Separating chip

Abstract

The present invention provides a separate chip, which is provided with: a substrate; a plurality of electrodes disposed on one surface of the substrate; an insulating film covering at least a portion of one surface of the electrode; and an introduction part constituting member that is disposed on one side of the substrate, surrounds at least a part of the electrode, and constitutes an introduction part into which a liquid containing dielectric particles is introduced. The one surface of the electrode has a first region and a second region different from the first region. A thickness of the insulating film on the first region is smaller than a thickness of the insulating film on the second region.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority based on Japanese Patent Application No. 2023-161225 filed on September 25, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The invention relates to a separation chip. Background Art

[0004] In the past, there is a known separation chip for separating specific cells from blood. For example, Japanese Patent Publication No. 2017-134020 describes a separation device, which includes: a replacement part, which extracts cells larger than a predetermined size from blood; and a separation part, which uses a dielectrophoretic force to separate cancer cells from multiple cells passing through the replacement part. The separation part is provided with a flow path for a liquid containing cells to flow, and a pair of electrodes. By applying an alternating voltage between the pair of electrodes, a dielectrophoretic force acts on cancer cells passing through the flow path, and cancer cells are separated from multiple cells. Summary of the invention

[0005] In the separation chip disclosed in Japanese Patent Publication No. 2017-134020, when an AC voltage is applied between a pair of electrodes, the dielectrophoretic force acts on the dielectric particles in the flow path, and the dielectric particles are attracted by the electrodes. Specifically, the dielectric particles are attracted to the two ends of the upper surface of the adjacent electrodes. Therefore, it is difficult to attract the dielectric particles to any position of the electrodes.

[0006] The present invention has been made in view of the above-mentioned problems, and one object of the present invention is to provide a separation chip capable of attracting dielectric particles to any position of an electrode.

[0007] A separation chip according to one embodiment of the present invention comprises a substrate, a plurality of electrodes, an insulating film, and an introduction part component. The plurality of electrodes are arranged on one surface of the substrate. The insulating film covers at least a portion of one surface of the electrode. The introduction part component is arranged on one side of the substrate. The introduction part component surrounds at least a portion of the electrode. The introduction part component constitutes an introduction part for introducing a liquid containing dielectric particles. The one surface of the electrode has a first region and a second region different from the first region. The thickness of the insulating film on the first region is smaller than the thickness of the insulating film on the second region.

[0008] In one aspect of the present invention, the insulating film may have an opening portion connecting the first region of the electrode and the introduction portion.

[0009] In one aspect of the present invention, the opening may be formed at a position offset from a center in a width direction of the electrode.

[0010] In one aspect of the present invention, a step may be formed on the one surface of the electrode.

[0011] In one aspect of the present invention, the electrode may have a concave shape in cross-section.

[0012] In one embodiment of the present invention, the electrode may include: a pair of side surfaces arranged at the ends in the width direction; and a pair of connecting surfaces. The second region may be provided with a pair. The pair of second regions may extend from the pair of side surfaces toward the inner side in the width direction, respectively. The first region may be arranged to be substantially parallel to the second region between the pair of second regions. The pair of connecting surfaces may connect the pair of second regions and the first region. The insulating film may not be formed on at least a portion of the connecting surface.

[0013] In one aspect of the present invention, the insulating film may include a silicon oxide film or a silicon nitride film.

[0014] In one aspect of the present invention, the introduction section may include a flow path through which the liquid flows. The introduction section component may constitute the flow path.

[0015] In one embodiment of the present invention, the plurality of electrodes may include a first electrode and a second electrode having a comb-tooth shape facing each other. The first electrode and the second electrode may each have a plurality of teeth arranged parallel to each other. One surface of the teeth may have the first region and the second region. The plurality of teeth may extend in a direction intersecting with the direction in which the flow path extends.

[0016] The above and other objects, features, and effects of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a plan view schematically showing the structure of a dielectrophoresis device including a separation chip according to one embodiment of the present invention.

[0018] Figure 2 It is an enlarged cross-sectional view schematically showing the cross-sectional structure of the separation chip according to the present embodiment.

[0019] Figure 3 This is an enlarged cross-sectional view schematically showing the structure around the electrode.

[0020] Figure 4 This is an enlarged cross-sectional view schematically showing the structure of a conventional separation chip.

[0021] Figure 5 It is an enlarged cross-sectional view schematically showing the structure of the separation chip according to the present embodiment.

[0022] Figure 6 This is a flowchart of the method for manufacturing the separation chip according to the present embodiment.

[0023] Figure 7 It is an enlarged cross-sectional view for explaining the method for manufacturing the separation chip according to the present embodiment.

[0024] Figure 8 It is an enlarged cross-sectional view for explaining the method for manufacturing the separation chip according to the present embodiment.

[0025] Fig. 9 It is an enlarged cross-sectional view schematically showing the structure of a separation chip according to a first modification.

[0026] Fig.10 It is an enlarged cross-sectional view schematically showing the structure of a separation chip according to a second modification.

[0027] Fig.11 It is an enlarged cross-sectional view schematically showing the structure of a separation chip according to a third modified example.

[0028] Fig.12 It is an enlarged cross-sectional view schematically showing the structure of a separation chip according to a fourth modified example.

[0029] Fig.13 It is an enlarged cross-sectional view schematically showing the structure of a separation chip according to a fifth modification.

[0030] Fig.14 It is a plan view schematically showing the structure of a separation chip according to a sixth modification.

[0031] Fig.15 It is a plan view schematically showing the structure of a separation chip according to a seventh modification example. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in the drawings, the same reference numerals are given to the same or corresponding parts, and the description thereof will not be repeated.

[0033] Reference Figures 1 to 8 , a dielectrophoresis device 1 including a separation chip 100 according to an embodiment of the present invention will be described. Figure 1 1 is a plan view schematically showing the structure of a dielectrophoresis device 1 including a separation chip 100 according to an embodiment of the present invention.

[0034] like Figure 1 As shown, a dielectrophoresis device 1 according to an embodiment of the present invention includes a separation chip 100 and a voltage control device 500. The dielectrophoresis device 1 separates the dielectric particles P1 from other components P2 and collects the dielectric particles P1 by applying a dielectrophoretic force to the dielectric particles P1 contained in the sample liquid (specimen liquid). The sample liquid is not particularly limited and may be, for example, blood. The dielectric particles P1 are not particularly limited and may be, for example, cells, proteins, nucleic acids or microorganisms. Cells are, for example, cancer cells. In addition, the sample liquid may also be seawater, saline, pure water or a medicine. Other components P2 are, for example, dielectric particles or non-dielectric particles of a different type from the dielectric particles P1. As an example, the sample liquid is blood, the dielectric particles P1 are cancer cells, and the other components P2 are white blood cells. In addition, the sample liquid is an example of "liquid" in the present invention.

[0035] The separation chip 100 causes the dielectrophoretic force to act on the dielectric particles P1 contained in the sample solution to separate the dielectric particles P1 from other components P2 and collect the dielectric particles P1. The diameter of the dielectric particles P1 is, for example, several μm or more and several tens of μm or less.

[0036] The separation chip 100 includes a substrate 101, a flow path 110, and an electrode 120. The flow path 110 includes a supply unit 111, a separation flow path 112, and a collection unit 113. The sample liquid is introduced into the supply unit 111. The supply unit 111 includes, for example, an opening. The supply unit 111 is connected to a supply source of the sample liquid, for example, through a tube. In addition, the flow path 110 is an example of the "introduction unit" of the present invention.

[0037] The separation flow path 112 connects the supply unit 111 and the collection unit 113. The sample liquid introduced into the supply unit 111 flows in the separation flow path 112 toward the collection unit 113. The collection unit 113 collects the sample liquid that has passed through the separation flow path 112. The collection unit 113 may also have an opening, for example. The collection unit 113 may also supply the sample liquid to the outside, for example. In addition, in the present embodiment, as described later, the collection unit 113 collects the sample liquid from which the dielectric particles P1 have been separated (removed).

[0038] The separation chip 100 includes a flow path cover 105. The flow path cover 105 is disposed on the substrate 101. The flow path cover 105 has a smaller area than the substrate 101. That is, the flow path cover 105 is disposed on a portion of the substrate 101. The flow path cover 105 has a recessed portion constituting the flow path 110. The flow path 110 is constituted by the substrate 101 and the flow path cover 105. In addition, the flow path cover 105 is an example of the "introduction portion constituent member" of the present invention.

[0039] The electrode 120 is formed of a conductive metal. In addition, in the present embodiment, the metal is a concept including an alloy. The electrode 120 is at least arranged in the separation channel 112. In other words, the electrode 120 at least overlaps with the separation channel 112. The electrode 120 includes a first electrode 121 and a second electrode 122. The first electrode 121 and the second electrode 122 have, for example, a comb-tooth shape facing each other. In addition, the first electrode 121 and the second electrode 122 may not have a comb-tooth shape.

[0040] The first electrode 121 has a plurality of teeth portions 1211 , a first connection portion 1212 , a second connection portion 1213 , and a pad portion 1214 .

[0041] The teeth 1211 extend in a substantially straight line. The plurality of teeth 1211 are arranged substantially parallel to each other. In addition, the plurality of teeth 1211 extend in a second direction Y intersecting with the first direction X extending the flow path 110. In the present embodiment, the second direction Y is substantially orthogonal to the first direction X. That is, in the present embodiment, the teeth 1211 are substantially orthogonal to the flow path 110.

[0042] The first connection part 1212 connects the plurality of teeth 1211 to each other. The plurality of teeth 1211 and the first connection part 1212 form a comb shape. The plurality of teeth 1211 are arranged, for example, across the separation flow path 112 when viewed from above. The first connection part 1212 is arranged outside the separation flow path 112 when viewed from above. The plurality of teeth 1211 and the first connection part 1212 are covered by the flow path cover 105.

[0043] The second connection portion 1213 connects the first connection portion 1212 and the pad portion 1214. At least a portion of the second connection portion 1213 is covered by the flow path cover 105. At least a portion of the pad portion 1214 is arranged outside the flow path cover 105 when viewed from above. In this embodiment, the second connection portion 1213 is covered by the flow path cover 105. A portion of the pad portion 1214 is arranged outside the flow path cover 105 when viewed from above. In this way, since at least a portion of the pad portion 1214 is not covered by the flow path cover 105, it is possible to easily electrically connect the pad portion 1214 to the voltage control device 500.

[0044] The second electrode 122 has a plurality of teeth portions 1221 , a first connection portion 1222 , a second connection portion 1223 , and a pad portion 1224 .

[0045] The teeth 1221 extend in a substantially straight line. The plurality of teeth 1221 are arranged substantially parallel to each other. In addition, the plurality of teeth 1221 are arranged substantially parallel to the plurality of teeth 1211. The first connecting portion 1222 connects the plurality of teeth 1221 to each other. A comb shape is formed by the plurality of teeth 1221 and the first connecting portion 1222. The plurality of teeth 1221 are arranged, for example, across the separation flow path 112 when viewed from above. The first connecting portion 1222 is arranged on the outside of the separation flow path 112 when viewed from above. The plurality of teeth 1221 and the first connecting portion 1222 are covered by the flow path cover 105.

[0046] The second connection portion 1223 connects the first connection portion 1222 and the pad portion 1224. At least a portion of the second connection portion 1223 is covered by the flow path cover 105. At least a portion of the pad portion 1224 is arranged outside the flow path cover 105 when viewed from above. In this embodiment, the second connection portion 1223 is covered by the flow path cover 105. A portion of the pad portion 1224 is arranged outside the flow path cover 105 when viewed from above. In this way, since at least a portion of the pad portion 1224 is not covered by the flow path cover 105, it is possible to easily electrically connect the pad portion 1224 to the voltage control device 500.

[0047] The voltage control device 500 is electrically connected to the pad portion 1214 and the pad portion 1224. The voltage control device 500 applies an AC voltage corresponding to the type of the dielectric particles P1 to the first electrode 121 and the second electrode 122 via the pad portion 1214 and the pad portion 1224. The AC voltage corresponding to the type of the dielectric particles P1 is, for example, a frequency that generates an electric field that specifically acts on the dielectric particles P1 with a dielectrophoretic force (attraction), and is a voltage of a magnitude that does not destroy the dielectric particles P1.

[0048] Specifically, the frequency of the AC voltage is set so that a positive dielectrophoretic force (attraction) acts on the dielectric particle P1 through the electric field between the first electrode 121 and the second electrode 122. Therefore, the positive dielectrophoretic force acts on the dielectric particle P1, and the dielectric particle P1 is attracted to the electrode 120 (the first electrode 121 and the second electrode 122). On the other hand, the frequency of the AC voltage is set so that no or almost no dielectrophoretic force acts on the other component P2. Therefore, the other component P2 is collected by the collection unit 113 through the separation flow path 112.

[0049] Continue to refer to Figure 1 , the voltage control device 500 is described. The voltage control device 500 includes a power supply unit 510 and a control unit 520.

[0050] The control unit 520 controls the power supply unit 510. The control unit 520 includes, for example, a processor and a storage device. The processor is, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The storage device stores data and computer programs. The storage device includes a main storage device such as a semiconductor memory and an auxiliary storage device such as a semiconductor memory, a solid-state drive, and / or a hard disk drive. The storage device may also include a removable medium. The storage device is equivalent to an example of a non-temporary computer-readable storage medium.

[0051] The power supply unit 510 generates an AC voltage corresponding to the dielectric particle P1 to be separated, and applies the AC voltage to the first electrode 121 and the second electrode 122 via the pad unit 1214 and the pad unit 1224. The power supply unit 510 is a signal generator such as a function generator.

[0052] The power supply unit 510 applies an AC voltage corresponding to the dielectric particle P1 to the first electrode 121 and the second electrode 122, so that a dielectrophoretic force (attraction) acts on the dielectric particle P1. As a result, the dielectric particle P1 is attracted by the electrode 120, and the dielectric particle P1 is separated from the other components P2. In this embodiment, the dielectric particle P1 is captured by the electrode 120, and the other components P2 are collected by the collection unit 113 through the separation flow path 112.

[0053] Furthermore, the voltage control device 500 may have a function of measuring the electrical characteristics (impedance, etc.) between the first electrode 121 and the second electrode 122. Furthermore, the voltage control device 500 may be configured by, for example, a source meter.

[0054] Next, refer to Figure 2 , further illustrating the structure of the separation chip 100. Figure 2 It is an enlarged cross-sectional view schematically showing the cross-sectional structure of the separation chip 100 according to the present embodiment.

[0055] like Figure 2 As shown, the separation chip 100 has an insulating film 103 in addition to a substrate 101, an electrode 120 and a flow path cover 105. The substrate 101 is, for example, a glass substrate. The material of the substrate 101 is, for example, quartz glass. However, the material of the substrate 101 is not limited to quartz glass. The substrate 101 has, for example, a roughly rectangular flat plate shape. However, the shape of the substrate 101 is not limited to a flat plate shape.

[0056] The electrode 120 is arranged on one surface 1011 of the substrate 101. The material of the electrode 120 is a metal such as aluminum, copper and / or titanium. However, the material of the electrode 120 may also be a metal other than aluminum, copper and / or titanium. For example, the material of the electrode 120 may be a metal such as indium, tin, molybdenum, silver, chromium, tantalum and / or silicon. In addition, the material of the electrode 120 may also be a material other than a metal, for example, it may also include an oxide such as a metal oxide or a semiconductor. In addition, the surface of the electrode 120 may also be oxidized. In addition, the electrode 120 may also be formed of, for example, ITO (Indium Tin Oxide). In addition, as long as the electrode 120 has conductivity, the material of the electrode 120 is not particularly limited.

[0057] The insulating film 103 covers at least a portion of a surface 1205 of the electrode 120. The surface 1205 of the electrode 120 is a surface on one side of the electrode 120 (the side opposite to the substrate 101). In the present embodiment, the surface 1205 of the electrode 120 is a surface that can be seen when the electrode 120 is observed from the flow path 110 side. In addition, in the present embodiment, the surface 1205 of the electrode 120 is a surface that is substantially parallel to the surface 1011 of the substrate 101. The insulating film 103 covers a portion of the surface 1011 of the substrate 101 where the electrode 120 is not configured and at least a portion of the electrode 120. In addition, the insulating film 103 does not cover at least a portion of the pad portions 1214 and 1224 that is connected to the voltage control device 500. In addition, the insulating film 103 also covers the side surface 1206 of the electrode 120.

[0058] The insulating film 103 has insulating properties. The material of the insulating film 103 is, for example, an oxide film such as a silicon oxide film, a nitride film such as a silicon nitride film, or a resin. In the present embodiment, the insulating film 103 is a silicon oxide film. The thickness and material of the insulating film 103 affect the electric field formed by the electrode 120. That is, the electric field formed by the electrode 120 can also be controlled by the thickness and material of the insulating film 103. The insulating film 103 also serves as a protective film for suppressing the electrochemical reaction between the electrode 120 and the sample solution.

[0059] Here, in the present embodiment, one surface 1205 of the electrode 120 has a first region 12051 and a second region 12052 different from the first region 12051. Specifically, the electrode 120 has a pair of side surfaces 1206 arranged at the end portions in the width direction (first direction X), and one surface 1205 arranged substantially parallel to one surface 1011 of the substrate 101. Hereinafter, a direction (here, the first direction X) intersecting the direction (the second direction Y) in which the electrode 120 extends is sometimes described as a width direction.

[0060] One surface 1205 is connected to a pair of side surfaces 1206. One surface 1205 has a first region 12051 located in the center in the width direction, and a pair of second regions 12052 arranged on the outer sides in the width direction relative to the first region 12051. The first region 12051 and the second region 12052 are formed on one surface 1205 of the tooth portion 1211 and the tooth portion 1221. In other words, one surface 1205 of the tooth portion 1211 and the tooth portion 1221 has the first region 12051 and the second region 12052.

[0061] In the present embodiment, a step 12053 is formed on one surface 1205 of the electrode 120. In addition, in the present embodiment, the electrode 120 has a concave shape in cross-section. Specifically, a pair of second regions 12052 extend inward in the width direction from a pair of side surfaces 1206, respectively. The first region 12051 is arranged between the pair of second regions 12052 and approximately parallel to the second region 12052. The first region 12051 is arranged at a position closer to the substrate 101 than the pair of second regions 12052. The electrode 120 has a pair of connecting surfaces 1251, and the pair of connecting surfaces 1251 connects the pair of second regions 12052 and the first region 12051. Moreover, a recess 1260 is formed on the electrode 120 through the first region 12051 and the pair of connecting surfaces 1251.

[0062] The insulating film 103 covers at least a portion of one surface 1205 of the electrode 120. In the present embodiment, the thickness of the insulating film 103 on the first region 12051 of the electrode 120 is smaller than the thickness of the insulating film 103 on the second region 12052 of the electrode 120. In addition, in the present embodiment, "the thickness of the insulating film 103 on the first region 12051" means that when the insulating film 103 is not formed on the first region 12051, the thickness of the insulating film 103 is zero.

[0063] Specifically, the insulating film 103 has an opening 1032 connecting the first region 12051 of the electrode 120 and the flow path 110. That is, in this embodiment, the insulating film 103 is not formed on the first region 12051. The opening 1032 is located on the first region 12051 and penetrates the insulating film 103.

[0064] In addition, the insulating film 103 is not formed on at least a portion of the connection surface 1251. That is, at least a portion of the connection surface 1251 is not connected to the flow path 110 via the insulating film 103. In the present embodiment, the insulating film 103 is not formed on the connection surface 1251.

[0065] Next, refer to Figure 3 The structure of the electrode 120 will be further described. Figure 3 1 is an enlarged cross-sectional view schematically showing the structure around the electrode 120. Figure 3 As shown, in this embodiment, the electrode 120 includes a first layer 1201 , a second layer 1202 , and a third layer 1203 .

[0066] The first layer 1201 is disposed on one surface 1011 of the substrate 101. The first layer 1201 is not particularly limited, and for example, preferably includes a metal having good adhesion to the substrate 101. In addition, the first layer 1201 preferably includes, for example, a metal that can suppress diffusion of the second layer 1202 into the substrate 101. In this embodiment, the first layer 1201 includes, for example, titanium.

[0067] The second layer 1202 is arranged on the first layer 1201. The second layer 1202 is arranged on the surface of the first layer 1201 opposite to the substrate 101. The second layer 1202 is not particularly limited, and for example, preferably includes a metal with low resistivity. The second layer 1202 preferably includes aluminum or copper, for example. In this embodiment, the second layer 1202 includes, for example, aluminum.

[0068] The third layer 1203 is disposed on the second layer 1202. The third layer 1203 is disposed on the surface of the second layer 1202 opposite to the first layer 1201. The third layer 1203 is not particularly limited, but preferably includes a metal that is insoluble or difficult to dissolve in the sample liquid. In this embodiment, the third layer 1203 includes, for example, titanium.

[0069] The thickness of the first layer 1201, the second layer 1202 and the third layer 1203 is not particularly limited. The first layer 1201 has a thickness of, for example, more than several nm and less than several 10 nm. The second layer 1202 has, for example, a thickness greater than the first layer 1201. The second layer 1202 has a thickness of, for example, more than several 10 nm and less than several 100 nm. The third layer 1203 has, for example, a thickness greater than the second layer 1202. The third layer 1203 has, for example, a thickness of more than several 10 nm and less than several 100 nm. In addition, the width of the electrode 120 is not particularly limited, for example, more than 40 μm and less than 300 μm. In addition, the distance between the electrodes 120 in the width direction (here, the first direction X) is not particularly limited, for example, more than 10 μm and less than 50 μm. In addition, the thickness of the insulating film 103 is not particularly limited, for example, more than several 100 nm and less than 1000 nm.

[0070] In the present embodiment, the recess 1260 is formed to a depth midway through the third layer 1203. That is, the first region 12051 of one surface 1205 constituting the recess 1260 is located within the third layer 1203. Therefore, the second layer 1202 is not in contact with the sample liquid. Therefore, even in the case where the second layer 1202 is formed of a metal that dissolves in the sample liquid, it is possible to suppress the second layer 1202 from dissolving in the sample liquid. In addition, in the case where the second layer 1202 is formed of a metal that does not dissolve in the sample liquid, the recess 1260 can also be formed to the second layer 1202.

[0071] like Figure 2 As shown, the flow path cover 105 is, for example, arranged on one surface 1031 of the insulating film 103. A portion of the flow path cover 105 may also be arranged on one surface 1011 of the substrate 101. In addition, the flow path cover 105 covers the electrode 120 and one side of the insulating film 103 (the side opposite to the substrate 101). In addition, the flow path cover 105 constitutes the flow path 110. Specifically, the flow path cover 105 includes a side wall 1051 (see Figure 1 ) and a top portion 1052. The flow path 110 through which the sample liquid flows is formed by the side wall 1051 and the top portion 1052. The side wall 1051 surrounds at least a portion of the electrode 120 in a plan view.

[0072] The material of the flow path cover 105 is not particularly limited, and may be, for example, a silicon-based resin. In the present embodiment, the material of the flow path cover 105 is PDMS (dimethylpolysiloxane). When the flow path cover 105 is formed of PDMS, the flow path cover 105, the insulating film 103, and the surface of the substrate 101 are firmly bonded to each other by plasma treatment of the flow path cover 105, the insulating film 103, and the surface of the substrate 101.

[0073] Next, refer to Figure 4 as well as Figure 5 Here, the effects of the separation chip 100 of the present embodiment will be described. Here, the effects of the separation chip 100 of the present embodiment will be described by comparison with a conventional separation chip 9100. Figure 4 It is an enlarged cross-sectional view schematically showing the structure of a conventional separation chip 9100 . Figure 5 is an enlarged cross-sectional view schematically showing the structure of the separation chip 100 of this embodiment. Figure 4 as well as Figure 5 In the figure, arrows crossing between electrodes are arrows schematically showing images of electric force lines in order to facilitate understanding of the present invention.

[0074] First, refer to Figure 4 , the existing separation chip 9100 is described. Figure 4As shown, the separation chip 9100 includes a substrate 9101, a flow path 9110, an electrode 9120, an insulating film 9103, and a flow path cover 9105. The electrode 9120 has a substantially rectangular shape in cross-section. That is, no step is formed on one surface 9205 of the electrode 9120. In addition, the insulating film 9103 has a substantially uniform thickness on one surface 9205 of the electrode 9120. In addition, the opening 1032 is not formed in the insulating film 9103.

[0075] In the existing separation chip 9100, the distance between the two electrodes 9120 is (in, represents the slope of the electric field strength), the distance between the adjacent corners 9127 of the two electrodes 9120 Therefore, the dielectric particle P1 is attracted to the corner portion 9127. Therefore, the dielectric particle P1 is attracted to the width direction end of the electrode 9120. In addition, in the conventional separation chip 9100, even if the frequency and the voltage are changed, the position where the dielectric particle P1 is attracted does not change.

[0076] On the other hand, Figure 5 As shown, in the separation chip 100 of this embodiment, the thickness of the insulating film 103 on the first region 12051 of the electrode 120 is smaller than the thickness of the insulating film 103 on the second region 12052 of the electrode 120. Therefore, by adjusting the voltage value and frequency applied between the electrodes 120, the first regions 12051 (here, the recesses 1260) can be made closer to each other. Therefore, the dielectric particle P1 is attracted to the first region 12051 (here, the concave portion 1260 ) of the electrode 120 . Therefore, the dielectric particle P1 is attracted to the center of the electrode 120 in the width direction.

[0077] More specifically, the dielectrophoretic force is represented by the following general formula (1).

[0078]

[0079] Where F is the dielectrophoretic force. r is the radius of the dielectric particle. ε m represents the dielectric constant (real part) of the surrounding medium. ω represents the angular frequency. K(ω) represents the Clausius-Mossotti function. E represents the electric field strength.

[0080] The above formula (1) contains From the term of , it can be seen that the dielectrophoretic force is generated in the region where the AC electric field is not uniform. The region where the AC electric field is not uniform is the region where the intervals between the electric lines of force vary. Figure 4In the conventional separation chip 9100 shown, a non-uniform electric field is generated around a corner 9127 located at the end in the width direction of the electrode 9120. Therefore, the position where the dielectric particle P1 is attracted is uniquely determined by the corner 9127. Therefore, even if the frequency is changed, for example, the position where the dielectric particle P1 is attracted cannot be changed.

[0081] On the other hand, Figure 5 In the separation chip 100 of the present embodiment shown, by making the thickness of the insulating film 103 on the first region 12051 of the electrode 120 smaller than the thickness of the insulating film 103 on the second region 12052 of the electrode 120, the region where the AC electric field is non-uniform on one surface 1205 of the electrode 120 changes relative to the separation chip 9100. For example, by arranging the first region 12051 at an arbitrary position, the portion that attracts the dielectric particles P1 can be set at an arbitrary position.

[0082] In addition, in the separation chip 100 of the present embodiment, by forming the step 12053 and / or the recess 1260 on one surface 1205 of the electrode 120, the AC electric field can be made more non-uniform around the predetermined position on one surface 1205 of the electrode 120. That is, the rate of change of the electric field intensity (the slope of the electric field intensity) around the predetermined position on one surface 1205 of the electrode 120 can be further increased. Therefore, the dielectrophoretic force can be further enhanced.

[0083] However, the separation chip 100 needs to accurately separate the specific dielectric particles P1 from the other components P2. However, due to the manufacturing error of the separation chip 100, the thickness and size of the electrode 120 and / or the insulating film 103 are deviated. Therefore, in order to properly use the separation chip 100, it is necessary to correct the applied voltage and / or frequency according to the reference voltage and / or reference frequency. In the case of calculating the correction value, in the present embodiment, since the opening 1032 is formed in the insulating film 103, the influence caused by the dielectric constant of the insulating film 103 can be reduced. Therefore, the calculation can be simplified.

[0084] In addition, in the separation chip 100 of the present embodiment, by adjusting the voltage value and frequency applied between the electrodes 120, the dielectric particles P1 are attracted to the center in the width direction of the electrode 120, unlike the conventional separation chip 9100. Therefore, for example, it is possible to easily determine whether the dielectric particles P1 are attracted to the electrode 120 due to the provision of the recess 1260 and / or the opening 1032 in the center in the width direction of one surface 1205 of the electrode 120.

[0085] Specifically, for example, it can be seen that when the dielectric particle P1 is attracted to the center in the width direction of the electrode 120, the dielectric particle P1 is attracted due to the electric field generated in the recess 1260 and / or the opening 1032. On the other hand, it can be seen that when the dielectric particle P1 is attracted to the end portion in the width direction of the electrode 120, the dielectric particle P1 is attracted to the electrode 120 regardless of the presence or absence of the recess 1260.

[0086] Above, as reference Figure 1 to Figure 5 As described above, one surface 1205 of the electrode 120 has a first region 12051 and a second region 12052 different from the first region 12051, and the thickness of the insulating film 103 on the first region 12051 is smaller than the thickness of the insulating film 103 on the second region 12052. Therefore, on the one surface 1205 of the electrode 120, the region where the AC electric field is not uniform varies, for example, relative to the separation chip 9100. Therefore, by configuring the first region 12051 at an arbitrary position of the electrode 120, for example, the site for attracting the dielectric particles P1 can be set at an arbitrary position.

[0087] In addition, as described above, the insulating film 103 has the opening 1032 that connects the first region 12051 of the electrode 120 and the flow path 110. Therefore, the electric field intensity generated between the adjacent first regions 12051 can be enhanced compared to the case where the opening 1032 is not formed. Therefore, the electric field intensity between the first regions 12051 can be further enhanced.

[0088] As described above, the step 12053 is formed on the one surface 1205 of the electrode 120. Therefore, a more non-uniform electric field can be generated around the step 12053 on the one surface 1205 of the electrode 120, so that the dielectrophoretic force generated between the steps 12053 can be easily enhanced.

[0089] As described above, the electrode 120 has a concave shape in cross section. Therefore, for example, the AC electric field can be made more non-uniform at the center in the width direction of one surface 1205 of the electrode 120 , and the dielectric particles P1 can be easily attracted to the center in the width direction of the electrode 120 .

[0090] As described above, the insulating film 103 is not formed on at least a portion of the connection surface 1251. Therefore, compared with the case where the insulating film 103 is formed on the entire surface of the connection surface 1251, the electric field intensity generated between the connection surfaces 1251 can be increased.

[0091] In addition, as described above, the insulating film 103 includes a silicon oxide film or a silicon nitride film. Therefore, it is possible to easily protect the electrode 120 from the sample liquid. In addition, when the flow path cover 105 is formed of, for example, a silicone resin, the flow path cover 105 and the insulating film 103 both contain silicon elements, so the flow path cover 105 can be firmly bonded to the insulating film 103.

[0092] As described above, the flow channel cover 105 forms the flow channel 110. Therefore, by allowing the sample liquid to flow through the flow channel 110, the dielectric particles P1 and other components P2 of the sample liquid can be easily separated.

[0093] In addition, as described above, the electrode 120 includes the first electrode 121 and the second electrode 122 having a comb-tooth shape facing each other, and the plurality of teeth 1211 and the plurality of teeth 1221 extend in the second direction Y intersecting the first direction X extending the flow path 110. Therefore, unlike the case where the plurality of teeth 1211 and the plurality of teeth 1221 are arranged to extend in the first direction X, the dielectric particles P1 contained in the sample liquid can be efficiently separated.

[0094] Next, refer to Figure 2 , Figure 3 , Figure 6 to Figure 8 , a method for manufacturing the separation chip 100 of this embodiment is described. Figure 6 It is a flowchart of the method for manufacturing the separation chip 100 according to the present embodiment. Figure 7 as well as Figure 8 This is an enlarged cross-sectional view for explaining the method for manufacturing the separation chip 100 of the present embodiment. The method for manufacturing the separation chip 100 of the present embodiment includes steps S1 to S4.

[0095] like Figure 6 As shown, in step S1, an electrode 120 is formed on a substrate 101. Specifically, Figure 7 As shown, an electrode layer to be the electrode 120 is formed on one surface 1011 of the substrate 101 by, for example, vacuum evaporation. Then, the electrode layer is patterned by, for example, photolithography and wet etching to form the electrode 120 having a predetermined shape. In addition, the method of forming the electrode layer on the substrate 101 is not limited to the vacuum evaporation method, and other methods such as sputtering may also be used.

[0096] Next, in step S2, Figure 8 As shown, an insulating layer 1030 is formed to cover the electrode 120. Specifically, the insulating layer 1030 serving as the insulating film 103 is formed on one surface 1011 of the substrate 101 and the electrode 120 by, for example, sputtering. The method of forming the insulating layer 1030 is not limited to sputtering, and other methods such as vacuum evaporation may also be used.

[0097] Next, in step S3, Figure 3 As shown, the opening 1032 and the recess 1260 are formed. Specifically, for example, the insulating layer 1030 and the electrode 120 are patterned by photolithography and wet etching to form the insulating film 103 and the electrode 120 having a predetermined shape. At this time, the area of ​​the insulating layer 1030 that is not covered by the flow path cover 105 is removed. In addition, at this time, in this embodiment, the predetermined area of ​​the insulating layer 1030 (the area to be the opening 1032) and the predetermined area of ​​the electrode 120 (the area to be the recess 1260) are removed. Thus, the insulating film 103 having the opening 1032 is formed, and the electrode 120 having the recess 1260 is formed.

[0098] Next, in step S4, Figure 2 As shown, the flow path cover 105 is mounted on the substrate 101 formed with the electrode 120 and the insulating film 103. Specifically, the surface of the flow path cover 105 on the substrate 101 side and the surface of the insulating film 103 and the substrate 101 on the flow path cover 105 side are plasma treated. Then, the plasma-treated surfaces are bonded to each other. Thus, the flow path cover 105 is bonded to the insulating film 103 and / or the substrate 101, and the flow path cover 105 is mounted on the substrate 101. At this time, the flow path 110 is formed between the flow path cover 105 and the substrate 101.

[0099] As described above, the separation chip 100 is manufactured.

[0100] (First Modification)

[0101] Next, refer to Fig. 9 , a separation chip 100 according to a first modified example will be described. Fig. 9 1 is an enlarged cross-sectional view schematically showing the structure of the separation chip 100 according to the first modification. In the first modification, unlike the above-described embodiment, an example in which the insulating film 103 is formed on the first region 12051 will be described.

[0102] like Fig. 9 As shown, in the separation chip 100 of the first modification, similarly to the above embodiment, the thickness of the insulating film 103 on the first region 12051 of the electrode 120 is smaller than the thickness of the insulating film 103 on the second region 12052 of the electrode 120. Also, similarly to the above embodiment, a step 12053 is formed on one surface 1205 of the electrode 120. Also, similarly to the above embodiment, the electrode 120 has a concave shape in cross-section.

[0103] On the other hand, in the first modification, the insulating film 103 is formed on the first region 12051. The insulating film 103 covers the entire surface of one surface 1205 of the electrode 120. In addition, the insulating film 103 covers the entire surface of the connection surface 1251.

[0104] In addition, the insulating film 103 is formed on the second region 12052 in such a manner that the thickness thereof increases toward the outer side in the width direction.

[0105] The other structures and effects of the first modified example are the same as those of the above-mentioned embodiment.

[0106] (Second Modification)

[0107] Next, refer to Fig.10 , a separation chip 100 according to a second variation will be described. Fig.10 1 is an enlarged cross-sectional view schematically showing the structure of the separation chip 100 according to the second modification. In the second modification, unlike the above-described embodiment, an example in which a step is not formed on one surface 1205 of the electrode 120 will be described.

[0108] like Fig.10 As shown, in the separation chip 100 of the second modified example, similarly to the above embodiment, the thickness of the insulating film 103 on the first region 12051 of the electrode 120 is smaller than the thickness of the insulating film 103 on the second region 12052 of the electrode 120. In addition, similarly to the above embodiment, the insulating film 103 has an opening 1032 connecting the first region 12051 of the electrode 120 and the flow path 110. That is, the insulating film 103 is not formed on the first region 12051.

[0109] On the other hand, in the second modification, the recessed portion 1260 is not formed in the electrode 120. In addition, no step is formed in the electrode 120. The electrode 120 has a substantially rectangular shape in cross-sectional view.

[0110] In the second modification, the opening 1032 is arranged at a position offset from the center in the width direction of the electrode 120. The opening 1032 is formed, for example, only in one portion in the width direction of one surface 1205 of the electrode 120. Therefore, the dielectric particles P1 can be attracted only to one portion in the width direction of the electrode 120.

[0111] The other structures and other effects of the second modified example are the same as those of the above-mentioned embodiment.

[0112] (Third Modification)

[0113] Next, refer to Fig.11 , a separation chip 100 according to a third variation will be described. Fig.11 1 is an enlarged cross-sectional view schematically showing the structure of a separation chip 100 according to a third modification of the present invention. In the third modification, unlike the above-described embodiment, an example in which the recess 1260 is not formed in the electrode 120 will be described.

[0114] like Fig.11 As shown, in the separation chip 100 of the third modified example, similarly to the above-mentioned embodiment, the thickness of the insulating film 103 on the first region 12051 of the electrode 120 is smaller than the thickness of the insulating film 103 on the second region 12052 of the electrode 120. Also, similarly to the above-mentioned embodiment, the insulating film 103 has an opening 1032 that connects the first region 12051 of the electrode 120 and the flow path 110. Also, similarly to the above-mentioned embodiment, a step 12053 is formed on one surface 1205 of the electrode 120. Also, similarly to the above-mentioned embodiment, one surface 1205 has a first region 12051 located in the center in the width direction, and a pair of second regions 12052 arranged on the outer sides in the width direction with respect to the first region 12051.

[0115] On the other hand, in the third variant, the electrode 120 has a convex shape in cross-section. Specifically, the electrode 120 has a pair of second regions 12052, a first region 12051, and a pair of connecting surfaces 1251. The pair of second regions 12052 extend inward in the width direction from a pair of side surfaces 1206, respectively. The first region 12051 is arranged between the pair of second regions 12052 and approximately parallel to the second region 12052. The first region 12051 is arranged at a position farther from the substrate 101 than the pair of second regions 12052. Moreover, a convex portion 1261 is formed on the electrode 120 by the first region 12051 and the pair of connecting surfaces 1251.

[0116] The other structures and effects of the third modification are the same as those of the above-mentioned embodiment.

[0117] (Fourth Modification)

[0118] Next, refer to Fig.12 , a separation chip 100 according to a fourth variation will be described. Fig.12 1 is an enlarged cross-sectional view schematically showing the structure of the separation chip 100 according to the fourth modification. In the fourth modification, unlike the above-described embodiment, an example in which the surface of the electrode 120 is formed into a curved surface will be described.

[0119] like Fig.12As shown, in the separation chip 100 of the fourth modification, similarly to the above-mentioned embodiment, the thickness of the insulating film 103 on the first region 12051 of the electrode 120 is smaller than the thickness of the insulating film 103 on the second region 12052 of the electrode 120. Also, similarly to the above-mentioned embodiment, the insulating film 103 has an opening 1032 connecting the first region 12051 of the electrode 120 and the flow path 110. Also, similarly to the above-mentioned embodiment, one surface 1205 has a first region 12051 located in the center in the width direction, and a pair of second regions 12052 arranged on the outer sides in the width direction with respect to the first region 12051.

[0120] On the other hand, in the fourth variation, the step 12053 is not formed on one surface 1205 of the electrode 120. Specifically, the electrode 120 has a substantially semicircular shape in cross-section. The thickness of the insulating film 103 on the first region 12051 gradually increases toward the outer side in the width direction. In addition, the thickness of the insulating film 103 on the second region 12052 gradually increases toward the outer side in the width direction. The opening 1032 is formed in a portion of the insulating film 103 corresponding to the center of the first region 12051 in the width direction.

[0121] The other structures and effects of the fourth variation are the same as those of the above-mentioned embodiment.

[0122] (Fifth Modification)

[0123] Next, refer to Fig.13 , a separation chip 100 according to a fifth variation will be described. Fig.13 1 is an enlarged cross-sectional view schematically showing the structure of the separation chip 100 according to the fifth modification. In the fifth modification, unlike the above-described embodiment, an example in which a plurality of recesses 1260 are formed on one surface 1205 of the electrode 120 will be described.

[0124] like Fig.13 As shown, in the separation chip 100 of the fifth modification, similarly to the above-mentioned embodiment, the thickness of the insulating film 103 on the first region 12051 of the electrode 120 is smaller than the thickness of the insulating film 103 on the second region 12052 of the electrode 120. In addition, similarly to the above-mentioned embodiment, the insulating film 103 has an opening 1032 that connects the first region 12051 of the electrode 120 and the flow path 110. That is, the insulating film 103 is not formed on the first region 12051. In addition, similarly to the above-mentioned embodiment, a step 12053 is formed on one surface 1205 of the electrode 120. In addition, similarly to the above-mentioned embodiment, the electrode 120 has a concave shape in cross-section.

[0125] On the other hand, in the fifth modification, the opening 1032 is arranged at a position offset from the center in the width direction of the electrode 120. The opening 1032 is formed, for example, only in one portion in the width direction of one surface 1205 of the electrode 120.

[0126] In the fifth modification, a plurality of recesses 1260 are formed on one surface 1205 of the electrode 120. The openings 1032 may be formed in portions of the insulating film 103 corresponding to the recesses 1260 or in portions of the insulating film 103 corresponding to the recesses 1260 above each other.

[0127] The other structures and effects of the fifth modification are the same as those of the above-mentioned embodiment and the second modification.

[0128] (Sixth Modification)

[0129] Next, refer to Fig.14 , a separation chip 100 according to a sixth variation will be described. Fig.14 1 is a plan view schematically showing the structure of the separation chip 100 according to the sixth modification. In the sixth modification, unlike the above-described embodiment, an example in which the teeth 1211 and the teeth 1221 of the electrode 120 are inclined with respect to the flow channel 110 will be described.

[0130] like Fig.14 As shown, in the separation chip 100 of the sixth variant, the plurality of teeth 1211 of the first electrode 121 and the plurality of teeth 1221 of the second electrode 122 extend in a second direction Y intersecting with the first direction X extending the flow path 110. In the sixth variant, unlike the above-mentioned embodiment, the second direction Y is inclined relative to the first direction X. That is, in the sixth variant, the teeth 1211 and the teeth 1221 are inclined relative to the flow path 110. By configuring in this way, for example, by applying an alternating voltage of a specific frequency between the first electrode 121 and the second electrode 122, the dielectric particles P1 can be moved along the teeth 1211 and the teeth 1221. Therefore, the dielectric particles P1 can be separated from the other components P2. The following is a detailed description.

[0131] In the sixth variation, the collecting section 113 of the flow path 110 has a first collecting section 1131 and a second collecting section 1132. The first collecting section 1131 collects dielectric particles P1. The second collecting section 1132 collects other components P2. The flow path 110 further has a first connecting flow path 1141 and a second connecting flow path 1142. The first connecting flow path 1141 connects the downstream portion of the separation flow path 112 and the first collecting section 1131. The second connecting flow path 1142 connects the downstream portion of the separation flow path 112 and the second collecting section 1132.

[0132] In the separation chip 100 of the sixth modification, by applying an AC voltage of a specific frequency between the first electrode 121 and the second electrode 122, the dielectrophoretic force acts on the dielectric particle P1 passing through the separation channel 112. As a result, the dielectric particle P1 moves along the tooth portion 1211 and the tooth portion 1221. In the sixth modification, the dielectric particle P1 moves toward the first connecting portion 1212 along the tooth portion 1211 and the tooth portion 1221. In addition, in the sixth modification, the frequency of the AC voltage is set so that the dielectric particle P1 is not captured by the electrode 120.

[0133] Then, the dielectric particles P1 are collected by the first collecting unit 1131 through the first connecting channel 1141 . On the other hand, the other components P2 move straight through the separation channel 112 , pass through the second connecting channel 1142 , and are collected by the second collecting unit 1132 .

[0134] The rest of the structure, manufacturing method, and effects of the sixth variation are the same as those of the above-described embodiment.

[0135] (Seventh Modification)

[0136] Next, refer to Fig.15 , a separation chip 100 according to a seventh variation will be described. Fig.15 1 is a plan view schematically showing the structure of a separation chip 100 according to a seventh modification. In the seventh modification, unlike the above-described embodiment, an example in which the separation chip 100 includes, for example, a HDF (Hydrodynamic filtration) 200 will be described.

[0137] like Fig.15 As shown, in the seventh variant, the separation chip 100 further includes an HDF200. The HDF200 is arranged on the upstream side relative to the electrode 120. The HDF200 has a function as a fluid dynamics filter. For example, the HDF200 is a microchannel for the purpose of separation / concentration of particles. The HDF200 has a plurality of branch channels 201 branching from the separation channel 112. The HDF200 is composed of a plurality of branch channels 201 and a portion of the separation channel 112. The plurality of branch channels 201 are arranged, for example, in a manner extending perpendicularly to the separation channel 112. In addition, the plurality of branch channels 201 are arranged, for example, at approximately equal intervals along the direction in which the separation channel 112 extends.

[0138] The liquid flowing through the separation channel 112 flows into the plurality of branch channels 201. In addition, a part of the particles contained in the liquid flowing through the separation channel 112 flows into the plurality of branch channels 201. Specifically, particles having a particle size smaller than a predetermined size flow into the branch channels 201, and particles having a particle size larger than the predetermined size do not flow into the branch channels 201 but move approximately straight in the separation channel 112. That is, the HDF 200 separates particles having a particle size smaller than a predetermined size from the liquid flowing through the separation channel 112. In the seventh modification, the dielectric particles P1 do not flow into the branch channels 201 of the HDF 200 but move approximately straight in the separation channel 112.

[0139] In the seventh modification, as described above, the separation chip 100 further includes the HDF 200 . Therefore, the HDF 200 can separate particles smaller than a predetermined size from particles contained in the sample solution, and then the electrode 120 can separate the dielectric particles P1 from particles larger than a predetermined size.

[0140] The rest of the structure, manufacturing method, and effects of the seventh variation are the same as those of the above-mentioned embodiment.

[0141] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-mentioned embodiments and can be implemented in various ways without departing from the main purpose thereof. In addition, various inventions can be formed by appropriately combining the multiple constituent elements disclosed in the above-mentioned embodiments. For example, several constituent elements can also be deleted from all the constituent elements shown in the embodiments. In addition, the constituent elements of different embodiments and modified examples can also be appropriately combined. In the accompanying drawings, for ease of understanding, each constituent element is schematically represented as the main body, and the thickness, length, number, spacing, etc. of each constituent element shown in the drawings are sometimes different from the actual ones for the convenience of making the drawings. In addition, the material, shape, size, etc. of each constituent element shown in the above-mentioned embodiment is an example, and is not particularly limited, and various changes can be made within the scope of the effect of the present invention.

[0142] For example, in the above embodiment, the electrode 120 includes the first layer 1201, the second layer 1202, and the third layer 1203, but the present invention is not limited thereto. For example, the electrode 120 may include one layer, two layers, or four or more layers.

[0143] In addition, in the above embodiment, an example in which the first electrode 121 and the second electrode 122 have a comb-teeth shape is shown, but the present invention is not limited thereto. For example, the first electrode 121 and the second electrode 122 may not have a comb-teeth shape.

[0144] In addition, in the above embodiment, an example in which the sample liquid flows in the flow path 110 is shown, but the present invention is not limited to this. That is, an example in which the introduction part is the flow path 110 in which the sample liquid flows is shown, but the present invention is not limited to this. For example, the introduction part may be a storage part for storing the sample liquid. In this case, the introduction part component may also have only side walls without a top.

[0145] In addition, in the above embodiment, an example is shown in which a predetermined area of ​​the insulating film 103 and a predetermined area of ​​the electrode 120 are removed by one process (step S3), but the present invention is not limited to this. For example, the electrode 120 may be formed into a predetermined shape, and after the insulating film 103 is formed in a manner covering the electrode 120, only the predetermined area of ​​the insulating film 103 may be removed. Figures 9 to 13 The shape of the electrode 120 and / or the shape of the insulating film 103 shown in the figure can be appropriately changed in the manufacturing process.

[0146] In addition, for example, in the above-mentioned embodiment, the first modification example, the third modification example and / or the fourth modification example, the recess 1260 , the opening 1032 and / or the protrusion 1261 may be formed at a position offset from the center in the width direction of the electrode 120 .

[0147] Although the embodiments of the present invention have been described in detail, these are merely specific examples used to clarify the technical content of the present invention, and the present invention should not be construed as being limited to these specific examples. The scope of the present invention is limited only by the appended claims.

Claims

1. A separation chip, characterized in that: have: substrate; A plurality of electrodes are arranged on one surface of the substrate; an insulating film covering at least a portion of one surface of the electrode; and an introduction part constituting member, which is arranged on one side of the substrate, surrounds at least a part of the electrode, and constitutes an introduction part for introducing a liquid containing dielectric particles, The one surface of the electrode has a first region and a second region different from the first region, The thickness of the insulating film on the first region is smaller than the thickness of the insulating film on the second region.

2. The separation chip according to claim 1, characterized in that: The insulating film has an opening portion connecting the first region of the electrode and the introduction portion.

3. The separation chip according to claim 2, characterized in that: The opening is formed at a position offset from the center in the width direction of the electrode.

4. The separation chip according to any one of claims 1 to 3, characterized in that A step is formed on the one surface of the electrode.

5. The separation chip according to claim 4, characterized in that: The electrode has a concave shape in cross-section.

6. The separation chip according to claim 5, characterized in that: The electrode has: a pair of side surfaces disposed at ends in the width direction; and A pair of connecting surfaces, The second area is provided with a pair of A pair of the second regions respectively extend from the pair of side surfaces toward the inner side in the width direction, The first region is arranged between a pair of the second regions so as to be substantially parallel to the second region. The pair of connection surfaces connects a pair of the second region and the first region, and the insulating film is not formed on at least a portion of the connection surfaces.

7. The separation chip according to any one of claims 1 to 3, characterized in that: The insulating film includes a silicon oxide film or a silicon nitride film.

8. The separation chip according to any one of claims 1 to 3, characterized in that: The introduction portion has a flow path through which the liquid flows, The introduction section constituent member constitutes the flow path.

9. The separation chip according to claim 8, characterized in that: The plurality of electrodes include a first electrode and a second electrode having a comb-tooth shape facing each other, the first electrode and the second electrode each having a plurality of teeth arranged parallel to each other, and one surface of the teeth having the first region and the second region, The plurality of teeth extend in a direction intersecting with a direction in which the flow path extends.

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