CN211274689U

CN211274689U - Micro-fluidic chip for preventing liquid leakage

Info

Publication number: CN211274689U
Application number: CN201921749636.0U
Authority: CN
Inventors: 张歆; 王毅; 张莉
Original assignee: Leadway HK Ltd
Current assignee: Leadway HK Ltd
Priority date: 2019-10-18
Filing date: 2019-10-18
Publication date: 2020-08-18
Anticipated expiration: 2029-10-18

Abstract

The utility model provides a prevent micro-fluidic chip of liquid seepage has a reservoir, is equipped with through hole one in the reservoir, and an opening of perforation one is located the internal surface of reservoir. An opening of the first through hole is formed in the liquid storage tank, and liquid directly flows out through the first through hole, so that the sealing liquid is prevented from leaking from a sealing part of the liquid storage tank. Meanwhile, the design can reduce the requirement on machining precision, save cost and the like.

Description

Micro-fluidic chip for preventing liquid leakage

Technical Field

The utility model belongs to the technical field of medical diagnosis class article, a prevent micro-fluidic chip of liquid seepage is related to.

Background

In the field of biomedical analysis and disease diagnosis, the development of the portable-of-care testing (POCT) industry is promoted by the advent of microfluidic technology. In the prior POCT equipment, liquid such as calibration liquid, detection reagent and the like is externally arranged in the equipment, so that the problems of large volume, complex pipeline, difficult maintenance, easy pollution and the like of the detection equipment are caused. Due to the characteristics of the detection principle, the conventional POCT product is difficult to realize simultaneous detection of multiple indexes while performing rapid and accurate quantitative analysis, so that the consumption and human errors of a sample to be detected are increased. On the contrary, the microfluidic detection technology has the greatest advantage that the full-automatic rapid detection of multiple indexes can be simultaneously carried out under the condition of microliter-level blood sample consumption, and an accurate result can be obtained. Meanwhile, the microfluidic chip with the square centimeter size can contain all functional units of conventional laboratories such as quantitative sample introduction, mixing, reaction, calibration, reagent storage, detection, waste liquid collection and the like.

Fluid control is the core of microfluidic chip design, and all functions of the microfluidic chip are realized by the unique design of microstructures and microchannel networks. The micro liquid storage device containing the reagent is arranged in the chip through ingenious design, liquid medicine can be released on time through simple, convenient and safe operation in the running process of the chip, and the adverse phenomena of liquid leakage, air bubbles and the like are avoided, so that the difficulty of product research and development is always high. In patent US5096669A, the chip is assembled by an upper and a lower layers of plates and a middle layer of double-sided adhesive layer, wherein the upper and the lower layers of plates are provided with liquid storage bag grooves and microchannels; the double-sided adhesive layer is provided with a structure of micro-channels and through holes. After the liquid storage bag is punctured by the extrusion, reagent gets into the passageway in the liquid storage bag groove of lower floor's plate, after through the through-hole on the double faced adhesive tape, reaches the passageway between double faced adhesive tape and the upper plate spare, flows into the electrode detection area in the extrusion process. This kind of design needs to carry out the microchannel to two-layer plate about to and matches the design, needs the machining precision height to plate about will two moulds make respectively. Therefore, the chip structure is complex, the structure of the two layers of plates and the double-sided adhesive tape need to be precisely cut, and the cost is increased. In addition, the requirement on the alignment assembly precision of the three-layer structure is high, and efficient production is not facilitated, so that the probability of processing defective products is increased. In patent US7842234B, built-in stock solution bag contains the micro valve, and the area makes the valve open in the valve need be squeezed earlier before releasing reagent, extrudees stock solution bag body release reagent again, and this micro valve design has increased the degree of difficulty and the expense of processing, and complicated operation has also increased the risk that detects the failure simultaneously.

SUMMERY OF THE UTILITY MODEL

Under the prerequisite of guaranteeing detection effect, in order to reduce the chip preparation degree of difficulty, simplify production technology, the utility model provides a prevent micro-fluidic chip for detecting analyte of liquid seepage, specific be:

a microfluidic chip for preventing liquid leakage includes a chip main body, a sealing plate, and a sensor for detecting an analyte; the chip main body is divided into a front surface and a back surface, and an injection port, a liquid storage tank and a micro-channel groove positioned on the surface of the chip main body are distributed on the chip main body; the opening of the micro-channel groove is sealed by the sealing plate in a watertight manner to form a micro-channel, the micro-channel comprises a main micro-channel, the chip main body is provided with a detection area, the sensor is positioned in the detection area, and the main micro-channel passes through the detection area and is in contact with a detection part which is arranged on the sensor and used for detecting an analyte; the injection port is communicated with the microchannel, so that the liquid injected into the injection port flows into the main microchannel; the liquid storage tank is provided with an opening which is sealed by a sealing member in a water-tight manner; and a first through hole is arranged in the liquid storage tank, one opening of the first through hole is positioned on the inner surface of the liquid storage tank, and the other opening of the first through hole is communicated with the micro-channel, so that the liquid in the liquid storage tank flows into the main micro-channel.

Preferably, the seal comprises a gland and/or a reservoir.

Preferably, the sealing member comprises the gland and the reservoir, the gland fixing the reservoir within the reservoir.

Preferably, the gland comprises a pressure plate with an opening in the middle and a side plate; the bottom edge of curb plate is followed the interior border of the opening of clamp plate encircles the setting to the slope is inside, but does not seal the opening of clamp plate.

Preferably, the reservoir includes bottom platform, reservoir lateral wall and marginal platform, marginal platform is located the top of bottom platform, the outer border of bottom platform with the inner border of marginal platform passes through the reservoir lateral wall is connected, the wall slope of reservoir lateral wall is up.

Preferably, an opening of the first through-hole is located on the edge platform, or on the side wall of the reservoir, or on the bottom platform.

Preferably, the micro flow channel comprises the main micro flow channel and a branch micro flow channel; the other opening of the first through hole and the injection port are respectively communicated with the main micro-channel through the branch micro-channel.

Preferably, the other opening of the first through hole and the branch micro channel connected with the first through hole are positioned on the reverse side of the chip main body; a second through hole is formed in the chip main body; the branch micro-flow channel is communicated with the main micro-flow channel positioned on the front surface of the chip main body through the second through hole.

Preferably, the inner surface of the liquid storage tank is provided with a diversion trench for guiding liquid, and the diversion trench is connected with the first through hole.

Preferably, the chip main body is provided with a hydrophobic waste liquid tank, the waste liquid tank is communicated with the main micro flow channel, and the tail end of the waste liquid tank is provided with an air-permeable but water-impermeable air-permeable channel.

Preferably, the air-permeable passage is a hydrophobic air-permeable flow passage, the tail end of the waste liquid tank is connected with one end of the air-permeable flow passage, the other end of the air-permeable flow passage is communicated with the outside atmosphere, and the sectional area of the air-permeable flow passage is not more than 1mm²。

Preferably, the air-permeable passage comprises an air-permeable groove and an air-permeable but water-impermeable air-permeable membrane; the tail end of the waste liquid tank is communicated with the ventilation groove, the edge of the tail end of the waste liquid tank is positioned in the ventilation groove, and the depth of the tail end of the waste liquid tank is greater than that of the ventilation groove; the bottom of the air-permeable groove is covered with the air-permeable film, the air-permeable film completely covers the tail end of the waste liquid groove, the air-permeable film is covered with the sealing plate, the sealing plate is provided with air-permeable holes, and the positions of the air-permeable holes correspond to those of the air-permeable groove, so that the air in the waste liquid groove can enter the external atmosphere through the air-permeable film.

Another microfluidic chip for detecting an analyte includes a chip body, a sealing plate, a pressing cover, and a sensor for detecting an analyte; an injection port, a liquid storage tank, a waste liquid tank and a micro-channel groove positioned on the surface are distributed on the chip main body; the micro-channel grooves are distributed on the front surface and the back surface of the chip main body, the openings of the micro-channel grooves are sealed by the sealing plate in a water-tight manner to form micro-channels, and the micro-channels distributed on the front surface of the chip main body are communicated with the micro-channels distributed on the back surface of the chip main body through the through holes; the micro-channel is divided into a branch micro-channel and a main micro-channel; the injection port and the liquid storage tank are respectively communicated with one end of the main micro-channel through the branch micro-channel, and the other end of the main micro-channel is communicated with one end of the waste liquid tank; the detection zone area of the sensor for detecting the analyte is exposed in the main micro-flow channel; the inner surface of the liquid storage tank is provided with a diversion trench for diversion of liquid, one end of the diversion trench is close to the edge of the liquid storage tank and is communicated with the branch micro-channel positioned on the other side of the chip main body through the through hole, and the gland covers the through hole positioned in the liquid storage tank.

Preferably, a reservoir bag capable of being crushed is included; the liquid storage cover covers the liquid storage tank.

Preferably, a puncture needle is arranged in the liquid storage tank, the puncture needle is positioned below the liquid storage bag, and the puncture needle is communicated with the diversion trench.

Preferably, be equipped with the detection groove in the main microchannel, the detection groove link up the chip main part is being equipped with the opposite face of main microchannel is installed the sensor, the water proofness of sensor covers the detection groove, and the electrode zone is located detect the inslot.

Preferably, be equipped with a contact groove in the chip main part, the contact groove link up the chip main part, the one side in contact groove by sensor water-tightness covers, the another side in contact groove does not have the cover, the contact of sensor is located the contact inslot, the contact groove not with arbitrary recess and the miniflow channel intercommunication in the chip main part.

Preferably, the other end of the main micro flow channel is communicated with one end of the waste liquid tank, and the waste liquid tank is communicated with an air-permeable channel which is air-permeable but not liquid-permeable.

A method of making a microfluidic chip:

step 1, selecting a hydrophobic material as a substrate, and forming a structure such as a micro-channel groove, a liquid storage tank, a through hole, an injection port and the like on a chip main body through etching, carving, hot pressing or injection molding;

specifically, the micro-channel groove comprises a main micro-channel groove, the through hole comprises a first through hole, the first through hole is arranged in the liquid storage tank, one opening of the first through hole is positioned on the inner surface of the liquid storage tank, and the other opening of the first through hole is communicated with the micro-channel groove, so that liquid in the liquid storage tank flows into the main micro-channel groove; the injection port is communicated with the micro-channel groove, so that the liquid injected into the injection port flows into the main micro-channel groove;

step 2, obtaining a sensor, and sticking the sensor on the surface of the chip main body to enable a detection area of the sensor to be positioned in the groove of the main micro-channel;

step 3, obtaining a sealing plate, covering the micro-channel groove on the surface of the chip main body with the sealing plate in a water-tight manner, and forming a micro-channel after the opening of the micro-channel groove is closed;

and 4, obtaining a gland, and covering the opening of the liquid storage tank with the gland in a watertight manner.

And finally obtaining the microfluid detection chip for detection by the method of the step 1-4. On the premise of no contradiction, the sequence of steps 2-4 can be adjusted.

Preferably, in step 1, a diversion trench for diversion of liquid is formed on the inner surface of the liquid storage tank, and one end of the diversion trench is connected with the first through hole.

Preferably, in step 4, a liquid storage bag and a gland are obtained, the liquid storage bag is fixed in the liquid storage tank, and then the gland is used for covering the opening of the liquid storage tank in a watertight manner.

Preferably, in step 1, a puncture needle is prepared on the inner surface of the reservoir, and the puncture needle is positioned below the reservoir bag.

Preferably, in step 1, the puncture needle is communicated with the first through hole through the diversion trench.

Preferably, in step 1, the chip main body is divided into a front surface and a back surface, and the micro-channel groove further comprises a sub-micro-channel groove; the branch micro-channel groove is positioned on the back side of the chip main body, and the main micro-channel groove is positioned on the front side of the chip main body; the diversion trench is communicated with the branch micro-channel groove through the first through hole, the branch micro-channel groove is communicated with the main micro-channel groove through the second through hole, and the second through hole is positioned outside the liquid storage tank.

Preferably, in step 1, the reservoir includes bottom platform, reservoir lateral wall and marginal platform, marginal platform is located the top of bottom platform, the outer fringe of bottom platform with the inner fringe of marginal platform passes through the reservoir lateral wall is connected, the slope of reservoir lateral wall is upwards.

Preferably, in step 1, one end of the guiding groove is disposed on the bottom platform, the other end of the guiding groove is disposed on the edge platform, one end of the through hole is opened on the edge platform, and in step 4, the through hole is covered by the gland.

Preferably, in step 4, the pressing cover comprises a pressing plate and a side plate with an opening in the middle; the bottom edge of curb plate is followed the interior border of the opening of clamp plate encircles the setting to the slope is inside, but does not seal the opening of clamp plate.

Preferably, in step 1, the bottom platform protrudes from the opposite side of the chip body.

Preferably, in step 1, a hydrophobic waste liquid tank is arranged on the chip main body, the waste liquid tank is communicated with the main micro-groove, and an air-permeable but water-impermeable air-permeable passage is arranged at the tail end of the waste liquid tank.

Preferably, in step 1, the chip main body is made of a hydrophobic material, and in step 3, a covering surface of the sealing plate covering the back surface of the chip main body is hydrophobic, and a covering surface of the sealing plate covering the front surface of the chip main body is hydrophilic.

Compared with the prior art, the utility model discloses following beneficial effect has:

1. micro channels are distributed on the front surface and the back surface of the same substrate, so that the size of the chip is reduced and the assembly step is facilitated;

2. an opening of the through hole is arranged in the liquid storage tank, and liquid directly flows out through the through hole, so that the liquid is prevented from leaking from the sealing position of the liquid storage tank;

3. when the liquid in the liquid storage tank flows to the edge of the liquid storage tank, the liquid flows into the micro-channel on the other side through the through hole opening of the surface platform, and the liquid is prevented from flowing through the gap and then seeping out;

4. the design of the breathable film at the tail end of the waste liquid tank prevents the waste liquid from flowing out, thereby avoiding the problem of waste liquid pollution.

Drawings

FIG. 1 is a schematic structural diagram of a microfluidic chip in one embodiment;

FIG. 2 is a schematic diagram of a gland in one embodiment;

FIG. 3 is a schematic perspective view of the front side of a chip body in an embodiment, in which micro flow channels on the back side of the chip body are shown in dotted lines;

FIG. 4 is a schematic structural diagram of the front side of the chip main body in FIG. 3;

FIG. 5-a is a schematic view of a partial cross section taken along the opposite side of A-A in FIG. 4, FIGS. 5-b and 5-c are schematic views of the edge of the gland contacting the grooves of the micro flow channels, and FIGS. 5-d, 5-e and 5-f are schematic views of the liquid reservoir portion in one embodiment, respectively;

FIG. 6 is a schematic view of the reverse side of the chip body of FIG. 3;

FIG. 7 is a schematic diagram of the structure of the reverse side of the chip body in one embodiment;

FIG. 8 is a schematic view showing the structure of a combination of a chip main body with a gas permeable membrane and a sealing plate in one embodiment;

FIG. 9 is a schematic sectional view of the portion of the ventilation channel of FIG. 8;

fig. 10-a and 10-b are schematic views of the sealing region formed between the sealing member and the reservoir.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the specific embodiments and the accompanying drawings. However, the embodiments described below are only a part of the embodiments of the present invention. According to the technical idea of the present invention, the following embodiments extending from any technical solution or the combination thereof all belong to the protection scope of the present invention.

Unless otherwise specified, the terms "upper", "lower", "left", "right", and the like in the following may be relative to each other and not absolute spatial positions.

Some phrases in the present invention are explained below:

the micro flow channel means that when the width or the depth of the flow channel reaches a certain millimeter or micron scale, the flow of the fluid in the flow channel is mainly influenced by interfacial tension;

the hydrophilic micro-channel refers to a hydrophilic micro-channel, and liquid capable of being fused with water flows forwards or has a forward flow tendency under the pulling of interfacial tension in the micro-channel;

the hydrophobic micro-channel refers to a hydrophobic micro-channel, and the liquid which can be fused with water in the micro-channel is dragged by interfacial tension, so that the flow of the liquid is hindered;

the through hole in the utility model is a hole which runs through the front and back surfaces of the chip main body except for special description, but for the through hole in the liquid storage tank, one opening is positioned on the inner surface of the liquid storage tank, and the other opening is positioned on the front surface (as shown in figure 5-d) or the back surface (as shown in figure 5-a, figure 5-e and figure 5-f) of the chip main body except the liquid storage tank;

the surface of the chip main body refers to an outer layer of the concave-convex structure of the chip main body and comprises the inner surface and the outer surface of the liquid storage tank;

the surface of the chip main body is divided into a front surface, a back surface and a side surface surrounding the chip main body, and the front surface of the chip main body is the surface shown in FIG. 4;

the inner surface of the reservoir is the surface shown by the reservoir in fig. 4, and the outer surface of the reservoir is the surface shown by the reservoir in fig. 6;

as shown in fig. 10-a and 10-b, the interior surface of the sump contacts and seals with the lower surface of the seal to form a seal area 1251, an outer boundary line around the seal area 1251 being an outer boundary 12511 corresponding to the outer boundary line around the lower surface of the seal, and an inner boundary line around the seal area 1251 being an inner boundary 12512.

The utility model provides a micro-fluidic chip for detecting analytes, which comprises a chip main body 1, a sealing plate and a sensor 4 for detecting analytes; the chip main body 1 is divided into a front surface and a back surface, and an injection port 13, a liquid storage tank 121 and a micro-channel groove positioned on the surface of the chip main body 1 are distributed on the chip main body 1; the opening of the micro-channel groove is sealed by the sealing plate in a water-tight manner to form a micro-channel.

The microchannel comprises a main microchannel, the chip body 1 has a detection region where the sensor 4 is located, and the main microchannel passes through the detection region and is in contact with a detection portion for detecting an analyte on the sensor 4;

a first through hole 141 is arranged in the reservoir 121, one opening of the first through hole 141 is positioned on the inner surface of the reservoir 121, and the other opening of the first through hole 141 is communicated with the micro channel, so that the liquid in the reservoir 121 flows into the main micro channel; the injection port 13 communicates with the microchannel so that the liquid injected into the injection port 13 flows into the main microchannel;

the reservoir 121 has an opening that is water-tightly closed by a seal, and the portion of the interior surface of the reservoir 121 that contacts the seal has an outer boundary 12511, and the microchannel groove does not contact the outer boundary 12511.

In a preferred embodiment, as shown in fig. 10-a, the inner boundary 12512 of the surface contacting portion of the seal with the sump 121 coincides with the inner edge of the rim platform 125. In other embodiments, as shown in fig. 10-b, inner boundary 12512 is not coincident with the inner edge of edge platform 125.

When the first through hole 141 is hydrophobic, the interfacial tension thereof hinders the liquid in the reservoir 121, so that the liquid can be directly encapsulated in the reservoir 121 without using the reservoir pack 7. In addition, it is necessary to design the bottom of the reservoir 121 and/or the pressing cover 8 to be deformable partially or completely for pressing the liquid in the reservoir 121 to force it to flow into the first through hole 141. Deformable portions include, but are not limited to, being made of a soft plastic or rubber. In addition, an interface may be provided on the reservoir 121 or the pressing cover 8 for connecting a pressurizing pump, so that the liquid in the reservoir 121 is pushed into the through hole 141 by the pressurizing pump.

In a preferred embodiment, a liquid storage bag 7 is arranged in the liquid storage tank 121, the liquid storage bag 7 is fixed in the liquid storage tank 121 by a gland 8, a puncture needle 122 is arranged below the liquid storage bag 7, and liquid in the liquid storage bag 7 flows into the liquid storage tank 121 after being punctured by the puncture needle 122 under extrusion.

When the reservoir 7 is made of a material having poor ductility or the width of the sealing edge is small, the reservoir 7 is easily broken by being pressed with a proper force, and the puncture needle 122 may not be provided in the reservoir 121.

The sealing member is one or more members for closing the opening of the reservoir 121, and when the reservoir 7 is not used, the opening of the reservoir 121 is sealed by the pressing cover 8 in a watertight manner, and the liquid in the reservoir 121 is stored in the reservoir 121 without external force, and the sealing member is the pressing cover 8. When the gland 8 is secured by adhesive or bonding layer 6, the seal includes the gland 8 and bonding layer 6. When the gland 8 is ultrasonically welded, the seal is the gland 8. In addition, when one or more spacer layers are further provided between the portions of the gland 8 in contact with the reservoir 121, the seal further includes these spacer layers. When the liquid storage pack 7 is used to store liquid, the liquid storage pack 7 is sealed in the reservoir 121 by a sealing member.

After the liquid storage bag 7 is fixed on the inner surface of the liquid storage tank 121, the liquid storage bag 7 can independently seal the opening of the liquid storage tank 121, and at the moment, the liquid storage bag 7 can be independently regarded as a sealing member. The liquid storage bag 7 is fixed by an adhesive or an adhesive layer 6 and covers the opening of the liquid storage tank 121 in a watertight manner, and the sealing members at this time are the liquid storage bag 7 and the adhesive layer 6. The reservoir 7 and the gland 8 may be combined as a seal for enclosing the reservoir 121. The seal member may include, on the basis of the reservoir pack 7 and the gland 8, an adhesive layer 6 adhering between the reservoir pack 7 and the reservoir 121, or an adhesive layer 6 between the reservoir pack 7 and the gland 8, or a spacer layer spacing between the reservoir pack 7 and the reservoir 121, or a spacer layer spacing between the reservoir pack 7 and the gland 8, or an adhesive layer 6 and a spacer layer as described above.

Chip main part 1 optional setting waste liquid groove, when not setting up waste liquid groove, can set up the interface that a liquid flows out, in collecting an independent module that is used for storing liquid with the liquid after the completion of will detecting, also can take out liquid with the pump.

The utility model discloses a distribute the miniflow channel on two faces of a base plate, not only reduced the area of chip, still reduced the preparation technology degree of difficulty. The preparation of the chip body 1 can be realized by one or more processing modes such as injection molding and etching.

Chip body example 1

Taking fig. 1, fig. 3, fig. 4, fig. 6 and fig. 7 as an example, the micro flow channel includes a second micro flow channel 112, a third micro flow channel 113 and a fourth micro flow channel 114, wherein the second micro flow channel 112 and the third micro flow channel 113 are used as branch micro flow channels, and the liquid in the liquid storage tank 121 and the liquid injected into the injection port 13 are sequentially introduced into the fourth micro flow channel 114 (main micro flow channel). The micro-channel groove on the inner surface of the reservoir 121 is a diversion groove for diverting the liquid in the reservoir 121 to flow to the first through hole 141.

Specifically, a liquid storage tank 121 and a fourth micro flow channel 114 are distributed on the front surface (the surface shown in fig. 4 is the front surface) of the chip main body 1, the fourth micro flow channel 114 is a hydrophilic micro flow channel, the liquid storage tank 121 is further provided with a flow guide groove 111 and a puncture needle 122, and the flow guide groove 111 is hydrophobic. The back surface of the chip body 1 is distributed with a second micro-channel 112, a third micro-channel 113, a waste liquid tank 115 and an air-permeable channel, and the second micro-channel 112 and the third micro-channel 113 are hydrophobic micro-channels. Penetrating the chip body 1 are: injection port 13, detection groove 151 and through holes (including first through hole 141, second through hole 142, third through hole 143 and fourth through hole 144). The connection relationship is as follows: the surface or the inside of the puncture needle 122 in the liquid storage tank 121 is provided with a channel for guiding the flow, and the channel is communicated with the front end of the flow guide groove 111 positioned on the surface of the liquid storage tank 121, so that the liquid flows into the flow guide groove 111 through the channel of the puncture needle 122; the tail end of the diversion trench 111 is communicated with the front end of the second micro-channel 112 positioned on the reverse side of the chip main body 1 through the first through hole 141, and the tail end of the diversion trench 111 is still in the range of the liquid storage tank 121 and is not contacted with the edge of the liquid storage tank 121; the end of the second microchannel 112 is connected to the fourth microchannel 114 on the front surface of the chip body 1 through the second through hole 142, and the second through hole 142 is not disposed at the front end of the fourth microchannel 114; the front end of the third micro-channel 113 on the back side of the chip body 1 is connected to the injection port 13, the end of the third micro-channel 113 is connected to the front end of the fourth micro-channel 114 through the third through hole 143, and the distance between the second through hole 142 and the third through hole 143 along the fourth micro-channel 114 is greater than 1mm, some embodiments are not less than 2mm, and some embodiments are not less than 3 mm; the middle part of the fourth microchannel 114 is overlapped (completely or partially overlapped) with the elongated detection groove 151, the elongated detection groove 151 is straight or curved, and the middle part of the fourth microchannel 114 is not a strictly spatially geometrically defined middle part but a part between the second through hole 142 and the fourth through hole 144; the end of the fourth microchannel 114 is connected to the front end of the waste liquid tank 115 via a fourth through-hole 144; the end of the fourth microchannel 114 is connected to the air-permeable channel.

The coincidence of the second through hole 142 and the third through hole 143 may cause the liquid in the second microchannel 112 to partially enter the third microchannel 113, or the liquid in the third microchannel 113 to partially enter the second microchannel 112. The second through hole 142 is not overlapped with the third through hole 143, so that the liquid in the second micro flow channel 112 and the liquid in the third micro flow channel 113 can enter the fourth micro flow channel 114. This is because the second microchannel 112 and the third microchannel 113 connecting the hydrophilic fourth microchannel 114 are hydrophobic, and the through-holes are also hydrophobic, so that the liquid tends to flow in the fourth microchannel 114 rather than into the hydrophobic second microchannel 112 or the third microchannel 113 after entering the fourth microchannel 114.

For those prior embodiments in which the micro flow channel grooves are distributed on the same side of the chip body 1, as shown in fig. 5-b and 5-c, the cover 8 covers the portion of the micro flow channel grooves located in the reservoir 121, and the remaining micro flow channel grooves are covered with the upper sealing plate 5 or other materials. If the cap 5, as shown in FIG. 5-b, is higher than the surface of the chip body 1, in order to completely cover the micro flow channel groove, one method is: the edge of the upper sealing plate 5 needs to be covered on the gland 8, so that a gap 9 is formed at the edge of the gland 8, and in order to eliminate this gap 9, the configuration of the part of the upper sealing plate 5 is required to be adapted to the undulation, which certainly requires higher machining and assembling accuracy to be adapted to the undulation, and this also increases the machining steps. The other method is to process the upper sealing plate 5 to be completely matched and tightly attached to the edge of the gland 8, and the method has high processing and assembling precision, and a gap 9 can be generated between the upper sealing plate 5 and the gland 8 with slight error. In another scheme, as shown in fig. 5-c, the edge of the liquid storage tank 121 is lower than the surface of the chip body 1, so that the top of the gland is coplanar with the surface of the chip body 1 after the gland 8 is embedded, however, the processing and assembly precision is high, the too large gland 8 cannot be embedded, the too small gland 8 easily causes a gap 9 between the side wall of the gland 8 and the chip body 1, and the existence of the gap 9 causes liquid to flow out of the groove because the side wall of the gland 8 also needs to cover the micro-channel groove in the scheme. In addition, the thicker and thinner glands 8 also form undulations which cause the liquid to flow out of the microchannel grooves, especially under external pressure. However, as shown in fig. 5-a, the micro flow channel groove for guiding the liquid to the other side through the through hole has low requirements on the processing and assembling precision because the edge of the gland 8 does not cover the micro flow channel groove, the upper sealing plate 5 does not need to extend to cover the edge of the gland 8 or the upper side of the edge, and in addition, the side wall of the gland 8 does not need to cover the micro flow channel groove, so that the requirements on the size and thickness of the gland 8 are not high. Thereby facilitating the processing and improving the yield.

Specifically, as an example, as shown in fig. 5-a (the reservoir bag is not shown), the reservoir 121 is a stepped recess, and includes an edge platform 125, a bottom platform 123, and a reservoir sidewall 124, the reservoir sidewall 124 connects an inner edge of the edge platform 125 and an outer edge of the bottom platform 123, the reservoir sidewall 124 is disposed obliquely and faces upward, and the outer edge of the edge platform 125 is an edge of the reservoir 121. The edge platform 125 is preferably lower than the surface of the chip body 1 and may also be higher than or coplanar with the surface of the chip body 1. The puncture needle 122 is disposed on the bottom platform 123, the end of the channel 111 is located on the edge platform 125 and is not close to the outer edge of the edge platform 125, and the distance between the end of the channel 111 and the outer edge of the edge platform 125 may be 1mm or more, preferably 2mm or more, and more preferably 3mm or more. After the gland 8 is covered on the liquid storage tank 121, the edge portion of the gland 8 is adhered to the edge platform 125, so that the opening of the diversion trench on the edge platform 125 is sealed by the gland 8, the opening of the first through hole 141 on the edge platform 125 is sealed by the gland 8, and finally, the liquid in the liquid storage tank 121 can only flow into the first through hole 141 through the diversion trench 111 under pressure. The portion of the gland 8 in contact with the edge platform 125 may be bonded entirely to the edge platform 125 or the outermost edge portion may be bonded to the edge platform 125. The bonding means may be replaced by other conventional attachment means including, but not limited to, ultrasonic welding, attachment via double-sided adhesive tape, plastic fusion attachment.

In a whole, the diversion trench 111 passes through the side wall 124 of the reservoir from the puncture needle 122 along the inner surface of the reservoir 121 in a straight direction or a curved path and reaches the edge platform 125, the end of the diversion trench 111 is communicated with one end of the second microchannel 112 (branch microchannel) on the opposite side of the chip body 1 through the first through hole 141, and the other end of the second microchannel 112 is communicated with the fourth microchannel 114 (main microchannel) through the second through hole 142. With this structure, the liquid pack 7 is pierced by the piercing needle 122 after being pressed, the liquid in the liquid pack 7 flows out, flows through the first through hole 141 after being guided by the guide groove 111, and flows into the second microchannel 112, and then flows from the second microchannel 112 into the fourth microchannel 114 through the second through hole 142.

Obviously, on the front side of the chip main body 1, no micro-channel groove is connected between the diversion trench 111 and the fourth micro-channel 114, but the micro-channel groove is communicated through the micro-channel groove on the back side, so that the micro-channel groove is skillfully prevented from flowing through the gap 9 between the gland 8 and the chip main body 1 or the gap 9 between the gland 8 and the sealing plate, and liquid is prevented from permeating into the gap 9.

In addition, the edge platform 125 is also beneficial to fixing the liquid storage bag 7, the edge of the liquid storage bag 7 is adhered to the edge platform 125, and the later covered gland 8 covers the through hole I141 in a water-tight manner, so that the fixing effect of the liquid storage bag 7 is further enhanced. Preferably, the gland 8 covers the channels 111 on the edge platform 125, either completely or partially, hermetically.

Preferably, as shown in fig. 5-a, the bottom platform 123 protrudes from the opposite side of the chip body 1, which design may increase the reservoir capacity of the reservoir 121.

The hydrophobic micro-channels and the hydrophilic micro-channels are distributed on the back side and the front side of the chip main body 1 respectively, so that the size of the micro-fluidic chip can be reduced, and the micro-channels are designed and processed on only one main body, so that the processing and the assembly are convenient, and the cost is reduced.

In addition, the diversion trench 111, the second microchannel 112 and the third microchannel 113 are designed as hydrophobic microchannels, so that bubbles generated due to too high flow velocity of liquid pushed by external pressure can be avoided. The fourth microchannel 114 is designed to be hydrophilic, and on the one hand, provides the power for the subsequent liquid flow. When liquid on the other side flows through the electrode area of the sensor 4, the diffusion performance of the fluid in the area is effectively adjusted, for example, under the action of hydrophilicity, the liquid is more favorable for completely covering the detection area (electrode area) of the sensor 4 in the micro-channel in the flowing process, even if a plurality of detection sites with different surface tensions are arranged in the micro-channel, the liquid can be diffused more fully, the generation of bubbles is avoided, and the detection accuracy is ensured. If the micro flow channel of the detection area is completely hydrophobic, when liquid flows in the micro flow channel, the surface tension of some areas of the electrodes of the sensor may be different and the liquid may bypass the micro flow channel, so that bubbles are formed, which affects the detection accuracy.

The utility model discloses a hydrophilic and hydrophobic nature to guiding gutter 111, second miniflow channel 112, third miniflow channel and 113 fourth miniflow channel 114 changes only in order to improve the detection precision of sensor 4. However, this does not mean that all of them cannot be arranged in a manner of combination of hydrophobicity, hydrophilicity or other hydrophilicity and hydrophobicity while satisfying the requirements of the basic test.

The function of the gas-permeable channel is to remove gas, because if there is no gas-removing channel, the air pressure of the liquid front rises due to the squeezing of the air of the liquid front, and the liquid fluid is stopped when the liquid flows in the microchannel.

In some embodiments, the width of the flow guide groove 111, the second micro flow channel 112, and the third micro flow channel 113 on the chip body 1 is 0.2-1 mm, and the depth is 0.2-0.6 mm; the width of the fourth micro channel 114 is 0.2-3 mm, and the depth is 0.2-0.6 mm; the thickness of the chip body 1 is 0.4-5 mm. Preferably, the width of the diversion trench 111, the second microchannel 112, and the third microchannel 113 is 0.4mm, and the depth is 0.3 mm. Preferably, the fourth microchannel 114 is a wider middle and narrower at both ends, with the widest being no more than 2mm and the narrowest being no more than 1 mm.

In some embodiments, the chip body 1 is made of a transparent material, or only the sealing plate may be made of a transparent material.

Chip body example 2

As shown in fig. 5-d, in the present embodiment, the through hole does not penetrate through the inner surface of the liquid storage tank 121 and the back surface of the chip body 1, but penetrates through the inner surface of the liquid storage tank 121 and the front surface of the chip body 1, that is, the micro flow channel on the back surface of the chip body 1 is not connected between the flow guide tank 111 and the fourth micro flow channel 114. This embodiment spans the gap 9 between the gland 8 and the chip body 1 and/or the upper sealing plate 5 through a through-hole one 141 in the chip body 1. Although this method does not require high precision in processing and assembly, it is difficult to dig a hole in the chip body 1 as compared with embodiment 1.

Chip body example 3

The difference from chip body embodiment 1 is that, as shown in fig. 5-e, through-hole one 141 is located on bottom platform 123, so that guiding trench 111 may be selectively disposed or not disposed. In addition, this solution is preferably used in the case where the bottom stage 123 does not protrude from the opposite surface of the chip body 1, and if the bottom stage 123 protrudes from the opposite surface of the chip body 1, the second microchannel is equivalently provided on an uneven surface, so that the lower sealing plate 2 is required to be fitted to the uneven surface, and thus, increased machining and assembling accuracy is required to avoid a gap 9 from occurring between the opposite surface of the chip body 1 and the lower sealing plate 2 when the bottom stage 123 is attached due to the unevenness, which may cause liquid leakage between the gaps 9.

Chip body example 4

The difference from the embodiment 3 of the chip main body is that, as shown in fig. 5-f, the fourth microchannel 114 is located on the side of the chip main body 1, so that the liquid flows directly into the fourth microchannel 114 through the first through hole 141, and does not need to flow into the microchannel on the front surface of the chip main body 1 through a through hole, which can prevent the liquid from leaking due to flowing through the gap between the cover 8 and the chip main body 1, and can reduce the number of through holes and the complexity of the microchannels.

Embodiments of the microfluidic chip

A complete microfluidic chip comprises, in addition to the chip body 1 described above: sealing plates (upper sealing plate 5, lower sealing plate 2), sensor 4 for detecting an analyte, reservoir 7, and gland 8. The following embodiments are described by taking the chip body 1 in example 1 as an example. The cover 8 covers the reservoir 121 and fixes the reservoir pack 7 therein, the upper sealing plate 5 covers the front surface of the chip body 1, and the upper sealing plate 5 covers the fourth microchannel 114, the detection tank 151, the second through hole 142, the third through hole 143, and the fourth through hole 144. The sensor 4 is adhered to the opposite surface of the chip body 1 through the adhesive layer 3 and covers the detection groove 151, and the portion of the sensor 4 for detecting an analyte is entirely or incompletely located in the detection groove 151, and the entire location in the detection groove 151 can improve detection accuracy. Preferably, a sensor slot 12 adapted to the sensor 4 may be provided on the opposite side of the chip body 1, so that the surface of the sensor 4 does not protrude from the opposite side of the chip body 1 after being placed therein. The back surface of the chip body 1 is covered with a lower sealing plate 2, and the lower sealing plate 2 covers the first through hole 141, the second through hole 142, the third through hole 143, the fourth through hole 144, the air-permeable channel, the waste liquid tank 115, the third micro-channel 113 and the second micro-channel 112. The lower sealing plate 2 may selectively cover, partially cover or uncover the sensor 4. In some embodiments, the contacts of the sensor 4 for connecting the wires extend beyond the edge of the microfluidic chip, outside the chip. In some embodiments, the contacts of the sensor 4 are not directed toward the opposite side of the chip main body 1, but are located on the side opposite to the detection portion, and therefore the contacts should not be covered by the lower sealing plate 2. In some embodiments, the contact of the sensor 4 faces the opposite side of the chip body 1, and therefore, in order to contact with the contact, a through contact groove 152 should be provided at a corresponding position of the chip body 1 so that the contact is located in the contact groove 152, and the contact groove 152 is covered by the sensor 4 but not covered by the upper sealing plate 5, or an opening 52 is provided at a corresponding position of the upper sealing plate 5.

The utility model provides an upper seal plate 5 and lower seal plate 2 can be one, also can be a plurality of, and seal plate 5 and lower seal plate 2 respectively one explain more than this embodiment. The gland 8 preferably has a gland opening 83 to facilitate insertion of a hand or other instrument into and squeezing of the reservoir 7 for piercing by the needle 122, wherein the fluid is forced into the channel 111. Or its open portion may be replaced by a plastic or rubber having stretchability, and when this portion is pressed, the lower reservoir 7 is also pressed. Or the opening portion may be provided with a detachable plastic cover (plastic film) which is removed when pressed.

In some embodiments, as shown in fig. 2, the gland 8 includes a pressure plate 81 having an opening in the middle and a side plate 82; the bottom edge of the side plate 82 is arranged around the inner edge of the opening of the pressing plate 81, and the side plate 82 is inclined inwards but does not seal the opening of the pressing plate. Thereby forming gland 8 with a gland opening 83. The side plate 82 may provide support, for example, in an accident situation, the side plate 82 may support some object to prevent the object from pressing on the reservoir 7, so that the reservoir 7 is punctured by the puncture needle 122.

In one embodiment, the chip body 1 is made of a hydrophobic material, the covering surface of the sealing plate covering the hydrophobic micro flow channel is hydrophobic, and the covering surface of the sealing plate covering the hydrophilic micro flow channel is hydrophilic.

The chip body 1 is made of a hydrophobic material, or the surface of the chip body 1 is subjected to hydrophobic treatment, or the surface of the chip body 1 which is in contact with liquid is subjected to hydrophobic treatment. The surface of the upper sealing plate 5 contacting with the chip body 1 is hydrophilic material or the surface is treated with hydrophilic material. The surface of the lower sealing plate 2 contacting the chip body 1 is made of hydrophobic material or surface treated with hydrophobic treatment. The hydrophobic material can be made of any one or two mixed materials of the following materials, such as silicon, ceramics, glass, plastics and the like, wherein the plastics are selected from the following materials: acrylonitrile-butadiene-styrene copolymer (ABS), cycloolefin polymer (COP), Polyamide (PA), polybutylene terephthalate (PBT), Polycarbonate (PC), Polydimethylsiloxane (PDMS), Polyethylene (PE), Polyetheretherketone (PEEK), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), Polyoxymethylene (POM), polypropylene (PP), polystyrene diethyl ether (PPE), Polystyrene (PS), Polysulfone (PSU), Polytetrafluoroethylene (PTFE), and the like. The hydrophilic material may be a material in which the surface of a hydrophobic material is treated to have hydrophilic groups, eventually exhibiting hydrophilic properties, such as plasma treatment or a hydrophilic coating. The material with hydrophilicity can also be directly selected, for example, hydrophilic substances are added into the raw materials during injection molding.

In some embodiments, the microfluidic chip is not provided with the reservoir 7, the puncture needle 122 and the gland 8, the liquid is sealed in the reservoir 121 by the sealing plate with elasticity, and the liquid flows into the diversion trench 111 after being squeezed.

In some embodiments, the microfluidic chip is free of a capping 8. The part of the diversion trench 111 on the platform at the edge of the liquid storage tank 121 and the first through hole 141 are covered by the adhesive layer 6.

In some embodiments, the waste fluid tank 115 is hydrophobic. To prevent liquid from flowing back from the waste liquid tank 115 to the fourth microchannel 114.

In some embodiments, the waste liquid tank 115 is hydrophobic, the waste liquid tank 115 is a flow channel, the width of the flow channel is not less than 2mm, and the inner diameter of a through hole communicating with the waste liquid tank 115 is not more than 1.5 mm. Preferably, the width of the flow channel is not more than 5 mm. On one hand, the control of the liquid can be enhanced, and the liquid can be prevented from flowing back to the fourth micro-channel 114; on the other hand, the flow channel is designed to prevent the generation of bubbles, which occupy a relatively large volume, thereby reducing the volume of the liquid in the waste liquid tank 115.

In some embodiments, the upper surface of the injection port 13 is higher than the front surface of the chip body 1. Preferably, the upper surface of the injection port 13 is higher than the front surface of the chip body 1 but not more than 5 mm. More preferably, the upper surface of the injection port 13 is higher than the front surface of the chip body 1 but not more than 3 mm. More preferably, the upper surface of the injection port 13 is higher than the front surface of the chip body 1 but not more than 2 mm. The deeper injection port 13 allows for easy positioning and fixation of the injection needle.

The utility model provides a design of two kinds of ventilative passageways:

the method comprises the following steps: as shown in fig. 3 and 6, the air-permeable passage is an air-permeable flow channel 116, the end of the waste liquid tank 115 is connected to the air-permeable flow channel 116 with hydrophobic property, the other end of the air-permeable flow channel 116 is communicated with the outside atmosphere, the width of the air-permeable flow channel 116 is not greater than 1mm, and the depth of the air-permeable flow channel 116 is not greater than 1 mm. Preferably, the cross-sectional dimension of the air-permeable flow channel 116 is not more than 1mm². Preferably, the connection between the gas-permeable flow channel 116 and the waste liquid tank 115 is a non-smooth transition treatment, so as to enhance the interface effect, and block the liquid from entering the gas-permeable flow channel 116, and play a role in allowing the gas to pass through but blocking the liquid from passing through.

The second is as follows: as shown in fig. 7 to 9, the air-permeable passage includes an air-permeable groove 16 and an air-permeable membrane 161 that is air-permeable but water-impermeable; the tail end of the waste liquid groove is communicated with the ventilation groove 16, the edge of the tail end of the waste liquid groove is positioned in the ventilation groove 16, and the depth of the tail end of the waste liquid groove is greater than that of the ventilation groove 16; the bottom of the air-permeable groove 16 is covered with the air-permeable film 161, the air-permeable film 161 completely covers the tail end of the waste liquid groove, the air-permeable film 161 is covered with the sealing plate, the sealing plate is provided with air-permeable holes 21, and the positions of the air-permeable holes 21 correspond to the positions of the air-permeable groove 16, so that the air in the waste liquid groove can enter the external atmosphere through the air-permeable film 161. In order not to cause the waste liquid to flow out of the waste liquid tank 115, it is preferable that the upper surface of the gas permeable membrane 161 fixed in the gas permeable tank 16 is not lower than the front surface of the chip body 1 so that there is no gap between the gas permeable membrane 161 and the upper sealing plate 2 after the upper sealing plate 2 is covered on the front surface of the chip body 1. Meanwhile, the gas can pass through the gas permeable membrane 161 only in a direction perpendicular to the gas permeable membrane 161, and therefore the end of the waste liquid tank 115 is disposed below the gas permeable membrane 161, as shown in FIG. 9. Further, in order to enhance the sealing effect, the contact portion between the gas permeable membrane 161 and the upper sealing plate 2 should be treated with an adhesive.

The working process of the micro-fluidic chip comprises the following steps:

taking the chip body 1 of fig. 3 as an example, in this embodiment, the microfluidic chip is inserted into the detection instrument horizontally, but may be inserted obliquely or vertically. After the microfluidic chip is inserted into a corresponding detection instrument or before the microfluidic chip is inserted into the corresponding detection instrument, the liquid storage bag 7 in the liquid storage tank 121 is squeezed by hands or instruments, after the liquid storage bag 7 is punctured by the puncture needle 122 in the liquid storage tank 121, the calibration solution in the liquid storage bag flows into the flow guide groove 111 under pressure, flows into the second micro flow channel 112 on the reverse side of the chip main body 1 through the first through hole 141, then flows into the fourth micro flow channel 114 on the front side of the chip main body 1 through the second through hole 142, the calibration solution is pulled by tension to fully cover the detection groove 151, because the tail end of the fourth micro flow channel 114 is connected with the hydrophobic waste liquid groove 115, the calibration solution cannot enter the waste liquid groove 115, or under some conditions, a part of the calibration solution enters the waste liquid groove 115 under the influence of squeezing of the liquid storage bag 7, at the moment, the detection instrument starts to work, and the related analytes (such as sodium ions, Potassium ions, calcium ions, etc.) and perform a calibration on itself.

Next, the injection needle is inserted into the injection port 13 while injecting the blood inside into the third microchannel 113, and then enters the fourth microchannel 114 through the third through-hole 143. Meanwhile, as the blood flows in the micro flow channel, the calibration solution in the fourth micro flow channel 114 is also completely pushed into the waste solution tank 115. After entering the fourth microchannel 114, the blood passes through the second through hole 142 but does not enter, and finally the blood is pulled by tension to be distributed in the detection groove 151, and the detection instrument starts to detect the relevant components in the blood.

A microfluidic preparation method comprises the following steps:

Preferably, in step 1, the puncture needle is connected with the first through hole through the diversion trench.

The detection method in the detection area can be a biosensor for treating the electrode, and can also be an optical detection method such as a turbidity method, a fluorescence method, a chemiluminescence method, a scattering method and the like.

The micro-fluidic detection chip can carry out quantitative, semi-quantitative or qualitative detection. For example, one or more test strips (either blank or pre-loaded) are fixed in the detection area, and after the detection reagent or the sample flows through the detection flow channel and contacts with the test strips, the reagent reacts with the sample to generate a color change, and then the detection result is obtained through instrument or human observation.

The above-listed embodiments are only preferred embodiments and can be combined with each other without contradiction. In addition, technical features derived from the drawings of the specification can also be combined.

Claims

1. A microfluidic chip for preventing liquid leakage includes a chip main body, a sealing plate, and a sensor for detecting an analyte; the chip main body is divided into a front surface and a back surface, and an injection port, a liquid storage tank and a micro-channel groove positioned on the surface of the chip main body are distributed on the chip main body; the opening of the micro-channel groove is sealed by the sealing plate in a water-tight manner to form a micro-channel, and the micro-channel is characterized in that:

the microchannel comprises a main microchannel, the chip body is provided with a detection zone, the sensor is positioned in the detection zone, and the main microchannel passes through the detection zone and is contacted with a detection part for detecting an analyte on the sensor;

the injection port is communicated with the microchannel, so that the liquid injected into the injection port flows into the main microchannel;

the liquid storage tank is provided with an opening which is sealed by a sealing member in a water-tight manner; and a first through hole is arranged in the liquid storage tank, one opening of the first through hole is positioned on the inner surface of the liquid storage tank, and the other opening of the first through hole is communicated with the micro-channel, so that the liquid in the liquid storage tank flows into the main micro-channel.

2. The microfluidic chip of claim 1, wherein:

the seal includes a gland and/or a reservoir.

3. The microfluidic chip of claim 2, wherein:

the sealing element comprises the gland and the liquid storage bag, and the gland fixes the liquid storage bag in the liquid storage tank.

4. The microfluidic chip according to claim 3, wherein:

the gland comprises a pressing plate and a side plate, wherein the middle of the pressing plate is provided with an opening;

the bottom edge of curb plate is followed the interior border of the opening of clamp plate encircles the setting to the slope is inside, but does not seal the opening of clamp plate.

5. The microfluidic chip according to one of claims 1 to 4, wherein:

the reservoir includes bottom platform, reservoir lateral wall and marginal platform, marginal platform is located the top of bottom platform, the outside of bottom platform along with the interior border of marginal platform passes through the reservoir lateral wall is connected, the wall slope of reservoir lateral wall is up.

6. The microfluidic chip according to claim 5, wherein:

and one opening of the first through hole is positioned on the edge platform, or on the side wall of the liquid storage tank, or on the bottom platform.

7. The microfluidic chip according to claim 6, wherein:

the micro-channel comprises the main micro-channel and the branch micro-channel;

the other opening of the first through hole and the injection port are respectively communicated with the main micro-channel through the branch micro-channel.

8. The microfluidic chip according to claim 7, wherein:

the other opening of the first through hole and the branch micro-channel connected with the opening are positioned on the reverse side of the chip main body;

a second through hole is formed in the chip main body;

the branch micro-flow channel is communicated with the main micro-flow channel positioned on the front surface of the chip main body through the second through hole.

9. The microfluidic chip of claim 8, wherein:

and a diversion trench for diversion of liquid is arranged on the inner surface of the liquid storage tank and is connected with the first through hole.

10. The microfluidic chip of claim 1, wherein:

the chip main body is provided with a hydrophobic waste liquid groove, the waste liquid groove is communicated with the main micro-channel, and the tail end of the waste liquid groove is provided with an air-permeable but water-impermeable air-permeable channel.