A stacked circulating liquid separation microfluidic chip

Abstract

The present invention discloses a stacked circulating liquid separation microfluidic chip, which relates to the field of microfluidic technology. The microfluidic chip is composed of three layers of circular plates coaxially bonded together. The three layers of circular plates are, from top to bottom, a first layer, a second layer and a third layer. A liquid storage cavity is provided at the inner center position of the second layer; a plurality of centrifugal channels are provided between the first layer and the second layer, and the inner ends of the centrifugal channels are connected to the liquid storage cavity; a plurality of reaction cavities corresponding to the centrifugal channels are provided on the same side of each centrifugal channel, and each reaction cavity is connected to its corresponding centrifugal channel through a microchannel; a plurality of reflux channels are provided between the second layer and the third layer, and the inner ends of the reflux channels are connected to the liquid storage cavity; a reflux hole is provided on the second layer. The present invention proposes a stacked circulating liquid separation microfluidic chip which can reduce the waste of sample liquid and make the sample liquid in each reaction cavity as uniform as possible.

Description

Technical Field

[0001] The present invention relates to the field of microfluidic technology, in particular to a laminated circulating liquid separation microfluidic chip. Background Art

[0002] A microfluidic chip, also known as a lab-on-a-chip, is a microchip that integrates multiple microfluidic channels and microstructures at the microscale. It utilizes the principles of microfluidics to control and manipulate microfluidics, enabling sample preparation, reaction, separation, and detection in biological, chemical, and medical analytical processes. Microfluidic chips are typically made of transparent materials.

[0003] When using a microfluidic chip to conduct a multi-sample test, the sample liquid needs to be injected into different reaction chambers in the microfluidic chip. The commonly used technology is centrifugation technology. By rotating the microfluidic chip, the sample liquid in the microfluidic chip is rapidly flowed outward by the centrifugal force. During the flow of the sample liquid, part of it enters the reaction chamber, and the sample liquid that does not enter the reaction chamber enters the waste liquid area. In this liquid separation method, the flow direction of the sample liquid is unidirectional. In order to ensure that enough sample liquid is injected into each reaction chamber, the total amount of sample liquid must be prepared that is much larger than the total capacity of the reaction chamber, which can easily lead to waste of sample liquid; if the total amount of sample liquid is insufficient, it is also easy to cause the problem of uneven sample volume in each reaction chamber. Summary of the Invention

[0004] In order to solve the above problems, the present invention proposes a laminated circulating liquid separation microfluidic chip which can reduce the waste of sample liquid and make the sample liquid in each reaction chamber as uniform as possible.

[0005] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0006] A stacked circulating liquid separation microfluidic chip, the microfluidic chip is composed of three layers of circular plates coaxially bonded together, the three layers of circular plates being, from top to bottom, a first layer, a second layer, and a third layer;

[0007] A liquid storage cavity is provided at the inner center of the second layer;

[0008] The first plate is provided with a liquid injection hole, the inner opening of the liquid injection hole is connected to the liquid storage cavity, and a hole plug is provided at the outer opening of the liquid injection hole;

[0009] A plurality of centrifugal channels are provided between the first plate and the second plate, and are circumferentially spaced around the liquid storage cavity. Each centrifugal channel is arranged along the radial direction of the liquid storage cavity, and the inner end of the centrifugal channel is connected to the liquid storage cavity. A plurality of reaction chambers corresponding to the centrifugal channel are provided on the same side of each centrifugal channel, and each reaction chamber is connected to its corresponding centrifugal channel via a microchannel.

[0010] A plurality of reflux channels are provided between the second plate and the third plate, and the plurality of reflux channels are circumferentially spaced and distributed around the liquid storage cavity. Each reflux channel is in a spiral line shape, and the inner end of the reflux channel is connected to the liquid storage cavity, and the outer end of the reflux channel is a blind end.

[0011] The second plate is provided with a plurality of reflux holes, each of which corresponds to a centrifugal channel. One end of the reflux hole is connected to the outer end of the corresponding centrifugal channel, and the other end of the reflux hole is connected to one of the centrifugal channels.

[0012] Preferably, the connection point between the microchannel and its corresponding reaction chamber is located on the side of the reaction chamber facing the center of the second layer plate.

[0013] Preferably, a plurality of flow-guiding protrusions are provided on the inner wall of each centrifugal channel, wherein the flow-guiding protrusions correspond to the microchannels one by one, and the flow-guiding protrusions are located on the inner wall of the centrifugal channel opposite to the connection point between the corresponding microchannel and the centrifugal channel.

[0014] Preferably, the liquid storage chamber is divided into a large diameter section and a small diameter section from top to bottom, the large diameter section and the small diameter section are coaxially arranged, the inner port of the centrifugal channel is located on the side wall of the large diameter section, and the inner port of the reflux channel is located on the side wall of the small diameter section.

[0015] Preferably, an annular chamfer is provided at the junction of the large diameter section and the small diameter section in the liquid storage cavity.

[0016] Preferably, the centrifugal channels are distributed at equal intervals around the liquid storage chamber, and the reaction chambers are distributed in a circular array.

[0017] Preferably, a centrifuge positioning block is provided at the inner center position of the second layer of plate, the centrifuge positioning block is located in the liquid storage cavity and the centrifuge positioning block and the liquid storage cavity are fixed by a bracket, the upper end surface of the centrifuge positioning block is fitted and sealed to the bottom surface of the first layer of plate, the lower end surface of the centrifuge positioning block is fitted and sealed to the top surface of the third layer of plate, and a centrifuge positioning hole is provided through the first layer of plate, the centrifuge positioning block and the third layer of plate.

[0018] Preferably, the centrifuge positioning hole is in the shape of a regular hexagonal prism, and the central axis of the centrifuge positioning hole coincides with the central axis of the second layer of plate.

[0019] Therefore, the present invention has the following beneficial effects: 1. By bonding the three-layer plates, two channel layers are formed, one for the sample liquid to flow outward, and the other for the sample liquid to flow back, so that the sample liquid can circulate continuously in the microfluidic chip, and ultimately achieve the goal of filling each reaction chamber with a smaller total amount of sample liquid, thereby reducing the waste of sample liquid; 2. Multiple reaction chambers are provided, and the reactions and changes of multiple samples can be observed simultaneously, thereby improving the efficiency and accuracy of the test; 3. By rotating the microfluidic chip, the sample liquid can be quickly dispersed and transferred to each reaction chamber, effectively improving the efficiency of multi-sample testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a perspective view of the present invention.

[0021] Figure 2 It is a structural schematic diagram of the present invention.

[0022] Figure 3 It is an exploded view of the present invention.

[0023] Figure 4 It is an exploded view from another angle of the present invention.

[0024] Figure 5 It is a top view of the second layer board in the present invention.

[0025] Figure 6 yes Figure 5 Enlarged view of point a in the middle.

[0026] Figure 7 It is a bottom view of the second layer of the present invention.

[0027] 1: First plate; 101: Liquid injection hole; 2: Second plate; 201: Centrifugal channel; 202: Reaction chamber; 203: Microchannel; 204: Guide protrusion; 3: Third plate; 301: Reflux channel; 302: Circular groove; 4: Liquid storage chamber; 5: Hole plug; 6: Reflux hole; 7: Centrifuge positioning block; 8: Centrifuge positioning hole. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] A stacked circulating liquid separation microfluidic chip, see Figures 1 to 7 The microfluidic chip is composed of three layers of circular plates coaxially bonded together, and the three layers of circular plates are, from top to bottom, a first layer plate 1, a second layer plate 2, and a third layer plate 3.

[0030] A liquid storage cavity 4 is provided at the inner center of the second plate 2 .

[0031] The first layer plate 1 is provided with a liquid injection hole 101 , the inner opening of the liquid injection hole 101 is communicated with the liquid storage chamber 4 , and a hole plug 5 is provided at the outer opening of the liquid injection hole 101 .

[0032] Six centrifugal channels 201 are provided between the first plate 1 and the second plate 2. These six channels 201 are equidistantly spaced around the liquid storage chamber 4. Each channel 201 is radially disposed along the liquid storage chamber 4, with its inner end communicating with the liquid storage chamber 4. Two corresponding reaction chambers 202 are located on the same side of each channel 201, with the reaction chambers 202 arranged in a circular array. Each reaction chamber 202 is connected to its corresponding centrifugal channel 201 via a microchannel 203. The connection between the microchannel 203 and its corresponding reaction chamber 202 is located on the side of the reaction chamber 202 facing the center of the second plate 2.

[0033] Each centrifugal channel 201 is provided with two guide protrusions 204 on its inner wall. These guide protrusions 204 correspond one-to-one with each microchannel 203 and are located on the inner wall of the centrifugal channel 201 opposite the point where the corresponding microchannel 203 connects to the centrifugal channel 201. As the sample liquid flows through the centrifugal channel 201 under the action of centrifugal force, the guide protrusions 204 act as guides, further facilitating the flow of the sample liquid through the microchannel 203 into the corresponding reaction chamber 202.

[0034] Two reflux channels 301 are provided between the second layer plate 2 and the third layer plate 3. The two reflux channels 301 are circumferentially spaced around the liquid storage chamber 4. Each reflux channel 301 is in a spiral line shape. The inner end of the reflux channel 301 is connected to the liquid storage chamber 4, and the outer end of the reflux channel 301 is a blind end.

[0035] The second plate 2 is provided with a plurality of reflux holes 6 , which correspond one to one with the centrifugal channels 201 . One end of the reflux hole 6 is connected to the outer end of the corresponding centrifugal channel 201 , and the other end of the reflux hole 6 is connected to one of the centrifugal channels 201 .

[0036] The liquid storage chamber 4 is divided from top to bottom into a large-diameter section and a small-diameter section, which are coaxially arranged. The inner port of the centrifugal channel 201 is located on the sidewall of the large-diameter section, while the inner port of the reflux channel 301 is located on the sidewall of the small-diameter section. An annular chamfer is provided at the junction of the large-diameter and small-diameter sections. This arrangement allows the return port of the reflux channel 301 within the liquid storage chamber 4 to be closer to the centerline of the second plate 2 than the outlet of the centrifugal channel 201. This arrangement prevents the centrifugal force acting on the sample liquid within the liquid storage chamber 4 from weakening the sample liquid backflow within the reflux channel 301 when the microfluidic chip is rotated.

[0037] A centrifuge positioning block 7 is provided at the inner center of the second layer plate 2. The centrifuge positioning block 7 is located in the liquid storage chamber 4 and is fixed to the liquid storage chamber 4 by a bracket. The upper end surface of the centrifuge positioning block 7 is sealed and fixed to the bottom surface of the first layer plate 1, and the lower end surface of the centrifuge positioning block 7 is sealed and fixed to the top surface of the third layer plate 3. A centrifuge positioning hole 8 is provided through the first layer plate 1, the centrifuge positioning block 7, and the third layer plate 3. The centrifuge positioning hole 8 is in the shape of a regular hexagonal prism, and the central axis of the centrifuge positioning hole 8 coincides with the central axis of the second layer plate 2.

[0038] When using this microfluidic chip to conduct a multi-sample test, first remove the plug 5 on the injection hole 101, and inject the sample liquid into the liquid storage chamber 4 through the injection hole 101. The total amount of sample liquid injected into the liquid storage chamber 4 can be slightly larger than the total capacity of all reaction chambers 202. Then, the injection hole 101 is sealed with the plug 5.

[0039] The microfluidic chip is placed on a centrifuge and is rotated by the centrifuge. During the rotation of the microfluidic chip, the sample liquid in the liquid storage chamber 4 flows out from each centrifugal channel 201 through centrifugal action.

[0040] See also Figures 5 to 7 Taking the clockwise rotation of the microfluidic chip as an example, reaction chambers 202 are located on the counterclockwise side of the corresponding centrifugal channel 201. When the sample liquid flows out of the centrifugal channel 201, it flows along the side of the centrifugal channel 201 where the reaction chamber 202 is located. With the help of the flow-guiding protrusions 204, when it encounters the microchannel 203, the sample liquid can flow from the microchannel 203 into the reaction chamber 202 connected to the microchannel 203. The sample liquid that does not enter the reaction chamber 202 continues to flow toward the outer end of the centrifugal channel 201, and finally enters the reflux hole 6 at the end of the centrifugal channel 201.

[0041] The sample liquid passes through the reflux hole 6 and enters the reflux channel 301 of the next layer. Since the reflux channel 301 is arranged in a spiral line, after calculating and setting a reasonable number of spiral coils and spiral pitch, the sample liquid in the reflux channel 301 can overcome the centrifugal force it is subjected to under the action of the rotating microfluidic chip and flow back to the liquid storage chamber 4 along the reflux channel 301.

[0042] The sample liquid that flows back into the liquid storage chamber 4 is again subjected to the centrifugal force and flows out of the centrifugal channel 201, thus completing the cycle. Furthermore, no more sample liquid will be injected into the reaction chamber 202 that is already filled with sample liquid. The sample liquid that has passed through will directly enter the reflux hole 6, and the cycle continues until each reaction chamber 202 is filled with sample liquid.

Claims

1. A stacked circulating liquid separation microfluidic chip, characterized by: The microfluidic chip is composed of three layers of circular plates coaxially bonded together, wherein the three layers of circular plates are, from top to bottom, a first layer (1), a second layer (2), and a third layer (3); A liquid storage cavity (4) is provided at the inner center of the second plate (2); The first layer (1) is provided with a liquid injection hole (101), the inner opening of the liquid injection hole (101) is connected to the liquid storage cavity (4), and a hole plug (5) is provided at the outer opening of the liquid injection hole (101); A plurality of centrifugal channels (201) are provided between the first plate (1) and the second plate (2), and the plurality of centrifugal channels (201) are circumferentially spaced and distributed around the liquid storage chamber (4). Each centrifugal channel (201) is arranged along the radial direction of the liquid storage chamber (4), and the inner end of the centrifugal channel (201) is communicated with the liquid storage chamber (4); a plurality of reaction chambers (202) corresponding to the centrifugal channel (201) are provided on the same side of each centrifugal channel (201), and each reaction chamber (202) is communicated with its corresponding centrifugal channel (201) via a microchannel (203); A plurality of reflux channels (301) are provided between the second plate (2) and the third plate (3), and the plurality of reflux channels (301) are circumferentially spaced and distributed around the liquid storage cavity (4). Each reflux channel (301) is in a spiral line shape, and the inner end of the reflux channel (301) is in communication with the liquid storage cavity (4), while the outer end of the reflux channel (301) is a blind end. The second plate (2) is provided with a plurality of reflux holes (6), each of the reflux holes (6) corresponding to a centrifugal channel (201) one by one, one end of the reflux hole (6) butting against the outer end of the corresponding centrifugal channel (201), and the other end of the reflux hole (6) communicating with one of the reflux channels (301); The centrifugal channels (201) are equidistantly distributed around the liquid storage chamber (4), and the reaction chambers (202) are distributed in a circular array; The connection point between the microchannel (203) and its corresponding reaction chamber (202) is located on the side of the reaction chamber (202) facing the center of the second plate (2).

2. The stacked circulating liquid separation microfluidic chip according to claim 1, characterized in that: A plurality of flow-guiding protrusions (204) are provided on the inner wall of each centrifugal channel (201), wherein the flow-guiding protrusions (204) correspond one-to-one with the microchannels (203), and the flow-guiding protrusions (204) are located on the inner wall of the centrifugal channel (201) opposite to the connection point between the corresponding microchannel (203) and the centrifugal channel (201).

3. The stacked circulating liquid separation microfluidic chip according to claim 1, characterized in that: The liquid storage chamber (4) is divided into a large diameter section and a small diameter section from top to bottom, the large diameter section and the small diameter section are coaxially arranged, the inner port of the centrifugal channel (201) is located on the side wall of the large diameter section, and the inner port of the reflux channel (301) is located on the side wall of the small diameter section.

4. The stacked circulating liquid separation microfluidic chip according to claim 3, characterized in that: An annular chamfer is provided at the junction of the large diameter section and the small diameter section in the liquid storage cavity (4).

5. The stacked circulating liquid separation microfluidic chip according to claim 1, characterized in that: A centrifuge positioning block (7) is provided at the inner center position of the second layer plate (2), the centrifuge positioning block (7) is located in the liquid storage cavity (4), and the centrifuge positioning block (7) and the liquid storage cavity (4) are fixed by a bracket, the upper end surface of the centrifuge positioning block (7) is fitted and sealed to the bottom surface of the first layer plate (1), the lower end surface of the centrifuge positioning block (7) is fitted and sealed to the top surface of the third layer plate (3), and a centrifuge positioning hole (8) is provided through the first layer plate (1), the centrifuge positioning block (7) and the third layer plate (3).

6. The stacked circulating liquid separation microfluidic chip according to claim 5, characterized in that: The centrifuge positioning hole (8) is in the shape of a regular hexagonal prism, and the central axis of the centrifuge positioning hole (8) coincides with the central axis of the second layer plate (2).

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