Micro-fluidic chip and in-vitro detection device

Abstract

The utility model discloses a micro-fluidic chip and an in vitro detection device, and relates to the field of containers or utensils for experiments, a drainage groove of the micro-fluidic chip extends along a tangent line of a reaction cavity and is arranged on the side wall of the bottom of the reaction cavity, and a first side wall positioned below the tangent line is provided with an arc section. The drainage groove not only tangentially guides liquid flow into the bottom of the reaction cavity to be in contact with a freeze-drying ball so as to prevent the liquid flow from directly flushing and blocking an exhaust flow channel, but also forms a gap with an increased width in the side wall of the reaction cavity, thereby being beneficial to destroying the interface energy at the front end of the liquid flow and enabling a liquid sample to enter the reaction cavity more easily. In addition, the side wall of the top of the reaction cavity is also provided with an intercepting groove which is used as a capillary valve to inhibit the liquid sample from entering the exhaust flow channel before the gas enters the exhaust flow channel. The micro-fluidic chip is provided with a liquid separation cavity, and secondary preferential distribution is carried out on liquid flow. The forked flow channels annularly surround the reaction cavities, the structure is compact, and the reaction cavities connected with the different forked flow channels are partitioned.

Description

Technical Field

[0001] The utility model relates to the field of containers or vessels for experiments, in particular to a microfluidic chip and an in vitro detection device. Background Art

[0002] Microfluidic chip technology is called a laboratory on a chip, which can integrate all aspects of the experiment on a chip. Microfluidic chips have the advantages of high integration, small size, small reagent usage, low cost, and easy operation.

[0003] The existing microfluidic chips have the following problems: (1) The liquid sample entering the reaction chamber tends to enter the exhaust channel first, blocking the exhaust channel, causing part of the gas in the reaction chamber to be unable to be discharged, forming bubbles. (2) As the freeze-dried balls in the reaction chamber come into contact with and dissolve the liquid sample, a hollow is created in the reaction chamber, forming large bubbles, which affect the detection results. During this period, small bubbles formed in the liquid sample due to sample addition or dissolution of the freeze-dried balls will also converge towards the large bubbles, further affecting the detection results. (3) In the existing microfluidic chips, there are few diversion structures for timing control, which makes it difficult to determine the order of liquid inlet into each bifurcated channel, making the timing of liquid inlet into the reaction chamber on each bifurcated channel uncontrollable. Summary of the invention

[0004] The utility model aims to provide a microfluidic chip and an in vitro detection device, which aims mainly to overcome the problem in the prior art that a liquid sample entering a reaction chamber tends to enter an exhaust channel first, blocking the exhaust channel, causing part of the gas in the reaction chamber to be unable to be discharged, and forming bubbles.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A microfluidic chip comprises a chip body provided with at least one reaction unit, wherein the reaction unit comprises a liquid inlet channel, a drainage groove, a reaction chamber and an exhaust channel which are sequentially connected along the liquid flow direction; the drainage groove is extended along the tangent line of the reaction chamber and is arranged on the bottom side wall of the reaction chamber, and the first side wall and the second side wall of the drainage groove are respectively located on both sides of the tangent line.

[0007] Furthermore, an arc segment is provided at one end of the second side wall close to the reaction chamber, and the concave surface of the arc segment faces the center of the reaction chamber.

[0008] Furthermore, the first side wall includes a first straight line segment and a first round chamfer, one end of the first straight line segment is connected to the liquid inlet channel, and the other end is smoothly connected to the side wall of the reaction chamber through the first round chamfer.

[0009] Furthermore, the second side wall includes a second straight line segment and the arc segment which are tangentially arranged, and the second straight line segment is connected to the liquid inlet channel, and the arc segment is smoothly connected to the side wall of the reaction chamber through a second round chamfer.

[0010] The top side wall of the reaction chamber is provided with the intercepting groove extending in the vertical direction.

[0011] Furthermore, the depth of the drainage groove gradually increases along the liquid flow direction.

[0012] Preferably, the bottom surface of the drainage groove is a sloped surface.

[0013] Preferably, the depth of the drainage groove increases three times along the liquid flow direction.

[0014] Furthermore, the intercepting groove comprises a straight section and a gradient section which are sequentially connected along the liquid flow direction, the width and length of the straight section are both less than or equal to 1 mm, and the width of the gradient section gradually decreases along the liquid flow direction.

[0015] Preferably, the depth ratio of the intercepting groove to the reaction chamber is 1:2-2:3.

[0016] Preferably, the cross section of the gradient section is semicircular.

[0017] Furthermore, the chip body is provided with a liquid separation chamber, a main channel is provided on the top of the liquid separation chamber, a second branched channel is provided on the bottom of the liquid separation chamber, and first branched channels are provided on both sides of the second branched channel, and the width of the first branched channel is smaller than the width of the second branched channel; the left and right side walls of the liquid separation chamber are arranged in an eight-shaped shape, and the bottom is stepped between the first branched channel and the second branched channel; the second branched channel and the first branched channel are both connected to a plurality of the reaction units.

[0018] Preferably, the stepped shape is composed of a first table top, a transition surface and a second table top connected in sequence.

[0019] Furthermore, two third branched flow channels are symmetrically arranged at one end of the second branched flow channel away from the liquid separation chamber, and the two third branched flow channels and the two first branched flow channels are annularly distributed to form a ring, and a dividing line is formed between the third branched flow channels and the first branched flow channels; the plurality of reaction units are annularly distributed on the inner side of the ring, and the reaction unit connected to the first branched flow channel is located above the dividing line, and the reaction unit connected to the third branched flow channel is located below the dividing line.

[0020] Furthermore, a first exhaust hole is disposed at one end of the exhaust channel away from the reaction chamber, and a plurality of first exhaust holes are distributed in an annular shape to form two annular rings, and two adjacent first exhaust holes are located on different annular rings.

[0021] Furthermore, the chip body is fixedly provided with an annular protrusion on the periphery of the first exhaust holes, and the inner side of the annular protrusion is sequentially paved with a hydrophobic breathable membrane and a cover plate, the cover plate is provided with an exhaust groove on the end face facing the first exhaust holes, and a second exhaust hole is provided at the center of the exhaust groove.

[0022] Furthermore, the chip body is provided with a sample loading cavity, the sample loading port of the sample loading cavity is threadedly connected with a sealing cover, the sealing cover is fixed with a plug body, and the plug body can be movably sealed and fitted to the inner wall of the sample loading cavity.

[0023] Furthermore, a boss is fixedly provided on the inner top surface of the sealing cover, and the boss is provided with a mounting hole. The plug body is fixedly provided with a clamping piece, and the clamping piece is clamped in the mounting hole.

[0024] Preferably, the boss is formed by a downward depression in the middle of the sealing cover.

[0025] Preferably, the plug body is provided with an annular flange, the inner peripheral surface of the annular flange is in contact with the boss, and the outer peripheral surface is sealingly in contact with the inner wall of the sample adding cavity.

[0026] An in vitro detection device comprises a reaction unit and a microfluidic chip with a structure as described above, wherein the reaction unit is used for detecting a liquid sample in a reaction chamber.

[0027] Compared with the prior art, the beneficial effects of the utility model are:

[0028] First, in the utility model, the drainage groove is extended along the tangent of the reaction chamber and arranged on the bottom side wall of the reaction chamber, and its first side wall and second side wall are respectively located on both sides of the tangent. The drainage groove can guide the liquid flow tangentially into the bottom of the reaction chamber, and then contact the freeze-dried balls, so as to avoid the liquid sample entering the reaction chamber and directly rushing into the exhaust flow channel to hinder the discharge of bubbles, which is conducive to the contact reaction between the liquid sample and the freeze-dried balls. In addition, since it is extended along the tangent of the reaction chamber, a gap with a larger width is formed on the side wall of the reaction chamber, and the gap is asymmetric, which helps to destroy the interfacial energy of the front end of the liquid flow, making it easier for the liquid sample to enter the reaction chamber.

[0029] Secondly, in the present invention, the second side wall of the drainage groove includes a second straight line segment and an arc segment arranged tangentially. The arc segment can better guide the liquid sample to the bottom of the freeze-dried ball, accelerate the contact dissolution of the freeze-dried ball, and at the same time, the arc segment can aggravate the asymmetry of the notch and destroy the interface energy at the front end of the liquid flow.

[0030] Third, in the present invention, when the liquid sample fills the reaction chamber and spreads to the intercepting groove, the intercepting groove acts as a capillary valve to prevent the liquid sample from entering the exhaust channel before the gas. The liquid sample will not flow into the intercepting groove until the liquid sample on the bottom of the reaction chamber wraps around and squeezes the gas on the top of the liquid sample into the exhaust channel, thereby effectively preventing the formation of large bubbles inside the reaction chamber.

[0031] Fourthly, in the present invention, the left and right side walls of the liquid separation chamber are arranged in an eight-shaped shape, with a narrow top and a wide bottom, so that the width of the liquid separation chamber gradually increases along the liquid flow direction. Compared with a straight rectangular chamber or other non-gradient shapes, when the liquid sample squeezed out of the sample chamber is slow, no air will be formed in the liquid separation chamber, avoiding the dead volume that cannot be filled with the sample liquid. In addition, the gradual change direction of the liquid separation chamber matches the direction of the first bifurcated flow channel, which can make the flow of the liquid sample smoother.

[0032] Fifth, in the utility model, the width of the first bifurcated flow channel is smaller than that of the second bifurcated flow channel, and the bottom of the liquid separation chamber is stepped between the first bifurcated flow channel and the second bifurcated flow channel, so that the entrance of the first bifurcated flow channel is lower. These designs make the capillary force of the first bifurcated flow channel greater and the entrance lower, and the liquid sample in the liquid separation chamber is easier to enter and fill the first bifurcated flow channel, and the liquid flow is preferentially distributed twice to realize the priority selection function. The left and right side walls of the liquid separation chamber are arranged in an eight-shaped shape, with a narrow top and a wide bottom. A drainage chamber is formed outside the entrance of the first bifurcated flow channel by the side walls and transition surface of the liquid separation chamber, so that the liquid sample can enter the first bifurcated flow channel more easily.

[0033] Sixth, in the utility model, each bifurcated flow channel, a plurality of reaction chambers and a plurality of first exhaust holes form a plurality of nested rings, the spacing between each structure is appropriate, the structure is compact, and the processing difficulty of the product can be effectively reduced and the size of the product can be controlled. In addition, the plurality of reaction units are divided into zones by each bifurcated flow channel, which helps to distinguish the reaction units connected to each bifurcated flow channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0035] Figure 2 It is a cross-sectional view of the utility model.

[0036] Figure 3 The explosion of the utility model Figure 1 .

[0037] Figure 4 The explosion of the utility model Figure 2 .

[0038] Figure 5 This is the front view of the chip body in the present invention.

[0039] Figure 6 for Figure 3 A partial enlarged view of part A.

[0040] Figure 7 for Figure 5 A partial enlarged view of part A'.

[0041] Figure 8 for Figure 3 A partial enlarged view of part B.

[0042] Fig. 9 for Figure 8 Schematic diagram from another perspective.

[0043] Fig.10 for Figure 5 A partial enlarged view of part B'. DETAILED DESCRIPTION

[0044] The specific implementation of the present invention is described below with reference to the accompanying drawings. In order to fully understand the present invention, many details are described below, but for those skilled in the art, the present invention can be implemented without these details.

[0045] For ease of understanding, the various parts of the utility model are described one by one mainly according to the direction of liquid flow.

[0046] like Figures 1 to 4 As shown, a microfluidic chip includes a chip body 1, a plug body 2, a sealing cover 3, a freeze-dried ball 4, a thin sheet 5, a hydrophobic breathable membrane 6 and a cover plate 7.

[0047] like Figures 1 to 4 As shown, the chip body 1 is a plate extending vertically, a sample loading chamber 11 is provided at the upper end of the chip body 1, and a sealing cover 3 is threadedly connected to the sample loading port of the sample loading chamber 11. The sealing cover 3 is fixed with a plug body 2, and the plug body 2 is a flexible material such as soft silicone. The plug body 2 can be movably sealed and fitted to the inner wall of the sample loading chamber 11. When in use, the sealing cover 3 can be rotated downward through the thread, so that the plug body 2 moves downward, and the sample in the sample loading chamber 11 is pressurized and pushed, thereby ensuring that each reaction unit is filled with a sufficient amount of liquid sample to achieve quantitative detection.

[0048] Specifically, a boss 31 is fixedly provided on the inner top surface of the sealing cover 3, and the boss 31 is provided with a mounting hole 311. The plug body 2 is fixedly provided with a clamping piece 21, and the clamping piece 21 is clamped in the mounting hole 311. The boss 31 is integrally formed with the sealing cover 3, and is formed by a downward depression in the middle of the sealing cover 3. The clamping piece 21 and the plug body 2 are integrally formed silicone products.

[0049] Preferably, the plug body 2 is provided with an annular flange 22 , the inner peripheral surface of the annular flange 22 is in contact with the boss 31 , and the outer peripheral surface is sealingly in contact with the inner wall of the sample adding cavity 11 .

[0050] like Figures 2 to 7 As shown, the chip body 1 is provided with a liquid separation chamber 13, and a main flow channel 12 is provided at the top of the liquid separation chamber 13. The upper end of the main flow channel 12 is connected to the bottom of the sample addition chamber 11 through a hole. A second bifurcated flow channel 142 is provided at the bottom of the liquid separation chamber 13, and a first bifurcated flow channel 141 is provided on both sides of the second bifurcated flow channel 142. Of course, the liquid separation chamber 13 can also be provided with the first bifurcated flow channel 141 only on one side of the second bifurcated flow channel 142.

[0051] like Figures 2 to 7 As shown, the inlet of the first bifurcated flow channel 141 is lower than the inlet of the second bifurcated flow channel 142 , and the width of the first bifurcated flow channel 141 is smaller than the width of the second bifurcated flow channel 142 .

[0052] like Figures 2 to 7 As shown, specifically, the left and right side walls of the liquid separation chamber 13 are arranged in an eight-shaped shape, with a narrow top and a wide bottom; and the bottom of the liquid separation chamber 13 is stepped between the first forked flow channel 141 and the second forked flow channel 142.

[0053] The above-mentioned stepped shape includes but is not limited to being composed of a first table 131, a transition surface 132 and a second table 133 connected in sequence.

[0054] Preferably, the transition surface 132 is an inclined plane parallel to the side wall (specifically the left side wall or the right side wall) of the liquid separation chamber 13 .

[0055] Preferably, the width ratio of the first bifurcated flow channel 141 to the second bifurcated flow channel 142 is 1:2.

[0056] Since the width of the first bifurcated flow channel 141 is smaller, the capillary force generated is greater. In unit time, the first bifurcated flow channels 141 on both sides pull more liquid, and the entrance of the first bifurcated flow channel 141 is lower, making it easier for the liquid sample in the liquid separation chamber 13 to enter the first bifurcated flow channels 141 on both sides, so that the first bifurcated flow channel 141 is preferentially filled with liquid samples. In other words, when the detection project requires a strict reaction sequence, the liquid separation chamber structure disclosed in the utility model can be used to perform a secondary preferential distribution of the liquid flow to achieve a preferential selection function. In addition, when the liquid sample inside the sample adding chamber 11 is pressurized by means of the downwardly rotating sealing cover 3, the preferential selection function formed by the liquid separation chamber 13, the first bifurcated flow channel 141 and the second bifurcated flow channel 14 is more obvious.

[0057] like Figures 2 to 5As shown, two third bifurcated flow channels 143 are symmetrically arranged at one end of the second bifurcated flow channel 142 away from the liquid separation chamber 13. The width of the third bifurcated flow channel 143 is smaller than that of the second bifurcated flow channel 142. Preferably, the width ratio of the third bifurcated flow channel 143 to the second bifurcated flow channel 142 is 1:2.

[0058] like Figure 3 and Figure 5 As shown, the third forked flow channel 143 and the first forked flow channel 141 are both bent and extended, so that the two third forked flow channels 143 and the two first forked flow channels 141 are annularly distributed to form a ring, and a dividing line e2 is formed between the third forked flow channel 143 and the first forked flow channel 141 .

[0059] like Figures 2 to 5 As shown, the chip body 1 is provided with sixteen reaction units 15. Among them, the two third bifurcated flow channels 143 are each connected to three reaction units 15, so that the second bifurcated flow channel 142 is connected to six reaction units 15, and the two first bifurcated flow channels 141 are each connected to five reaction units 15. Of course, the number of reaction units 15 can be increased or decreased as needed, and is not limited to sixteen.

[0060] Preferably, the reaction units 15 are annularly distributed inside the annular shape, and the reaction unit 15 connected to the first bifurcated flow channel 141 is located above the dividing line e2, and the reaction unit 15 connected to the third bifurcated flow channel 143 is located below the dividing line e2. This arrangement can not only make the structural design of the product more reasonable and compact, but also divide the reaction units 15 into different zones according to different bifurcated flow channels.

[0061] like Figure 3 and Figure 5 As shown, in order to facilitate flow diversion and ensure smooth liquid flow, the end of the third bifurcated flow channel 143 connected to the second bifurcated flow channel 142 is tilted from top to bottom along the liquid flow direction, so that the two third bifurcated flow channels 143 and the second bifurcated flow channel 142 form an inverted Y shape.

[0062] like Figures 3 to 10 As shown, the reaction unit 15 includes a liquid inlet channel 151, a drainage groove 152, a reaction chamber 153, a intercepting groove 154 and an exhaust channel 155 which are sequentially connected along the liquid flow direction, and a freeze-dried ball 4 is placed inside the reaction chamber 153. Among them, the end of the liquid inlet channel 151 away from the reaction chamber 153 is connected to the first bifurcated channel 141 or the third bifurcated channel 143, and the end of the exhaust channel 155 away from the reaction chamber 153 is provided with a first exhaust hole 1551 penetrating the chip body 1.

[0063] like Figures 3 to 10As shown, these first exhaust holes 1551 are arranged in two rings in an annular distribution, and two adjacent first exhaust holes 1551 are located on different rings. Compared with arranging all the first exhaust holes 1551 on the same ring, this arrangement can make the distance between two adjacent first exhaust holes 1551 larger, which helps to improve the mechanical strength of the chip body 1 and reduce the difficulty of processing. When the hot melt process is used to bond the hydrophobic breathable membrane 6, the larger gap also helps the implementation of the hot melt process and reduces the interference of the hot melt process.

[0064] like Figures 3 to 10 As shown, the drainage groove 152 includes a first side wall 152a, a second side wall 152b and a bottom surface 152c. The drainage groove 152 is extended along the tangent e1 of the reaction chamber 153 and is arranged on the bottom side wall of the reaction chamber 153, and the first side wall 152a and the second side wall 152b are respectively located on both sides of the tangent e1, and the first side wall 152a and the reaction chamber 153 are on the same side of the tangent e1. The drainage groove 152 forms a gap with a larger width on the side wall of the reaction chamber, and the gap is asymmetric, which helps to destroy the interfacial energy of the front end of the liquid flow, making it easier for the liquid sample to enter the reaction chamber 153. In addition, the liquid flow can be tangentially entered into the bottom of the reaction chamber 153 to avoid the liquid sample directly rushing into the exhaust channel 155 after entering the reaction chamber 153, which hinders the discharge of bubbles, and helps the contact reaction between the liquid sample and the freeze-dried ball 4.

[0065] like Figures 3 to 10 As shown, as a preference, the first side wall 152a includes a first straight segment 152a-1 and a first round chamfer 152a-2, one end of the first straight segment 152a-1 is connected to the liquid inlet channel 151, and the other end is smoothly connected to the side wall of the reaction chamber 153 through the first round chamfer 152a-2. The second side wall 152b includes a second straight segment 152b-1, an arc segment 152b-2 and a second round chamfer 152b-3. Among them, one end of the second straight segment 152b-1 is connected to the liquid inlet channel 151, and the other end is tangent to the arc segment 152b-2 close to the reaction chamber 153. The concave surface of the arc segment 152b-2 faces the center of the reaction chamber 153, and the other end of the arc segment 152b-2 is smoothly connected to the side wall of the reaction chamber 153 through the second round chamfer 152b-3. The arc segment 152b-2 can play a smooth guiding role on the liquid flow, and guide the liquid flow to the bottom of the freeze-dried ball 4 and contact it. Of course, the arc segment 152b-2 can also be replaced by an inclined straight line segment.

[0066] like Figures 3 to 10As shown, in addition, the groove depth of the drainage groove 152 gradually increases along the liquid flow direction, that is, gradually increases from the liquid inlet channel 151 to the reaction chamber 153. The drainage groove 152 has a change in groove depth, which helps to destroy the interfacial energy at the front end of the liquid flow. Specifically, the bottom surface 152c is a slope surface, so that the groove depth gradually increases. Preferably, the groove depth of the drainage groove 152 increases three times from the liquid inlet channel 151 to the reaction chamber 153.

[0067] like Figures 3 to 10 As shown, the intercepting groove 154 extends in the vertical direction and is arranged on the top side wall of the reaction chamber 153. Specifically, the intercepting groove 154 includes a straight section 154-1 and a gradient section 154-2 which are connected in sequence along the liquid flow direction, and the width of the gradient section 154-2 gradually decreases along the liquid flow direction. When the liquid sample wants to break through the notch and enter the straight section 154-1, a larger and more drastic change in the liquid surface contact angle is required, thereby inhibiting the liquid sample in the reaction chamber 153 from entering the exhaust channel before the gas, acting as a capillary valve. When the reaction chamber is gradually filled with liquid, the gas is first squeezed into the exhaust channel, and the gradient section is conducive to the gathering and discharge of bubbles in the intercepting groove. As the liquid spreads toward the intercepting groove, the liquid will converge into the intercepting groove to prevent the gas in the reaction chamber from being unable to be discharged.

[0068] Preferably, the width and length of the straight section 154 - 1 are both less than or equal to 1 mm, which is a tiny feature and has a better intercepting effect, and can better act as a capillary valve.

[0069] Preferably, the cross section of the gradual section 154-2 is semicircular. The semicircular shape has the characteristics of smooth transition, which is conducive to the gathering and discharge of bubbles and prevents bubbles from adhering to the corners. Of course, the cross section of the gradual section 154-2 can also be trapezoidal and limited to a semicircle.

[0070] like Figures 3 to 10 As shown, the bottom surface of the intercepting groove 154 is parallel to and higher than the bottom surface of the reaction chamber 153. This allows the side wall of the reaction chamber near the bottom of the chamber to maintain a complete circumference, which is conducive to the liquid preferentially filling the bottom of the reaction chamber, so that the gas is more easily discharged to the intercepting groove 154. Preferably, the depth ratio of the intercepting groove 154 to the reaction chamber 153 is 1:2-2:3.

[0071] When the liquid sample fills the reaction chamber 153 and spreads to the intercepting groove 154, the intercepting groove 154 acts as a capillary valve to prevent the liquid sample from entering the exhaust channel 155 before the gas. After the liquid sample on the bottom of the reaction chamber 153 is wrapped around and the gas on the top of the liquid sample is squeezed into the exhaust channel 155, the liquid sample will flow into the intercepting groove 154, thereby effectively suppressing the formation of bubbles inside the reaction chamber 153. In other words, it can effectively prevent the liquid from entering and blocking the exhaust channel 154 when the reaction chamber 153 is not fully filled, thereby causing the gas in the reaction chamber 153 to be unable to be discharged. In addition, while acting as a capillary valve, the intercepting groove 154 can also collect and accommodate bubbles in the reaction chamber 153, so that there are no dense bubbles in the circular groove of the reaction chamber 153.

[0072] In addition, when the liquid sample in the sample adding chamber 11 is pressurized by screwing down the sealing cover 3 or when heated, the hydraulic pressure in the device increases, thereby making it easier for the bubbles in the reaction chamber 153 to transfer to the intercepting groove 154 and be eliminated.

[0073] like Figure 3 to Figure 4 As shown, if the end face provided with the reaction unit 15 is the front face of the chip body 1. The front face of the chip body 1 is sealed and paved with a thin sheet 5. The thin sheet 5 can be a pressure-sensitive film or a transparent PC cover sheet. The back side of the chip body 1 is fixedly provided with an annular protrusion 16 on the periphery of these first exhaust holes 1551, and the inner side of the annular protrusion 16 is sequentially paved with a hydrophobic breathable membrane 6 and a cover plate 7. The cover plate 7 is provided with an exhaust groove 71 on the end face facing the first exhaust holes 1551, and a second exhaust hole 711 is provided at the center of the exhaust groove 71. The cover plate 7 is in the shape of a thin sheet, which is used to isolate the hydrophobic breathable membrane 6 to prevent the hydrophobic breathable membrane 6 from being contaminated by external contact. The exhaust groove 71 can increase the distance between the hydrophobic breathable membrane 6 and the cover plate 7, which is conducive to the discharge of gas.

[0074] Specifically, the hydrophobic breathable membrane 6 is bonded to the back of the chip body 1 by hot melting, and the hydrophobic breathable membrane 6 seals each first exhaust hole 1551 separately to prevent the liquid samples from mixing between different reaction units 15 through the first exhaust holes 1551 and affecting the detection results. Of course, the hydrophobic breathable membrane 6 can also be physically locked and attached, such as double-sided tape, pressure-sensitive adhesive, etc. The edge of the cover plate 7 is fixedly connected to the inner circumference of the annular protrusion 16 by gluing or the like.

[0075] The utility model also discloses and protects an in vitro detection device, including a detector and a microfluidic chip with the structure as described above. The detector has a detection station where the microfluidic chip can be placed, which is used to detect the liquid sample in the reaction chamber. In addition, other specific structures and detection principles of the detector belong to the prior art and will not be repeated here.

[0076] The above is only a specific implementation method of the utility model, but the design concept of the utility model is not limited to this. Any non-substantial changes to the utility model using this concept shall be deemed as an infringement of the protection scope of the utility model.

Claims

1. A microfluidic chip, comprising a chip body (1) provided with at least one reaction unit (15), wherein the reaction unit (15) comprises a liquid inlet channel (151), a drainage groove (152), a reaction chamber (153) and an exhaust channel (155) which are sequentially connected along a liquid flow direction; characterized in that: The drainage groove (152) is extended along a tangent line (e1) of the reaction chamber (153) and is arranged on the bottom side wall of the reaction chamber (153), and the first side wall (152a) and the second side wall (152b) of the drainage groove (152) are respectively located on both sides of the tangent line (e1).

2. A microfluidic chip according to claim 1, characterized in that: An arc segment (152b-2) is provided at one end of the second side wall (152b) close to the reaction chamber (153), and the concave surface of the arc segment (152b-2) faces the center of the reaction chamber (153).

3. A microfluidic chip according to claim 1, characterized in that: A cut-off groove (154) is provided on the top side wall of the reaction chamber (153) extending in the vertical direction, and the other end of the cut-off groove (154) is connected to the exhaust flow channel (155); the cut-off groove (154) comprises a straight section (154-1) and a gradient section (154-2) which are connected in sequence along the liquid flow direction, and the width of the gradient section (154-2) gradually decreases along the liquid flow direction.

4. A microfluidic chip according to claim 1, characterized in that: The chip body (1) is provided with a liquid separation chamber (13), the top of the liquid separation chamber (13) is provided with a main flow channel (12), the bottom of the liquid separation chamber (13) is provided with a second branched flow channel (142), and first branched flow channels (141) are provided on both sides of the second branched flow channel (142), and the width of the first branched flow channel (141) is smaller than the width of the second branched flow channel (142); the left and right side walls of the liquid separation chamber (13) are arranged in an eight-shaped shape, and the bottom is stepped between the first branched flow channel (141) and the second branched flow channel (142); the second branched flow channel (142) and the first branched flow channel (141) are both connected to a plurality of reaction units (15).

5. A microfluidic chip according to claim 4, characterized in that: Two third branched flow channels (143) are symmetrically arranged at one end of the second branched flow channel (142) away from the liquid separation chamber (13); the two third branched flow channels (143) and the two first branched flow channels (141) are annularly distributed to form a ring, and a dividing line (e2) is formed between the third branched flow channels (143) and the first branched flow channels (141); a plurality of reaction units (15) are annularly distributed on the inner side of the ring, and the reaction unit (15) connected to the first branched flow channel (141) is located above the dividing line (e2), and the reaction unit (15) connected to the third branched flow channel (143) is located below the dividing line (e2).

6. A microfluidic chip according to claim 1, characterized in that: A first exhaust hole (1551) is provided at one end of the exhaust channel (155) away from the reaction chamber (153), and a plurality of first exhaust holes (1551) are annularly distributed to form two rings, and two adjacent first exhaust holes (1551) are located on different rings.

7. A microfluidic chip according to claim 1, characterized in that: The chip body (1) is provided with a sample loading chamber (11), the sample loading port of the sample loading chamber (11) is threadedly connected to a sealing cover (3), the sealing cover (3) is fixed with a plug body (2), and the plug body (2) can be movably sealed and fitted to the inner wall of the sample loading chamber (11).

8. A microfluidic chip according to claim 7, characterized in that: The inner top surface of the sealing cover (3) is fixedly provided with a boss (31), and the boss (31) is provided with a mounting hole (311). The plug body (2) is provided with a clamping piece (21) and an annular flange (22), and the clamping piece (21) is clamped in the mounting hole (311), and the outer peripheral surface of the annular flange (22) is sealed and affixed to the inner wall of the sample adding chamber (11).

9. An in vitro detection device, characterized in that: A microfluidic chip comprising a reaction unit and a structure as described in any one of claims 1 to 8, wherein the reaction unit is used to detect a liquid sample in a reaction chamber (153).

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