Microfluidic chip

Abstract

The invention provides a micro-fluidic chip. The micro-fluidic chip comprises a substrate, and the substrate comprises a sample groove, at least one first separation groove, at least one second separation groove, a first micro-channel and a second micro-channel. The first separation groove is communicated with the sample groove through the first micro-channel, the communication position of the first separation groove and the first micro-channel is located at the top of the side wall of the first separation groove, the second micro-channel is communicated with the first micro-channel, and the second separation groove is communicated with the first separation groove through the first micro-channel and the second micro-channel. Therefore, after the separation of the at least two separation grooves, the plasma with lower blood cell content or completely removed blood cells can be obtained, so that the separation degree of the micro-fluidic chip on the blood cells and the plasma is improved, and the detection precision is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of analytical detection, and in particular, to a microfluidic chip. Background Art

[0002] Microfluidics technology has great potential in the fields of biology, chemistry, medicine, etc., and has developed into a new research field that intersects multiple disciplines such as biology, chemistry, medicine, fluidics, electronics, materials, and machinery. Centrifugal microfluidics that drives fluids and controls fluid volume in microchannels through centrifugal force has the advantages of high integration, automation, miniaturization, and parallel detection of multiple samples or indicators, and has become an important branch in the field of microfluidics technology.

[0003] However, due to the limitations of its own structural design, when the current microfluidic chip is performing detection, it is prone to a situation where the separation efficiency is difficult to further improve, resulting in inaccurate detection results, thus unable to meet the user's demand for high detection accuracy. Summary of the Invention

[0004] The first aspect of the present disclosure provides a microfluidic chip, which includes a substrate. The substrate includes a sample tank, at least one first separation tank, at least one second separation tank, a first microchannel, and a second microchannel. The first separation tank is communicated with the sample tank through the first microchannel, and the communication position between the first separation tank and the first microchannel is located at the top of the side wall of the first separation tank. The second microchannel is communicated with the first microchannel, and the second separation tank is communicated with the first separation tank through the first microchannel and the second microchannel.

[0005] In the above solution, when blood enters the separation tank under the action of centrifugal force, it will first fill the first separation tank, and then enter the subsequent second separation tank through the first microchannel at the top. During this process, the blood cells with a larger density will concentrate at the bottom of the first separation tank and the second separation tank. Thus, with the separation effect of the first separation tank and the second separation tank, the content of blood cells included in the blood will decrease. After separation by at least two separation tanks, plasma with a lower blood cell content or completely removed blood cells can be obtained. In this way, the separation degree of blood cells and plasma by the microfluidic chip can be improved to improve the detection accuracy.

[0006] In a specific embodiment of the first aspect of the present disclosure, the substrate includes a rotation axis center. The distance from the sample tank to the rotation axis center is less than the distance from the first separation tank to the rotation axis center, and the distance from the first separation tank to the rotation axis center is less than the distance from the second separation tank to the rotation axis center. Thus, when the microfluidic chip is rotated, under the action of centrifugal force, the blood sample will automatically enter the first separation tank through the sample tank and enter the second separation tank through the first separation tank.

[0007] Optionally, the sample slot is located on the side of the first microchannel facing the rotation axis, and the first separation slot is located on the side of the first microchannel away from the rotation axis, so that the blood sample can enter the first separation slot from the sample slot under the action of centrifugal force.

[0008] In a specific embodiment of the first aspect of the present disclosure, the microfluidic chip may further include a transition groove, which is located between the first microfluidic channel and the second microfluidic channel and communicates with the first microfluidic channel and the second microfluidic channel. The transition groove can cooperate with the first separation groove and the second separation groove to separate blood cells, and can be used as an auxiliary sample groove for adding samples or other reagents.

[0009] Optionally, the distance from the position of the transition groove connected to the second microchannel to the rotation axis is greater than the distance from the position of the transition groove connected to the first microchannel to the rotation axis. In this way, under the action of centrifugal force, the blood sample can enter the second microchannel from the first microchannel via the transition groove.

[0010] In a specific embodiment of the first aspect of the present disclosure, the microfluidic chip may further include a first quantitative groove and a third microfluidic channel, the first quantitative groove is located between the second microfluidic channel and the third microfluidic channel, the third microfluidic channel is located between the second separation groove and the first quantitative groove, the second microfluidic channel is located between the first quantitative groove and the transition groove, and the distance from the second separation groove to the rotation axis is greater than the distance from the first quantitative groove to the rotation axis. The first quantitative groove can store plasma in the blood sample for subsequent detection.

[0011] Optionally, the connection position between the third microchannel and the second separation tank is located at the top of the side wall of the second separation tank. In this way, the blood cell capture ability of the second separation tank can be increased, so that the blood cells are more easily gathered in the second separation tank, thereby reducing the amount of blood cells remaining in the third microchannel.

[0012] Optionally, the second microchannel is connected to the first quantitative groove at the top of the side wall of the first quantitative groove, and the third microchannel is connected to the first quantitative groove at the top of the side wall of the first quantitative groove. In this way, under the action of centrifugal force, if the plasma entering the first quantitative groove still includes blood cells, the connection between the first quantitative groove and the third microchannel can further separate the blood cells in the plasma to further reduce the content of blood cells entering the second separation groove.

[0013] In a specific embodiment of the first aspect of the present disclosure, the microfluidic chip may further include a mixing tank and a fourth microfluidic channel, the mixing tank is connected to the third microfluidic channel through the fourth microfluidic channel, and the distance from the mixing tank to the rotation axis is greater than the distance from the first quantitative tank to the rotation axis.

[0014] In the above solution, if there are still residual blood cells in the plasma entering the second separation tank, these blood cells will gather at the bottom of the second separation tank under the action of centrifugal force. Since the fourth microchannel is connected to the third microchannel, the blood cells will not enter the mixing tank through the fourth microchannel, thereby improving the accuracy of the test results.

[0015] In a specific embodiment of the first aspect of the present disclosure, the fourth microchannel is a siphon channel, and the distance from a part of the fourth microchannel to the rotation axis is less than the distance from the position where the fourth microchannel is connected to the third microchannel to the rotation axis.

[0016] Optionally, the microfluidic chip is configured to have a first rotation speed and a second rotation speed. The fluid in the sample tank enters the third microchannel and the second separation tank at the first rotation speed, and a part of the fluid in the third microchannel and the first metering tank enters the mixing tank at the second rotation speed.

[0017] Optionally, the first rotation speed is equal to the second rotation speed.

[0018] Optionally, the first rotation speed is greater than the second rotation speed.

[0019] In a specific embodiment of the first aspect of the present disclosure, the microfluidic chip may further include a delivery channel and at least one detection group. The detection group is connected to the mixing tank through the delivery channel, and the detection group is configured to detect the liquid entering from the mixing tank via the delivery channel.

[0020] In a specific embodiment of the first aspect of the present disclosure, the detection group includes a second metering tank, a fluid tank, a fifth microchannel, a detection tank, and a sixth microchannel. The second metering tank is connected to the delivery channel, the fluid tank is connected to the second metering tank through the fifth microchannel, and the detection tank is connected to the fluid tank through the sixth microchannel.

[0021] In a specific embodiment of the first aspect of the present disclosure, the transition tank is reused as a filtration tank, or the microfluidic chip may further include a filtration tank, which is located between the first microchannel and the transition tank. In this way, the filtration tank can be used to directly filter out large particle objects in the plasma, such as chylomicrons and blood cells, etc., to further improve the separation efficiency of the plasma. It should be noted that setting the filtration tank after the separation tank can ensure that most of the blood cells in the sample have been removed by the separation tank before reaching the filtration tank, thereby avoiding blockage of the flow channel (such as the filter membrane) due to the aggregation of a large number of blood cells at the filtration tank.

[0022] Optionally, a filter membrane is provided in the filtration tank, and the filter membrane is located between the position where the filtration tank is connected to the first microchannel and the position where the filtration tank is connected to the transition tank.

[0023] Optionally, the filtration tank is configured to filter out particle objects with a size not less than 100 nanometers.

[0024] Optionally, the material of the filter membrane includes any one of polycarbonate, polyethersulfone, nylon, and cellulose acetate.

[0025] In a specific embodiment of the first aspect of the present disclosure, the microfluidic chip may further include a cover plate, which is located on the side of the substrate where the sample chamber is provided and is hermetically sealed with the substrate. Description of the Drawings

[0026] Figure 1 A schematic plan view of a partial structure of a microfluidic chip provided for an embodiment of the disclosure.

[0027] Figure 2 For Figure 1 A cross-sectional view of a partial structure of the microfluidic chip shown.

[0028] Figure 3 For Figure 2 A schematic diagram of the working principle of the microfluidic chip shown.

[0029] Figure 4 A schematic plan view of a partial structure of another microfluidic chip provided for an embodiment of the disclosure.

[0030] Figure 5 A physical diagram of a microfluidic chip provided for an embodiment of the present disclosure.

[0031] Figure 6 A schematic plan view of a partial structure of another microfluidic chip provided for an embodiment of the disclosure.

[0032] Figure 7A A schematic plan view of a partial structure of another microfluidic chip provided for an embodiment of the present disclosure.

[0033] Figure 7B For Figure 7A A physical diagram of the microfluidic chip corresponding to the structure shown.

[0034] Figure 8A A schematic plan view of a partial structure of another microfluidic chip provided for an embodiment of the present disclosure.

[0035] Figure 8B For Figure 8A A physical diagram of the microfluidic chip corresponding to the structure shown.

[0036] Figures 9A to 9E A schematic diagram of the fluid state of a microfluidic chip provided for an embodiment of the present disclosure at different stages.

[0037] Description of the Reference Numerals: 10 - Rotating axis; 110 - Sample slot; 200 - Separation slot; 210 - First separation slot; 220 - Second separation slot; 230 - Transition slot; 310 - First microchannel; 320 - Second microchannel; 330 - Third microchannel; 340 - Fourth microchannel; 350 - Fifth microchannel; 360 - Sixth microchannel; 410 - First quantitative slot; 420 - Second quantitative slot; 500 - Fluid slot; 600 - Mixing slot; 700 - Delivery channel; 800 - Detection group; 810 - Detection slot; 900 - Filtering slot. Detailed implementation

[0038] The following will clearly and completely describe the technical solutions in the embodiments of this specification with reference to the accompanying drawings in the embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this specification.

[0039] Blood biochemical tests are an important and commonly used clinical diagnostic method. Usually, serum or plasma is separated from blood cells by centrifugation, and the content of various biochemical indicators in the serum or plasma is detected to evaluate the body's metabolic function and health status. If the blood cells are not separated thoroughly, hemolysis will occur, and substances with high concentrations in the blood cells (such as K, CK, LDH, AST, etc.) will enter the serum or plasma, resulting in inaccurate test results, such as being too high. In addition, incomplete separation may also cause the presence of blood cell components in the serum or plasma, and these components will interfere with the colorimetric or turbidimetric methods commonly used in biochemical tests, thus affecting the accuracy of the test results. Additionally, for severely lipemic samples, chylomicrons suspended in the serum or plasma will also interfere with the colorimetric or turbidimetric methods commonly used in biochemical tests. If the separation degree of chylomicrons is insufficient, it will also lead to inaccurate test results.

[0040] Due to its miniaturization, high integration, simplicity, and rapidity, microfluidic chip technology has been widely applied in the field of biomedical testing. Because microfluidic chips have the advantage of high integration, especially when users use centrifugal microfluidic chips, they tend to integrate the separation step of blood cells and plasma on the chip. In this way, anticoagulated whole blood can be directly used, simplifying the operation process and improving the detection efficiency. Since centrifugal microfluidic chips are generally small in size, the centrifugal force obtained at ordinary rotational speeds is also small, resulting in incomplete separation of blood cells and inaccurate subsequent test results. In practical applications, the separation of blood cells can be made more thorough by increasing the rotational speed or extending the centrifugation time. However, increasing the rotational speed also raises the performance requirements for the centrifugation module and the encapsulation of the microfluidic chip, leading to increased costs and reduced reliability of the microfluidic chip. Or, if the separation time is extended, the separation efficiency can be improved, but the detection efficiency will be reduced. Additionally, when using a microfluidic chip to detect lipemic samples, in order to obtain accurate results, the chylomicrons in the plasma are separated by methods such as ether extraction, precipitation separation, or high-speed centrifugation and then added to the microfluidic chip for detection. This results in low detection efficiency and a large amount of sample required.

[0041] In view of this, at least one embodiment of the present disclosure provides a microfluidic chip to at least solve the above technical problems. The microfluidic chip includes a substrate, and the substrate includes a sample tank, at least one first separation tank, at least one second separation tank, a first microchannel, and a second microchannel. The first separation tank is communicated with the sample tank through the first microchannel, and the communication position between the first separation tank and the first microchannel is located at the top of the side wall of the first separation tank. The second microchannel is communicated with the first microchannel, and the second separation tank is communicated with the first separation tank through the first microchannel and the second microchannel. In this microfluidic chip, when blood enters the separation tank under the action of centrifugal force, it will first fill the first separation tank and then enter the subsequent second separation tank through the first microchannel at the top. During this process, the blood cells with a larger density will concentrate at the bottom of the first separation tank and the second separation tank. Thus, with the separation effect of the first separation tank and the second separation tank, the content of blood cells included in the blood will decrease. After separation through at least two separation tanks, plasma with a lower blood cell content or completely free of blood cells can be obtained. In this way, the separation degree of blood cells and plasma by the microfluidic chip can be improved to enhance the detection accuracy.

[0042] Next, with reference to the drawings, the specific structure of the microfluidic chip according to at least one embodiment of the present disclosure will be described in detail. In these drawings, a spatial rectangular coordinate system is established based on the plane where the substrate of the microfluidic chip is located to present the arrangement positions of various structures in the microfluidic chip. In this spatial rectangular coordinate system, the X-axis and the Y-axis are parallel to the plane where the substrate is located, and the Z-axis is perpendicular to the plane where the substrate is located.

[0043] AsFigure 1 and Figure 3 As shown in Figure 3 , the microfluidic chip includes a substrate, which includes a sample tank 110, at least two separation tanks 200 (such as a first separation tank 210 and a second separation tank 220), a first microchannel 310, and a second microchannel 320. Both the sample tank 110 and the first separation tank 210 are in communication with the first microchannel 310. The communication position between the first separation tank 210 and the first microchannel 310 is at the top of the side wall of the first separation tank 210. The second microchannel 320 is in communication with the first microchannel 310, and the second separation tank 220 is in communication with the first separation tank 210 through the first microchannel 310 and the second microchannel 320. Thus, after the blood sample is added from the sample tank 110, under the action of centrifugal force, it will flow through the first microchannel 310 (the part between the first separation tank 210 and the sample tank 110), the first separation tank 210, the first microchannel 310 (the part of the first separation tank 210 away from the sample tank 110), the second microchannel 320, and the second separation tank 220 in sequence. It should be noted that the communication between the above-mentioned separation tanks and microchannels can be direct communication or indirect communication. In actual operation, after the blood sample is injected into the sample tank 110, the blood will pass through the first separation tank 210, the first microchannel 310, the transition tank 230, the second microchannel 320 in sequence, and then enter the second separation tank 220 (or the first quantitative tank 410 described below). During this process, the blood cells in the blood will be separated step by step, so as to separate the blood cells and plasma.

[0044] As Figure 3 shown in Figure 3 , when the blood enters the separation tank 200 under the action of centrifugal force, it will first fill the first separation tank 210. During this process, the blood will flow along the side wall of the first separation tank 210 to the bottom of the first separation tank 210 under the action of centrifugal force, and the blood cells with a large mass density will gather at the bottom of the first separation tank 210 under the action of centrifugal force. Thus, after the first separation tank 210 is filled with blood, the upper layer of the first separation tank 210 mainly gathers plasma. As the blood continues to flow in, the blood in the first separation tank 210 enters the subsequent structures such as the second microchannel 320 and the second separation tank 220 through the first microchannel 310 at the top. At this time, the main component of the blood sample flowing into the first microchannel 310 again through the first separation tank 210 is plasma. Similarly, after the blood sample enters the second separation tank 220 through the second microchannel 320, the blood cells will be separated again. Thus, after being separated by at least two separation tanks 200, plasma with a lower blood cell content or completely removed blood cells can be obtained. In this way, the separation degree of blood cells and plasma by the microfluidic chip can be improved to improve the detection accuracy.

[0045] In at least one embodiment of the present disclosure, refer back to Figure 1 and Figure 2The substrate includes a rotation axis 10, the distance between the sample slot 110 and the rotation axis 10 is smaller than the distance between the separation slot 200 and the rotation axis 10, the distance between the first separation slot 210 and the rotation axis 10 is smaller than the distance between the second separation slot 220 and the rotation axis 10, and the distance between the separation slot 200 far from the sample slot 110 and the rotation axis 10 is larger than the distance between the separation slot 200 near the sample slot 110 and the rotation axis 10. Thus, when the microfluidic chip is rotated, under the action of centrifugal force, the blood sample will automatically enter the first separation slot 210 farther from the rotation axis 10 through the sample slot 110 closer to the rotation axis 10, and enter the second separation slot 220 farther from the rotation axis 10 through the first separation slot 210.

[0046] In at least one embodiment of the present disclosure, the sample slot 110 is located on the side of the first microchannel 310 facing the rotation axis 10, and the first separation slot 210 is located on the side of the first microchannel 310 away from the rotation axis 10. In this way, the blood sample can enter the first separation slot 210 from the sample slot 110 under the action of centrifugal force.

[0047] In at least one embodiment of the present disclosure, Figure 1 and Figure 2 As shown, the microfluidic chip may further include a transition groove 230, which is located between the first microfluidic channel 310 and the second microfluidic channel 320 and communicates with the first microfluidic channel 310 and the second microfluidic channel 320. The transition groove 230 may cooperate with the first separation groove 210 and the second separation groove 220 to separate blood cells, and may be used as an auxiliary sample groove 110 for adding samples or other reagents.

[0048] In at least one embodiment of the present disclosure, Figure 1 and Figure 2 As shown, the distance from the position where the transition groove 230 is connected to the second microchannel 320 to the rotation axis 10 is greater than the distance from the position where the transition groove 230 is connected to the first microchannel 310 to the rotation axis 10. In this way, under the action of centrifugal force, it is convenient for the blood sample to enter the second microchannel 320 from the first microchannel 310 via the transition groove 230.

[0049] In the embodiments of the present disclosure, under the condition that the above-mentioned design is satisfied, there is no restriction on the specific arrangement positions of the various structures in the substrate, the shapes of the various grooves and microchannels, etc., and they can be designed according to the actual process requirements. For example, an example structure can be referred to as follows: Figure 4 The design structure shown.

[0050] In an embodiment of the present disclosure, the number of the first separation grooves 210 is not limited and can be set according to actual process requirements. It should be noted that the more the number of the first separation grooves 210, the higher the separation effect on blood cells. For example, in some embodiments, the first separation groove 210 can be set to only one as shown in Figures 1 to 4 ; or, in some other embodiments, as shown in Figure 4 , the first separation grooves 210 are set to at least two connected in series on the first microchannel 310, so as to improve the separation efficiency of blood cells.

[0051] In at least one embodiment of the present disclosure, as shown in Figure 5 and Figure 6 , the substrate of the microfluidic chip may further include a first quantitative groove 410 and a third microchannel 330. The first quantitative groove 410 is located between the second microchannel 320 and the third microchannel 330. The third microchannel 330 is located between the second separation groove 220 and the first quantitative groove 410. The second microchannel 320 is located between the first quantitative groove 410 and the transition groove. The distance from the second separation groove 220 to the rotation axis 10 is greater than the distance from the first quantitative groove 410 to the rotation axis 10. The first quantitative groove 410 can store the plasma in the blood sample for subsequent detection.

[0052] In at least one embodiment of the present disclosure, as shown in Figure 5 and Figure 6 , the connection position of the third microchannel 330 and the second separation groove 220 is located at the top of the side wall of the second separation groove 220. In this way, the capture ability of the second separation groove 220 for blood cells can be increased, so that the blood cells are more likely to aggregate in the second separation groove 220, thereby reducing the amount of remaining blood cells at the third microchannel 330.

[0053] In at least one embodiment of the present disclosure, as shown in Figure 5 and Figure 6 , the connection position of the second microchannel 320 and the first quantitative groove 410 is located at the top of the side wall of the first quantitative groove 410, and the connection position of the third microchannel 330 and the first quantitative groove 410 is located at the top of the side wall of the first quantitative groove 410. If the plasma entering the first quantitative groove 410 still includes blood cells and the blood cells escape from the bottom of the first quantitative groove, then under the action of centrifugal force, the blood cells with large mass density will enter the second separation groove 220 through the third microchannel 330 and aggregate at one end of the second separation groove 220 away from the rotation axis 10, thereby further reducing the blood cell content in the plasma of the first quantitative groove 410; in addition, the first quantitative groove 410 has enough space to store the plasma sample from which blood cells have been separated to ensure the plasma sample volume for subsequent detection, that is, the plasma sample in the first quantitative groove 410 will enter the subsequent flow channels (such as the following fourth microchannel 340, etc.).

[0054] In at least one embodiment of the present disclosure, as Figure 5 and Figure 6 shown, the substrate of the microfluidic chip may further include a mixing tank 600 and a fourth microchannel 340. The mixing tank 600 is communicated with the third microchannel 330 through the fourth microchannel 340. The distance from the mixing tank 600 to the rotation axis 10 is greater than the distance from the first metering tank 410 to the rotation axis 10. If there are still residual blood cells in the plasma entering the second separation tank 220, these blood cells will aggregate at the bottom of the second separation tank 220 under the action of centrifugal force. Since the fourth microchannel 340 is communicated with the third microchannel 330, the blood cells will not enter the mixing tank 600 through the fourth microchannel 340, thereby improving the accuracy of the test result.

[0055] In at least one embodiment of the present disclosure, as Figure 5 and Figure 6 shown, the fourth microchannel 340 may be a siphon channel, and the distance from a part of the fourth microchannel 340 to the rotation axis 10 is less than the distance from the position where the fourth microchannel 340 is communicated with the third microchannel 330 to the rotation axis 10. For example, the microfluidic chip is configured to have a first rotation speed and a second rotation speed. The fluid in the sample tank 110 enters the third microchannel 330 and the second separation tank 220 at the first rotation speed, and a part of the fluid in the third microchannel 330 and the first metering tank 410 enters the mixing tank 600 at the second rotation speed. Thus, at the first rotation speed, after the blood fills the first metering tank 410, the third microchannel 330 and the second separation tank 220, the blood sample (plasma) will not enter the fourth microchannel 340; then at the second rotation speed, the blood sample (plasma) starts to enter the mixing tank 600 through the fourth microchannel 340 under the siphon action.

[0056] It should be noted that in the embodiments of the present disclosure, the first rotation speed may be equal to or greater than the second rotation speed. In both of these cases, it can ensure that the siphon action (capillary force action) enters the mixing tank 600.

[0057] For example, in some embodiments of the present disclosure, the first rotation speed and the second rotation speed are equal. Thus, at the first rotation speed, after the blood fills the first metering tank 410, the third microchannel 330 and the second separation tank 220, the rotation stops. Then, the fourth microchannel 340 enters the plasma under the capillary force, and then the motor is started to the second rotation speed. Under the siphon action, the blood sample (plasma) starts to enter the mixing tank 600 through the fourth microchannel 340. In this case, the first rotation speed and the second rotation speed are equal.

[0058] For example, in some other embodiments of the present disclosure, the first rotation speed is greater than the second rotation speed. Thus, at the first rotation speed, after the blood fills the first metering tank 410, the third microchannel 330, and the second separation tank 220, the rotation speed is directly reduced to the second rotation speed. The second rotation speed is small enough so that the siphon effect can overcome the centrifugal force, thereby ensuring that the blood sample can still enter the mixing tank 600 through the fourth microchannel 340. In this case, since the microfluidic chip is always in a rotating state, it can ensure that the blood cells are always under the action of centrifugal force, thereby reducing the risk of inaccurate test results caused by the backflow of blood cells.

[0059] In at least one embodiment of the present disclosure, refer back to Figure 5 , the microfluidic chip may further include a delivery channel 700 and at least one detection group 800. The detection group 800 is connected to the mixing tank 600 through the delivery channel 700, and the detection group 800 is configured to detect the liquid entering from the mixing tank 600 via the delivery channel 700.

[0060] In at least one embodiment of the present disclosure, refer back to Figure 5 , the detection group 800 includes a second metering tank 420, a fluid tank 500, a fifth microchannel 350, a detection tank 810, and a sixth microchannel 360. The second metering tank 420 is in communication with the delivery channel 700, the fluid tank 500 is in communication with the second metering tank 420 through the fifth microchannel 350, and the detection tank 810 is in communication with the fluid tank 500 through the sixth microchannel 360. The second metering tank 420 can pre-store the amount of the fluid finally used for detection to ensure the detection accuracy. The fluid tank 500 can play a buffering role to prevent the fluid in the second metering tank 420 from entering the detection tank 810 in advance.

[0061] In at least one embodiment of the present disclosure, as Figures 7A to 8B shown, the microfluidic chip may further include a filtration tank 900. The filtration tank 900 is located between the first microchannel 310 and the transition tank 230. Thus, the filtration tank 900 can directly filter out large particulate objects such as chylomicrons and blood cells in the plasma to further improve the separation efficiency of the plasma. It should be noted that the filtration tank 900 is arranged after the first separation tank 210, so that most of the blood cells in the blood sample have been removed by the first separation tank 210 before reaching the filtration tank 900, thereby avoiding the blockage of the flow channel (such as the filter membrane) caused by the aggregation of a large number of blood cells at the filtration tank 900.

[0062] For example, the filtration tank 900 includes a chamber and a filter membrane. The filter membrane is located in the chamber and is located between the position of the filtration tank 900 in communication with the first microchannel 310 and the position of the filtration tank 900 in communication with the transition tank 230, so as to filter all the blood samples flowing out of the first separation tank 210.

[0063] For example, as Figures 7A to 8B shown, the filtration tank 900 is configured to filter out particulate objects with a size not less than 100 nanometers, such as chylomicrons and the like.

[0064] For example, the material of the filter membrane may include polycarbonate, polyethersulfone, nylon, cellulose acetate, and the like.

[0065] In at least one embodiment of the present disclosure, the filtration tank 900 can also serve as a sample loading tank. For example, the plasma to be detected can be directly added. If the blood lipids in the plasma are high, they can be filtered and separated through the filter membrane. For example, in some detection scenarios, the plasma sample to be detected is limited in quantity due to the source (such as small individual animals such as birds, etc.), so it is necessary to minimize the amount of plasma loss caused by separation. In this case, the filtration tank 900 can be directly used for separation to reduce the loss of plasma.

[0066] In some embodiments of the present disclosure, as Figure 7A and Figure 7B shown, a filter membrane can be provided in the transition tank 230 to take into account the functions of the above-mentioned filtration tank 900, so that the above-mentioned filtration tank 900 does not need to be additionally provided, thereby simplifying the structure of the microfluidic chip.

[0067] In other embodiments of the present disclosure, as Figure 8A and Figure 8B shown, the filtration tank 900 can be separately provided independent of the transition tank 230 to avoid the influence of the filter membrane setting on the function of the transition tank 230.

[0068] It should be noted that the substrate may also include structures such as an overflow tank, a dilution tank, an air inlet hole, a waste liquid tank, etc. For details, reference can be made to the relevant designs in the current microfluidic chip, which will not be elaborated here.

[0069] Next, in combination with Figures 9A to 9E , an exemplary description will be given of the structure of the microfluidic chip of the present disclosure and the flow state of the fluid (plasma) therein at different times during application, so as to briefly introduce the working principle of the microfluidic chip.

[0070] As Figure 9A shown, a plasma sample is added to the sample tank 110.

[0071] As Figures 9A to 9B shown, the microfluidic chip is driven to have a first rotational speed. Under the action of centrifugal force, the plasma sample enters the first separation tank 210, the filtration tank 900, the transition tank 230 in sequence through the first microchannel 310, and further enters the first quantitative tank 410 via the second microchannel 320, and then enters the second separation tank 220 via the third microchannel 330. During this process, the blood cells in the plasma sample will be separated. For the specific process, reference can be made to the relevant descriptions in the foregoing embodiments, which will not be elaborated here.

[0072] As Figures 9B to 9C shown, stop rotating (or reduce the rotational speed to the second rotational speed), and the plasma sample enters the fourth microfluidic channel 340 (siphon channel) under capillary action; rotate the microfluidic chip (at the second rotational speed), and the plasma sample in the fourth microfluidic channel 340 will be connected to the mixing tank 600, and then under centrifugal force and capillary action, the plasma sample is introduced into the mixing tank 600. The relationship between the second rotational speed and the first rotational speed can be referred to the relevant descriptions in the foregoing embodiments, and will not be elaborated here.

[0073] As Figures 9C to 9D shown, the same method of adjusting the rotational speed is also adopted to enable the plasma sample in the mixing tank 600 to enter the delivery channel 700 under capillary action. Since the second metering tank 420 is connected to the delivery channel 700, the plasma sample will fill the second metering tank 420 while entering the delivery channel 700.

[0074] As Figures 9D to 9E shown, increase the rotational speed to enable the plasma sample stored in the second metering tank 420 to enter the detection tank 810.

[0075] In at least one embodiment of the present disclosure, referring back to Figure 2 , the microfluidic chip may further include a cover plate 2, the cover plate is located on the side of the substrate 1 where the sample tank 110 is provided, and is hermetically encapsulated with the substrate 1. For example, the cover plate 2 and the substrate 1 can be adhesively bonded together in a watertight manner.

[0076] The above are only the preferred embodiments of this specification and are not intended to limit this specification. Any modifications, equivalent replacements, etc. made within the spirit and principles of this specification shall be included within the protection scope of this specification.

Claims

1. A microfluidic chip, characterized in that, The invention comprises a substrate, wherein the substrate comprises: Sample trough; at least one first separation slot and a first microfluidic channel, wherein the first separation slot is connected to the sample slot through the first microfluidic channel, and the connecting position between the first separation slot and the first microfluidic channel is located at the top of the side wall of the first separation slot; A second separation groove and a second microfluidic channel, wherein the second microfluidic channel is communicated with the first microfluidic channel, and the second separation groove is communicated with the first separation groove through the first microfluidic channel and the second microfluidic channel.

2. The microfluidic chip according to claim 1, wherein The substrate comprises a rotation axis, the distance from the sample slot to the rotation axis is smaller than the distance from the first separation slot to the rotation axis, and the distance from the first separation slot to the rotation axis is smaller than the distance from the second separation slot to the rotation axis; Preferably, the sample slot is located on a side of the first microfluidic channel facing the rotation axis, and the first separation slot is located on a side of the first microfluidic channel away from the rotation axis.

3. The microfluidic chip according to claim 2, wherein Also included is a transition groove, wherein the transition groove is located between the first microfluidic channel and the second microfluidic channel and is in communication with the first microfluidic channel and the second microfluidic channel; Preferably, the distance from the position of the transition groove communicating with the second microchannel to the rotation axis is greater than the distance from the position of the transition groove communicating with the first microchannel to the rotation axis.

4. The microfluidic chip according to claim 3, characterized in that, It also includes a first quantitative groove and a third microfluidic channel, wherein, The first quantitative groove is located between the second microchannel and the third microchannel, the third microchannel is located between the second separation groove and the first quantitative groove, the second microchannel is located between the first quantitative groove and the transition groove, and the distance from the second separation groove to the rotation axis is greater than the distance from the first quantitative groove to the rotation axis; Preferably, the communication position between the third microchannel and the second separation groove is located at the top of the side wall of the second separation groove; Preferably, the communication position between the second microchannel and the first quantitative groove is located at the top of the side wall of the first quantitative groove, and the communication position between the third microchannel and the first quantitative groove is located at the top of the side wall of the first quantitative groove.

5. The microfluidic chip according to claim 4, characterized in that, It also includes a liquid mixing tank and a fourth microfluidic channel, wherein the liquid mixing tank is connected to the third microfluidic channel through the fourth microfluidic channel, and The distance from the liquid mixing tank to the rotation axis is greater than the distance from the first quantitative tank to the rotation axis.

6. The microfluidic chip according to claim 5, wherein, The fourth microfluidic channel is a siphon channel, and the distance from the fourth microfluidic channel portion to the rotation axis is smaller than the distance from the position where the fourth microfluidic channel is connected to the third microfluidic channel to the rotation axis; Preferably, the microfluidic chip is configured to have a first rotation speed and a second rotation speed, the fluid in the sample tank enters the third microfluidic channel and the second separation tank at the first rotation speed, and part of the fluid in the third microfluidic channel and the second separation tank enters the mixing tank at the second rotation speed; Preferably, The first speed is equal to the second speed; or The first rotation speed is greater than the second rotation speed.

7. The microfluidic chip according to claim 5, characterized in that, It further includes a delivery channel and at least one detection group, wherein the detection group is connected to the liquid mixing tank through the delivery channel, and the detection group is configured to detect the liquid entering from the liquid mixing tank via the delivery channel.

8. The microfluidic chip according to claim 7, characterized in that, The detection group includes: A second metering tank, which is in communication with the delivery channel; A fluid tank and a fifth microchannel, the fluid tank is connected to the second metering tank through the fifth microchannel; A detection tank and a sixth microchannel, the detection tank is connected to the fluid tank through the sixth microchannel.

9. The microfluidic chip according to claim 4, wherein The transition tank is reused as a filtration tank; or The microfluidic chip further includes a filtration tank, wherein the filtration tank is located between the first microchannel and the transition tank; Preferably, a filter membrane is provided in the filtration tank, and the filter membrane is located between the position of the filtration tank communicating with the first microchannel and the position of the filtration tank communicating with the transition tank; Preferably, the filter membrane is configured to filter out particulate objects with a size of not less than 100 nanometers; Preferably, the material of the filter membrane includes any one of polycarbonate, polyethersulfone, nylon, and cellulose acetate.

10. The microfluidic chip according to claim 1, characterized in that, It further includes a cover plate, the cover plate is located on the side of the substrate where the sample tank is provided, and is encapsulated in opposition to the substrate.

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