by the requirement for the separation electrode 50 to apply a dielectrophoretic force to a specific type of dielectric particle P1. However, in this embodiment, the sensor electrode 60 is an electrode independent of the separation electrode 50, and therefore the configuration of the sensor electrode 60 is not limited by the requirement for the separation electrode 50. Therefore, the sensor electrode 60 does not depend on the structure of the separation electrode 50, allowing for greater design flexibility in adjusting the detection sensitivity of the sensor electrode 60. As a result, the separation of the specific type of dielectric particle P1 from the suspension L1 can be stabilized.

[0034] The configuration of the sensor electrode 60 will be further described below. In this embodiment, the area of the portion of the sensor electrode 60 located within the flow path 30 is larger than the area of the portion of the separated electrode 50 located within the flow path 30. In this embodiment, the area of the portion of the sensor electrode 60 located within the flow path 30 is the sum of the areas of the portions of the multiple teeth 611, 621 of the sensor electrode 60 located within the flow path 30. The area of the portion of the sensor electrode 60 located within the flow path 30 can be changed by, for example, the dimensions (mainly the width) of the teeth 611, 621, the spacing between the teeth 611, 621, and the number of teeth 611, 621. When adjusting the area of the portion of the sensor electrode 60 located within the flow path 30, it is preferable to change the number of teeth 611, 621. In this embodiment, the area of the portion of the separated electrode 50 located within the flow path 30 is the sum of the areas of the portions of the multiple teeth 511, 521 of the separated electrode 50 located within the flow path 30. The area of the portion of separation electrode 50 located within flow channel 30 can be changed, for example, by changing the dimensions (mainly the width) of tooth portions 511, 521, the spacing between tooth portions 511, 521, and the number of tooth portions 511, 521. When adjusting the area of the portion of separation electrode 50 located within flow channel 30, it is preferable to change the number of tooth portions 511, 521.

[0035] In the separation electrode 50, in order to reduce the burden on the dielectric particles P1, it is preferable that the contact time between the dielectric particles P1 and the separation electrode 50 is short. Therefore, the area of the portion of the separation electrode 50 located within the flow path 30 tends to be set small. On the other hand, there are cases where it is better that the area of the portion of the sensor electrode 60 located within the flow path 30 is large.

[0036] Fig. 4 is a double logarithmic graph showing the change in the measured impedance value versus the frequency of the measurement voltage due to differences in the area of the sensor electrode 60. In Fig. 4, G11 corresponds to the case where the area of the sensor electrode is small, and G12 corresponds to the case where the area of the sensor electrode is large. The area of the portion of the sensor electrode 60 located within the flow path 30 is larger in G12 than in G11. As can be seen from Fig. 4, the change in the measured impedance value versus the frequency of the measurement voltage differs depending on the area of the sensor electrode 60.

[0037] FIG. 5 is a semi-logarithmic graph showing the change in measurement efficiency versus the frequency of the measurement voltage for different areas of the sensor electrode 60. The measurement efficiency is the percentage of the electrical resistance of the suspension L1 relative to the measured impedance. In FIG. 5, G21 corresponds to a case where the sensor electrode area is small, and G22 corresponds to a case where the sensor electrode area is large. As shown in FIG. 5, the maximum measurement efficiency for G21 is approximately 40%, while the maximum measurement efficiency for G22 exceeds 90%. High measurement efficiency means that the impedance of the sensor electrode 60 has little effect on the measured impedance, thereby reducing the effect of variations in the performance of the sensor electrode 60 and reducing variations in performance in the channel chip 10. Therefore, a high measurement efficiency is preferable.

[0038] The electrical resistance of the suspension L1 may change over time. The extent to which changes in the electrical resistance of the suspension L1 can be tolerated is determined by the impedance (mainly the reactance) of the sensor electrode 60. FIG. 6 is a double logarithmic graph showing the range of changes in the measured impedance versus frequency when the area of the sensor electrode 60 is small. FIG. 7 is a double logarithmic graph showing the range of changes in the measured impedance versus frequency when the area of the sensor electrode 60 is large. Changes in the electrical resistance of the suspension L1 cause changes in the measured impedance versus frequency. This is reflected by the up and down movement of the graph in FIGS. 6 and 7. The extent to which the graph can change is determined by the impedance of the sensor electrode 60. In FIGS. 6 and 7, the area between dotted lines G31 and G32 represents the range in which the graph of the measured impedance versus frequency can change, and the dotted lines G31 and G32 are determined by the impedance of the sensor electrode 60. The dotted lines G31 and G32 are not affected by changes in the electrical resistance of the suspension L1. The greater the distance between dotted lines G31 and G32 and the greater the range of change in the impedance measurement value in the frequency direction, the greater the measurement efficiency of the electrical resistance of suspension L1 and the wider the frequency band available for measurement. As is clear from Figures 6 and 7, when the area of sensor electrode 60 is large, the frequency band available for measurement is wide, and it may be possible to read fluctuations in the electrical resistance of suspension L1 by an order of magnitude or more at a single frequency. On the other hand, when the area of sensor electrode 60 is small, the measurable frequency band is narrow, and the measurement performance of sensor electrode 60 is inferior to that when the area of sensor electrode 60 is large.

[0039] As described above, it is preferable that the area of the portion of the sensor electrode 60 located within the flow path 30 is large. Therefore, in this embodiment, the area of the portion of the sensor electrode 60 located within the flow path 30 is set to be larger than the area of the portion of the separation electrode 50 located within the flow path 30. This reduces the burden on the dielectric particles P1 caused by the separation electrode 50, while improving the measurement performance of the sensor electrode 60.

[0040] As described above, a high measurement efficiency (the percentage of the electrical resistance of the suspension L1 relative to the measured impedance) is preferable. Therefore, the reactance of the sensor electrode 60 is preferably set so as to obtain a measurement efficiency equal to or greater than a specified value. In this embodiment, the reactance of the sensor electrode 60 is smaller than the lower limit of the measurement range of the electrical resistance of the suspension L1. For example, the reactance of the sensor electrode 60 may be equal to or less than 1 / 5 of the lower limit of the measurement range of the electrical resistance of the suspension L1. The reactance of the sensor electrode 60 is a value relative to the frequency of the measurement voltage. The measurement range of the electrical resistance of the suspension L1 is set appropriately based on the properties of the suspension L1 supplied to the channel chip 10. For example, when the measurement range of the electrical resistance of the suspension L1 is approximately 700 Ω to 1000 Ω, the reactance of the sensor electrode 60 is set to approximately 100 Ω.

[0041] [1.1.2.2 Voltage Regulator] The voltage control device 11 in FIG. 1 controls a voltage applied to the channel chip 10 to generate a dielectrophoretic force. In this embodiment, the voltage control device 11 controls the voltage of the separation electrode 50 to separate a specific type of dielectric particle P1 from multiple types of dielectric particles P1, P2 contained in the suspension L1. The voltage control device 11 includes, for example, a function generator. The voltage control device 11 in FIG. 1 is connected to the separation electrode 50 via separation electrode pads 71, 72. The voltage control device 11 controls the voltage of the separation electrode 50 to generate a dielectrophoretic force that guides a specific type of dielectric particle P1, among the multiple types of dielectric particles P1, P2, in a predetermined direction. In this embodiment, the voltage control device 11 applies a predetermined voltage to the separation electrode 50 via the separation electrode pads 71, 72. The predetermined voltage is, for example, an AC voltage. The frequency of the predetermined voltage is set so that the separation electrode 50 exerts a positive dielectrophoretic force on the specific type of dielectric particle P1. In this case, the frequency is set so that no dielectrophoretic force acts on the dielectric particles P2 other than the specific type of dielectric particles P1 among the plurality of types of dielectric particles P1, P2, or even if a positive or negative dielectrophoretic force (attractive or repulsive force) acts on the dielectric particles P2, the dielectrophoretic force is relatively small. The frequency of the predetermined voltage is, for example, 600 kHz.

[0042] 1.1.2.3 Measuring equipment The measuring device 12 in FIG. 1 measures the electrical resistance of the suspension L1 based on the output from the sensor electrode 60. In this embodiment, the measuring device 12 measures the electrical resistance of the suspension L1 by controlling the voltage of the sensor electrode 60. The measuring device 12 includes, for example, a combination of a signal generator such as a function generator and a measuring instrument such as an oscilloscope, or a source / measure unit. The measuring device 12 in FIG. 1 is connected to the sensor electrode 60 via sensor electrode pads 81 and 82. The measuring device 12 applies a measurement voltage between the first and second electrode patterns 61 and 62 of the sensor electrode 60 via the sensor electrode pads 81 and 82, and measures the current flowing between the first and second electrode patterns 61 and 62 of the sensor electrode 60 as the output from the sensor electrode 60. The impedance between the first and second electrode patterns 61 and 62 of the sensor electrode 60 is calculated from the measurement voltage and the output from the sensor electrode 60. The impedance between the first and second electrode patterns 61, 62 of the sensor electrode 60 includes a reactance component determined by the sensor electrode 60 and a resistance component determined by the electrical resistance of the suspension L1. Therefore, the measuring device 12 can determine the electrical resistance of the suspension L1 from the impedance between the first and second electrode patterns 61, 62 of the sensor electrode 60 with respect to the measurement voltage.

[0043] [1.1.2.4 Analysis device] The analysis device 13 in Fig. 1 performs an analysis regarding the separation of a specific type of dielectric particle P1 from multiple types of dielectric particles P1, P2 contained in the suspension L1. The analysis device 13 in Fig. 1 includes an imaging device 131, a processing device 132, and a display device 133.

[0044] The imaging device 131 acquires an image of a target portion in the channel chip 10. The target portion is, for example, the main channel 31. From the image of the main channel 31, the movement trajectories of the dielectric particles P1 and P2 passing through the channel 30 can be obtained. The imaging device 131 includes, for example, a camera having an imaging element such as a CCD image sensor or a CMOS image sensor, and an optical microscope module. The optical microscope module may be a phase-contrast microscope or an epi-illumination microscope. The optical microscope module may be configured to be switchable between a phase-contrast microscope and an epi-illumination microscope, for example, by lens replacement. When performing fluorescent observation, a fluorescent filter is used as appropriate. The operation of the imaging device 131 may be controlled by the processing device 132.

[0045] The display device 133 displays information from the processing device 132. The display device 133 is, for example, a liquid crystal display or an organic EL display.

[0046] The processing device 132 controls the operation of the analysis device 13. The processing device 132 can be realized, for example, by a computer system including one or more processors (microprocessors) and one or more memories. The one or more processors execute programs (stored in one or more memories, etc.) to realize predetermined functions. As an example, the processing device 132 performs image analysis on the image captured by the imaging device 131 and determines the movement trajectories of the dielectric particles P1 and P2 passing through the main flow path 31. The processing device 132 may display, on the display device 133, the image captured by the imaging device 131 or the movement trajectories determined by image analysis.

[0047] [1.1.3 Effects, etc.] The flow channel chip 10 described above includes a substrate 10a having an inlet 21 into which a suspension L1 containing multiple types of dielectric particles P1, P2 including a specific type of dielectric particle P1 is introduced and a flow channel 30 through which the multiple types of dielectric particles P1, P2 of the suspension L1 introduced from the inlet 21 flows, a separation electrode 50 located within the flow channel 30 for generating a dielectrophoretic force that guides the specific type of dielectric particles P1 of the multiple types of dielectric particles P1, P2 in a predetermined direction, and a sensor electrode 60 located within the flow channel 30 for measuring the electrical resistance of the suspension L1. This configuration stabilizes the separation of the specific type of dielectric particles P1 from the suspension L1.

[0048] Furthermore, in the channel chip 10, the separation electrode 50 and the sensor electrode 60 are separate electrodes. With this configuration, the separation electrode 50 and the sensor electrode 60 can be designed under conditions suited to their respective purposes, and the separation operation of the specific type of dielectric particles P1 can be stabilized.

[0049] Furthermore, in the flow channel chip 10, the area of the portion of the sensor electrode 60 located within the flow channel 30 is larger than the area of the portion of the separation electrode 50 located within the flow channel 30. This configuration can reduce the variation in performance of the flow channel chip 10, and further improve the measurement performance of the sensor electrode 60.

[0050] Furthermore, in the channel chip 10, the reactance of the sensor electrode 60 is smaller than the lower limit of the measurement range of the electrical resistance of the suspension L1. With this configuration, the variation in performance of the channel chip 10 can be reduced.

[0051] Furthermore, in the channel chip 10, the reactance of the sensor electrode 60 is equal to or less than 1 / 5 of the lower limit of the measurement range of the electrical resistance of the suspension L1. With this configuration, it is possible to reduce the variation in performance of the channel chip 10, and further to improve the measurement performance of the sensor electrode 60.

[0052] In addition, in the channel chip 10, the sensor electrode 60 is a comb-shaped electrode having a plurality of teeth 611, 621 arranged on the bottom surface of the channel 30 along the length direction of the channel 30. This configuration stabilizes the separation operation of the specific type of dielectric particles P1 from the suspension L1.

[0053] Furthermore, in channel chip 10, sensor electrode 60 is located on the opposite side of inlet 21 from separation electrode 50 in channel 30. This configuration makes it possible to stabilize the separation of specific types of dielectric particles P1 from suspension L1.

[0054] Furthermore, in the channel chip 10, the channel 30 includes multiple branch channels 32 connected to multiple collection units 40. The sensor electrode 60 is provided across the multiple branch channels 32. This configuration allows the electrical resistance of all suspensions L1 passing through the channel 30 to be measured. For example, if the electrical resistance of the suspension L1 is distributed across the width of the channel 30, the suspensions L1 flowing into the multiple collection units 40 may have different electrical resistances. With the above configuration, the electrical resistance of all suspensions L1 passing through the channel 30 is measured, thereby reducing the influence of such a distribution of the electrical resistance of the suspension L1 and enabling more accurate measurement of the electrical resistance of the suspension L1. Furthermore, appropriate feedback to external devices such as the voltage control device 11, the measuring device 12, and the analyzing device 13 is possible.

[0055] The separation system 1 described above includes the channel chip 10 and the measurement device 12 that measures the electrical resistance of the suspension L1 based on the output from the sensor electrode 60. This configuration makes it possible to stabilize the separation operation of the specific type of dielectric particles P1 from the suspension L1.

[0056] Furthermore, the channel chip 10 is disposable in the separation system 1. This configuration makes it possible to prevent contamination, and further improves the ease of use of the separation system 1.

[0057] 1.2 Second Embodiment Fig. 8 is a schematic plan view of a configuration example of a channel chip according to the second embodiment. Hereinafter, the channel chip in Fig. 8 will be denoted by the reference symbol 10A. Channel chip 10A in Fig. 8 includes a plurality of sensor electrodes 60A-1 and 60A-2 (hereinafter collectively denoted by the reference symbol 60A). The plurality of sensor electrodes 60A-1 and 60A-2 are provided in the plurality of branch channels 32-1 and 32-2, respectively.

[0058] As shown in FIG. 8 , the sensor electrode 60A-1 is a comb-shaped electrode having multiple teeth 611, 621 arranged along the length of the flow channel 30 on the bottom surface of the flow channel 30. In this embodiment, the multiple teeth 611, 621 of the sensor electrode 60A-1 are arranged along the length of the first branch flow channel 32-1 of the flow channel 30. The sensor electrode 60A-1 includes a first electrode pattern 61A-1 and a second electrode pattern 62A-1. The first electrode pattern 61A-1 includes multiple first teeth 611 located in the first branch flow channel 32-1 and a connecting portion 612 located outside the first branch flow channel 32-1 and connecting the base ends of the multiple first teeth 611. The second electrode pattern 62A-2 includes multiple second teeth 621 located in the second branch flow channel 32-2 and a connecting portion 622 located outside the first branch flow channel 32-1 and connecting the base ends of the multiple second teeth 621.

[0059] As shown in FIG. 8 , the sensor electrode 60A-2 is a comb-shaped electrode having multiple teeth 611, 621 arranged along the length of the flow channel 30 on the bottom surface of the flow channel 30. In this embodiment, the multiple teeth 611, 621 of the sensor electrode 60A-2 are arranged along the length of the second branch flow channel 32-2 of the flow channel 30. The sensor electrode 60A-2 includes a first electrode pattern 61A-2 and a second electrode pattern 62A-2. The first electrode pattern 61A-2 includes multiple first teeth 611 located in the second branch flow channel 32-2 and a connecting portion 612 located outside the second branch flow channel 32-2 and connecting the base ends of the multiple first teeth 611. The second electrode pattern 62A-2 includes multiple second teeth 621 located in the second branch flow channel 32-2 and a connecting portion 622 located outside the second branch flow channel 32-2 and connecting the base ends of the multiple second teeth 621.

[0060] 8 includes sensor electrode pads 81-1 and 82-1 connected to sensor electrode 60A-1, and sensor electrode pads 81-2 and 82-2 connected to sensor electrode 60A-2. A voltage can be applied to each of the multiple sensor electrodes 60A individually.

[0061] As described above, in the flow channel chip 10A, the flow channel 30 includes multiple branch flow channels 32 connected to multiple collection units 40. A sensor electrode 60A is provided in each of the multiple branch flow channels 32. This configuration allows the electrical resistance of the suspension L1 passing through each of the multiple branch flow channels 32 to be measured. For example, if the electrical resistance of the suspension L1 varies across the width of the flow channel 30, the suspension L1 flowing into the multiple collection units 40 may have different electrical resistances. With the above configuration, the resistance of the suspension L1 passing through each branch flow channel 32 is measured, thereby reducing the influence of this variation in the electrical resistance of the suspension L1 and enabling more accurate measurement of the electrical resistance of the suspension L1. Furthermore, appropriate feedback to external devices such as the voltage control device 11, the measurement device 12, and the analysis device 13 is possible. Since the flow channel chip 10A includes multiple sensor electrodes 60A, the outputs from the multiple sensor electrodes 60A can be utilized. For example, the electrical resistance of the suspension L1 can be calculated by averaging the outputs from the multiple sensor electrodes 60A. In this case, the influence of variations in the sensor electrodes 60A can be reduced. Furthermore, even if some of the plurality of sensor electrodes 60A are broken, the electrical resistance of the suspension L1 can still be determined.

[0062] 1.3 Third Embodiment FIG. 9 is a schematic plan view of a first configuration example of the channel chip of the third embodiment. Hereinafter, the channel chip of FIG. 9 will be denoted by the reference symbol 10B1. The channel chip 10B1 of FIG. 9 has a channel 30B that is different from the channel 30 of the channel chip 10 of the first embodiment. The channel 30B of FIG. 9 does not have a branch channel 32 as in the first embodiment, and is composed of a main channel 31. A first end (left end in FIG. 9) of the main channel 31 in the length direction (left-right direction in FIG. 9) is connected to the inlet 21. A second end (right end in FIG. 9) of the main channel 31 in the length direction is connected to the collection section 40.

[0063] The channel chip 10B1 of FIG. 9 includes a sensor electrode 60B that is different from the sensor electrode 60 of the channel chip 10 of the first embodiment. The sensor electrode 60B of FIG. 9 is located on the opposite side of the separation electrode 50 from the inlet 21. More specifically, the sensor electrode 60B is located in the main channel 31 between the separation electrode 50 and the collection unit 40. As shown in FIG. 9, the sensor electrode 60B is a comb-shaped electrode having a plurality of teeth 611, 621 arranged along the length of the main channel 31 on the bottom surface of the main channel 31. The sensor electrode 60B includes a first electrode pattern 61B and a second electrode pattern 62B. The first electrode pattern 61B includes a plurality of first teeth 611 located in the main channel 31 and a connecting portion 612 located outside the main channel 31 and connecting the base ends of the plurality of first teeth 611. The second electrode pattern 62B includes a plurality of second teeth 621 located in the main flow channel 31, and a connecting portion 622 located outside the main flow channel 31 and connecting the base ends of the plurality of second teeth 621.

[0064] In the channel chip 10B1 of FIG. 9, the sensor electrode pads 81 and 82 are connected to the first electrode pattern 61B and the second electrode pattern 62B of the sensor electrode 60B, respectively.

[0065] In the channel chip 10B1, the separation electrode 50 may be configured to capture a specific type of dielectric particles P1. That is, the separation electrode 50 is located in the channel 30B to generate a dielectrophoretic force that guides a specific type of dielectric particles P1, among the multiple types of dielectric particles P1 and P2, in a predetermined direction, and the predetermined direction may be a direction approaching the separation electrode 50.

[0066] Figure 10 is a schematic plan view of a second configuration example of the flow channel chip of the third embodiment. Hereinafter, the flow channel chip in Figure 10 will be denoted by the reference symbol 10B2. Flow channel chip 10B2 in Figure 10 differs from flow channel chip 10B1 in Figure 9 in the positional relationship between separation electrode 50 and sensor electrode 60B. Sensor electrode 60B in Figure 10 is not on the opposite side of inlet 21 from separation electrode 50 in flow channel 30B, but is located between inlet 21 and separation electrode 50 in flow channel 30B.

[0067] In the channel chip of the third embodiment, the sensor electrode 60B may be located both between the inlet 21 of the channel 30B and the separation electrode 50, and on the opposite side of the separation electrode 50 from the inlet 21. When a plurality of sensor electrodes 60B are provided in this manner, it is possible to determine the electrical resistance of the suspension L1, for example, by using the average value of the outputs from the plurality of sensor electrodes 60B. In this case, the influence of variations in the sensor electrodes 60B can be reduced. Furthermore, even if some of the plurality of sensor electrodes 60B are broken, the electrical resistance of the suspension L1 can still be determined.

[0068] As described above, the sensor electrode 60B may be located at least either between the inlet 21 and the separation electrode 50 or on the opposite side of the separation electrode 50 from the inlet 21. This configuration stabilizes the separation of the specific type of dielectric particles P1 from the suspension L1. This also applies to the first embodiment described above and the fourth embodiment described below.

[0069] 1.4 Fourth embodiment FIG. 11 is a schematic plan view of a first configuration example of the channel chip according to the fourth embodiment. Hereinafter, the channel chip in FIG. 11 will be denoted by the reference symbol 10C1. The channel chip 10C1 in FIG. 11 includes a channel 30C that is different from the channel 30 of the channel chip 10 according to the first embodiment. The channel 30C in FIG. 11 includes a connection path 33 that connects the main channel 31 and an inlet 22. The inlet 22 is formed in the base 10a. The inlet 22 is a portion of the base 10a into which the replacement liquid is introduced. The replacement liquid is used, for example, to remove unnecessary components from the suspension liquid L1 and transport multiple types of dielectric particles P1 and P2 in the suspension liquid L1. The unnecessary components are components that are unnecessary for separating a specific type of dielectric particle P1 from the suspension liquid L1. Examples of the unnecessary components include small cells P3 such as red blood cells contained in blood and a solution. The replacement liquid may be selected so as to be capable of transporting multiple types of dielectric particles P1 and P2 and not to inhibit the application of dielectrophoretic force to the multiple types of dielectric particles P1 and P2. In particular, the replacement liquid is a liquid having a lower conductivity than the solution of the suspension L1 in order to facilitate separation of the specific type of dielectric particles P1. The base 10a may be provided with an outlet for discharging unnecessary components of the suspension L1 that have been replaced by the replacement liquid.

[0070] 12 is a schematic plan view of a second configuration example of the channel chip of the fourth embodiment. Hereinafter, the channel chip of FIG. 12 is denoted by the reference symbol 10C2. The channel chip 10C2 of FIG. 12 includes a channel 30C that is different from the channel 30 of the channel chip 10A of the second embodiment. The channel 30C of FIG. 12 includes a connection path 33 that connects the main channel 31 and the inlet 22.

[0071] 13 is a schematic plan view of configuration example 3 of the channel chip of embodiment 4. Hereinafter, the channel chip of FIG. 13 will be denoted by the reference symbol 10C3. Channel chip 10C3 of FIG. 13 includes channel 30C that is different from channel 30B of channel chip 10B1 of embodiment 3. Channel 30C of FIG. 13 includes connecting path 33 that connects main channel 31 and inlet 22.

[0072] As described above, in the fourth embodiment, the flow path 30C may have the connection path 33 connected to the inlet 22 for introducing the replacement liquid, thereby making it possible to remove unnecessary components from the suspension L1.

[0073] When using a replacement liquid as in the fourth embodiment, replacement with the replacement liquid may not be sufficient. In such cases, the electrical resistance of the suspension L1 is likely to become unstable. However, because the fourth embodiment also includes sensor electrodes 60, 60A, and 60B, it is possible to adjust the voltage applied to separation electrode 50 and adjust the components of suspension L1 supplied to flow path chips 10C1, 10C2, and 10C3 based on the electrical resistance of the suspension L1 measured by sensor electrodes 60, 60A, and 60B. If the electrical resistance of the suspension L1 measured by sensor electrodes 60, 60A, and 60B is abnormal, it is possible to stop the separation operation. Therefore, flow path chips 10C1, 10C2, and 10C3 stabilize the separation operation of a specific type of dielectric particles P1 from the suspension L1.

[0074] [2. Modifications] The embodiments of the present disclosure are not limited to the above-described embodiments. The above-described embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the above-described embodiments are listed below. The modifications described below can be applied in appropriate combinations.

[0075] In one modified example, the separation system 1 does not necessarily have to include the analysis device 13. The separation system 1 may include the channel chip 10 and the measurement device 12.

[0076] In one variation, the suspension L1 is not limited to blood. The suspension L1 is not particularly limited as long as it contains dielectric particles to be separated. The dielectric particles are not limited to the above-mentioned cells. The dielectric particles may be, for example, membrane vesicles, microorganisms, fungi, spores, viruses, exosomes, or nucleic acids such as DNA and RNA.

[0077] In one modified example, the shapes of the channel chips 10, 10A, 10B1, 10B2, 10C1, 10C2, and 10C3 can be changed. In particular, the shape of the base 10a is not limited to that of the above embodiment. The shape of the base 10a may be appropriately set depending on the channels 30, 30B, and 30C. The channels 30, 30B, and 30C may be curved rather than linear as in the above embodiment. Furthermore, depending on the shapes of the channels 30, 30B, and 30C, the collection section 40 may not be essential.

[0078] In one modification, the number and shape of the separation electrodes 50 can be changed. The separation electrodes 50 only need to generate a dielectrophoretic force that guides a specific type of dielectric particles from multiple types of dielectric particles in a predetermined direction. Depending on the shape of the separation electrodes 50, the separation electrode pads 71 and 72 can be omitted.

[0079] In one modification, the shapes of the sensor electrodes 60, 60A, and 60B can be changed. The sensor electrodes 60, 60A, and 60B only need to be able to measure the electrical resistance of the suspension L1. Depending on the shapes of the sensor electrodes 60, 60A, and 60B, the sensor electrode pads 81 and 82 may be omitted.

[0080] In one modified example, in the channel chip 10A, 10C2, the sensor electrode 60A does not need to be provided in all of the plurality of branch channels 32. The sensor electrode 60A only needs to be provided in at least one of the plurality of branch channels 32. In this case, it becomes possible to measure the electrical resistance of the suspension liquid (L1) for each branch channel (32). In particular, by providing the sensor electrode 60A in only some of the branch channels 32 rather than all of the plurality of branch channels 32, it is possible to reduce the space and cost required for installing the sensor electrode 60A.

[0081] In one modified example, a sensor electrode 60B may be provided between the inlet 21 and the separation electrode 50 in the channels 30, 30B, and 30C in the channel chips 10, 10A, 10C1, 10C2, and 10C3.

[0082] In one modification, the flow path 30 may include a filter between the inlet 21 and the separation electrode 50. The filter, for example, removes particles smaller in size than the plurality of types of dielectric particles P1, P2 from the suspension liquid L1. Particles smaller in size than the plurality of types of dielectric particles P1, P2 are particles smaller in size than the smallest of the plurality of types of dielectric particles P1, P2. Particles smaller in size than the plurality of types of dielectric particles P1, P2 are, for example, small cells such as red blood cells contained in the suspension liquid L1. Such a filter can separate the plurality of types of dielectric particles P1, P2 from particles smaller in size than the plurality of types of dielectric particles P1, P2 in the suspension liquid L1 based on the principle of hydrodynamic filtration (HDF).

[0083] [3. Aspects] As is clear from the above-described embodiment and modifications, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses only to clarify the correspondence with the embodiment.

[0084] The first aspect is a flow path chip (10; 10A; 10B1; 10B2; 10C1; 10C2; 10C3) comprising a substrate (10a) having an inlet (21) into which a suspension (L1) containing multiple types of dielectric particles (P1, P2) including a specific type of dielectric particle (P1) is introduced and flow paths (30; 30B; 30C) through which the multiple types of dielectric particles (P1, P2) of the suspension (L1) introduced from the inlet (21) flow, a separation electrode (50) located in the flow path (30; 30B; 30C) for generating a dielectrophoretic force that guides a specific type of dielectric particle (P1) of the multiple types of dielectric particles (P1, P2) in a predetermined direction, and a sensor electrode (60; 60A; 60B) located in the flow path (30; 30B; 30C) for measuring the electrical resistance of the suspension (L1). According to this embodiment, the separation of a specific type of dielectric particles (P1) from the suspension (L1) can be stabilized.

[0085] The second aspect is a channel chip (10; 10A; 10B1; 10B2; 10C1; 10C2; 10C3) based on the first aspect. In the second aspect, the separation electrode (50) and the sensor electrode (60; 60A; 60B) are separate electrodes. According to this aspect, the separation electrode (50) and the sensor electrode (60) can be designed under conditions suitable for their respective purposes, thereby stabilizing the separation operation of a specific type of dielectric particle (P1).

[0086] A third aspect is a channel chip (10; 10A; 10B1; 10B2; 10C1; 10C2; 10C3) based on the first or second aspect. In the third aspect, the area of the portion of the sensor electrode (60; 60A; 60B) located within the channel (30; 30B; 30C) is larger than the area of the portion of the separation electrode (50) located within the channel (30; 30B; 30C). This aspect reduces performance variation in the channel chip 10 and further improves measurement performance using the sensor electrode (60).

[0087] The fourth aspect is a channel chip (10; 10A; 10B1; 10B2; 10C1; 10C2; 10C3) based on any one of the first to third aspects. In the fourth aspect, the impedance (or reactance and resistance) of the sensor electrode (60; 60A; 60B) is smaller than the lower limit of the measurement range of the electrical resistance of the suspension (L1). According to this aspect, it is possible to reduce the variation in performance of the channel chip 10.

[0088] A fifth aspect is a channel chip (10; 10A; 10B1; 10B2; 10C1; 10C2; 10C3) based on the fourth aspect. In the fifth aspect, the impedance (or reactance and resistance) of the sensor electrode (60; 60A; 60B) is equal to or less than 1 / 5 of the lower limit of the measurement range of the electrical resistance of the suspension (L1). According to this aspect, it is possible to reduce the variation in performance of the channel chip 10, and further to improve the measurement performance of the sensor electrode (60).

[0089] A sixth aspect is a channel chip (10; 10A; 10B1; 10B2; 10C1; 10C2; 10C3) based on any one of the first to fifth aspects. In the sixth aspect, the sensor electrode (60; 60A; 60B) is a comb-shaped electrode having a plurality of teeth (611, 621) arranged along the length of the channel (30; 30B; 30C) on the bottom surface of the channel (30; 30B; 30C). This aspect stabilizes the separation of a specific type of dielectric particles (P1) from a suspension (L1).

[0090] A seventh aspect is a channel chip (10; 10A; 10B1; 10B2; 10C1; 10C2; 10C3) based on any one of the first to sixth aspects. In the seventh aspect, the sensor electrode (60; 60A; 60B) is located in at least one of the channel (30B) between the inlet (21) and the separation electrode (50) and the channel (30B) on the opposite side of the separation electrode (50) from the inlet (21). This aspect stabilizes the separation of a specific type of dielectric particles (P1) from a suspension liquid (L1).

[0091] An eighth aspect is a flow channel chip (10A; 10C2) based on any one of the first to seventh aspects. In the eighth aspect, the flow channel (30; 30C) includes a plurality of branch flow channels (32) connected to a plurality of collection sections (40). The sensor electrode (60A) is provided in at least one of the plurality of branch flow channels (32). According to this aspect, it is possible to measure the electrical resistance of the suspension (L1) for each branch flow channel (32). Here, by providing the sensor electrodes (60A) in all of the plurality of branch flow channels (32), even if a distribution in the electrical resistance of the suspension (L1) occurs in the width direction of the flow channel (30), the influence of such a distribution in the electrical resistance of the suspension (L1) can be reduced, thereby enabling more accurate measurement of the electrical resistance of the suspension (L1). On the other hand, by providing the sensor electrodes (60A) in only some of the branch flow channels (32) rather than all of the plurality of branch flow channels (32), it is possible to reduce the space and cost required for installing the sensor electrodes (60A).

[0092] A ninth aspect is a channel chip (10; 10C1) based on any one of the first to seventh aspects. In the ninth aspect, the channel (30; 30C) includes a plurality of branch channels (32) connected to a plurality of collecting sections (40). The sensor electrode (60) is provided across the plurality of branch channels (32). According to this aspect, the electrical resistance of all of the suspension (L1) passing through the channel (30) can be measured, enabling more accurate measurement of the electrical resistance of the suspension (L1).

[0093] A tenth aspect is a separation system (1) comprising a channel chip (10; 10A; 10B1; 10B2; 10C1; 10C2; 10C3) based on any one of the first to ninth aspects, and a measuring device (12) that measures the electrical resistance of the suspension (L1) based on the output from the sensor electrode (60; 60A; 60B). According to this aspect, the separation operation of a specific type of dielectric particles (P1) from the suspension (L1) can be stabilized.

[0094] An eleventh aspect is a separation system (1) based on the tenth aspect. In the eleventh aspect, the channel chips (10; 10A; 10B1; 10B2; 10C1; 10C2; 10C3) are disposable. This aspect can prevent contamination and further improve the usability of the separation system (1). [Industrial Applicability]

[0095] The present disclosure is applicable to a channel chip and a separation system, specifically to a channel chip and a separation system for separating a specific type of dielectric particles from multiple types of dielectric particles contained in a suspension. [Explanation of symbols]

[0096] 1 Separation System 10, 10A, 10B1, 10B2, 10C1, 10C2, 10C3 Flow channel chip 10a Base 12 Measuring equipment 21 Entrance 30, 30B, 30C flow path 40-1 First Collection Section (Collection Section) 40-2 Second Collection Section (Collection Section) 50 Separate Electrodes 60, 60A, 60B sensor electrodes 611 First tooth part (tooth part) 621 Second tooth part (tooth part) L1 suspension P1, P2 dielectric particles

Claims

1. a substrate having an inlet through which a suspension containing a plurality of types of dielectric particles including a specific type of dielectric particles is introduced and a flow path through which the plurality of types of dielectric particles in the suspension introduced from the inlet flows; a separation electrode located within the flow channel for generating a dielectrophoretic force that guides a specific type of dielectric particles among the plurality of types of dielectric particles in a predetermined direction; a sensor electrode located within the flow path for measuring the electrical resistance of the suspension; Equipped with Flow channel chip.

2. the separation electrode and the sensor electrode are separate electrodes; The channel chip according to claim 1 .

3. an area of a portion of the sensor electrode located within the flow channel is larger than an area of a portion of the separation electrode located within the flow channel; The channel chip according to claim 1 or 2.

4. the impedance of the sensor electrode is smaller than the lower limit of the measurement range of the electrical resistance of the suspension; The channel chip according to any one of claims 1 to 3.

5. The impedance of the sensor electrode is 1 / 5 or less of the lower limit of the measurement range of the electrical resistance of the suspension. The channel chip according to claim 4 .

6. the sensor electrode is a comb-shaped electrode having a plurality of teeth arranged on a bottom surface of the flow channel along a longitudinal direction of the flow channel; The channel chip according to any one of claims 1 to 5.

7. the sensor electrode is located in at least one of the flow path between the inlet and the separation electrode and the flow path on the opposite side of the separation electrode from the inlet. The channel chip according to any one of claims 1 to 6.

8. the flow path includes a plurality of branch flow paths connected to a plurality of collecting portions; The sensor electrode is provided in at least one of the plurality of branch flow paths. The channel chip according to any one of claims 1 to 7.

9. the flow path includes a plurality of branch flow paths connected to a plurality of collecting portions; The sensor electrode is provided across the plurality of branch flow paths. The channel chip according to any one of claims 1 to 7.

10. The channel chip according to any one of claims 1 to 9, a measuring device for measuring the electrical resistance of the suspension based on an output from the sensor electrode; Equipped with Separation system.

11. The channel chip is disposable. The separation system of claim 10.

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