Separation chip

Abstract

To provide a separation chip capable of attracting dielectric particles to an arbitrary position of an electrode.SOLUTION: A separation chip 100 comprises: a substrate 101; a plurality of electrodes 120; an insulator film 103; and a flow path cover 105. The electrodes 120 are arranged on one surface 1011 of the substrate 101. The insulator film 103 covers at least a part of one surface 1205 of each electrode 120. The flow path cover 105 is disposed on one side of the substrate 101. The flow path cover 105 surrounds at least a part of the electrode 120. The flow path cover 105 constitutes a flow path 110 through which a liquid containing dielectric particles P1 is introduced. One surface 1205 of the electrode 120 includes a first region 12051 and a second region 12052 different from the first region 12051. The thickness of the insulator film 103 on the first region 12051 is smaller than that of the insulator film 103 on the second region 12052.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a separation chip. [Background technology]

[0002] Conventionally, separation chips that separate specific cells from blood are known (see, for example, Patent Document 1). Patent Document 1 describes a separation device that includes a replacement section that extracts cells of a predetermined size or larger from blood, and a separation section that separates cancer cells from multiple types of cells that have passed through the replacement section by dielectrophoretic force. The separation section is provided with a flow path through which a liquid containing cells flows, and a pair of electrodes. By applying an AC voltage between the pair of electrodes, a dielectrophoretic force acts on the cancer cells passing through the flow path, and the cancer cells are separated from the multiple types of cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-134020 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a separation chip such as that disclosed in Patent Document 1, when an AC voltage is applied between a pair of electrodes, a dielectrophoretic force acts on the dielectric particles in the flow channel, and the dielectric particles are attracted to the electrodes. Specifically, the dielectric particles are attracted to both ends of the upper surface of the adjacent electrodes. For this reason, it is difficult to attract the dielectric particles to any position on the electrodes.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a separation chip capable of attracting dielectric particles to any position of an electrode. [Means for solving the problem]

[0006] A separation chip according to one aspect of the present invention comprises a substrate, a plurality of electrodes, an insulating film, and an introduction portion constituent member. The plurality of electrodes are arranged on one surface of the substrate. The insulating film covers at least a portion of the one surface of the electrodes. The introduction portion constituent member is arranged on one side of the substrate. The introduction portion constituent member surrounds at least a portion of the electrodes. The introduction portion constituent member constitutes an introduction portion 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. The thickness of the insulating film on the first region is smaller than the thickness of the insulating film on the second region.

[0007] In one aspect of the present invention, the insulating film may have an opening that connects the first region of the electrode and the injection portion.

[0008] In one aspect of the present invention, the opening may be formed at a position offset from the center of the electrode in the width direction.

[0009] In one aspect of the present invention, a step may be formed on the one surface of the electrode.

[0010] In an aspect of the present invention, the electrode may have a concave shape in cross section.

[0011] In one aspect of the present invention, the electrode may have a pair of side surfaces arranged at ends in the width direction and a pair of connection surfaces. The second regions may be provided in pairs. The pair of second regions may each extend inward in the width direction from the pair of side surfaces. The first region may be arranged between the pair of second regions and approximately parallel to the second regions. The pair of connection 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 connection surfaces.

[0012] In one aspect of the present invention, the insulating film may include a silicon oxide film or a silicon nitride film.

[0013] In one aspect of the present invention, the inlet may have a flow path through which the liquid flows. The inlet component may constitute the flow path.

[0014] In one aspect 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. Each of the first electrode and the second electrode may 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 a direction in which the flow channel extends. Effect of the Invention

[0015] According to the present invention, a separation chip capable of attracting dielectric particles to any position of an electrode can be provided. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a plan view illustrating a schematic structure of a dielectrophoresis device including a separation chip according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view that illustrates a schematic cross-sectional structure of the separation chip of the present embodiment. [Diagram 3] FIG. 4 is an enlarged cross-sectional view showing a schematic structure around an electrode. [Figure 4] FIG. 1 is an enlarged cross-sectional view showing a schematic structure of a conventional separation chip. [Diagram 5] FIG. 2 is an enlarged cross-sectional view illustrating a schematic structure of the separation chip of the present embodiment. [Figure 6] FIG. 2 is a flow diagram of a method for producing a separation chip according to the present embodiment. [Figure 7] 5A to 5C are enlarged cross-sectional views for explaining the method for manufacturing the separation chip of the present embodiment. [Figure 8] 5A to 5C are enlarged cross-sectional views for explaining the method for manufacturing the separation chip of the present embodiment. [Figure 9] FIG. 4 is an enlarged cross-sectional view illustrating a schematic structure of a separation chip according to a first modified example of the present invention. [Figure 10]FIG. 11 is an enlarged cross-sectional view illustrating a schematic structure of a separation chip according to a second modified example of the present invention. [Figure 11] FIG. 11 is an enlarged cross-sectional view illustrating a schematic structure of a separation chip according to a third modified example of the present invention. [Figure 12] FIG. 13 is an enlarged cross-sectional view that typically shows the structure of a separation chip according to a fourth modified example of the present invention. [Figure 13] FIG. 13 is an enlarged cross-sectional view that illustrates a schematic structure of a separation chip according to a fifth modified example of the present invention. [Figure 14] FIG. 13 is a plan view diagrammatically showing the structure of a separation chip according to a sixth modified example of the present invention. [Figure 15] FIG. 13 is a plan view illustrating a structure of a separation chip according to a seventh modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0018] A dielectrophoretic device 1 including a separation chip 100 according to one embodiment of the present invention will be described with reference to Figures 1 to 8. Figure 1 is a plan view showing a schematic structure of a dielectrophoretic device 1 including a separation chip 100 according to one embodiment of the present invention.

[0019] As shown in FIG. 1, the dielectrophoretic device 1 according to an embodiment of the present invention includes a separation chip 100 and a voltage control device 500. The dielectrophoretic device 1 separates the dielectric particles P1 from other components P2 by applying a dielectrophoretic force to the dielectric particles P1 contained in a sample liquid (specimen liquid), and collects the dielectric particles P1. The sample liquid is not particularly limited, but may be, for example, blood. The dielectric particles P1 are not particularly limited, but may be, for example, cells, proteins, nucleic acids, or microorganisms. The cells are, for example, cancer cells. The sample liquid may be seawater, saline, pure water, or a chemical. The other components P2 are, for example, dielectric particles of a type different from the dielectric particles P1, or non-dielectric particles. As an example, the sample liquid is blood, the dielectric particles P1 are cancer cells, and the other components P2 are white blood cells. The sample liquid is an example of the "liquid" of the present invention.

[0020] The separation chip 100 separates the dielectric particles P1 from other components P2 by applying a dielectrophoretic force to the dielectric particles P1 contained in the sample liquid, and collects 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.

[0021] The separation chip 100 includes a substrate 101, a flow path 110, and an electrode 120. The flow path 110 includes a supply section 111, a separation flow path 112, and a collection section 113. A sample liquid is introduced into the supply section 111. The supply section 111 has, for example, an opening. The supply section 111 is connected to a supply source of the sample liquid by, for example, a tube. The flow path 110 is an example of an "introduction section" in the present invention.

[0022] The separation flow channel 112 connects the supply unit 111 and the collection unit 113. The sample liquid introduced into the supply unit 111 flows through the separation flow channel 112 toward the collection unit 113. The collection unit 113 collects the sample liquid that has passed through the separation flow channel 112. The collection unit 113 may have, for example, an opening. The collection unit 113 may supply, for example, the sample liquid to the outside. In this embodiment, as described later, the collection unit 113 collects the sample liquid from which the dielectric particles P1 have been separated (removed).

[0023] The separation chip 100 includes a channel cover 105. The channel cover 105 is disposed on a substrate 101. The channel cover 105 has an area smaller than that of the substrate 101. In other words, the channel cover 105 is disposed on a part of the substrate 101. The channel cover 105 has a recess that constitutes a channel 110. The channel 110 is constituted by the substrate 101 and the channel cover 105. The channel cover 105 is an example of an "introduction part constituent member" of the present invention.

[0024] The electrode 120 is made of a metal having electrical conductivity. In this embodiment, the concept of metal includes alloys. The electrode 120 is disposed at least in the separation channel 112. In other words, the electrode 120 overlaps at least 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, comb-tooth shapes facing each other. The first electrode 121 and the second electrode 122 do not have to have a comb-tooth shape.

[0025] The first electrode 121 has a plurality of teeth 1211 , a first connection portion 1212 , a second connection portion 1213 , and a pad portion 1214 .

[0026] Each of the tooth portions 1211 extends substantially linearly. The tooth portions 1211 are arranged substantially parallel to one another. The tooth portions 1211 extend in a second direction Y that intersects with a first direction X in which the flow passage 110 extends. In this embodiment, the second direction Y is substantially perpendicular to the first direction X. That is, in this embodiment, the tooth portions 1211 are substantially perpendicular to the flow passage 110.

[0027] The first connection portion 1212 connects the multiple teeth 1211 to each other. The multiple teeth 1211 and the first connection portion 1212 form a comb-tooth shape. The multiple teeth 1211 are arranged, for example, straddling the separation channel 112 in a planar view. The first connection portion 1212 is arranged outside the separation channel 112 in a planar view. The multiple teeth 1211 and the first connection portion 1212 are covered by the channel cover 105.

[0028] 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 disposed outside the flow path cover 105 in a planar view. In this embodiment, the second connection portion 1213 is covered by the flow path cover 105. A portion of the pad portion 1214 is disposed outside the flow path cover 105 in a planar view. In this manner, since at least a portion of the pad portion 1214 is not covered by the flow path cover 105, the pad portion 1214 can be easily electrically connected to the voltage control device 500.

[0029] The second electrode 122 has a plurality of teeth 1221 , a first connection portion 1222 , a second connection portion 1223 , and a pad portion 1224 .

[0030] Each of the tooth portions 1221 extends in a substantially straight line. The tooth portions 1221 are arranged substantially parallel to one another. The tooth portions 1221 are arranged substantially parallel to the tooth portions 1211. The first connection portion 1222 connects the tooth portions 1221 to one another. The tooth portions 1221 and the first connection portion 1222 form a comb-tooth shape. The tooth portions 1221 are arranged, for example, straddling the separation channel 112 in a plan view. The first connection portion 1222 is arranged outside the separation channel 112 in a plan view. The tooth portions 1221 and the first connection portion 1222 are covered by the channel cover 105.

[0031] 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 disposed outside the flow path cover 105 in a planar view. In this embodiment, the second connection portion 1223 is covered by the flow path cover 105. A portion of the pad portion 1224 is disposed outside the flow path cover 105 in a planar view. In this manner, since at least a portion of the pad portion 1224 is not covered by the flow path cover 105, the pad portion 1224 can be easily electrically connected to the voltage control device 500.

[0032] The voltage control device 500 is electrically connected to the pad section 1214 and the pad section 1224. The voltage control device 500 applies an AC voltage according to the type of the dielectric particle P1 to the first electrode 121 and the second electrode 122 via the pad section 1214 and the pad section 1224. The AC voltage according to the type of the dielectric particle P1 is, for example, a voltage of a frequency that generates an electric field that specifically acts on the dielectric particle P1 with a dielectrophoretic force (attractive force) and of a magnitude that does not destroy the dielectric particle P1.

[0033] Specifically, the frequency of the AC voltage is set so that a positive dielectrophoretic force (attractive force) acts on the dielectric particle P1 due to the electric field between the first electrode 121 and the second electrode 122. Therefore, a positive dielectrophoretic force acts on the dielectric particle P1, and the dielectric particle P1 is attracted to the electrode 120 (the first electrode 121, the second electrode 122). On the other hand, the frequency of the AC voltage is set so that the dielectrophoretic force does not act, or barely acts, on the other component P2. Therefore, the other component P2 passes through the separation channel 112 and is collected in the collection section 113.

[0034] 1, the following describes the voltage control device 500. The voltage control device 500 includes a power supply unit 510 and a control unit 520.

[0035] 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 include a removable medium. The storage device corresponds to an example of a non-transitory computer-readable storage medium.

[0036] The power supply unit 510 generates an AC voltage according to the dielectric particles P1 to be separated. Then, the power supply unit 510 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, for example, a signal generator such as a function generator.

[0037] A dielectrophoretic force (attractive force) acts on the dielectric particles P1 by applying an AC voltage corresponding to the dielectric particles P1 to the first electrode 121 and the second electrode 122 by the power supply unit 510. As a result, the dielectric particles P1 are attracted to the electrode 120, and the dielectric particles P1 are separated from the other components P2. In this embodiment, the dielectric particles P1 are captured by the electrode 120, and the other components P2 pass through the separation flow path 112 and are collected in the collection unit 113.

[0038] The voltage control device 500 may have a function of measuring electrical characteristics (such as impedance) between the first electrode 121 and the second electrode 122. The voltage control device 500 may be configured by, for example, a source measure unit.

[0039] Next, the structure of the separation chip 100 will be further described with reference to Fig. 2. Fig. 2 is an enlarged cross-sectional view that typically shows the cross-sectional structure of the separation chip 100 of this embodiment.

[0040] 2, the separation chip 100 includes an insulating film 103 in addition to a substrate 101, an electrode 120, and a channel 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 substantially rectangular flat plate shape. However, the shape of the substrate 101 is not limited to a flat plate shape.

[0041] The electrode 120 is disposed on one surface 1011 of the substrate 101. The material of the electrode 120 is, for example, a metal such as aluminum, copper, and / or titanium. However, the material of the electrode 120 may 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. The material of the electrode 120 may be other than a metal, and may include, for example, an oxide such as a metal oxide, or a semiconductor. The surface of the electrode 120 may be oxidized. The electrode 120 may be formed of, for example, ITO (Tin Tin Oxide). The material of the electrode 120 is not particularly limited as long as the electrode 120 has electrical conductivity.

[0042] The insulating film 103 covers at least a part of one surface 1205 of the electrode 120. The one surface 1205 of the electrode 120 is a surface on one side of the electrode 120 (the side opposite to the substrate 101). In this embodiment, the one surface 1205 of the electrode 120 is a surface that is visible when the electrode 120 is viewed from the flow channel 110 side. In addition, in this embodiment, the one surface 1205 of the electrode 120 is a surface that is approximately parallel to the one surface 1011 of the substrate 101. The insulating film 103 covers a portion of the one surface 1011 of the substrate 101 where the electrode 120 is not arranged and at least a part of the electrode 120. Note that the insulating film 103 does not cover at least the portions of the pad portions 1214 and 1224 that are connected to the voltage control device 500. The insulating film 103 also covers the side surface 1206 of the electrode 120.

[0043] 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 this 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. In other words, it is possible to control the electric field formed by the electrode 120 depending on the thickness and material of the insulating film 103. The insulating film 103 also functions as a protective film that suppresses the occurrence of an electrochemical reaction between the electrode 120 and the sample liquid.

[0044] Here, in this 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 ends in the width direction (first direction X), and one surface 1205 arranged approximately parallel to one surface 1011 of the substrate 101. Hereinafter, the direction (here, the first direction X) intersecting the extending direction (second direction Y) of the electrode 120 may be referred to as the width direction.

[0045] 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 located on the outer side in the width direction with respect 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.

[0046] In this embodiment, a step 12053 is formed on one surface 1205 of the electrode 120. In addition, in this embodiment, the electrode 120 has a concave shape in cross section. Specifically, the pair of second regions 12052 extend inward in the width direction from the pair of side surfaces 1206, respectively. The first region 12051 is disposed between the pair of second regions 12052 and approximately parallel to the second regions 12052. The first region 12051 is disposed at a position closer to the substrate 101 than the pair of second regions 12052. The electrode 120 has a pair of connection surfaces 1251, and the pair of connection surfaces 1251 connect the pair of second regions 12052 and the first region 12051. The first region 12051 and the pair of connection surfaces 1251 form a concave portion 1260 in the electrode 120.

[0047] The insulating film 103 covers at least a part of one surface 1205 of the electrode 120. In 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. Note that in this embodiment, the "thickness of the insulating film 103 on the first region 12051" indicates that the thickness of the insulating film 103 is zero when the insulating film 103 is not formed on the first region 12051.

[0048] Specifically, the insulating film 103 has an opening 1032 that connects the first region 12051 of the electrode 120 and the flow channel 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.

[0049] Moreover, the insulating film 103 is not formed on at least a part of the connection surface 1251. In other words, at least a part of the connection surface 1251 is connected to the flow channel 110 without the insulating film 103. In this embodiment, the insulating film 103 is not formed on the connection surface 1251.

[0050] Next, the structure of the electrode 120 will be further described with reference to Fig. 3. Fig. 3 is an enlarged cross-sectional view showing a schematic structure around the electrode 120. As shown in Fig. 3, in this embodiment, the electrode 120 has a first layer 1201, a second layer 1202, and a third layer 1203.

[0051] The first layer 1201 is disposed on one surface 1011 of the substrate 101. The first layer 1201 is not particularly limited, but preferably contains, for example, a metal having good adhesion to the substrate 101. The first layer 1201 also preferably contains, for example, a metal capable of suppressing the diffusion of the second layer 1202 into the substrate 101. In this embodiment, the first layer 1201 contains, for example, titanium.

[0052] The second layer 1202 is disposed on the first layer 1201. The second layer 1202 is disposed on the surface of the first layer 1201 opposite to the substrate 101. The second layer 1202 is not particularly limited, but preferably includes, for example, a metal having a low electrical resistivity. The second layer 1202 preferably includes, for example, aluminum or copper. In this embodiment, the second layer 1202 includes, for example, aluminum.

[0053] 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 contains a metal that is insoluble or difficult to dissolve in the sample liquid. In this embodiment, the third layer 1203 contains, for example, titanium.

[0054] The thicknesses of the first layer 1201, the second layer 1202, and the third layer 1203 are not particularly limited. The first layer 1201 has a thickness of, for example, several nm or more and several tens of nm or less. The second layer 1202 has a thickness, for example, larger than the first layer 1201. The second layer 1202 has a thickness, for example, several tens of nm or more and several hundreds of nm or less. The third layer 1203 has a thickness, for example, larger than the second layer 1202. The third layer 1203 has a thickness, for example, several tens of nm or more and several hundreds of nm or less. The width of the electrode 120 is not particularly limited, but is, for example, 40 μm or more and 300 μm or less. The distance between the electrodes 120 in the width direction (here, the first direction X) is not particularly limited, but is, for example, 10 μm or more and 50 μm or less. The thickness of the insulating film 103 is not particularly limited, but is, for example, not less than several hundred nm and not more than 1000 nm.

[0055] In this embodiment, the recess 1260 is formed to a depth partway through the third layer 1203. That is, the first region 12051 of the one surface 1205 constituting the recess 1260 is located in the third layer 1203. Therefore, the second layer 1202 does not contact the sample liquid. Therefore, even if the second layer 1202 is formed of a metal that dissolves in the sample liquid, the second layer 1202 can be prevented from dissolving in the sample liquid. Note that, when the second layer 1202 is formed of a metal that does not dissolve in the sample liquid, the recess 1260 may be formed up to the second layer 1202.

[0056] As shown in FIG. 2, the channel cover 105 is disposed, for example, on one surface 1031 of the insulating film 103. A part of the channel cover 105 may be disposed on one surface 1011 of the substrate 101. The channel cover 105 covers the electrode 120 and one side (the side opposite to the substrate 101) of the insulating film 103. The channel cover 105 also constitutes the channel 110. Specifically, the channel cover 105 includes a side wall 1051 (see FIG. 1) and a ceiling 1052. The side wall 1051 and the ceiling 1052 constitute the channel 110 through which the sample liquid flows. The side wall 1051 surrounds at least a part of the electrode 120 in a plan view.

[0057] The material of the flow path cover 105 is not particularly limited, but is, for example, a silicone-based resin. In this embodiment, the material of the flow path cover 105 is PDMS (dimethylpolysiloxane). When the flow path cover 105 is made of PDMS, the flow path cover 105 is firmly bonded to the insulating film 103 and the surface of the substrate 101 by performing a plasma treatment on the surfaces of the flow path cover 105, the insulating film 103, and the substrate 101.

[0058] Next, the effects of the separation chip 100 of this embodiment will be described with reference to Figs. 4 and 5. Here, the effects of the separation chip 100 of this embodiment will be described in comparison with a conventional separation chip 9100. Fig. 4 is an enlarged cross-sectional view that typically shows the structure of the conventional separation chip 9100. Fig. 5 is an enlarged cross-sectional view that typically shows the structure of the separation chip 100 of this embodiment. Note that in Figs. 4 and 5, the arrows spanning between the electrodes are a schematic representation of electric field lines to make the invention easier to understand.

[0059] First, a conventional separation chip 9100 will be described with reference to Fig. 4. As shown in Fig. 4, 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 generally rectangular shape in cross section. That is, no step is formed on one surface 9205 of the electrode 9120. Furthermore, the insulating film 9103 has a generally uniform thickness on one surface 9205 of the electrode 9120. Furthermore, no opening 1032 is formed in the insulating film 9103.

[0060] In a conventional separation chip 9100, ∇E 2 (where ∇E denotes the gradient of the electric field intensity) is the gradient of ∇E between adjacent corners 9127 of two electrodes 9120. 2 is largest. Therefore, the dielectric particle P1 is attracted to the corner 9127. Therefore, the dielectric particle P1 is attracted to the width direction end of the electrode 9120. Note that in the conventional separation chip 9100, even if the frequency and voltage are changed, the position to which the dielectric particle P1 is attracted does not change.

[0061] 5, 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 ∇E 2can be maximized. Therefore, the dielectric particles P1 are attracted to the first region 12051 (here, the recess 1260) of the electrode 120. Therefore, the dielectric particles P1 are attracted to the center of the electrode 120 in the width direction.

[0062] More specifically, the dielectrophoretic force is expressed by the following general formula (1).

[0063] (Number 1) F=2πr 3 ε m Re[K(ω)]∇E 2 (1)

[0064] where F is the dielectrophoretic force, r is the radius of the dielectric particle, and ε m denotes the dielectric constant (real part) of the surrounding medium. ω denotes the angular frequency. K(ω) denotes the Clausius-Mossotti function. E denotes the electric field strength.

[0065] In the above formula (1), ∇E 2 As can be seen from the inclusion of the term, the dielectrophoretic force occurs in a region where the AC electric field is non-uniform. A region where the AC electric field is non-uniform refers to a region where the distance between the electric field lines changes. In the conventional separation chip 9100 shown in FIG. 4, a non-uniform electric field occurs around a corner 9127 located at the end of the electrode 9120 in the width direction. For this reason, the location where the dielectric particle P1 is attracted is uniquely determined to be the corner 9127. Therefore, for example, even if the frequency or the like is changed, the position where the dielectric particle P1 is attracted cannot be changed.

[0066] 5, the thickness of the insulating film 103 on the first region 12051 of the electrode 120 is made smaller than the thickness of the insulating film 103 on the second region 12052 of the electrode 120, so that the region of the non-uniform AC electric field 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 location to which the dielectric particles P1 are attracted can be set at an arbitrary position.

[0067] Furthermore, in the separation chip 100 of this 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 a predetermined position on one surface 1205 of the electrode 120. In other words, the rate of change of the electric field intensity (the gradient of the electric field intensity) around the predetermined position on one surface 1205 of the electrode 120 can be made larger. This makes it possible to make the dielectrophoretic force stronger.

[0068] Incidentally, the separation chip 100 needs to accurately separate a specific dielectric particle P1 from other components P2. However, due to manufacturing errors in the separation chip 100, variations occur in the thickness and size of the electrode 120 and / or the insulating film 103. Therefore, in order to properly use the separation chip 100, it is necessary to correct the applied voltage and / or frequency from the reference voltage and / or reference frequency. When calculating this correction value, in this embodiment, the opening 1032 is formed in the insulating film 103, so that the influence of the dielectric constant of the insulating film 103 can be reduced. This allows the calculation to be simplified.

[0069] Moreover, in the separation chip 100 of this 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 can be easily determined 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.

[0070] Specifically, for example, when the dielectric particle P1 is attracted to the center of the electrode 120 in the width direction, it is understood that 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, when the dielectric particle P1 is attracted to the end of the electrode 120 in the width direction, it is understood that the dielectric particle P1 is attracted to the electrode 120 regardless of the presence or absence of the recess 1260.

[0071] As described above with reference to FIGS. 1 to 5, 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, the region of the non-uniform AC electric field on one surface 1205 of the electrode 120 changes relative to, for example, the separation chip 9100. Therefore, for example, by arranging the first region 12051 at an arbitrary position on the electrode 120, the location to attract the dielectric particles P1 can be set at an arbitrary position.

[0072] As described above, the insulating film 103 has the opening 1032 that connects the first region 12051 of the electrode 120 and the flow channel 110. Therefore, the electric field strength generated between the adjacent first regions 12051 can be made stronger than when the opening 1032 is not formed. Therefore, it is possible to make the electric field strength between the first regions 12051 stronger.

[0073] As described above, the step 12053 is formed on one surface 1205 of the electrode 120. Therefore, a more non-uniform electric field can be generated around the step 12053 on one surface 1205 of the electrode 120, and the dielectrophoretic force generated between the steps 12053 can be easily strengthened.

[0074] 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.

[0075] As described above, the insulating film 103 is not formed on at least a part of the connection surface 1251. Therefore, compared to the case where the insulating film 103 is formed on the entire surface of the connection surface 1251, the electric field strength generated between the connection surfaces 1251 can be made stronger.

[0076] As described above, the insulating film 103 includes a silicon oxide film or a silicon nitride film. Therefore, the electrodes 120 can be easily protected from the sample liquid. In addition, when the flow path cover 105 is formed of, for example, a silicone-based resin, both the flow path cover 105 and the insulating film 103 include silicon elements, so that the flow path cover 105 can be firmly adhered to the insulating film 103.

[0077] As described above, the flow path cover 105 constitutes the flow path 110. Therefore, by passing the sample liquid through the flow path 110, the dielectric particles P1 can be easily separated from the other components P2 of the sample liquid.

[0078] 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 in which the flow channel 110 extends. 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 separated efficiently.

[0079] Next, a method for manufacturing the separation chip 100 of this embodiment will be described with reference to Fig. 2, Fig. 3, and Fig. 6 to Fig. 8. Fig. 6 is a flow diagram of the method for manufacturing the separation chip 100 of this embodiment. Figs. 7 and 8 are enlarged cross-sectional views for explaining the method for manufacturing the separation chip 100 of this embodiment. The method for manufacturing the separation chip 100 of this embodiment includes steps S1 to S4.

[0080] As shown in Fig. 6, in step S1, an electrode 120 is formed on a substrate 101. Specifically, as shown in Fig. 7, an electrode layer that becomes the electrode 120 is formed on one surface 1011 of the substrate 101 by, for example, a vacuum deposition method. Then, the electrode layer is patterned by, for example, a photolithography method and wet etching to form the electrode 120 having a predetermined shape. Note that the method of forming the electrode layer on the substrate 101 is not limited to the vacuum deposition method, and other methods such as a sputtering method may also be used.

[0081] 8, an insulating layer 1030 is formed to cover the electrode 120. Specifically, the insulating layer 1030 that will become the insulating film 103 is formed on one surface 1011 of the substrate 101 and the electrode 120 by, for example, a sputtering method. The method for forming the insulating layer 1030 is not limited to the sputtering method, and other methods such as a vacuum deposition method may also be used.

[0082] Next, in step S3, the opening 1032 and the recess 1260 are formed as shown in FIG. 3. 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 region of the insulating layer 1030 that is not covered by the flow path cover 105 is removed. Also, at this time, in this embodiment, a predetermined region of the insulating layer 1030 (a region that becomes the opening 1032) and a predetermined region of the electrode 120 (a region that becomes the recess 1260) are removed. As a result, the insulating film 103 having the opening 1032 is formed, and the electrode 120 having the recess 1260 is formed.

[0083] Next, in step S4, as shown in Fig. 2, the flow path cover 105 is attached to the substrate 101 on which the electrode 120 and the insulating film 103 are formed. Specifically, the surface of the flow path cover 105 facing the substrate 101 and the surfaces of the insulating film 103 and the substrate 101 facing the flow path cover 105 are plasma-treated. Then, the plasma-treated surfaces are bonded together. As a result, the flow path cover 105 is bonded to the insulating film 103 and / or the substrate 101, and the flow path cover 105 is attached to the substrate 101. At this time, a flow path 110 is formed between the flow path cover 105 and the substrate 101.

[0084] In this manner, the separation chip 100 is manufactured.

[0085] (First Modification) Next, a separation chip 100 according to a first modified example of the present invention will be described with reference to Fig. 9. Fig. 9 is an enlarged cross-sectional view that illustrates a structure of a separation chip 100 according to a first modified example of the present invention. In the first modified example, unlike the above embodiment, an example in which an insulating film 103 is formed on a first region 12051 will be described.

[0086] 9, in the separation chip 100 of the first modification, 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, similar to the above embodiment. Also, a step 12053 is formed on one surface 1205 of the electrode 120, similar to the above embodiment. Also, the electrode 120 has a concave shape in cross section, similar to the above embodiment.

[0087] 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. The insulating film 103 also covers the entire surface of the connection surface 1251.

[0088] Moreover, the insulating film 103 is formed on the second region 12052 so that the thickness increases toward the outside in the width direction.

[0089] The other structures and effects of the first modified example are similar to those of the above embodiment.

[0090] (Second Modification) Next, a separation chip 100 according to a second modified example of the present invention will be described with reference to Fig. 10. Fig. 10 is an enlarged cross-sectional view that illustrates a structure of a separation chip 100 according to a second modified example of the present invention. In the second modified example, unlike the above embodiment, an example in which no step is formed on one surface 1205 of the electrode 120 will be described.

[0091] 10, in the separation chip 100 of the second modification, 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, similar to the above embodiment. Also, similar to the above embodiment, the insulating film 103 has an opening 1032 that connects the first region 12051 of the electrode 120 and the flow channel 110. In other words, the insulating film 103 is not formed on the first region 12051.

[0092] On the other hand, in the second modified example, the recess 1260 is not formed in the electrode 120. Furthermore, no step is formed in the electrode 120. The electrode 120 has a generally rectangular shape in cross section.

[0093] In the second modified example, the opening 1032 is disposed at a position offset from the center in the width direction of the electrode 120. The opening 1032 is formed, for example, in only one portion in the width direction of one surface 1205 of the electrode 120. Therefore, it is possible to attract the dielectric particles P1 to only one portion in the width direction of the electrode 120.

[0094] The other structures and other effects of the second modified example are similar to those of the above embodiment.

[0095] (Third Modification) Next, a separation chip 100 according to a third modified example of the present invention will be described with reference to Fig. 11. Fig. 11 is an enlarged cross-sectional view that typically shows the structure of the separation chip 100 according to the third modified example of the present invention. In the third modified example, unlike the above embodiment, an example in which the recess 1260 is not formed in the electrode 120 will be described.

[0096] 11, in the separation chip 100 of the third modification, 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, as in the above embodiment. Also, as in the above embodiment, the insulating film 103 has an opening 1032 connecting the first region 12051 of the electrode 120 and the flow channel 110. Also, as in the above embodiment, a step 12053 is formed on one surface 1205 of the electrode 120. Also, as in the above embodiment, the 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 side in the width direction with respect to the first region 12051.

[0097] On the other hand, in the third modified example, the electrode 120 has a convex shape in a cross-sectional view. Specifically, the electrode 120 has a pair of second regions 12052, a first region 12051, and a pair of connection surfaces 1251. The pair of second regions 12052 extend inward in the width direction from the pair of side surfaces 1206, respectively. The first region 12051 is disposed between the pair of second regions 12052 and approximately parallel to the second regions 12052. The first region 12051 is disposed at a position farther from the substrate 101 than the pair of second regions 12052. The first region 12051 and the pair of connection surfaces 1251 form a convex portion 1261 in the electrode 120.

[0098] The other structures and effects of the third modified example are similar to those of the above embodiment.

[0099] (Fourth Modification) Next, a separation chip 100 according to a fourth modified example of the present invention will be described with reference to Fig. 12. Fig. 12 is an enlarged cross-sectional view that illustrates a structure of a separation chip 100 according to a fourth modified example of the present invention. In the fourth modified example, unlike the above embodiment, an example in which the surface of the electrode 120 is formed as a curved surface will be described.

[0100] 12, in the separation chip 100 of the fourth modification, 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, similar to the above embodiment. Also, similar to the above embodiment, the insulating film 103 has an opening 1032 connecting the first region 12051 of the electrode 120 and the flow channel 110. Also, similar to the above 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 relative to the first region 12051.

[0101] On the other hand, in the fourth modified example, the step 12053 is not formed on one surface 1205 of the electrode 120. Specifically, the electrode 120 has a generally semicircular shape in cross section. The thickness of the insulating film 103 on the first region 12051 gradually increases toward the outside in the width direction. Also, the thickness of the insulating film 103 on the second region 12052 gradually increases toward the outside 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.

[0102] The other structures and effects of the fourth modified example are similar to those of the above embodiment.

[0103] (Fifth Modification) Next, a separation chip 100 according to a fifth modified example of the present invention will be described with reference to Fig. 13. Fig. 13 is an enlarged cross-sectional view that typically shows the structure of a separation chip 100 according to a fifth modified example of the present invention. In the fifth modified example, unlike the above embodiment, an example will be described in which a plurality of recesses 1260 are formed on one surface 1205 of an electrode 120.

[0104] As shown in FIG. 13, in the separation chip 100 of the fifth modification, 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, similar to the above embodiment. Also, similar to the above embodiment, the insulating film 103 has an opening 1032 connecting the first region 12051 of the electrode 120 and the flow channel 110. That is, the insulating film 103 is not formed on the first region 12051. Also, similar to the above embodiment, a step 12053 is formed on one surface 1205 of the electrode 120. Also, similar to the above embodiment, the electrode 120 has a concave shape in cross section.

[0105] On the other hand, in the fifth modified example, the opening 1032 is disposed at a position shifted from the center in the width direction of the electrode 120. The opening 1032 is formed, for example, in only one portion in the width direction of one surface 1205 of the electrode 120.

[0106] In the fifth modification, a plurality of recesses 1260 are formed on one surface 1205 of electrode 120. Openings 1032 may be formed in portions of insulating film 103 corresponding to the recesses 1260, or may be formed in portions of insulating film 103 corresponding to the spaces between adjacent recesses 1260.

[0107] The other structures and effects of the fifth modified example are similar to those of the above embodiment and the second modified example.

[0108] (Sixth Modification) Next, a separation chip 100 according to a sixth modified example of the present invention will be described with reference to Fig. 14. Fig. 14 is a plan view that illustrates a structure of a separation chip 100 according to a sixth modified example of the present invention. In the sixth modified example, unlike the above embodiment, an example in which the tooth portion 1211 and the tooth portion 1221 of the electrode 120 are inclined with respect to the flow channel 110 will be described.

[0109] As shown in FIG. 14, in the separation chip 100 of the sixth modified example, the multiple teeth 1211 of the first electrode 121 and the multiple teeth 1221 of the second electrode 122 extend in a second direction Y intersecting with the first direction X in which the flow path 110 extends. In the sixth modified example, unlike the above embodiment, the second direction Y is inclined with respect to the first direction X. That is, in the sixth modified example, the teeth 1211 and the teeth 1221 are inclined with respect to the flow path 110. By configuring in this way, for example, by applying an AC voltage of a specific frequency between the first electrode 121 and the second electrode 122, it is possible to move the dielectric particle P1 along the teeth 1211 and the teeth 1221. Therefore, it is possible to separate the dielectric particle P1 from the other component P2. This will be described in detail below.

[0110] In the sixth modified example, the collecting section 113 of the flow channel 110 has a first collecting section 1131 and a second collecting section 1132. The first collecting section 1131 collects the dielectric particles P1. The second collecting section 1132 collects the other components P2. The flow channel 110 further has a first connecting flow channel 1141 and a second connecting flow channel 1142. The first connecting flow channel 1141 connects the downstream part of the separation flow channel 112 to the first collecting section 1131. The second connecting flow channel 1142 connects the downstream part of the separation flow channel 112 to the second collecting section 1132.

[0111] In the separation chip 100 of the sixth modified example, an AC voltage of a specific frequency is applied between the first electrode 121 and the second electrode 122, so that a dielectrophoretic force acts on the dielectric particles P1 passing through the separation channel 112. This causes the dielectric particles P1 to move along the teeth 1211 and the teeth 1221. In the sixth modified example, the dielectric particles P1 move toward the first connection portion 1212 along the teeth 1211 and the teeth 1221. In the sixth modified example, the frequency of the AC voltage is set so that the dielectric particles P1 are not captured by the electrode 120.

[0112] Then, the dielectric particles P1 pass through the first connection flow path 1141 and are collected in the first collection section 1131. On the other hand, the other component P2 travels straight through the separation flow path 112, passes through the second connection flow path 1142 and is collected in the second collection section 1132.

[0113] The other structure, manufacturing method, and effects of the sixth modified example are similar to those of the above embodiment.

[0114] (Seventh Modification) Next, a separation chip 100 according to a seventh modified example of the present invention will be described with reference to Fig. 15. Fig. 15 is a plan view that illustrates a structure of a separation chip 100 according to a seventh modified example of the present invention. In the seventh modified example, unlike the above embodiment, an example in which the separation chip 100 includes, for example, a HDF (Hydrodynamic filtration) 200 will be described.

[0115] As shown in FIG. 15, in the seventh modified example, the separation chip 100 further includes an HDF 200. The HDF 200 is disposed upstream of the electrode 120. The HDF 200 functions as a hydrodynamic filter. For example, the HDF 200 is a microchannel intended for separating and concentrating particles. The HDF 200 has a plurality of branch channels 201 branching off from the separation channel 112. The HDF 200 is configured by the plurality of branch channels 201 and a part of the separation channel 112. The plurality of branch channels 201 are disposed, for example, so as to extend perpendicularly to the separation channel 112. Moreover, the plurality of branch channels 201 are disposed, for example, at approximately equal pitches along the direction in which the separation channel 112 extends.

[0116] The liquid flowing through the separation channel 112 flows into the branch channels 201. Some of the particles contained in the liquid flowing through the separation channel 112 also flow into the branch channels 201. Particles with smaller diameters flow more easily into the branch channels 201, and particles with larger diameters flow less easily into the branch channels 201. In other words, the HDF 200 separates relatively small particles from the liquid flowing through the separation channel 112. In the seventh modified example, the dielectric particles P1 do not flow into the branch channels 201 of the HDF 200, but travel approximately straight through the separation channel 112.

[0117] In the seventh modified example, 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 liquid, and then the electrode 120 can separate the dielectric particles P1 from particles equal to or larger than the predetermined size.

[0118] The other structure, manufacturing method, and effects of the seventh modified example are similar to those of the above embodiment.

[0119] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In addition, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be deleted from all components shown in the embodiments. Furthermore, components from different embodiments and modified examples may be appropriately combined. The drawings are mainly shown schematically for ease of understanding, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of drawing. In addition, the material, shape, dimensions, etc. of each component shown in the above embodiments are examples and are not particularly limited, and various modifications are possible within a range that does not substantially deviate from the effects of the present invention.

[0120] For example, in the above embodiment, the electrode 120 has the first layer 1201, the second layer 1202, and the third layer 1203, but the present invention is not limited to this. For example, the electrode 120 may have one layer, two layers, or four or more layers.

[0121] In the above embodiment, the first electrode 121 and the second electrode 122 have a comb-tooth shape, but the present invention is not limited to this. For example, the first electrode 121 and the second electrode 122 do not have to have a comb-tooth shape.

[0122] In the above embodiment, an example in which the sample liquid flows through the flow path 110 has been described, but the present invention is not limited to this. That is, an example in which the inlet portion is the flow path 110 through which the sample liquid flows has been described, but the present invention is not limited to this. For example, the inlet portion may be a storage portion in which the sample liquid is stored. In this case, the inlet portion component may not have a ceiling and may only have a side wall.

[0123] In the above embodiment, the example in which the predetermined region of the insulating film 103 and the predetermined region of the electrode 120 are removed in one step (step S3) has been described, but the present invention is not limited to this. For example, the electrode 120 may be formed in a predetermined shape, the insulating film 103 may be formed so as to cover the electrode 120, and then only the predetermined region of the insulating film 103 may be removed. For example, the manufacturing flow may be appropriately changed depending on the shape of the electrode 120 and / or the shape of the insulating film 103 shown in FIGS. 9 to 13.

[0124] Furthermore, for example, in the above embodiment, the first modification, the third modification, and / or the fourth modification, the recess 1260, the opening 1032, and / or the protrusion 1261 may be formed at a position offset from the center of the electrode 120 in the width direction. [Industrial Applicability]

[0125] The present invention can be used in the field of separation chips. [Explanation of symbols]

[0126] 100: Separation chip 101: Substrate 103: Insulating film 105: Flow path cover (introduction part component) 110: Flow path (inlet) 120: Electrode 121: 1st electrode 122: 2nd electrode 1011: One side 1032 : Opening 1205: One side 1206: Side 1211, 1221: Tooth 1251: Connection surface 12051 :First area 12052 :Second area 12053: Step P1: Dielectric particles

Claims

1. 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; an introduction portion component that is disposed on one side of the substrate, surrounds at least a portion of the electrode, and configures an introduction portion into which a liquid containing dielectric particles is introduced; Equipped with 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 , wherein the insulating film has an opening that connects the first region of the electrode and the injection portion.

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

4. The separation chip according to claim 1 , wherein a step is formed on the one surface of the electrode.

5. The separation chip according to claim 4 , wherein the electrode has a concave shape in cross section.

6. The electrode is A pair of side surfaces disposed at the ends in the width direction; A pair of connecting surfaces having The second region is provided in a pair, The pair of second regions each extend inward in the width direction from the pair of side surfaces, the first region is disposed between the pair of second regions and substantially parallel to the second regions; The pair of connection surfaces connect the pair of second regions and the first region. The separation chip according to claim 5 , wherein the insulating film is not formed on at least a part of the connection surface.

7. The separation chip according to claim 1 , wherein the insulating film includes a silicon oxide film or a silicon nitride film.

8. the introduction section has a flow path through which the liquid flows, The separation chip according to claim 1 , wherein the introduction part component constitutes the flow channel.

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

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