Micro-fluidic chip and micro-fluidic system

Abstract

The invention discloses a micro-fluidic chip which comprises a chip body capable of generating centrifugal force around a centrifugal center; the liquid temporary storage pool is arranged on the chip body and is used for containing target liquid; the uniform mixing pool is arranged on the chip body and is positioned on the telecentric side of the liquid temporary storage pool; the first end of the siphon is communicated with the liquid temporary storage pool; the proximal end of the suction pipe is communicated with the second end of the siphon, the second end of the siphon is a distal end, a pipe section higher than the proximal end of the liquid temporary storage pool is arranged between the first end and the second end of the siphon, and the diameter of the suction pipe is larger than that of the siphon; the transfer structure is communicated with the proximal end of the suction pipe, at least part of the transfer structure is higher than the proximal end of the suction pipe, under the action of centrifugal force, liquid, higher than the proximal end of the suction pipe, in the transfer structure can flow to the uniform mixing pool through the suction pipe, and a preset negative pressure value is generated at the proximal end of the suction pipe. The micro-fluidic chip pulls gas and target liquid in the siphon under the action of negative pressure generated at the proximal end of the suction pipe, so that the target liquid fills the siphon and crosses the proximal end of the siphon, and the liquid level is lower than the liquid level in the liquid temporary storage pool, so that a siphonic effect is generated, and the liquid level in the liquid temporary storage pool is lowered. And the target liquid is transferred into the uniform mixing pool through the suction pipe, so that the transfer of the target liquid is completed.

Description

Technical Field

[0001] This invention relates to the field of biological detection technology, and in particular to a microfluidic chip and a microfluidic system. Background Technology

[0002] With the rise and development of the in vitro diagnostics industry, centrifugal force-driven microfluidic technology has gained increasing attention due to its small size, ease of control, low cost, and simple operation, and has been widely used in various biochemical, immunological, and molecular diagnostic products.

[0003] In centrifugal-driven microfluidic chips, the primary flow direction of liquid samples is the direction of centrifugal force, i.e., from the centrifugal center outwards. Therefore, in the design of microfluidic chips, the structures involved in the liquid flow process are arranged from the inside out. Specifically, liquid samples in structures closer to the centrifugal center (also known as the proximal side or higher position) are transferred to structures farther from the centrifugal center (also known as the distal side or lower position) under the action of centrifugal force. It can be understood that in such chips, the distance from different structures to the centrifugal center is often described using "high" and "low," or "near" and "far."

[0004] In microfluidic chips, siphons are structures that regulate the order of liquid sample transfer during centrifugation. Because the siphon has a proximal end near the centrifugation center, when connected to other taller structures, it allows for brief residence of the liquid within those taller structures under centrifugal force when the liquid level is lower than the proximal end. By controlling the liquid to fill the siphon and extend beyond its proximal end, the liquid level within the siphon is lower than that within the taller structures, creating a siphon effect. This allows the liquid to be transferred from the taller structures to the shorter structures during centrifugation within the microfluidic chip.

[0005] Based on the above analysis, it can be seen that in order to ensure the normal flow of liquid samples, the siphon tube needs to be filled with a sufficient amount of liquid to induce the siphon effect.

[0006] Therefore, how to provide a microfluidic chip that can stably achieve siphon filling and ensure siphon effect is a technical problem that urgently needs to be solved by the technical personnel. Summary of the Invention

[0007] In view of this, the present invention provides a microfluidic chip that can stably achieve siphon filling and ensure the siphon effect. Furthermore, the present invention also provides a microfluidic system incorporating the aforementioned microfluidic chip.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A microfluidic chip, comprising:

[0010] The chip body is capable of generating centrifugal force around the centrifugal center;

[0011] A liquid storage tank is disposed on the chip body and is used to hold the target liquid;

[0012] A mixing cell is disposed on the chip body, and both the liquid storage cell and the mixing cell are liquid containment spaces, with the mixing cell located on the distal side of the liquid storage cell.

[0013] A siphon tube, the first end of which is connected to the liquid storage tank;

[0014] A suction tube, the proximal end of which is connected to the second end of the siphon tube, the second end of which is the distal end, a tube section between the first end and the second end of the siphon tube that is higher than the proximal end of the liquid storage tank, and the highest point of the tube section that is higher than the proximal end of the liquid storage tank forms the proximal end of the siphon tube, the diameter of the suction tube is larger than the diameter of the siphon tube;

[0015] A transfer structure is connected to the proximal end of the suction tube, and at least a portion of the transfer structure is higher than the proximal end of the suction tube. Under centrifugal force, liquid in the transfer structure that is higher than the proximal end of the suction tube can flow through the suction tube to the mixing tank, and a preset negative pressure value is generated at the proximal end of the suction tube.

[0016] The height is the distance to the centrifugal center, and the closer to the centrifugal center, the higher the height.

[0017] Preferably, in the above-mentioned microfluidic chip, the siphon tube includes:

[0018] The first pipe section, one end of which is connected to the distal end of the liquid storage tank;

[0019] The second pipe section has one end connected to the other end of the first pipe section, and the other end of the second pipe section is connected to the proximal end of the suction pipe. The height of the connection point between the first pipe section and the second pipe section is higher than the height of the proximal end of the liquid storage tank.

[0020] Preferably, in the microfluidic chip described above, the first tube segment and the second tube segment are connected in an N-type structure.

[0021] Preferably, in the above-mentioned microfluidic chip, the transfer structure includes:

[0022] A transfer tank for holding auxiliary transfer liquid, wherein the height of the transfer tank is at least partially higher than the height of the proximal end of the suction tube;

[0023] The proximal end of the suction tube is connected to the transfer pool at a position lower than the proximal end of the transfer pool.

[0024] Preferably, in the above-mentioned microfluidic chip, the transfer structure further includes:

[0025] The transfer tube has its proximal end connected to the distal end of the transfer pool, and its distal end connected to the proximal end of the suction tube. The transfer tube, the suction tube, and the siphon tube are arranged in a Y-shape.

[0026] Preferably, in the above-mentioned microfluidic chip, the transfer structure further includes:

[0027] A transfer tube, the proximal end of which is connected to the distal end of the suction tube;

[0028] The transfer pool has a curved structure, with its first end connected to the proximal end of the suction tube and its second end being the distal end, connected to the mixing pool. The two ends of the transfer pool are curved to form the proximal end of the transfer pool, which is higher than the proximal end of the suction tube. The transfer tube is connected to the distal end of the transfer pool. The suction tube, the siphon tube, and the transfer pool are arranged in a Y-shape at positions higher than the proximal end of the suction tube.

[0029] Preferably, in the microfluidic chip described above, the transfer pool is S-shaped from the first end to the second end, and the height of the second end of the transfer pool is lower than the height of the first end of the transfer pool.

[0030] Preferably, in the microfluidic chip described above, the liquid storage tank, the mixing tank, and / or the transfer tank are connected.

[0031] Preferably, in the above-described microfluidic chip, the transfer tube is a straight tube or a siphon tube. A microfluidic system includes a microfluidic chip, wherein the microfluidic chip is any of the microfluidic chips described above.

[0032] This invention discloses a microfluidic chip that utilizes a siphon tube to connect a proximal liquid storage tank and a distal mixing tank, and a suction tube to connect the distal end of the siphon tube. Centrifugal force is used to draw auxiliary transfer liquid into the suction tube, and the liquid continues to be discharged from the suction tube under the action of centrifugal force. During the discharge process, a local negative pressure is formed at the proximal end of the suction tube. Under the action of negative pressure, the gas and target liquid in the siphon tube are pulled, causing the target liquid to fill the siphon tube and pass through the proximal end of the siphon tube. The liquid level in the siphon tube is lower than the liquid level in the liquid storage tank, thereby triggering a siphon effect. The target liquid is then transferred sequentially through the siphon tube and the suction tube into the mixing tank, completing the transfer of the target liquid. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the first structure of the microfluidic chip disclosed in an embodiment of the present invention;

[0035] Figure 2 for Figure 1 A schematic diagram of the liquid inside a microfluidic chip in its first state;

[0036] Figure 3 for Figure 1 A schematic diagram of the liquid inside a microfluidic chip in the second state;

[0037] Figure 4 for Figure 1 A schematic diagram of the liquid inside a microfluidic chip in its third state;

[0038] Figure 5 For this Figure 1 A schematic diagram of the liquid in the fourth state inside a microfluidic chip;

[0039] Figure 6 This is a schematic diagram of the second structure of the microfluidic chip disclosed in the embodiments of the present invention;

[0040] Figure 7 for Figure 6 A schematic diagram of the liquid inside a microfluidic chip in its first state;

[0041] Figure 8 for Figure 6 A schematic diagram of the liquid inside a microfluidic chip in the second state;

[0042] Figure 9 for Figure 6 A schematic diagram of the liquid inside a microfluidic chip in its third state;

[0043] Figure 10 for Figure 6 A schematic diagram of the liquid in the fourth state inside a microfluidic chip;

[0044] Figure 11 This is a schematic diagram of a third structure of the microfluidic chip disclosed in an embodiment of the present invention.

[0045] Figure 12 for Figure 11 A schematic diagram of the liquid inside a microfluidic chip in its first state;

[0046] Figure 13 for Figure 11 A schematic diagram of the liquid inside a microfluidic chip in the second state;

[0047] Figure 14 for Figure 11 A schematic diagram of the liquid inside a microfluidic chip in its third state;

[0048] Figure 15 for Figure 11 A schematic diagram of the liquid in the fourth state inside a microfluidic chip;

[0049] Figure 16 for Figure 11 A schematic diagram of the liquid in the fifth state inside a microfluidic chip;

[0050] in,

[0051] O is the centrifuge center, 1 is the chip body, 2 is the liquid storage tank, 3 is the siphon tube, 31 is the first tube section, 32 is the second tube section, 4 is the suction tube, 5 is the mixing tank, 6 is the transfer structure, 61 is the transfer tank, 62 is the transfer tube, 71 is the first ventilation structure, and 72 is the second ventilation structure. Detailed Implementation

[0052] This invention discloses a microfluidic chip that can stably achieve siphon filling and ensure siphon effect. Furthermore, this invention also discloses a microfluidic system incorporating the aforementioned microfluidic chip.

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] In centrifugal-driven microfluidic chips, the primary flow direction of liquid samples is the direction of centrifugal force, i.e., from the centrifugal center outwards. Therefore, in the design of microfluidic chips, the structures involved in the liquid flow process are arranged from the inside out. Specifically, liquid samples in structures closer to the centrifugal center (also known as the proximal side or higher position) are transferred to structures farther from the centrifugal center (also known as the distal side or lower position) under the action of centrifugal force. It can be understood that in such chips, the distance from different structures to the centrifugal center is often described using "high" and "low," or "near" and "far." All embodiments in this article refer to the above description.

[0055] In microfluidic chips, siphons are structures that regulate the order of liquid sample transfer during centrifugation. Because the siphon has a proximal end near the centrifugation center, when connected to other taller structures, it allows for brief residence of liquid within those taller structures under centrifugal force when the liquid level is lower than the proximal end. By controlling the liquid to fill the siphon and extend beyond its proximal end, the liquid level within the siphon is lower than that within the taller structures, thus fulfilling the conditions for inducing a siphon effect. This siphon effect allows liquid to be transferred from the taller structures to the shorter structures during centrifugation within the microfluidic chip.

[0056] Based on the above analysis, it can be seen that in order to ensure the normal flow of liquid samples, the siphon tube needs to be filled with a sufficient amount of liquid to induce the siphon effect.

[0057] Based on this, the present invention discloses a microfluidic chip that uses a suction tube to generate negative pressure. The negative pressure drives the distal end of the siphon tube connected to the suction tube, thereby driving the liquid in the siphon tube to pass over the proximal end of the siphon tube, thus ultimately triggering a siphon.

[0058] like Figure 1 The microfluidic chip shown includes a chip body 1, a liquid storage tank 2, a siphon tube 3, a suction tube 4, a mixing tank 5, a transfer structure 6, a first ventilation structure 71, and a second ventilation structure 72.

[0059] The microfluidic chip contains recesses and channels, which can form a closed structure between the chip body 1 and the cover plate through fastening. The recesses include, but are not limited to, the liquid storage tank 2 and the mixing tank 5 disclosed in this invention, and the channels include, but are not limited to, the siphon tube 3, the suction tube 4, the first ventilation structure 71 and the second ventilation structure 72 disclosed in this invention.

[0060] The chip body 1 rotates around the centrifugal center O to generate centrifugal force. The shape and size of the chip body 1 can be set according to different needs, and all are within the protection range.

[0061] Both the liquid storage tank 2 and the mixing tank 5 are liquid containment spaces disposed on the chip body 1, and their shapes and sizes are not specifically limited. For example, the liquid storage tank 2 is located proximal to the chip body 1, and the mixing tank 5 is located distal to the chip body 1. It can be understood that the mixing tank 5 is the liquid containment space distal to the liquid storage tank 2. In this invention, the mixing tank 5 and the liquid storage tank 2 can be containment spaces of any function during the microfluidic chip detection process.

[0062] The siphon tube 3 has an N-shaped structure, with the middle position of the siphon tube 3 forming the proximal end. One end of the siphon tube 3 is connected to the liquid storage tank 2, and the distal end of the siphon tube 3 is connected to the proximal end of the suction tube 4. The proximal end of the siphon tube 3 is higher than the proximal end of the liquid storage tank 2 (it should be noted that the proximal end of the siphon tube 3 is higher than the liquid level in the liquid storage tank 2, which ensures that the centrifugal force will not cause the target liquid to shift before the siphon effect occurs).

[0063] For example, the siphon tube 3 includes a first tube segment 31 and a second tube segment 32. The first end of the first tube segment 31 is connected to the distal end of the liquid storage tank 2, and the second end of the first tube segment 31 extends from the liquid storage tank 2 towards a higher position, i.e., near the centrifugal center O. The first end of the second tube segment 32 is connected to and communicates with the second end of the first tube segment 31, and the second end of the second tube segment 32 extends away from the centrifugal center O and communicates with the proximal end of the suction tube 4. That is, the connection point between the first tube segment 31 and the second tube segment 32 of the siphon tube 3 forms the proximal end, and the second end of the second tube segment 32 forms the distal end.

[0064] For example, the suction tube 4 is a straight tube, and its proximal end is connected to the distal side of the siphon tube 3, while the distal end of the suction tube 4 is connected to the mixing tank 5. In some embodiments, the suction tube 4 extends in the centrifugal direction, including but not limited to extending radially along the chip body 1, and the suction tube 4 may also be a bent tube segment.

[0065] The transfer structure 6 includes a transfer pool 61 and a transfer tube 62. The transfer pool 61 is a space for containing liquid and is higher than the proximal end of the suction tube 4. The transfer pool 61 is connected to the proximal end of the suction tube 4 via the transfer tube 62. Optionally, the distal end of the transfer pool 61 is connected to the proximal end of the transfer tube 62, and the distal end of the transfer tube 62 is connected to the proximal end of the suction tube 4.

[0066] Since the distal end of the transfer tube 62 and the distal end of the siphon tube 3 are both connected to the proximal end of the suction tube 4, the transfer tube 62, the suction tube 4, and the second tube segment 32 can form a Y-shaped structure.

[0067] The first venting structure 71 connects the mixing tank 5 and the transfer tank 61, and the second venting structure 72 connects the first venting structure 71 and the liquid storage tank 2. Specifically, both the first venting structure 71 and the second venting structure 72 can be channel structures. One end of the first venting structure 71 is connected to the proximal end of the mixing tank 5, and the other end is connected to the proximal end of the transfer tank 61. One end of the second venting structure 72 is connected to the proximal end of the liquid storage tank 2, and the other end is connected to the first venting structure 71. This allows all liquid-containing spaces in the microfluidic chip to be connected using venting structures, thereby ensuring the pressure within each space and ensuring that the liquid can flow smoothly out of the corresponding space.

[0068] The ventilation structure in this invention can be a number of connected or unconnected ventilation pipes or ventilation holes. The ventilation structure can be connected to all the recesses or pipes on the chip body 1 that need ventilation. Specifically, the ventilation method can be that the recesses, pipes or ventilation holes are directly connected to the atmosphere, or the internal structure of the chip body 1 can be ventilated to each other but not to the atmosphere, so as to replenish the gas in the recesses or pipes.

[0069] Referring to the disclosed structure of the microfluidic chip above, and in conjunction with... Figures 2 to 5 right Figure 1 The process of internal liquid flow during the use of the microfluidic chip is explained, in which... Figures 2 to 5 The shaded area in the image represents liquid.

[0070] like Figure 2 As shown, Figure 2 The liquid storage tank 2 is filled with the target liquid, and the transfer tank 61 is filled with an auxiliary transfer liquid, which can be set according to different requirements.

[0071] The first end of the first section 31 of the siphon tube 3 is connected to the distal end of the liquid storage tank 2. Due to the communicating vessel effect, the liquid in the liquid storage tank 2 flows into the first section 31 and fills it. Since the liquid level in the proximal end of the liquid storage tank 2 is lower than that in the proximal end of the siphon tube 3, the height of the liquid filling the first section 31 is lower than that in the proximal end of the siphon tube 3, meaning it will not exceed the proximal end of the siphon tube 3.

[0072] The space between the proximal end of the suction tube 4 and the liquid surface inside the siphon tube 3 is filled with air from inside the siphon tube 3.

[0073] Depend on Figures 2 to 3 The process is as follows: Under the action of centrifugal force, the auxiliary transfer liquid in the transfer tank 61 enters the suction pipe 4 through the transfer pipe 62. However, since the liquid in the siphon pipe 3 does not cross the proximal end, the liquid in the siphon pipe 3 does not change under the action of centrifugal force.

[0074] Depend on Figures 3 to 5The process is as follows: Because the suction tube 4 is located at a lower position, it experiences a greater centrifugal force. Therefore, the centrifugal force on the liquid inside the suction tube 4 is greater than that on the liquid inside the transfer structure 6, resulting in a greater centrifugal force at the distal end of the suction tube 4 than the pressure at the proximal end. During the process of the liquid flowing from the distal end of the suction tube 4 to the mixing tank 5, a gas-liquid exchange with pressure balance is formed between the mixing tank 5 and the transfer tank 61. As a result, the liquid at the distal end of the suction tube 4 is not subject to gas resistance when centrifugally flowing down. Since the height difference between the two ends of the suction tube 4 is sufficient, the centrifugal force on the liquid at the distal end of the suction tube 4 is greater than the sum of the centrifugal force on the liquid at the proximal end and the pressure exerted on the suction tube 4 by the liquid in the transfer tank 61 and the transfer tube 62. Therefore, a negative pressure is generated at the proximal end of the suction tube 4, which pulls on the structure connected to the proximal end of the suction tube 4 under the action of negative pressure.

[0075] Since both the second section 32 of the siphon tube 3 and the transfer tube 62 are connected to the proximal end of the suction tube 4, under negative pressure, the air in the siphon tube 3 and the auxiliary transfer liquid in the transfer tank 61 are simultaneously pulled into the suction tube 4. As the air in the siphon tube 3 is continuously pulled, the liquid filling the first section 31 of the siphon tube 3 passes over the proximal end of the siphon tube 3 and enters the second section 32. When the liquid level in the siphon tube 3 is lower than the liquid level in the liquid storage tank 2, under the action of centrifugal force, the liquid in the liquid storage tank 2 will pass through the siphon tube 3, undergo siphon transfer, and enter the mixing tank 5 through the suction tube 4.

[0076] In some embodiments, by adjusting the size, shape, relative position of the suction tube 4, the second tube section 32, and the transfer tube 62, as well as the rotation speed of the chip body 1 during rotation, the negative pressure in the suction tube 4 and the volume of air in the siphon tube 3 can be changed, thereby controlling the order in which the target liquid and the auxiliary transfer liquid enter the mixing tank 5.

[0077] For example:

[0078] If the negative pressure generated by the suction tube 4 is less than the preset value, the volume of air pulled in the siphon tube 3 is insufficient, causing the liquid level in the siphon tube 3 to fail to pass the proximal end of the siphon tube 3 and enter the second tube section 32. As a result, the liquid in the liquid storage tank 2 will not be transferred by siphon. During the rotation of the microfluidic chip, only the auxiliary transfer liquid enters the mixing tank 5.

[0079] If the maximum negative pressure generated by the suction tube 4 can pull a sufficient volume of air in the siphon tube 3, but the liquid in the transfer tank 61 partially offsets the pulling force caused by the negative pressure during its entry into the suction tube 4, this will result in the pulling force not reaching a value sufficient to pull the air in the siphon tube 3 before the liquid transfer in the transfer tank 61 is complete. Therefore, only when the auxiliary transfer liquid in the transfer tank 61 has completely entered the suction tube 4, and the negative pressure value at the proximal end of the suction tube 4 reaches the maximum suction force, can the air in the siphon tube 3 be pulled, and the liquid level filling the siphon tube 3 be pulled past the proximal end of the siphon tube 3 and into the second tube section. When the liquid level in the siphon tube 3 is lower than the liquid level in the liquid storage tank 2, under the action of centrifugal force, the liquid in the liquid storage tank 2 will pass through the siphon tube 3, undergo siphon transfer, and enter the mixing tank 5 through the suction tube 4. Under the aforementioned negative pressure conditions, the auxiliary transfer liquid will enter the mixing tank 5 before the target liquid.

[0080] If the negative pressure generated by the suction tube 4 is high enough, it can pull the gas in the siphon tube 3 while the auxiliary transfer liquid flows, so that the target liquid in the siphon tube 3 has already undergone siphon transfer before the auxiliary transfer liquid completely enters the mixing tank 5. Under the aforementioned negative pressure conditions, except for the auxiliary transfer liquid that initially fills the suction tube 4, the target liquid and the auxiliary transfer liquid flow simultaneously through the suction tube 4 to the mixing tank 5 during the entire liquid transfer process, and are mixed to a certain extent during the flow. Figure 4 As shown.

[0081] The microfluidic chip in this invention utilizes a siphon tube 3 to connect a liquid storage tank 2 on the proximal side and a mixing tank 5 on the distal side, and a suction tube 4 to connect the distal end of the siphon tube 3. Centrifugal force is used to draw the auxiliary transfer liquid into the suction tube 4, and the liquid continues to be discharged from the suction tube 4 under the action of centrifugal force. During the discharge process, a local negative pressure is formed at the proximal end of the suction tube 4. Under the action of negative pressure, the gas and target liquid in the siphon tube 3 are pulled, causing the target liquid to fill the siphon tube 3. The liquid level in the siphon tube 3 is lower than the liquid level in the liquid storage tank 2 after passing the proximal end of the siphon tube 3, thereby triggering a siphon effect, allowing the target liquid to be transferred into the mixing tank through the suction tube, thus completing the transfer of the target liquid.

[0082] like Figure 6 The illustrated embodiment discloses another structure for a microfluidic chip, which is similar to... Figure 1 Compared to the structure of the microfluidic chip shown, the difference is that the liquid storage tank 2 does not have a second ventilation structure 72, that is, the liquid storage tank 2 does not have gas replenishment.

[0083] It should be noted that, due to Figure 6 The structure of the microfluidic chip shown is similar to Figure 1The microfluidic chips shown have the same structure and the same principle of liquid flow; therefore, for Figure 6 The flow process of the liquid within the microfluidic chip shown will not be elaborated further. Specifically, Figure 7 For further explanation, please refer to Figure 2 The explanation, Figure 8 For further explanation, please refer to Figure 3 The explanation, Figure 9 For further explanation, please refer to Figure 4 The explanation, Figure 10 For further explanation, please refer to Figure 5 Explanation.

[0084] Without a ventilated structure, the siphon pipe 3, connected to the liquid storage tank 2, allows centrifugal force to overcome air pressure during high-speed centrifugation, forcing the liquid level in the siphon pipe 3 to be at the same height as the liquid level in the liquid storage tank 2. The target liquid in the liquid storage tank 2 fills the first section 31 of the siphon pipe 3. Because the liquid storage tank 2 lacks a ventilated pipe connecting it to other structures or the external atmosphere for gas replenishment, when a negative pressure is generated in the second section 32, pulling the liquid in the first section 31 forward, a certain negative pressure is generated in the liquid storage tank 2. This negative pressure hinders the target liquid from filling the siphon pipe 3.

[0085] Therefore, when the liquid storage tank 2 is not connected to the ventilation structure, during the process of filling the target liquid into the siphon tube 3 in the liquid storage tank 2, the suction tube 4 will be required to generate a higher negative pressure, so that it can pull the target liquid into the siphon tube 3 in the liquid storage tank 2 while resisting the negative pressure in the liquid storage tank 2, so as to generate a siphon effect.

[0086] For example, a scenario where the chip does not require gas replenishment is when it is used for nucleic acid amplification experiments without the use of special materials. For any chip / cassette involved in nucleic acid amplification, the internal gas pathways should not be directly connected to the atmosphere, unless a special hydrophobic and breathable membrane is used.

[0087] For example, in the application scenario where the liquid storage tank 2 is not ventilated: if the target liquid is an aqueous liquid, and there is a small amount of oil liquid at the liquid surface of the first section 31 of the siphon tube 3, the oil liquid blocks the contact between the target liquid and the air, thus preventing the evaporation of the target liquid, thereby enabling long-term storage of the target liquid; since the oil liquid covers the only outward channel of the target liquid, it also achieves fixation of the target liquid. Only when the suction tube 4 generates sufficient negative pressure can this fixation be broken, allowing the liquid surface of the target liquid to pass over the proximal end of the siphon tube 3, completing the transfer of the target liquid.

[0088] In the above Figure 1 and Figure 2As shown in the embodiment, by adjusting whether the liquid storage tank 2 is connected to the venting structure, the negative pressure required by the suction tube 4 can be changed. Those skilled in the art can set whether the liquid storage tank 2 is equipped with a venting structure according to the different needs of the microfluidic chip fluid. The liquid storage tank 2 is connected to the second venting structure 72 to replenish gas in the liquid storage tank 2, reduce the negative pressure generated inside the liquid storage tank 2 after the liquid is discharged, thereby reducing the pressure requirement at the proximal end of the suction tube 4.

[0089] In some embodiments, the transfer tube 62 disclosed above may be a straight tube or an N-type siphon tube. If the transfer tube 62 is a siphon tube, for example, the diameter of the transfer tube 62 may be set to be larger than the diameter of the siphon tube 3 in this document. One end of the transfer tube 62 is connected to the transfer pool 61, and the other end of the transfer tube 62 is connected to the suction tube 4. Because the diameter of the transfer tube 62 is relatively large, during the shaking of the microfluidic chip, the Euler force generated by the shaking can cause the liquid in the transfer pool 61 to fill the transfer tube 62 and pass over the proximal end of the transfer tube 62, thereby triggering a siphon effect, so that the liquid in the transfer pool 61 enters the suction tube 4 through the transfer tube 62.

[0090] Those skilled in the art will understand that the shape and size of the transfer tube 62 can be selected according to different needs, and all are within the scope of protection. In some embodiments, different arrangements of the suction tube 4, the transfer structure 6, and the siphon tube 3 are also disclosed, such as... Figure 11 As shown.

[0091] like Figure 11 The structure of the microfluidic chip shown includes: chip body 1, liquid storage cell 2, siphon tube 3, suction tube 4, mixing cell 5, transfer structure 6, first ventilation structure 71 and second ventilation structure 72.

[0092] in, Figure 11 The structure and arrangement of the chip body 1, liquid storage pool 2, and siphon tube 3 can be found in [reference]. Figure 1 The structure and arrangement of the chip body 1, liquid storage pool 2 and siphon tube 3 in the microfluidic chip shown are not described in detail here.

[0093] Figure 11 The mixing cell 5 is located on the distal side of the chip body 1. It can be understood that the mixing cell 5 is the liquid containment space on the distal side of the liquid storage cell 2.

[0094] The transfer structure 6 includes a transfer pool 61 and a transfer tube 62.

[0095] The transfer tank 61 is a space for containing liquid, and at least a portion of the transfer tank 61 is higher than the proximal end of the suction tube 4. For example, the transfer tank 61 has a bent structure, with its first end connected to the proximal end of the suction tube 4 and its second end connected to the mixing tank 5. The transfer tank 61 is bent from the first end to the second end. Specifically, after the first end of the transfer tank 61 is connected to the suction tube 4, it first bends towards the centrifugal center O and then bends away from the centrifugal center O before connecting to the mixing tank 5.

[0096] The curvature of the transfer pool 61 makes the closest point of the transfer pool 61 to the center of the heart O the proximal end of the transfer pool 61.

[0097] One end of the transfer tube 62 is connected to the distal end of the suction tube 4. The distal end of the transfer tube 62 is higher than the distal end of the mixing tank 5, ensuring that all liquid is ultimately contained within the mixing tank 5. In some embodiments, the end of the transfer tube 62 connected to the suction tube 4 is the proximal end, and the end connected to the transfer tank 61 is the distal end.

[0098] The distal end of the second tube segment 32 is connected to the proximal end of the suction tube 4, so that the curved portion of the second tube segment 32, the suction tube 4 and the transfer pool 61 form a Y-shaped structure.

[0099] The transfer tube 62 is connected to atmospheric pressure via a first venting structure 71, including but not limited to, to prevent the formation of air embolisms within the transfer tube 62. The liquid storage tank 2 is connected to the mixing tank 5 via a second venting structure 72 and another first venting structure 71 to achieve gas circulation within the liquid storage tank 2, the mixing tank 5, and the transfer tank 61, thereby achieving gas pressure balance during the liquid inlet process and ensuring that there is no air resistance obstructing the liquid flow.

[0100] It should be noted that, as the liquid in the mixing tank 5 flows to the left, the transfer tank 61 is venting and inletting liquid. The ample internal space of the transfer tank 61 is sufficient to achieve gas-liquid exchange within itself, without relying on a sufficiently large external structure. Therefore, it can achieve gas-liquid exchange within itself, combined with the above-mentioned connection method. Figure 11 In the microfluidic chip shown, the auxiliary transfer liquid exists within the mixing chamber 5; therefore, Figure 11 The siphon tube 3 in the middle cannot be like Figure 1 The siphon tube 3 in the microfluidic chip shown uses centrifugal force to directly transfer the auxiliary transfer liquid in the transfer cell 61 into the suction tube 4, which can be understood as: Figure 1 The microfluidic chip in the middle can use centrifugation to allow the auxiliary transfer liquid to enter the suction tube 4 and drive it to fill the siphon tube 3, while Figure 11 The position of the siphon tube 3 in the microfluidic chip determines that it cannot do this.

[0101] Based on this Figure 11 The microfluidic chip in the middle uses a method to control the rotation of a motor. Specifically, it controls the motor to rotate at low speed and high acceleration, so that... Figure 12 The liquid in the mixing tank 5 is subjected to Euler force, and under the influence of Euler force, the auxiliary transfer liquid in the mixing tank 5 flows in a back-and-forth oscillating manner. This is achieved by adjusting the control motors on both sides of the chip body 1 (the mixing tanks 5 are at both ends of the chip body 1 extending in the direction of extension; exemplarily, they could be...). Figure 11 The magnitude of the acceleration on both sides (left and right) causes the Euler force on one side of the auxiliary transfer liquid in the mixing tank 5 to be stronger than that on the other side, thus causing the auxiliary transfer liquid in the mixing tank 5 to gradually flow into the transfer tank 61, such as... Figure 13 As shown.

[0102] It should be noted that during the shaking of the microfluidic chip, the auxiliary transfer liquid in the mixing tank 5 can flow to the transfer tank 61 under the action of Euler force. However, the liquid in the liquid storage tank 2 cannot enter the siphon tube 3. Specifically, because the siphon tube 3 is very thin (the specific size is not specifically limited), and the liquid in the liquid storage tank 2 is usually quite full, the liquid in the liquid storage tank 2 is difficult to shake. Therefore, during the shaking of the microfluidic chip, the liquid in the liquid storage tank 2 cannot enter the siphon tube 3.

[0103] like Figure 13 As shown, under the action of Euler force, the auxiliary transfer liquid in the mixing tank 5 is transferred to the transfer tank 61, and part of the liquid crosses the proximal end of the transfer tank 61 and contacts the proximal end of the suction tube 4; in some embodiments, part of the auxiliary transfer liquid is transferred to the transfer tube 62.

[0104] Since the first section 31 of the siphon 3 is connected to the liquid storage tank 2, forming a communicating vessel, the target liquid in the liquid storage tank 2 will flow into the first section 31 and fill it due to the communicating vessel effect. Because the liquid level in the proximal end of the liquid storage tank 2 is lower than that in the proximal end of the siphon 3, the height of the liquid filling the first section 31 is lower than that in the proximal end of the siphon 3, meaning it will not exceed the proximal end of the siphon 3.

[0105] Depend on Figure 13 The state of the microfluidic chip shown Figure 14As shown in the diagram, the microfluidic chip body 1 generates centrifugal force. Under this centrifugal force, the auxiliary transfer liquid near the proximal end of the transfer cell 61, or between the proximal end and the first end, enters the suction tube 4, passes through the suction tube 4, and enters the transfer tube 62. Together with the auxiliary transfer liquid temporarily stored in the transfer tube 62, it flows back to the mixing cell 5 through the transfer tube 62. During the transfer of the auxiliary transfer liquid in the transfer cell 61 through the suction tube 4, a negative pressure is generated at the proximal end of the suction tube 4. This negative pressure simultaneously exerts a pulling force on the first end of the transfer cell 61 and the distal end of the siphon tube 3 connected to the proximal end of the suction tube 4.

[0106] like Figure 15 As shown, when the negative pressure generated at the proximal end of the suction tube 4 is large enough, the target liquid in the siphon tube 3 will be pulled and fill the siphon tube 3, thereby forming a siphon effect to transfer the target liquid in the liquid storage pool 2.

[0107] like Figure 15 and Figure 16 As shown, when the liquid level in the siphon tube 3 is lower than the liquid level in the liquid storage tank 2, under the action of centrifugal force, the liquid in the liquid storage tank 2 will be transferred through the siphon tube 3 and enter the mixing tank 5 through the suction tube 4.

[0108] like Figures 11 to 15 As shown, the filling of the liquid in the transfer tank 61 utilizes Euler force. In some cases, under the action of Euler force, the liquid in the liquid storage tank 2 can directly fill the siphon tube 3. However, when the liquid in the liquid storage tank 2 is very full, making it difficult to move, or when the liquid storage tank 2 is like... Figure 6 In cases where there is no ventilation or the siphon tube 3 is very thin, the liquid in the liquid storage tank 2 cannot provide enough impact force to fill the siphon tube 3. Therefore, a suction tube 4 is needed to suction the siphon tube 3. At this time, the auxiliary transfer liquid is located in the mixing tank 5 at a lower position, so a transfer structure 6 is required.

[0109] It should be noted that the auxiliary transfer liquid is a liquid that does not react with the target liquid and does not affect the detection process of the target liquid.

[0110] Regarding the filling of liquid within the siphon tube 3 disclosed in this invention, there are several existing technical solutions (e.g., static capillary, Euler force filling), each with its limitations. For example, when the siphon tube 3 is too thin, the sidewalls of the siphon tube 3 are irregular, there are a small amount of solid particles inside the siphon tube 3, the liquid storage tank 2 is too full, or the liquid storage tank 2 lacks a venting structure, these conditions will greatly limit the existing filling methods. However, this invention employs negative pressure, thereby creating a "vacuuming" effect. As long as the negative pressure is large enough, siphoning can be stably achieved.

[0111] In summary, the core of this invention lies in the ability to generate sufficient negative pressure, ensure that the suction tube 4 is thicker than the siphon tube 3, and provide sufficient centrifugal force (i.e., a stable motor speed). There is no need to pre-treat or coat the siphon tube 3 with special consumables, which helps to reduce costs. In addition, the requirements for the shape of the liquid storage tank 2, the size, precision, and smoothness of the siphon tube 3 are low, and the success rate of achieving the siphon effect is high.

[0112] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0113] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A microfluidic chip, characterized in that, include: Chip body (1), the chip body (1) is capable of generating centrifugal force around the centrifugal center; Liquid storage tank (2), which is disposed on the chip body (1) and is used to hold the target liquid; Mixing pool (5), the mixing pool (5) is disposed on the chip body (1), and both the liquid storage pool (2) and the mixing pool (5) are liquid containment spaces, and the mixing pool (5) is located on the distal side of the liquid storage pool (2). A siphon tube (3), the first end of which is connected to the liquid storage tank (2); A suction tube (4) is provided, the proximal end of which is connected to the second end of the siphon tube (3), the second end of which is the distal end, and a tube segment between the first end and the second end of the siphon tube (3) that is higher than the proximal end of the liquid storage tank (2), and the highest point of the tube segment that is higher than the proximal end of the liquid storage tank (2) forms the proximal end of the siphon tube (3), and the diameter of the suction tube (4) is larger than the diameter of the siphon tube (3); The transfer structure (6) is connected to the proximal end of the suction tube (4), and at least a portion of the structure in the transfer structure (6) is higher than the proximal end of the suction tube (4). Under the action of centrifugal force, the liquid in the transfer structure (6) that is higher than the proximal end of the suction tube (4) can flow through the suction tube (4) to the mixing tank (5), and the proximal end of the suction tube (4) generates a preset negative pressure value. The height is the distance to the centrifugal center, and the closer to the centrifugal center, the higher the height.

2. The microfluidic chip according to claim 1, characterized in that, The siphon tube (3) includes: The first pipe section (31) is connected at one end to the distal end of the liquid storage tank (2); The second pipe section (32) has one end connected to the other end of the first pipe section (31), and the other end of the second pipe section (32) is connected to the proximal end of the suction pipe (4). The height of the connection point between the first pipe section (31) and the second pipe section (32) is higher than the height of the proximal end of the liquid storage tank (2).

3. The microfluidic chip according to claim 2, characterized in that, The first pipe segment (31) and the second pipe segment (32) are connected in an N-type structure.

4. The microfluidic chip according to claim 1, characterized in that, The transfer structure (6) includes: The transfer tank (61) is used to hold the auxiliary transfer liquid, and the transfer tank (61) has at least a portion of its height higher than the height of the proximal end of the suction tube (4). The proximal end of the suction tube (4) is connected to the position of the transfer pool (61) below the proximal end of the transfer pool (61).

5. The microfluidic chip according to claim 4, characterized in that, The transfer structure (6) also includes: The transfer tube (62) is connected to the distal end of the transfer pool (61) at its proximal end and to the proximal end of the suction tube (4) at its distal end. The transfer tube (62), the suction tube (4) and the siphon tube (3) are arranged in a Y-shape.

6. The microfluidic chip according to claim 4, characterized in that, The transfer structure (6) also includes: The transfer tube (62) is connected to the distal end of the suction tube (4); The transfer pool (61) has a curved structure, and the first end of the transfer pool (61) is connected to the proximal end of the suction tube (4). The second end of the transfer pool (61) is the distal end and is connected to the mixing pool (5). The two ends of the transfer pool (61) are bent to form the proximal end of the transfer pool (61). The height of the proximal end of the transfer pool (61) is higher than the height of the proximal end of the suction tube (4). The transfer tube (62) is connected to the distal end of the transfer pool (61). The suction tube (4), the siphon tube (3), and the transfer pool (61) are arranged in a Y-shape at positions higher than the proximal end of the suction tube (4).

7. The microfluidic chip according to claim 6, characterized in that, From the first end of the transfer pool (61) to the second end of the transfer pool (61), the transfer pool (61) is S-shaped and the height of the second end of the transfer pool (61) is lower than the height of the first end of the transfer pool (61).

8. The microfluidic chip according to any one of claims 4 to 7, characterized in that, The liquid storage tank (2), the mixing tank (5), and / or the transfer tank (61) are connected.

9. The microfluidic chip according to any one of claims 5 to 7, characterized in that, The transfer pipe (62) is a straight pipe or a siphon pipe.

10. A microfluidic system, comprising a microfluidic chip, characterized in that, The microfluidic chip is the microfluidic chip as described in any one of claims 1 to 9.

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