JP2020201239A - Particle classification device - Google Patents

Abstract

To eliminate the influence of a passivation layer on a dielectrophoretic electrode and classify particles without reducing a dielectrophoretic force; and to eliminate the step between a surface of the dielectrophoretic electrode and an interlayer insulating film along a channel, stabilize the flow of particles included in a specimen, and detect target particles.SOLUTION: A particle classification device (1) comprises: a channel (14) that is formed along a specific top face; and electrodes for classification (16) to (23) that classify a plurality of particles in a direction substantially perpendicular to the top face by dielectrophoresis. The particle classification device (1) includes a semiconductor substrate (10) and forms a groove on the semiconductor substrate in the same direction as the channel (14) including the electrodes for classification (16) to (23); a bottom face of the groove is formed to have the same height to be matched with the surfaces of the electrodes for classification (16) to (23).SELECTED DRAWING: Figure 5

Description

The present invention relates to a particle separator.

As one of the methods for analyzing minute objects to be inspected such as cells, there is a method called a flow cytometry method. In this method, a liquid in which fine objects to be inspected are dispersed is optically analyzed while flowing through a microchannel. Then, there is also a particle sorting device that separates particles based on the result of analyzing the test object by the dielectrophoresis method using this flow cytometry method.

As an example of the particle sorting device as described above, in Patent Document 1, a fluid containing cells is allowed to flow in a microchannel, and the cell type is specified based on the results of measuring the complex impedance and the complex dielectric constant in the channel. , A particle sorting apparatus that sorts cells by dielectrophoresis and separates particles is disclosed.

Further, when a sensor having a complicated structure is configured and the sensor is integrated to reduce the size and enhance the functionality, it is conceivable to configure the sensor and the dielectrophoresis electrode on the same semiconductor substrate. Patent Document 2 discloses an apparatus for manipulating particles by dielectrophoresis, and further, in one example of the embodiment, a sensor for detecting particles by integrated circuit technology and a dielectrophoresis electrode are on the same semiconductor substrate. It is configured.

Japanese Unexamined Patent Publication No. 2014-169925 Special Table 2002-543972

However, in the case where a CMOS (Complementary Metal Oxide Semiconductor) integrated circuit is used as an integrated circuit to form a dielectricing electrode and a dielectricing force is applied to particles flowing on the surface of the CMOS integrated circuit, the dielectricing electrode Is formed of the uppermost metal layer of the CMOS integrated circuit, so that the efficiency of imparting a dielectricing force to the particles is improved. Therefore, when the dielectric migration electrode is formed by using the CMOS integrated circuit, the CMOS integrated circuit is coated with a passivation layer formed by laminating silicon oxide, silicon nitride, or the like on the outermost surface of the silicon semiconductor substrate.

Therefore, when a microchannel is formed on a CMOS integrated circuit and a fluid containing a sample is allowed to flow through the microchannel, a passivation layer exists between the surface of the CMOS integrated circuit and the dielectrophoresis electrode. Then, an electric field is generated in the liquid by the signal voltage applied to the dielectrophoretic electrode, so that the dielectrophoretic force acting on the sample is generated. However, depending on the thickness of the passivation layer formed on the surface of the CMOS integrated circuit, there is a problem that the electric field strength in the liquid is weakened and the dielectrophoretic force is lowered, so that the efficiency of separating the sample is lowered. Further, the thickness of the passivation layer affects the yield at the time of manufacturing the COMS integrated circuit in the formation of the CMOS integrated circuit. Further, the thickness of the passivation layer may affect the variation in the dielectrophoretic force.

(1) One embodiment of the present invention includes a flow path formed along a specific upper surface and a particle separation electrode for separating a plurality of particles in a direction substantially perpendicular to the upper surface by dielectric migration. The particle sorting device includes a semiconductor substrate and forms a groove on the semiconductor substrate in the same direction as the flow path including the sorting electrode, and the bottom surface of the groove is the surface of the sorting electrode. A particle separator that forms at the same height so that they match.
(2) Further, in an embodiment of the present invention, in addition to the configuration of (1) above, one or more sets of the sorting electrodes are paired to form a sorting electrode pair, and a plurality of the sorting electrode pairs are used. A particle separation device that arranges multiple particles along the flow path.
(3) Further, in an embodiment of the present invention, in addition to the configuration of (1) or (2) above, a switch circuit corresponding to one or more sets of the sorting electrodes is provided, and the sorting is performed by the switch circuit. A particle separator that controls the application of AC voltage to the electrodes.
(4) Further, in an embodiment of the present invention, in addition to the above (1), the above (2), or the above (3), the particles are passed through the upper surface of the sorting electrode. A particle sorting device that applies an AC voltage to the sorting electrode by the switch circuit only when it is presumed to be directly above the sorting electrode pair.
(5) Further, in an embodiment of the present invention, in addition to the above (1), the above (2), the above (3), or the above (4), the light for individually distinguishing a plurality of particles is described. A plurality of photodiodes that receive light are provided, and the timing at which the first particle in the plurality of particles passes over the separation electrode is specified by referring to the output signals of each of the plurality of photodiodes, and the timing is specified. A particle separation device including a control unit that controls a period for driving the separation electrode based on the specific result of the above.
(6) Further, in an embodiment of the present invention, in addition to the above (1), the above (2), the above (3), the above (4), or the above (5), the bottom surface of the groove is the said. A particle separator that is formed up to the surface on the photodiode and at the same height.

With the above-described configuration, the influence of the passivation layer on the dielectrophoretic electrode is eliminated, so that the particles can be separated without lowering the dielectrophoretic force. Furthermore, by eliminating the step between the surface of the dielectrophoresis electrode and the interlayer insulating film along the flow path, the flow of particles contained in the sample can be stabilized, and the sorting efficiency for detecting the target particles is improved. ..

(A) It is a schematic diagram of the cross section of the particle sorting apparatus which concerns on one Embodiment of this invention, and (b) is the schematic diagram of another cross section of the particle separating apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the force applied to the particle in the particle sorting apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of the particle separation apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows another example of the particle separation apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the particle separation method in the particle separation apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the particle separation method in the particle separation apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the method of the particle separation in the particle separation apparatus which concerns on one Embodiment of this invention. It is a flow figure which shows the method of the particle separation in the particle separation apparatus which concerns on one Embodiment of this invention.

Hereinafter, the particle sorting apparatus according to the embodiment of the present invention will be described.

<Overview of particle separator>
The outline of the particle sorting apparatus 1 will be described with reference to FIG. 1A, FIG. 1B, and FIG.

FIG. 1A is a schematic view of a cross section of a microchannel of the particle sorting device, and FIG. 1B is a schematic view showing a cross section of the microchannel different from that of FIG. 1A. Is. Further, FIG. 2 is a schematic view showing the force applied to the particles in the particle sorting device of the particle sorting device.

[About the force applied to particles]
The force (dielectrophoretic force) applied to the particles in the particle sorting device 1 will be described with reference to FIG. In FIG. 2, the force applied to the particles 40 by the dielectrophoretic force applied to the dielectrophoretic electrode 18 and the dielectrophoretic electrode 19 as the particles 40 move from left to right toward the paper surface by the liquid 41 will be described.

Dielectrophoretic force exerted on the particles 40 in the liquid 41 by a sinusoidal voltage signal having an angular frequency ω on the particles 40.

Is the complex permittivity of the liquid 41,

, Complex permittivity of particle 40,

, The radius r of the particle 40, and the effective value _ERMS of the electric field strength generated by the sinusoidal voltage can be expressed by the following equation (4).

Then, in the dielectrophoretic force exerted on the particles 40 in the liquid 41,

When is negative, a force (negative dielectrophoretic force) that repels the force in the direction of strong electric field strength acts on the particles 40. When the equation (5) is positive, a force (positive dielectrophoretic force) toward the dielectric particles in the direction of strong electric field strength acts on the particles 40. Then, these positive dielectrophoretic forces and negative dielectrophoretic forces are proportional to the absolute value of the gradient obtained by squared the effective value of the electric field strength as shown in the equation (6).

Further, as shown in FIG. 2, the surfaces of the dielectrophoresis electrode (separation electrode) 18 and the dielectrophoresis electrode (separation electrode) 19 (dielectrophoresis electrode pair (separation electrode pair) 33) are formed on the bottom of the substrate groove 12. Is forming. In other words, the dielectrophoresis electrode pair 33 is exposed from the passivation layer 15 into the liquid 41. As a result, the electric field strength in the liquid 41 is such that the passivation layer 15 does not block the electric field as compared with the structure in which the dielectrophoresis electrode pair 33 is covered with the passivation layer 15 (not shown). As a result, the electric field strength in the liquid 41 in the structure in which the dielectrophoretic electrode pair 33 is not covered with the passivation layer 15 becomes large.

The effective value of the electric field strength generally decreases exponentially as the distance from the dielectrophoretic electrode pair increases. Therefore, from the above equation (4), the enhancement of the electric field strength is equivalent to the enhancement of the dielectrophoretic force. Further, an element such as a transistor constituting an integrated circuit such as a CMOS integrated circuit has a predetermined upper limit voltage withstand voltage. Therefore, there is a risk that the integrated circuit will break down by applying a voltage exceeding the upper limit withstand voltage to the above-mentioned element. Therefore, when the microchannel (channel) 14 is formed in the integrated circuit, it is difficult to increase the effective value of the AC voltage indefinitely, and it is efficient with respect to the voltage amplitude of the signal supplied from the signal source 38 described later. It is necessary to increase the electric field strength.

<Particle separator>
The particle sorting apparatus 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 8. FIG. 1 is a schematic diagram of a particle separator composed of a CMOS integrated circuit and a microfluidic system. FIG. 2 is a schematic cross-sectional view of one surface of the particle sorting device. FIG. 3 is a schematic view of the particle sorting device having a cross section different from that of FIG. FIG. 4 is a schematic cross-sectional view of the particle separation device when the passivation layer is removed. 5 to 7 are schematic cross-sectional views showing a state of particle separation in the particle separation device. FIG. 8 is a flow chart of a particle separation method in the particle separation device.

[Configuration of particle separator]
The particle separation device 1 includes a control device 39, a CMOS integrated circuit (semiconductor substrate) 10, and a microfluidic system 11, a substrate groove 12 formed in the CMOS integrated circuit 10, and a flow path formed in the microfluidic system 11. A microchannel 14 is formed by the groove 13. The CMOS integrated circuit 10 and the microfluidic system 11 are formed so as to be stacked. The particle sorting device 1 may include a single CMOS integrated circuit 10, or may include a plurality of circuits similar to the CMOS integrated circuit 10 on the same substrate. By including a plurality of circuits similar to the CMOS integrated circuit 10, the target particles can be separated more accurately.

(Control device)
The control device 39 receives the signals transmitted from the photodiode (first sensor) 36 and the photodiode (second sensor) 37, and the dielectricing electrodes 16 to 23 (dielectric electrode 16, dielectric electrode 17, dielectric). A switch for connecting a running electrode 18, a dielectricing electrode 19, a dielectricing electrode 20, a dielectricing electrode 21, a dielectricing electrode 22, and a dielectricing electrode 23) and a signal source 38 connected to the electrophoresis electrodes 16 to 23. The connection state with the circuits 24 to 31 (switch circuit 24, switch circuit 25, switch circuit 26, switch circuit 27, switch circuit 28, switch circuit 29, switch circuit 30, and switch circuit 31) is set to an open state or a short-circuit state. Each of the switch circuits 24 to 31 is individually controlled so as to be. The function of the control device 39 may be realized by the CPU (Central Processing Unit) executing the program stored in the storage device (not shown). Further, the control device 39 may be built in the particle sorting device 1 independently of the CPU, for example, or may be mounted in an information processing device external to the particle sorting device 1. When the control device 39 is mounted on an external information processing device, for example, by transmitting and receiving signals transmitted from the first sensor 36 and the second sensor 37 between the information processing device and the control device 39, the dielectric The connection between the migration electrodes 16 to 23 and the signal source 38 connected to the dielectric migration electrodes 16 to 23 is switched between an open state and a short-circuit state.

(CMOS integrated circuit)
The CMOS integrated circuit 10 has a photodiode (first sensor) 36, a photodiode (second sensor) 37, dielectric electrodes 16 to 23, and switch circuits 24 to 31, and faces the microfluidic system 11. The substrate groove 12 is formed on the surface side. Then, the passivation layer 15 is formed on the surface side of the CMOS integrated circuit 10 facing the microfluidic system 11. The photodiode (first sensor) 36, the photodiode (second sensor) 37, the dielectrophoresis electrodes 16 to 23, and the switch circuits 24 to 31 are formed in the same CMOS integrated circuit 10.

The CMOS integrated circuit 10 is formed so that the insulating film 42 is laminated on the surface side of the CMOS integrated circuit 10 facing the microfluidic system 11, and the passivation layer 15 faces the microfluidic system 11 of the insulating film 42. It is formed so as to be laminated on the surface side. Then, the dielectrophoresis electrodes 16 to 23 are formed by being embedded in the insulating film 42 so as to be substantially flush with the insulating film 42. As a result, the dielectric film 42 insulates the dielectrophoretic electrodes (for example, the dielectrophoretic electrode 16 and the dielectrophoretic electrode 17) from each other, so that the CMOS integrated circuit 10 can be prevented from malfunctioning. The substrate groove 12 may be formed by removing the passivation layer 15 or not forming the passivation layer 15.

The photodiode (first sensor) 36 and the photodiode (second sensor) 37 are not particularly limited as long as they can detect the target particle 40, but the photodiode is used as the first sensor and the second sensor. Therefore, the accuracy of detecting the particles 40 can be improved. Further, the mechanism for detecting the particles 40 by the first sensor 36 and the second sensor 37 may be changed. Further, if the flow speed of the particles 40 can be measured by one sensor, it is not necessary to provide the first sensor, the second sensor, and the two sensors.

The first sensor 36 and the second sensor 37 are embedded in the CMOS integrated circuit 10. Further, the first sensor 36 and the second sensor 37 are formed on the upstream side of the dielectrophoresis electrodes 16 to 23 in the microchannel 14 described later. Here, the upstream side is the side where the particles 40 and the liquid 41 flow into the microchannel 14 (on the left side of the paper surface in FIG. 2) in the microchannel 14, and the downstream side is the particles in the microchannel 14. This is the side where the 40 and the liquid 41 flow out from the microchannel 14 (on the right side of the paper in FIG. 2). The liquid 41 is moved from the upstream side to the downstream side by a pump (not shown). Then, the particles 40 follow the liquid 41 and move from the upstream side to the downstream side.

The dielectrophoresis electrodes 16 to 23 are formed in the CMOS integrated circuit 10 so that the dielectrophoresis electrodes 16 to 23 are arranged in a sleeper shape and at least a part of the dielectrophoresis electrodes 16 to 23 is in contact with the microchannel 14. To. In other words, the dielectrophoresis electrodes 16 to 23 form the bottom surface of the substrate groove 12 forming the microchannel 14 (the surface of the substrate groove 12 facing the microfluidic system 11). The exposure of the dielectrophoresis electrodes 16 to 23 on the bottom surface of the substrate groove 12 may be a part of the dielectrophoresis electrodes 16 to 23 as shown in FIG. 1 (b). By providing the plurality of dielectrophoretic electrodes described above in the CMOS integrated circuit 10, the dielectrophoretic force applied to the particles can be improved, and the accuracy of separating the particles can be improved.

The dielectrophoresis electrodes 16 to 23 are connected to the signal source 38 via switch circuits 24 to 31, respectively. Then, the dielectrophoretic force is generated by applying the dielectrophoretic electrodes 16 to 23 by the signal source 38. The dielectrophoretic force is generated by forming a pair of dielectrophoretic electrodes using two dielectrophoretic electrodes. Therefore, for example, the dielectrophoretic electrode 16 and the dielectrophoretic electrode 17 may be combined to form a dielectrophoretic electrode pair 32 to generate a dielectrophoretic force. Similarly, by combining the dielectrophoresis electrode 18 and the dielectrophoresis electrode 19, the dielectrophoresis electrode pair 33, by combining the dielectrophoresis electrode 20 and the dielectrophoresis electrode 21, the dielectrophoresis electrode pair 34, or the dielectrophoresis electrode 22 and the dielectric A dielectrophoretic electrode pair 35 may be formed by combining with the dielectrophoretic electrode 23. By having a plurality of dielectrophoretic electrode pairs in this way, the dielectrophoretic force can be strengthened as compared with the case where one set of dielectrophoretic electrodes (one dielectrophoretic electrode pair) is used, and the particles can be more reliably obtained. Can be sorted. Further, since the dielectrophoresis electrodes 16 to 23 are connected to the signal source via the switch circuits 24 to 31, respectively, even when the target particles and the non-target particles are mixed, the switch circuits 24 to 24 to By switching 31, the dielectrophoretic force can be applied only to the target particles. As a result, individual particles can be reliably separated.

Further, as shown in FIG. 3, the dielectricing electrodes 16 to 23 include the distance from the surface of the CMOS integrated circuit 10 facing the microfluidic system 11 side to the microfluidic system 11, and the microfluidics of the dielectricing electrodes 16 to 23. It is preferable that the distances from the surface facing the system 11 to the microfluidic system 11 are substantially the same. In other words, as shown in FIG. 4, if the surface of the CMOS integrated circuit 10 facing the microfluidic system 11 side and the surface of the dielectrophoresis electrodes 16 to 23 facing the microfluidic system 11 should not be uneven. Good. Since the flow of the liquid 41 does not become non-uniform due to the unevenness, the flow of the liquid 41 can be made constant, and the efficiency of separating the particles 40 can be improved.

The passivation layer 15 is usually not particularly limited as long as it is made of a material conventionally used as a passivation layer. Further, the passivation layer 15 has a thickness of 1 μm or more. Therefore, in the microchannel 14, where the dielectrophoretic electrode and the passivation layer 15 are laminated, the passivation layer 15 blocks a part of the dielectrophoretic force emitted from the dielectrophoretic electrode, so that the dielectrophoretic force decreases. To do.

The substrate groove 12 forms a pad electrode using, for example, the outermost wiring layer. Then, the CMOS integrated circuit 10 can be formed by selectively etching the CMOS integrated circuit 10 along the shape of the substrate groove 12 by a lithography technique.

(Microfluidic system)
The microfluidic system 11 is not particularly limited, and is not particularly limited as long as the flow path groove 13 can be formed in the microfluidic system 11. The material forming the microfluidic system 11 may be, for example, polydimethylsiloxane (PMDS), which is a type of silicone rubber.

The flow path groove 13 can be formed, for example, by selectively etching the microfluidic system 11 by a lithography technique.

(Micro flow path)
The microchannel 14 is composed of a substrate groove 12 and a channel groove 13, and a front outlet 60 and a rear outlet 61 are formed on the downstream side of the dielectrophoresis electrodes 16 to 23. Then, in the microchannel 14, the particles 40 are separated by moving the particles 40 by the dielectrophoretic force generated from the dielectrophoretic electrodes 16 to 23 formed in the CMOS integrated circuit 10.

In the microchannels 14 shown in FIGS. 1 to 8, the liquid 41 flowing inside the microchannels 14 is a laminar flow in which viscosity is more dominant than inertia. Therefore, the flow of the liquid 41 passing above the micro flow path 14 on the upstream side (for example, above the paper surface in FIG. 3 and on the flow path groove 13 side) is offset forward to the upper layer at the branch between the front outlet 60 and the rear outlet 61. Flow to exit 60. Further, the flow of the liquid 41 passing below the micro flow path 14 on the upstream side (for example, below the paper surface in FIG. 3, on the substrate groove 12 side) is offset to the lower layer at the branch between the front outlet 60 and the rear outlet 61, and the rear outlet. Flow to 61.

[Separation by particle separator]
An example of sorting by the particle sorting device 1 will be described with reference to FIGS. 5 to 8.

As shown in FIGS. 5 to 7, a case where the target particle A50, the non-target particle 51, and the target particle B52 flow from upstream to downstream in the above-mentioned order will be described as an example. Then, a particle sorting device 1 that separates the CMOS integrated circuit 10 in a direction substantially perpendicular to the upper surface of the CMOS integrated circuit 10 will be described downstream. In the particle sorting device 1, the target particle A50, the non-target particle 51, and the target particle B52 have a flow structure that passes downward (on the substrate groove 12 side) in the microchannel 14 as an example. Further, the target particle A50 and the target particle B52 show a case where a marker by a fluorescent molecule is given, but the marker is not limited to the fluorescent molecule.

As shown in FIG. 8, first, it is determined whether or not the particle is the target particle (S101). In the determination of whether or not the particle is the target particle, for example, as shown in FIGS. 5 to 7, the particle is irradiated with the laser 2 to excite the fluorescent molecule imparted to the target particle as a marker, and the excited fluorescent molecule is photographed. Whether or not it is a target particle may be determined by measuring with a diode (first sensor) 36 and a photodiode (second sensor) 37. As long as the target particle can be determined, the determination mechanism is not particularly limited.

Then, as a result of the determination, when the measured particle is the non-target particle 51 (No. in S101), it is determined whether or not the other particles flowing through the liquid 41 (for example, the target particle B52) are the target particles. ..

In FIGS. 5 to 7, fluorescent molecules are not added to the non-target particles 51. Therefore, even when the unintended particles 51 are irradiated with the laser 2, the particles are not excited, and the photodiodes 36 and 37 do not detect (receive) fluorescence. Therefore, no signal is output from the photodiodes 36 and 37 toward the control device 39, and the dielectrophoretic force does not work on the dielectrophoretic electrode pairs 32 to 35. As a result, the unintended particles 51 move while flowing downward.

On the other hand, when the measured particle was the target particle A50 or the target particle B52 as a result of the determination (Yes in S101), it took time for the target particle A50 or the target particle B52 to pass through the photodiode 36 and the photodiode 37. Detect time (S102). Then, the speed at which the target particle A50 or the target particle B52 flows is calculated using the distance from the photodiode 36 to the photodiode 37 (S103).

Then, the time (timing) at which the target particles A50 and the target particles B52 arrive at the dielectrophoresis electrode pairs 32 to 36 (dielectrophoresis electrodes 16 to 23) is estimated from the calculated flow speeds of the target particles A50 and the target particles B52. (S104). Then, the control device 39 operates the switch circuits 24 to 31 at the timing when the target particles A50 and the target particles B52 arrive at the dielectrophoretic electrode pairs 32 to 35, and the AC voltage to be applied to the dielectrophoretic electrode pairs 32 to 35. give. As a result, a dielectrophoretic force is exerted on the target particles A50 and the target particles B52 (S105). As an example, when an AC voltage for exerting a negative dielectrophoretic force is applied to the target particle A50 and the target particle B52, the target particle A50 and the target particle B52 move away from the dielectrophoretic electrode pairs 32 to 35. Moving. In other words, as shown in FIG. 6, the target particles A50 and the target particles B52 move toward the flow path groove 13. In this way, by applying the dielectrophoretic force only to the target particles A50 and the target particles B52, only the target particles A50 and the target particles B52 can be reliably separated. Further, as shown in FIGS. 5 to 7, when the particles are a mixture of the target particles and the non-target particles such as the target particles A50, the non-target particles 51, and the target particles B52. However, by using the switch circuits 24 to 31, the accuracy of sorting can be improved.

Then, the target particles A50 and the target particles B52 are discharged from the front outlet 60 by the wall surface 62 that separates the front outlet 60 and the rear outlet 61. Further, the unintended particles 51 are not separated by the wall surface 62 and are discharged from the rear outlet 61. Thereby, the target particles A50 and the target particles B52 can be distinguished from the non-target particles 51. Further, by adding different markers to the target particles A50 and the target particles B52 and repeating the above-mentioned processes (S101 to S105), the accuracy of separating the target particles can be improved.

[Additional notes]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

1 Particle separation device 2 Laser 10 CMOS integrated circuit 11 Microfluidic system 12 Substrate groove 13 Channel groove 14 Microchannel 15 Passion layer 16, 17, 18, 19, 20, 21, 22, 23, 32 Dielectric migration electrode 24, 25, 26, 27, 28, 29, 30, 31 Switch circuit 32, 33, 34, 35 Dielectric electrode pair 36 photodiode (first sensor)
37 Photodiode (second sensor)
38 Signal source 39 Control device 40 Particle 41 Liquid 42 Insulating film 51 Non-target particle 60 Front outlet 61 Rear exit 62 Wall surface 50 Target particle A
51 Non-target particle 52 Target particle B

Claims (6)

A particle separation device including a flow path formed along a specific upper surface and a separation electrode for separating a plurality of particles in a direction substantially perpendicular to the upper surface by dielectrophoresis.
The particle separator includes a semiconductor substrate and includes a semiconductor substrate.
A groove is formed on the semiconductor substrate in the same direction as the flow path including the separation electrode.
A particle sorting device characterized in that the bottom surface of the groove is formed at the same height so as to coincide with the surface of the sorting electrode. The particle sorting apparatus according to claim 1, wherein one or more sets of the sorting electrodes are paired to form a sorting electrode pair, and a plurality of the sorting electrode pairs are arranged along the flow path. .. The particle sorting apparatus according to claim 1 or 2, further comprising a switch circuit corresponding to one or more sets of the sorting electrodes, and controlling the application of an AC voltage to the sorting electrodes by the switch circuit. It is characterized in that an AC voltage is applied to the sorting electrode by the switch circuit only when it is presumed that the particles are directly above the sorting electrode pair as the particles flow on the upper surface of the sorting electrode. The particle sorting apparatus according to claim 1 or 2. It has a plurality of photodiodes that receive light for individually distinguishing the plurality of particles, and the first particle in the plurality of particles is used for sorting by referring to the output signals of the plurality of photodiodes. The invention according to claim 1 or 2, further comprising a control unit that specifies the timing of passing over the electrodes and controls the period for driving the sorting electrode based on the specific result of the timing. Particle separator. The particle sorting apparatus according to claim 1 or 2, wherein the bottom surface of the groove is formed up to the surface on the photodiode and is formed at the same height.

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