CN114225979B

CN114225979B - Microfluidic device and microfluidic working system

Info

Publication number: CN114225979B
Application number: CN202111481920.6A
Authority: CN
Inventors: 段学欣; 李铁川; 李智伟; 刘雨暄
Original assignee: Tianjin University
Current assignee: Kangwosi (Tianjin) Biotechnology Co.,Ltd.
Priority date: 2021-12-06
Filing date: 2021-12-06
Publication date: 2023-02-21
Anticipated expiration: 2041-12-06
Also published as: CN114225979A

Abstract

The invention discloses a microfluidic device and a microfluidic working system. The microfluidic device mainly comprises: circuit bottom plate, miniflow channel base plate, detection chip, apron, locating pin, rotary valve, valve spanner and syringe. The invention adopts a rotation mode to switch the selection of the positioning pin, and then utilizes the valve slot structure to realize the rotation motion and simultaneously control the up-and-down motion of the positioning pin so as to realize the gating of a fluid channel, thereby realizing the multi-path switching under the driving of a single motor; the introduction of the ultrahigh frequency acoustic wave device can realize the intensive mixing of local samples, can prevent the particle solution from being blocked in a flow channel, ensures that the biochemical reaction is sufficient and the device has complete functions, and can integrate the functions of sample driving, mixing and switching control. The invention has the advantages of good sealing performance, smooth rotation, high repeated utilization rate, easy processing, low price, simple operation, easy combination with downstream biochemical analysis chips and the like, and has promotion significance for promoting the popularization and application of technologies such as gene analysis and the like.

Description

Microfluidic device and microfluidic working system

Technical Field

The invention relates to the technical field of microfluidics, in particular to a microfluidic device and a microfluidic working system.

Background

Due to the characteristics of high integration, automation and the like, the microfluidic chip technology is widely applied to the field of biomedicine, such as scenes of molecular diagnosis, protein detection and the like. Since this technology is a fluid fine manipulation technology, the importance of pump and valve systems is becoming more important, and is directly related to the portability, integration and automation of this microfluidic chip. In particular, a complete set of biochemical reactions, in particular nucleic acids or immunoassays, require multiple liquid handling steps, such as sample introduction, liquid exchange, mixing, dilution and detection. Therefore, the pump valve assembly is used for carrying out flow control on the sample, the reagent and the waste liquid according to the sample control requirement of the biochemical detection microfluidic chip. The pump valve assembly needs to meet the following requirements: 1) The processing is easy, and the industrial production requirements are met; 2) The integration degree is high, and the difficulty of chip combination is small; 3) Switching and diversion of different reagents can be realized; 4) The mechanical driving device is simple, and is easy to be instrumented and industrialized.

CN107096580A discloses a microfluidic chip with a rotary valve structure, which comprises a valve core, a substrate and a bottom sheet, wherein one surface of the substrate is attached to the bottom sheet, the other surface of the substrate is provided with a valve chamber and a flow channel, at least two valve chamber through holes are arranged in the valve chamber, each valve chamber through hole is respectively connected with the flow channel, and the substrate is also provided with an inlet and an outlet which are respectively connected with the flow channel; the valve core comprises a sealing layer and a supporting layer, the sealing layer is arranged in the valve cavity, the supporting layer is arranged on the sealing layer, and the sealing layer is provided with a conversion channel; when the supporting layer rotates, the sealing layer is driven to rotate, and the switching channel is communicated with the through holes of the at least two valve chambers.

CN110857743A discloses a liquid flow guide valve for a micro-fluidic chip and the micro-fluidic chip. Wherein, a liquid flow guide valve for a microfluidic chip comprises: the rotating piece is internally provided with a flow guide channel and a first flow guide hole and a second flow guide hole which correspond to the flow guide channel; the first flow guide hole is used for communicating the flow guide channel with a first liquid flow channel outside the rotating piece; the second diversion hole is used for communicating the diversion channel with a second liquid flow channel outside the rotating piece; and the positioning piece is used for limiting the rotating piece in the chip body and allowing the rotating piece to rotate relative to the chip body, so that the first flow guide holes can be selectively communicated with different first flow channels in the chip body, and the second flow guide holes are always communicated with the same second flow channel in the chip body.

CN 110075935A discloses a multi-index detection microfluidic cartridge and an application method, wherein, the cartridge comprises: the piston pump, the liquid storage pipe lid, the card box base, the apron, sealed the pad, gate valve and bottom plate, wherein, piston pump push-and-pull drive card box fluid, the rotatory runner that leads to of gate valve is connected, the liquid storage pipe storage reagent sample, the liquid storage pipe is sealed to the liquid storage pipe lid, each part is connected in the support of card box base, flow path pipeline and cavity on the sealed card box base of apron, sealed pad is sealed in the installation between card box base and gate valve, the bottom plate is through fixed the construction assembly gate valve at the card box base.

The problems of the three prior art schemes are as follows: (1) Since the above pump-valve system not only plays a role of guiding liquid but also plays a role of rotation, the rotary valve increases the difficulty of rotation on the premise of ensuring the liquid tightness. (2) The valve body assembly inside the device can directly contact with the sample, and the repeated utilization rate is low when the valve body assembly is used for biological detection.

Disclosure of Invention

In view of the above, the main objective of the present invention is to provide a microfluidic device and a microfluidic working system with good sealing performance, smooth rotation and high recycling rate.

In a first aspect the present invention provides a microfluidic device comprising: the micro-channel substrate 20, the detection chip 40 and the cover plate 50 are sequentially arranged from bottom to top in the longitudinal direction, wherein the micro-channel substrate 20, the detection chip 40 and the cover plate 50 are respectively provided with a central through hole and N reagent holes surrounding the central through hole, N is a positive integer, the ultrahigh frequency acoustic wave device 101 is arranged in the central position of the top surface of the circuit substrate 10, and the radio frequency connector 102 is arranged on the side surface of the circuit substrate 10; the micro-channel substrate 20 is made of an elastic material, and the top surface of the micro-channel substrate 20 further comprises a micro-channel outlet 204; the bottom surface of the micro flow channel substrate 20 is provided with a micro flow channel chamber 203, the micro flow channel chamber 203 comprises a central region 203a for substance mixing reaction, N +1 peripheral regions 203b for respectively communicating the N reagent holes and 1 micro flow channel outlet 204, and N +1 sections of micro flow channels 203c for respectively communicating the central region 203a and the N +1 peripheral regions 203b, the detection chip 40 further comprises N +1 positioning pin through holes 403 and a detection part 404, and the detection part 404 is connected with the micro flow channel outlet 204; n +1 positioning pins 60 disposed inside the N +1 positioning pin through holes 403, the positioning pins 60 having a height greater than the depth of the positioning pin through holes 403, the bottoms of the N +1 positioning pins 60 contacting the top of the microchannel substrate 20, and the N +1 positioning pins 60 being positioned in one-to-one correspondence with the N +1 microchannel 203 c; a rotary valve 70 disposed over the N +1 dowel pins 60, the rotary valve 70 having a gating notch 701 in a bottom surface thereof matching the top shape of the single dowel pin 60; a valve wrench 80 provided above the rotary valve 70; the injector 90, which penetrates the rotary valve 70 and the valve key 80, and penetrates the central through-holes of the micro flow channel substrate 20, the detection chip 40, and the cover plate 50, respectively, the bottom outlet of the injector 90 is aligned with the uhf device 101.

Optionally, the micro flow channel chamber 203 has micro pillars 205 distributed in an array inside.

Alternatively, the height of the microcolumn 205 located at the center of the central region 203a is smaller than the height of the microcolumn 205 located at the edge of the central region 203 a.

Optionally, the elastic material is one or a combination of more of the following materials: polydimethylsiloxane, polyurethane, silica gel.

Alternatively, the thickness of the micro flow channel substrate 20 is 0.5 to 5mm, or 1 to 2 mm.

Alternatively, the cross-sectional diameter of the locating pin 60 is 0.5 to 5 millimeters, alternatively 1 to 2 millimeters.

Optionally, the top of the locating pin 60 is hemispherical.

Optionally, the gating slot 701 is wedge-shaped.

Alternatively, the detection chip 40 is made of black polycarbonate.

Optionally, the method further comprises: a sealing layer 30 between the micro flow channel substrate 20 and the detection chip 40.

In a second aspect, the present invention provides a microfluidic working system including the microfluidic device disclosed herein.

In the technical scheme of the embodiment of the invention, the selection of the positioning pin is switched in a rotating mode, and then the valve slot structure is skillfully introduced to realize the rotating motion and simultaneously control the up-and-down motion of the positioning pin so as to realize the gating of a fluid channel, so that the multi-channel switching can be realized under the driving of a single motor. The introduction of the ultrahigh frequency acoustic wave device can realize strong mixing of local samples, prevent particle solution from being blocked in a flow channel, ensure that biochemical reaction is sufficient and the device has complete functions, and integrate the functions of sample driving, mixing and switching control. The microfluidic device provided by the embodiment of the invention also has the advantages of easiness in processing, low price, simplicity in operation, easiness in combination with a downstream biochemical analysis chip and the like, and has promotion significance for promoting popularization and application of technologies such as gene analysis and the like.

Drawings

For purposes of illustration and not limitation, the present invention will now be described in accordance with its preferred embodiments, particularly with reference to the accompanying drawings, wherein:

fig. 1 is an exploded schematic view of a microfluidic device according to an embodiment of the present invention;

FIG. 2 is a schematic assembled perspective view of a microfluidic device according to an embodiment of the present invention;

fig. 3 is a schematic diagram in top perspective of a microfluidic device according to an embodiment of the present invention;

fig. 4 is a schematic bottom perspective view of a microfluidic device according to an embodiment of the present invention;

FIG. 5 is a schematic perspective view of a micro flow channel substrate of a micro flow control device according to an embodiment of the present invention;

FIG. 6 is a schematic perspective view of a micro flow channel substrate of a micro flow control device according to an embodiment of the present invention;

FIG. 7 is a schematic bottom view of a micro flow channel substrate of a micro flow control device according to an embodiment of the present invention;

FIG. 8 is a schematic view of microcolumns of uniform height in a micro flow channel substrate of a micro flow control device according to an embodiment of the present invention;

FIG. 9 is a schematic view of a microcolumn having a step height in a micro flow channel substrate of a micro flow control device according to an embodiment of the present invention;

fig. 10 is a schematic perspective view of a sealing layer of a microfluidic device according to an embodiment of the present invention;

fig. 11 is a perspective schematic view of a detection chip of a microfluidic device according to an embodiment of the present invention;

fig. 12 is a schematic bottom view of a detection chip of a microfluidic device according to an embodiment of the present invention;

fig. 13 is a schematic perspective view of a cover plate of a microfluidic device according to an embodiment of the present invention;

fig. 14 is a schematic perspective view of a positioning pin of a microfluidic device according to an embodiment of the present invention;

fig. 15 is a schematic perspective view of a rotary valve of a microfluidic device according to an embodiment of the present invention;

fig. 16 is a schematic bottom view of a rotary valve of a microfluidic device according to an embodiment of the present invention;

fig. 17 is a perspective schematic view of a valve key of a microfluidic device according to an embodiment of the present invention;

fig. 18 is a schematic bottom view of a valve key of a microfluidic device according to an embodiment of the present invention;

fig. 19 is a schematic view of a partial assembly in a microfluidic device according to an embodiment of the present invention;

fig. 20 is a schematic cross-sectional perspective view of a microfluidic device according to an embodiment of the present invention;

fig. 21 is a schematic sectional elevation view corresponding to fig. 20.

In the figure:

a circuit substrate 10; an ultra-high frequency acoustic wave device 101; a radio frequency connector 102;

a micro flow channel substrate 20; a micro flow channel substrate central through-hole 201; micro flow channel substrate reagent wells 202; a microchannel chamber 203 (including a central reaction region 203a, a peripheral reservoir region 203b, and microchannels 203 c); a microchannel outlet 204; a microcolumn 205; a microcolumn 205-a located at the center of the central region 203 a; microcolumns 205-b located at the edge of the central region 203 a;

a sealing layer 30; a seal layer central through hole 301; sealing layer reagent wells 302; a locating pin through hole 303; an outlet via 304;

a detection chip 40; detecting a chip central through hole 401; detection chip reagent wells 402; a locating pin through hole 403; a detection unit 404;

a cover plate 50; a cover plate central through hole 501; a cover plate reagent well 502;

positioning pins 60; a locating pin 60-a located below the gate notch of the rotary valve; a positioning pin 60-b located below the position other than the gate notch of the rotary valve;

rotating the valve 70; a gating slot 701; the valve central through bore 702 is rotated;

a valve wrench 80; valve wrench central through hole 801;

an injector 90;

the bolt through hole 001.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments. It should be apparent that the described embodiments are only some of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without inventive step, shall fall within the scope of protection of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be taken as limiting the scope of the present invention.

As shown in fig. 1 to 19, the microfluidic device according to the embodiment of the present invention mainly includes: a circuit substrate 10, a micro flow channel substrate 20, a sealing layer 30 (optional), a detection chip 40, a cover plate 50, a positioning pin 60 rotary valve 70, a valve key 80, and an injector 90.

The circuit substrate 10, the micro flow channel substrate 20, the detection chip 40, and the cover plate 50 are sequentially disposed from bottom to top along the longitudinal direction. The structures of all layers can be fastened by means of bolt assemblies, external clamping assemblies or adhesives. In this embodiment, the circuit substrate 10, the micro flow channel substrate 20, the detection chip 40, and the cover plate 50 are provided with bolt through holes 001 at four corners, which can be used for inserting and fastening bolt members (the bolt members are not shown).

The circuit substrate 10 may be an EVB substrate or a PCB substrate. The circuit substrate 10 has an rf connector 102 on its side, which may be an SMA connector. The circuit substrate 10 has an ultra-high frequency acoustic wave device 101 at a central position of a top surface thereof. The uhf acoustic wave device 101 can generate acoustic field vortex, which has strong mixing effect, and its working principle can be referred to patent CN112410167A "solution sample processing apparatus, device and system and its use". The shape of the uhf acoustic wave device 101 is a regular pentagon in this embodiment, but this is by way of example only and not by way of limitation.

The micro flow channel substrate 20 is made of an elastic material. The micro flow channel substrate 20 has a micro flow channel substrate central through hole 201 and N micro flow channel substrate reagent holes 202 surrounding the micro flow channel substrate central through hole 201. The top surface of the microchannel substrate 20 also includes a microchannel outlet 204. The N is a positive integer and represents the maximum number of types of reaction reagents which can be accommodated, the application range of the device is narrow when the N is too small, the structure of the device is complex when the N is too large, and the preferable value range of the N is 3 to 11. In this embodiment N =5, but this is merely for convenience of example and not limitation.

The micro flow channel substrate 20 has a micro flow channel chamber 203 on the bottom surface. The shape of the micro flow channel chamber 203 can be flexibly set, and the micro flow channel chamber 203 includes a central region 203a for substance mixing reaction, N +1 peripheral regions 203b for respectively communicating the N reagent wells 202 and 1 micro flow channel outlet 204, and N +1 micro flow channels 203c for respectively communicating the central region 203a and the N +1 peripheral regions.

The detection chip 40 has a detection chip central through hole 401, and N detection chip reagent wells 402 surrounding the detection chip central through hole 401. Since the test chip 40 generally has a certain thickness, each test chip reagent well 402 actually corresponds to a reagent reservoir, and has a volume of the order of microliters (for example, the test chip reagent well 402 has a diameter of 3mm and a depth of 15 mm). If the reagent required in the application scene is in milliliter level, a catheter can be additionally arranged for extension.

The detection chip 40 further includes N +1 positioning pin through holes 403 and a detection portion 404, and the detection portion 404 is connected to the micro flow channel outlet 204.

The cover plate 50 has a cover plate central through hole 501 and N cover plate reagent holes 502 surrounding the cover plate central through hole. Note that, unlike the detection chip reagent well 402, the cover plate reagent well 502 does not serve as a reservoir. The cover plate reagent well 502 is only convenient for adding reagents to the detection chip reagent well 402. A conduit for expanding the reagent volume may also penetrate the cover plate reagent well 502 if necessary.

As can be seen from the drawings of the specification: the positions of the through holes of the micro flow channel substrate 20, the detection chip 40, and the cover plate 50 are uniformly arranged. Specifically, the center points of all the central through holes are aligned; the center points of the reagent wells in the respective layer structures are also aligned with each other.

The number of the positioning pins 60 is N + 1. The N +1 positioning pins 60 are disposed inside the N +1 positioning pin through holes 403. The height of the dowel pin 60 needs to be greater than the depth of the dowel pin through hole 403. The bottoms of the N +1 positioning pins 60 are in contact with the top of the microchannel substrate 20, and the positions of the N +1 positioning pins 60 correspond to the N +1 microchannels 203c one to one. In other words, the N +1 positioning pins are pressed above the N +1 micro flow paths 203c.

The rotary valve 70 is disposed over N +1 of the positioning pins 60, and the bottom surface of the rotary valve 70 has a gating notch 701 that matches the shape of the top of a single positioning pin 60. When the gate notch 701 of the rotary valve 70 is aligned with a certain positioning pin 60, the positioning pin 60 exerts a small pressure on the lower microchannel 203c, and the microchannel 203c is opened. When the other position of the rotary valve 70 is aligned with a certain positioning pin 60, the positioning pin 60 exerts a large pressure on the lower microchannel 203c, and the microchannel 203c is closed.

A valve key 80 is provided above the rotary valve 70 for controlling the rotary valve 70 to rotate about its central axis in a horizontal plane using a lever principle.

The syringe 90 penetrates the rotary valve 70 and the valve wrench 80, and penetrates the central through-hole of each of the micro flow channel substrate 20, the detection chip 40, and the cover plate 50. The bottom outlet of injector 90 is aligned with the uhf acoustic wave device 101. Since the injector 90 is inserted all the way from the top of the device into the p microchannel substrate 20 and over the uhf acoustic device 101, it can communicate with each channel.

The operation of the microfluidic device is substantially as follows: first, the entire device is screwed down by four studs (not shown), and since the length of the positioning pin 60 is greater than the depth of the positioning pin through hole 403, after the studs are screwed down, the positioning pin 60 presses the micro flow channel substrate 20 to deform the middle portion thereof, thereby closing the flow channel and functioning as a "valve". The sample can flow because the rotary valve 70 has the gating notch 701 to make a certain positioning pin 60 bounce, i.e. the "valve" of the flow channel corresponding to the positioning pin 60 is opened. By rotating the rotary valve 70, flow switching of the flow channel sample can be achieved. Then, the rf adapter 102 receives a high frequency signal from an external signal generator, and then transmits the high frequency signal to the uhf acoustic wave device 101, so that the uhf acoustic wave device 101 vibrates, and then drives the sample inside the microchannel substrate 20 to vibrate, thereby generating a substance mixing effect. Finally, after the sample reaction is finished, the position of the rotary valve 70 may be set to open the flow channel corresponding to the micro flow channel outlet 204, and at this time, the injector 90 may be pushed to make the reaction end product flow out of the micro flow channel outlet 204 and enter the detection portion 404 of the detection chip 40 for detection. From the above, the syringe 90 provides the function of a pump, the vhf device 101 provides the function of a mixer, and the rotary valve 70 functions as a liquid change valve.

Because the microfluidic substrate is made of an elastic material, a local position of the microfluidic substrate can be obviously/slightly deformed under larger/smaller pressure, so that a microfluidic channel at the local position is closed/unblocked. The pressure distribution above the microfluidic substrate can be controlled by controlling the specific gating condition of the rotary valve in the microfluidic device, so that the on-off of different micro-channels in the micro-channel chamber can be controlled. Since the rotary valve is completely separated from the microchannel chamber at the bottom of the microfluidic substrate by the top of the microfluidic substrate, the reactant does not flow through the rotary valve. Therefore, the microfluidic device provided by the embodiment of the invention can overcome the technical defects in the prior art in the background art, a complex valve body sealing component is not needed, the microfluidic device also has good sealing performance, and the rotary valve can smoothly rotate with low resistance and can be repeatedly used.

The microfluidic device provided by the embodiment of the invention adopts a rotating mode to switch the selection of the positioning pin, and then the valve slot structure is skillfully introduced to realize the rotating motion and control the up-and-down motion of the positioning pin so as to realize the gating of a fluid channel, so that the multi-path switching can be realized under the driving of a single motor. The introduction of the ultrahigh frequency acoustic wave device can realize strong mixing of local samples, prevent particle solution from being blocked in a flow channel, ensure that biochemical reaction is sufficient and the device has complete functions, and integrate the functions of sample driving, mixing and switching control. The microfluidic device provided by the embodiment of the invention also has the advantages of easiness in processing, low price, simplicity in operation, easiness in combination with a downstream biochemical analysis chip and the like, and has promotion significance for promotion and application of technologies such as gene analysis and the like.

Preferably, the micro flow channel chamber 203 has micro pillars 205 distributed in an array inside. In the case of providing the microcolumn 205, the flow channel of the micro flow channel chamber 203 is reduced in average height, has a narrow volume, and is easy to be locally locked, and different regions are not easy to have spatial communication, so that the cross flow of the reagent liquid can be reduced. In addition, the microcolumn 205 plays a supporting role, so that the micro flow channel chamber 203 is not easy to collapse and has certain mechanical strength. In some applications where the reactant includes microspheres, the microcolumn 205 may also serve to prevent the microspheres from running off and to confine the microspheres to the central region 203 a. However, in other application scenarios, the micro-column 205 is not necessary, for example, when the microsphere is made of a magnetic material, a magnet may be disposed below to adsorb and fix the microsphere, and the micro-column 205 is not required to limit the moving range of the microsphere.

In the application scene of nucleic acid detection and the like, the particle size of the microsphere can be selected from 20 micrometers to 100 micrometers, preferably from 20 micrometers to 30 micrometers, and the specific surface area of the microsphere in the size range is larger, so that the microsphere can carry more nucleic acid adsorption groups. At the moment, the height of the inner ring of the microcolumn and the flow channel needs to be set below 20 micrometers so as to avoid the loss of the microspheres, and the height of the flow channel of the microcolumn and the outer ring can be above 100 micrometers. The size range of the microspheres is not easy to be too small, otherwise, the defects of high processing difficulty, high flow resistance, easy blockage and the like of the flow channel are caused.

The plurality of microcolumns 205 distributed in the array may be of uniform height, as shown in fig. 8, which is a design that is easy to manufacture.

The plurality of micropillars 205 distributed in the array may also have a step height, as shown in fig. 9, the height of the micropillar 205-a located at the center of the central region 203a is smaller than the height of the micropillar 205-b located at the edge of the central region 203 a. The design is favorable for reducing the flow resistance.

The elastic material for manufacturing the micro flow channel substrate 20 may be one or a combination of more than one of the following materials: polydimethylsiloxane, polyurethane, silica gel. Polydimethylsiloxane (PDMS) is preferably adopted, and the material is a high-molecular organic silicon compound, has high light transmittance, low cost, simple processing, good biocompatibility and good adhesion with a silicon wafer, and is widely applied to the field of microfluidics.

The micro flow channel substrate 20 has a thickness of 0.5 to 5 mm. The thickness is too thick, and the micro flow path 203c is not easily closed, so that micro flow control cannot be realized; the thickness is too thin, the substrate is too soft and the micro flow channel chamber 203 is liable to collapse or clog. When the micro flow channel substrate 20 is made of PDMS, the optimum thickness is 1 to 2 mm.

To make the rotation process of the rotary valve 70 smoother, the top of the positioning pin 60 may be provided in a hemispherical shape, and/or the gating notch 701 of the rotary valve 70 may be provided in a wedge shape.

The cross-sectional diameter of the positioning pin 60 may be 0.5 to 5mm, preferably 1 to 2 mm. The diameter of the positioning pin 60 should not be too thin, and the positioning pin is too thin and needle-shaped, so that the micro-channel substrate made of the elastic material is easily damaged; the diameter of the positioning pin 60 is not too thick, too thick would occupy too much space, and it is not easy to expand multi-sample switching, and it too much covers the part of the micro flow channel substrate other than the micro flow channel, and it is not easy to completely close the fine micro flow channel.

The detecting chip 40 may be made of a high molecular hard material or a metal material, and is preferably made of black Polycarbonate (PC). The black PC has good rigidity, is not easy to deform, has certain heat resistance and small fluorescence interference, and can be used for quantitative fluorescence PCR and other fluorescence detection.

The microfluidic device may further include a sealing layer 30 between the microchannel substrate 20 and the detection chip 40. Sealing layer 30 may be a double sided tape or the like, which acts to prevent leakage. The sealing layer 30 comprises a sealing layer central through hole 301, N sealing layer reagent holes 302, N +1 positioning pin through holes 303 and 1 outlet via hole 304. The outlet via hole 304 is used to communicate the microchannel outlet 204 on the microchannel substrate 20 with the detection unit 404 on the detection chip 40.

To make it better understood by those skilled in the art, the following describes both the case where the flow path is clear and the case where the flow path is blocked, in conjunction with fig. 20 and 21. In fig. 20 and 21, a piston inside the syringe 90 is omitted and a rear portion of the syringe 90 is simplified. As shown, the detent pin 60-a is located below the gate notch of the rotary valve and its corresponding flow path is clear; the detent pin 60-b is located below the rotary valve at a position other than the gate notch and its corresponding flow path is blocked.

An example of nucleic acid detection using a microfluidic device according to an embodiment of the present invention will be described in detail below.

Firstly, after the whole microfluidic device is assembled, a sample to be detected (blood, serum, nasopharyngeal swab, urine, etc.), lysis solution, cleaning solution 1, cleaning solution 2, and eluent with a micro-upgrade volume are sequentially added into 5 detection chip reagent wells (equivalent to 5 reagent wells, respectively). Polystyrene microspheres with nucleic acid adsorption functional groups with hydroxyl groups are preset in an injector and then inserted into central through holes of all structural layers of the whole device until the polystyrene microspheres reach the upper part of the ultrahigh frequency acoustic wave device. The rotary valve spanner makes the gating notch of rotary valve aim at the detection chip reagent hole of waiting to call, this moment because the microchannel base plate has elastic film, the locating pin bounces and arrives selection notch department, the passageway of sample cell is opened, the pull syringe makes the sample that awaits measuring get into in the syringe, rotary wedge valve spanner makes rotary valve wedge gating notch aim at lysate stock solution hole, lysate stock solution hole corresponds the locating pin and bounces, the passageway is opened, the pull syringe draws the lysate into in the syringe, open the hyperfrequency acoustic wave device, produce strong vortex, with the polystyrene microballon, sample and lysate mix 10 minutes, treat when nucleic acid adsorbs on the microballon, the syringe pushes out the waste liquid and gets into lysate stock solution hole, because the runner is internal to block at the microcolumn, consequently, inject the microballon in the central zone of microchannel chamber. And continuously rotating the valve wrench to enable the gating notch of the rotary valve to be aligned with the liquid storage hole of the cleaning liquid 1, bouncing the liquid storage hole of the cleaning liquid 1 corresponding to the positioning pin, opening the passage, drawing the cracking liquid into the injector by the drawing injector, starting the ultrahigh frequency acoustic wave device, generating strong vortex to clean impurities on the microsphere, and pushing out waste liquid in the injector after 30 seconds. And continuously rotating the valve wrench to enable the gating notch of the rotary valve to be aligned with the liquid storage hole of the cleaning liquid 2, enabling the liquid storage hole of the cleaning liquid 2 to be corresponding to the positioning pin to bounce, opening the passage, pulling the pyrolysis liquid into the injector by the drawing injector, opening the ultrahigh frequency acoustic wave device, generating strong vortex, cleaning impurities on the microsphere and the residue of the cleaning liquid 1, and pushing out the waste liquid in the injector after 30 seconds. Continue the rotary valve spanner and make rotary valve gating notch to eluant liquid storage hole, eluant liquid storage hole corresponds the locating pin and bounces, the passageway is opened, the pull syringe draws in the lysate into the syringe, open hyperfrequency acoustic wave device, produce strong vortex, mix microballon and eluant and make nucleic acid desorb from the microballon and get into the eluant, after 5 minutes, the rotary valve spanner makes rotary valve gating notch aim at the miniflow channel export, the locating pin that this miniflow channel export corresponds bounces, the passageway is opened, the eluant outflow miniflow channel export of nucleic acid in the syringe and push in detecting the chip runner, then the rotary valve spanner makes rotary valve gating notch no longer aim at the miniflow channel export can. The nucleic acid sample is stored in the flow channel of the detection chip, primer probes and the like are preset in the flow channel of the detection chip, and the flow channel part of the detection chip is arranged above the temperature changing device, so that the nucleic acid amplification can be carried out, and the aim of molecular diagnosis is fulfilled.

In conclusion, the microfluidic device and the system with the same have the advantages of simplicity and convenience in operation and the like.

The above-described embodiments should not be construed as limiting the scope of the invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions can occur, depending on design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A microfluidic device, comprising:

the device comprises a circuit bottom plate (10), a micro-channel substrate (20), a detection chip (40) and a cover plate (50) which are sequentially arranged from bottom to top in the longitudinal direction, wherein the micro-channel substrate (20), the detection chip (40) and the cover plate (50) are respectively provided with a central through hole and N reagent holes surrounding the central through hole, N is a positive integer, an ultrahigh frequency acoustic wave device (101) is arranged in the central position of the top surface of the circuit bottom plate (10), and a radio frequency connector (102) is arranged on the side surface of the circuit bottom plate (10); the micro-channel substrate (20) is made of elastic materials, and the top surface of the micro-channel substrate (20) also comprises a micro-channel outlet (204); the bottom surface of the micro-channel substrate (20) is provided with a micro-channel chamber (203), the micro-channel chamber (203) comprises a central area (203 a) for substance mixing reaction, N +1 peripheral areas (203 b) for respectively communicating the N reagent holes and 1 micro-channel outlet (204), and N +1 sections of micro-channels (203 c) for respectively communicating the central area (203 a) and the N +1 peripheral areas (203 b), the detection chip (40) further comprises N +1 positioning pin through holes (403) and a detection part (404), and the detection part (404) is connected with the micro-channel outlet (204);

n +1 positioning pins (60) arranged in the N +1 positioning pin through holes (403), wherein the height of each positioning pin (60) is greater than the depth of each positioning pin through hole (403), the bottoms of the N +1 positioning pins (60) are in contact with the top of the micro flow channel substrate (20), and the positions of the N +1 positioning pins (60) correspond to the positions of the N +1 micro flow channels (203 c) one by one;

a rotary valve (70) disposed over N +1 locating pins (60), the rotary valve (70) having a gating notch (701) on a bottom surface thereof that matches a top shape of a single locating pin (60);

a valve wrench (80) disposed over the rotary valve (70);

an injector (90) penetrating through the rotary valve (70) and the valve wrench (80) and through the central through holes of the micro flow channel substrate (20), the detection chip (40) and the cover plate (50), wherein the bottom outlet of the injector (90) is aligned with the UHF device (101).

2. The microfluidic device according to claim 1, wherein the micro flow channel chamber (203) has micro pillars (205) distributed in an array inside.

3. The microfluidic device according to claim 2, wherein the height of the micro-pillars (205) located at the center of the central region (203 a) is smaller than the height of the micro-pillars (205) located at the edges of the central region (203 a).

4. The microfluidic device according to claim 1, wherein the elastic material is one or a combination of more of the following materials: polydimethylsiloxane, polyurethane, silica gel.

5. The microfluidic device according to claim 1, wherein the thickness of the microchannel substrate (20) is 0.5 to 5 mm.

6. Microfluidic device according to claim 1, characterized in that the positioning pins (60) have a cross-sectional diameter of 0.5 to 5 mm.

7. Microfluidic device according to claim 1, characterized in that the top of the positioning pin (60) is hemispherical.

8. The microfluidic device according to claim 1, wherein the gating slot (701) is wedge-shaped.

9. The microfluidic device according to claim 1, wherein the detection chip (40) is made of black polycarbonate.

10. The microfluidic device according to claim 1, further comprising: and a sealing layer (30) located between the micro flow channel substrate (20) and the detection chip (40).

11. A microfluidic working system comprising a microfluidic device according to any one of claims 1 to 10.