Valve device, microfluidic chip and method for controlling liquid flow

Abstract

The application relates to a valve device, a micro-fluidic chip and a method for controlling liquid flow. By improving the positional relationship between the inlet port and the outlet port of the air pressure chamber, liquid flow interruption is not prone to occur, and the upstream chamber is more conducive to completely discharging liquid. Before the valve device is designed, the internal pressure of the air pressure chamber, the liquid flow relationship between the inlet port and the outlet port of the air pressure chamber need not be accurately calculated, and the universality of the product is greatly improved. Compared with the capillary siphon valve, the spring valve and the phase change valve of the traditional technology, the valve device of the application is irrelevant to the hydrophilicity or hydrophobicity of the material surface, a special valve processing procedure need not be added after the completion of the manufacturing of the carrier, the closing and opening of the valve need not be assisted by any device outside the carrier, and therefore, the valve device is easier to mass-produce, easier to save cost and easier to use, has longer stability and maneuverability, and is more compatible with various biochemical reaction processes.

Description

Technical Field

[0001] This application relates to the field of centrifugal microfluidics, and in particular to valve devices, microfluidic chips, and methods for controlling liquid flow, also referred to as valve devices, microfluidic chips, and methods for controlling liquid flow using valve devices. Background Technology

[0002] A centrifugal microfluidic chip system refers to a microelectromechanical system (MEMS) that utilizes microelectromechanical fabrication (MEMS) technology to miniaturize and integrate components such as valves, flow channels, mixing reactors, heaters, separation devices, and detectors involved in sampling, pretreatment, derivatization, mixing, and detection processes in biological, chemical, and medical analyses onto a CD-shaped chip. Centrifugal force is used as the driving force for fluid flow, enabling fluid flow and unit operations on the chip, thereby completing various biochemical reactions and detection processes. Valves are key functional units for fluid control in microfluidics. Closing a valve achieves fluid throttling; opening a valve achieves fluid transfer. Capillary siphon valves are the most commonly used type of valve on centrifugal microfluidic chips. When the centrifugal force is greater than the capillary force, the capillary siphon valve cannot automatically complete siphoning, thus the liquid is throttled; however, when the centrifugal force is less than the capillary force, the capillary force can drive the liquid flow to complete capillary siphoning, and thus, liquid transfer can be achieved at higher centrifugal forces. However, common centrifugal microfluidic chips are made from polymer materials. Due to the hydrophobicity of polymer surfaces, capillary siphon valves must be modified with hydrophilic agents to achieve capillary action. This hydrophilic modification leads to difficulties in mass production and long-term storage of the chips. Furthermore, after a single use, the residual liquid inside the capillary makes the valve unusable; therefore, capillary siphon valves are generally single-use valves.

[0003] CN212868723U proposes a centrifugal force microfluidic chip microvalve that can achieve liquid sealing via a spring valve. A spring with a ball connected to it is installed within the microfluidic chip's structural channel. When the centrifugal force on the ball is less than the spring force, the ball presses against the funnel-shaped channel opening near the center, preventing liquid from passing through the spring valve. However, when the centrifugal force on the ball is greater than the spring force, the ball compresses the spring, opening the spring valve and allowing liquid to pass through. However, manufacturing the spring valve within the chip channel complicates the chip manufacturing process and requires a precise fit between the ball and the funnel-shaped channel opening to achieve the valve-closing effect, making mass production of this chip quite difficult.

[0004] CN101070927B proposes a phase change valve that achieves channel sealing by injecting a phase change material into a predetermined section of a microfluidic chip channel and hardening the material. When it is necessary to open the channel and allow liquid to pass through the phase change valve, a heat source is used to melt the phase change material. The manufacturing process and use of the phase change valve are complex because the valve area needs to be filled with phase change material during manufacturing, and an external heat source is required to open the valve. Furthermore, the melted phase change material may re-block the channel outside the valve, hindering liquid flow and posing a risk. Finally, the phase change valve cannot re-seal the channel after use, thus limiting its reusability.

[0005] CN107949437A discloses a liquid handling device for rotary-driven liquid flow, which requires the inlet port of the ventilated chamber to be located radially inside the outlet port. However, this design causes the gas trapped in the ventilated chamber to expand when the centrifugal force is less than a certain threshold, resulting in the liquid front of the upstream pipe moving radially outward. Gas exists between the inlet port of the ventilated chamber and the liquid front of the upstream pipe, and the amount of this gas affects the rate at which liquid from the subsequent ventilated upstream chamber enters the ventilated chamber. If the flow rate at the inlet port of the ventilated chamber is less than the flow rate at the outlet port, the liquid flow to the ventilated downstream chamber will be interrupted, and the liquid in the ventilated upstream chamber cannot completely flow out. Therefore, precise calculations of the internal pressure of the ventilated chamber and the liquid flow rate relationship between the inlet and outlet ports of the ventilated chamber are required before designing such a device, making its application inconvenient. Summary of the Invention

[0006] Therefore, it is necessary to provide a valve device, a microfluidic chip, and a method for controlling liquid flow.

[0007] A valve device is applied in a carrier having a center of rotation, the valve device comprising an upstream chamber, a downstream chamber, a pneumatic chamber, a first fluid channel, and a second fluid channel;

[0008] The upstream chamber is sequentially connected to the downstream chamber via the first fluid channel, the pneumatic chamber, and the second fluid channel;

[0009] The fluid inlet of the pneumatic chamber, which communicates with the first fluid channel, has a larger radial distance from the center of rotation relative to the fluid outlet of the pneumatic chamber, which communicates with the second fluid channel.

[0010] The aforementioned valve device, by improving the positional relationship between the inlet and outlet ports of the pressure chamber, is less prone to liquid flow interruption and is more conducive to the complete discharge of liquid from the upstream chamber. Furthermore, it eliminates the need for precise calculations of the internal pressure of the pressure chamber and the liquid flow relationship between the inlet and outlet ports before designing the valve device, greatly enhancing the product's versatility. Compared to traditional capillary siphon valves, spring valves, and phase change valves, the valve device described in this application is independent of the hydrophilicity or hydrophobicity of the material surface, does not require a dedicated valve processing step after the carrier is manufactured, and the valve's closing and opening do not require any external device assistance. Therefore, it is easier to mass-produce, easier to save costs, and easier to use, exhibiting longer-lasting stability and operability, and is more compatible with a wide variety of biochemical reaction processes.

[0011] In one embodiment, by setting a minimum radial distance between the bend of the second fluid channel and the center of rotation, the centrifugal force required for the fluid in the pneumatic chamber to enter the downstream chamber through the second fluid channel is limited.

[0012] In one embodiment, the first fluid inlet of the first fluid channel, which communicates with the pneumatic chamber, is located radially outside the second fluid outlet of the second fluid channel, which communicates with the pneumatic chamber.

[0013] In one embodiment, the second fluid channel is provided with a connected bend and a conveying section;

[0014] The curved section is connected to the pneumatic chamber through the second fluid outlet, and the conveying section is connected to the downstream chamber through the second fluid inlet. The minimum radial distance between the curved section and the rotation center is less than the radial distance between the second fluid outlet and the rotation center.

[0015] Furthermore, the position of the pneumatic chamber and the second fluid outlet forms a sloping guide channel to keep the liquid in the second fluid channel in communication with the liquid in the pneumatic chamber when the valve device is in the open state, so as to release the liquid in the pneumatic chamber into the second fluid channel to the maximum extent.

[0016] In one embodiment, depending on the rotation direction of the carrier or the valve device, the first fluid channel and the second fluid channel are respectively disposed on both sides of the pneumatic chamber; and / or,

[0017] The first fluid outlet of the first fluid channel, which communicates with the upstream chamber, is located at the position of the maximum radial distance between the upstream chamber and the rotation center, and is configured according to the rotation direction of the carrier or the valve device to adapt to the effect of the Coriolis force on the fluid during rotation.

[0018] In one embodiment, the upstream chamber and the downstream chamber are respectively used to connect to the pressure balancing chamber of the carrier; or,

[0019] The upstream chamber and the downstream chamber are each provided with an air outlet that connects to the atmospheric environment; or,

[0020] One of the upstream chamber and the downstream chamber is provided with an air outlet connected to the atmospheric environment. The upstream chamber and the downstream chamber are connected by an additional flow channel, and the additional flow channel has a smaller radial distance relative to the maximum liquid level of the upstream chamber.

[0021] In one embodiment, a microfluidic chip includes any of the valve devices and the carrier described above.

[0022] In one embodiment, a method for controlling liquid flow using a valve device includes the steps of:

[0023] A measured amount of the first liquid is placed in the upstream chamber;

[0024] Driven by the preset first centrifugal force, the valve device rotates, and the first liquid in the upstream chamber is driven by the centrifugal force to flow into the pneumatic chamber through the first fluid channel, so that the liquid volume in the pneumatic chamber gradually increases, and the gas in the pneumatic chamber is gradually discharged from the second fluid channel.

[0025] When the liquid level in the pressure chamber exceeds the fluid outlet of the pressure chamber, the gas in the pressure chamber is prevented from continuing to be discharged through the bend of the second fluid channel. As the liquid level rises, the gas in the pressure chamber is compressed, and the pressure gradually increases.

[0026] When the air pressure in the air pressure chamber reaches force balance with the first centrifugal force, the liquid level in the air pressure chamber will no longer rise, thus closing the valve.

[0027] Driven by a preset second centrifugal force, the first liquid in the pneumatic chamber overcomes the restriction of the bend and flows into the downstream chamber, forming a valve open state, until the liquid level in the pneumatic chamber is lower than the fluid outlet of the pneumatic chamber and the flow stops, so that the first liquid in the upstream chamber is completely discharged.

[0028] In one embodiment, the second centrifugal force is greater than the first centrifugal force, so that the air pressure in the air pressure chamber increases to the point that the first liquid in the air pressure chamber overcomes the restriction of the bend and flows into the downstream chamber; or...

[0029] The second centrifugal force is less than the first centrifugal force, so that the air pressure in the air pressure chamber is reduced. Under the action of gas expansion, the first liquid in the air pressure chamber overcomes the restriction of the bend and flows into the downstream chamber. At the same time, during the gas expansion process, the liquid in the first fluid channel is always in communication with the liquid in the air pressure chamber, and the liquid in the second fluid channel is always in communication with the liquid in the air pressure chamber.

[0030] In one embodiment, the valve device is controlled to open and close at least twice by adjusting the rotation speed. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of an embodiment of the valve device described in this application.

[0033] Figure 2 To adopt Figure 1 A schematic diagram of an embodiment of the microfluidic chip for the valve device shown.

[0034] Figure 3 To adopt Figure 1 A schematic diagram of another embodiment of the microfluidic chip for the valve device shown.

[0035] Figure 4 for Figure 1 An enlarged schematic diagram of point A in the illustrated embodiment.

[0036] Figure 5 This is a schematic flowchart of an embodiment of the method for controlling liquid flow using a valve device as described in this application.

[0037] Figure 6 for Figure 1 The illustrated embodiment shows a schematic diagram of the state in which the first liquid is added to the upstream chamber.

[0038] Figure 7 for Figure 6 The illustrated embodiment shows a schematic diagram of the state in which the first liquid flows into the pneumatic chamber.

[0039] Figure 8 for Figure 7 A schematic diagram of the valve device when the gas pressure and centrifugal force reach equilibrium in the illustrated embodiment.

[0040] Figure 9 for Figure 8A schematic diagram of one state of the valve device in the embodiment shown when it is open.

[0041] Figure 10 for Figure 9 A schematic diagram of the state of the first liquid flowing into the downstream chamber in the embodiment shown.

[0042] Figure 11 for Figure 8 A schematic diagram of another state of the valve device in the illustrated embodiment when it is open.

[0043] Figure 12 for Figure 11 A schematic diagram of the state of the first liquid flowing into the downstream chamber in the embodiment shown.

[0044] Figure 13 for Figure 6 The schematic diagram of the embodiment shown shows the state in which the first liquid has flowed substantially completely into the downstream chamber.

[0045] Figure 14 for Figure 13 The illustrated embodiment shows a schematic diagram of the state in which the second liquid is added to the upstream chamber.

[0046] Figure 15 for Figure 14 A schematic diagram of the valve device when the gas pressure and centrifugal force reach equilibrium in the illustrated embodiment.

[0047] Reference numerals: Valve device 100, upstream chamber 110, downstream chamber 120, pneumatic chamber 130, first fluid channel 140, first fluid outlet 141, first fluid inlet 142, second fluid channel 150, second fluid outlet 151, second fluid inlet 152, bend 153, conveying section 154, first liquid 200, second liquid 300, carrier 400, rotation center 410, radial direction 500, reference line 600. Detailed Implementation

[0048] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0049] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0051] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0052] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0053] This application discloses a valve device, a microfluidic chip, and a method for controlling liquid flow, which includes some or all of the technical features of the following embodiments. In one embodiment of this application, a valve device is applied in a carrier having a center of rotation. The valve device includes an upstream chamber, a downstream chamber, a pneumatic chamber, a first fluid channel, and a second fluid channel. The upstream chamber is sequentially connected to the downstream chamber through the first fluid channel, the pneumatic chamber, and the second fluid channel. The fluid inlet of the pneumatic chamber, which communicates with the first fluid channel, has a larger radial distance from the center of rotation relative to the fluid outlet of the pneumatic chamber, which communicates with the second fluid channel. The aforementioned valve device, by improving the positional relationship between the inlet and outlet ports of the pressure chamber, is less prone to liquid flow interruption and is more conducive to the complete discharge of liquid from the upstream chamber. Furthermore, it eliminates the need for precise calculations of the internal pressure of the pressure chamber and the liquid flow relationship between the inlet and outlet ports before designing the valve device, greatly enhancing the product's versatility. Compared to traditional capillary siphon valves, spring valves, and phase change valves, the valve device described in this application is independent of the hydrophilicity or hydrophobicity of the material surface, does not require a dedicated valve processing step after the carrier is manufactured, and the valve's closing and opening do not require any external device assistance. Therefore, it is easier to mass-produce, easier to save costs, and easier to use, exhibiting longer-lasting stability and operability, and is more compatible with a wide variety of biochemical reaction processes.

[0054] In one embodiment, a valve device 100 such as Figure 1 As shown, the valve device 100 includes an upstream chamber 110, a downstream chamber 120, a pneumatic chamber 130, a first fluid passage 140, and a second fluid passage 150. (The last sentence appears to be incomplete and possibly refers to a different device.) Figure 1 The valve device 100 shown is a microfluidic chip such as Figure 2 As shown, using Figure 1 Another microfluidic chip of the valve device 100 shown is as follows: Figure 3 As shown. The microfluidic chip includes the valve device 100 and the carrier 400 described in any embodiment.

[0055] like Figure 2As shown, the valve device 100 is applied in a carrier 400 having a rotation center 410. One carrier 400 may have two, three, four, or more valve devices 100. Further, each valve device 100 is centrally symmetrically distributed with respect to the rotation center 410 of the carrier 400. In various embodiments, the valve device 100 is a structural functional component of the test carrier 400 having a rotation axis and a rotation center 410, used to control the liquid flow in the fluid channel when the test carrier 400 rotates centrifugally. The valve device 100 includes at least an upstream chamber 110, a downstream chamber 120, a pneumatic chamber 130, and fluid channels connecting them, including but not limited to a first fluid channel 140 and a second fluid channel 150.

[0056] In this embodiment, the carrier 400 is circular. In other embodiments, the carrier 400 may have other shapes. In one embodiment, the carrier 400 is as follows: Figure 3 As shown, it has a fan-shaped or partially fan-shaped shape.

[0057] The upstream chamber 110 has at least a fluid inlet and a fluid outlet. The fluid inlet is used to introduce liquid into the upstream chamber 110, and the fluid outlet is used to discharge liquid from the upstream chamber 110. The fluid inlet is closer to the center of rotation 410 in the radial direction relative to the fluid outlet; that is, the radial distance of the fluid inlet is less than the radial distance of the fluid outlet. The downstream chamber 120 has at least a fluid inlet to allow liquid from the upstream chamber 110 to flow into the downstream chamber 120. Figure 4 As shown, the upstream chamber 110 is sequentially connected to the downstream chamber 120 via the first fluid channel 140, the pneumatic chamber 130, and the second fluid channel 150. The fluid inlet of the pneumatic chamber 130, which communicates with the first fluid channel 140, has a larger radial distance from the rotation center 410 relative to the fluid outlet of the pneumatic chamber 130, which communicates with the second fluid channel 150. This design, by improving the positional relationship between the inlet and outlet ports of the pneumatic chamber, reduces the likelihood of liquid flow interruption and facilitates complete liquid discharge from the upstream chamber.

[0058] Combination Figure 3The carrier 400 has a radial distance of 500 relative to its rotation center 410. The fluid inlet of the pneumatic chamber 130 that communicates with the first fluid channel 140 is the first fluid inlet 142. The fluid outlet of the pneumatic chamber 130 that communicates with the second fluid channel 150 is the second fluid outlet 151. The first fluid inlet 142 is further radially away from the rotation center 410 than the second fluid outlet 151, that is, the first fluid inlet 142 has a larger radial distance from the rotation center 410 than the second fluid outlet 151. That is, the first fluid inlet 142 of the first fluid channel 140, which communicates with the pneumatic chamber 130, is located radially 500 degrees outside the second fluid outlet 151 of the second fluid channel 150, which also communicates with the pneumatic chamber 130. Using reference line 600 as a comparison reference, the second fluid outlet 151 is closer to the rotation center 410 relative to the first fluid inlet 142. The second fluid outlet 151 is located inside reference line 600, i.e., radially 500 degrees inside, while the first fluid inlet 142 is located outside reference line 600, i.e., radially 500 degrees outside. As mentioned above, due to the improved positional relationship, a valve switching solution completely different from traditional technologies is provided. Therefore, it is not necessary to accurately calculate the internal pressure of the pneumatic chamber and the liquid flow relationship between the inlet and outlet ports of the pneumatic chamber before designing the valve device, greatly improving the product's versatility.

[0059] It is understood that the radial distance of a certain structure is the distance between the structure and the rotation center 410 along the radial direction. When the structure is small, such as an outlet or inlet, the radial distance can be simply understood as a numerical value. When the structure is large, such as a pipe or a shape, the radial distance is a range, and there may be a minimum radial distance and a maximum radial distance.

[0060] In order to control the flow of fluid into the downstream chamber 120, i.e., to effectively control the opening and closing of the valve, such as... Figure 4 As shown, the pressure chamber 130 has a fluid inlet and a fluid outlet, with the fluid inlet having a larger radial distance relative to the fluid outlet. The radial distance of the fluid inlet of the pressure chamber 130 is greater than the radial distance of the fluid outlet of the upstream chamber 110. The fluid outlet of the upstream chamber 110 is connected to the fluid inlet of the pressure chamber 130 via a first fluid channel 140, allowing liquid in the upstream chamber 110 to flow into the pressure chamber 130 through the first fluid channel 140. The fluid outlet of the pressure chamber 130 is connected to the fluid inlet of the downstream chamber 120 via a second fluid channel 150, allowing liquid in the pressure chamber 130 to flow into the downstream chamber 120. The second fluid channel 150 has a radially inwardly curved portion 153 located at the fluid outlet of the pressure chamber 130, meaning the radial distance of the curved portion 153 is less than the radial distance of the fluid outlet of the pressure chamber 130.

[0061] In one embodiment, by setting the minimum radial distance between the bend 153 of the second fluid channel 150 and the rotation center 410, the centrifugal force required for the fluid in the pneumatic chamber 130 to enter the downstream chamber 120 through the second fluid channel 150 is limited. Further, the minimum radial distance between the bend 153 and the rotation center 410 is less than the minimum radial distance between the pneumatic chamber 130 and the rotation center 410. In one embodiment, the second fluid channel 150 is provided with a connected bend 153 and a conveying section 154; the bend 153 connects to the pneumatic chamber 130 through the second fluid outlet 151, and the conveying section 154 connects to the downstream chamber 120 through the second fluid inlet 152, and the minimum radial distance between the bend 153 and the rotation center 410 is less than the radial distance between the second fluid outlet 151 and the rotation center 410. This design, by controlling the structure of the second fluid channel 150 and balancing the gas pressure and centrifugal force in the pneumatic chamber 130, achieves valve opening and closing control. This is something that traditional capillary siphon valves, spring valves, and phase change valves neglect. In comparison, the valve device described in this application is independent of the hydrophilicity or hydrophobicity of the material surface, thus eliminating the need for a dedicated valve processing step after the carrier is manufactured. The valve's opening and closing do not require any external device assistance. Due to the simplified structure and control design, it is easier to mass-produce, more cost-effective, and easier to use, exhibiting longer-lasting stability and operability, and is more compatible with a wide variety of biochemical reaction processes.

[0062] In one embodiment, the first fluid channel 140 and the second fluid channel 150 are respectively disposed on both sides of the pneumatic chamber 130 according to the rotation direction of the carrier 400 or the valve device 100. In one embodiment, the first fluid outlet 141 of the first fluid channel 140, which communicates with the upstream chamber 110, is disposed at the position of the maximum radial distance between the upstream chamber 110 and the rotation center 410, and is configured according to the rotation direction of the carrier 400 or the valve device 100 to adapt to the effect of the Coriolis force on the fluid, i.e., the liquid, during rotation, thereby releasing the fluid in the upstream chamber 110 as fully as possible. In one embodiment, depending on the rotation direction of the carrier 400 or the valve device 100, the first fluid channel 140 and the second fluid channel 150 are respectively disposed on both sides of the pressure chamber 130; the first fluid outlet 141 of the first fluid channel 140, which communicates with the upstream chamber 110, is disposed at the position of the maximum radial distance between the upstream chamber 110 and the rotation center 410, and is configured according to the rotation direction of the carrier 400 or the valve device 100 to adapt to the effect of the Coriolis force on the fluid during rotation. Other embodiments follow the same principle and will not be described in detail. Further, the positions of the pressure chamber 130 and the second fluid outlet 151 form a sloping guide channel to maintain communication between the liquid in the second fluid channel 150 and the liquid in the pressure chamber 130 when the valve device 100 is in the open state, so as to maximize the release of liquid from the pressure chamber 130 into the second fluid channel 150. Furthermore, the sloping guide channel is located at the maximum radial distance between the pressure chamber 130 and the rotation center 410 and forms a smooth and / or partially spherical surface to accommodate the Coriolis force during rotation and reduce resistance, allowing the liquid in the pressure chamber 130 to flow out as much as possible. This design, on the one hand, facilitates the complete discharge of liquid from the upstream chamber 110 into the pressure chamber 130; on the other hand, because it adapts to the effect of the Coriolis force on the liquid during rotation, it facilitates the discharge of as much liquid as possible from the pressure chamber 130 into the downstream chamber 120.

[0063] To facilitate liquid flow, external atmospheric pressure needs to be provided. The upstream chamber 110 and downstream chamber 120 can be pressure balancing chambers connected to the atmosphere outside the test carrier 400; they can also be interconnected via fluid channels or connected to other chambers on the test carrier 400 to form a closed-loop gas path. In one embodiment, the upstream chamber 110 and downstream chamber 120 are respectively used to connect to the pressure balancing chambers of the carrier 400; in one embodiment, the upstream chamber 110 and downstream chamber 120 are respectively provided with air outlets connected to the atmospheric environment; in one embodiment, one of the upstream chamber 110 and downstream chamber 120 is provided with an air outlet connected to the atmospheric environment, and the upstream chamber 110 and downstream chamber 120 are connected by an additional flow channel with a smaller radial distance relative to the maximum liquid level of the upstream chamber 110.

[0064] In one embodiment, a method for controlling liquid flow using a valve device is as follows: Figure 5 As shown, it includes the following steps: S100, placing a measured amount of first liquid 200 into the upstream chamber 110; S200, under the drive of a preset first centrifugal force, the valve device 100 rotates, and the first liquid 200 in the upstream chamber 110 is driven by the centrifugal force to flow into the pneumatic chamber 130 through the first fluid channel 140, so that the liquid volume in the pneumatic chamber 130 gradually increases, and the gas in the pneumatic chamber 130 gradually exits from the second fluid channel 150; S300, when the liquid level in the pneumatic chamber 130 exceeds the fluid outlet of the pneumatic chamber 130, the gas in the pneumatic chamber 130 is restricted by the bend 153 of the second fluid channel 150. The liquid cannot continue to be discharged, and as the liquid level rises, the gas in the pressure chamber 130 is compressed, and the pressure gradually increases. At S400, when the pressure in the pressure chamber 130 reaches force balance with the first centrifugal force, the liquid level in the pressure chamber 130 stops rising, forming a closed valve state. At S500, driven by a preset second centrifugal force, the first liquid 200 in the pressure chamber 130 overcomes the restriction of the bend 153 and flows into the downstream chamber 120, forming an open valve state, until the liquid level in the pressure chamber 130 is lower than the fluid outlet of the pressure chamber 130 and the flow stops, so that the first liquid 200 in the upstream chamber 110 is completely discharged. In one embodiment, the valve device 100 is controlled to open and close at least twice by adjusting the rotation speed. This design allows the valve device 100 to add different liquids to the upstream chamber 110 multiple times, thus enabling multiple uses in a single complex detection process. Complex reaction control can be achieved through multiple valve opening and closing controls, and the sequential reaction control of multiple liquids can also be achieved through the cooperation of multiple valve devices 100.

[0065] In specific implementation, the pressurization opening method can be adopted. In one embodiment, the second centrifugal force is greater than the first centrifugal force, so that the air pressure in the air pressure chamber 130 increases to the point that the first liquid 200 in the air pressure chamber 130 overcomes the restriction of the bend 153 and flows into the downstream chamber 120.

[0066] In specific implementation, decompression opening can also be used. In one embodiment, the second centrifugal force is less than the first centrifugal force, so that the air pressure in the air pressure chamber 130 is reduced. Under the action of gas expansion, the first liquid 200 in the air pressure chamber 130 overcomes the restriction of the bend 153 and flows into the downstream chamber 120. At the same time, during the gas expansion process, the liquid in the first fluid channel 140 is always in communication with the liquid in the air pressure chamber 130, and the liquid in the second fluid channel 150 is always in communication with the liquid in the air pressure chamber 130.

[0067] In a specific implementation, the method of controlling liquid flow using a valve device initially involves the upstream chamber 110 containing a certain amount of first liquid 200. Driven by a first centrifugal force, the test carrier 400 rotates, and the first liquid 200 in the upstream chamber 110 flows through the first fluid channel 140 into the pressure chamber 130, causing the liquid volume in the pressure chamber 130 to gradually increase. Simultaneously, the gas in the pressure chamber 130 gradually exits through the second fluid channel 150. However, when the liquid level in the pressure chamber 130 exceeds the fluid outlet of the pressure chamber 130, the gas in the pressure chamber 130 cannot continue to exit, and as the liquid level rises, the gas in the pressure chamber 130 is compressed, and the pressure gradually increases. When the pressure in the pressure chamber 130 reaches force equilibrium with the first centrifugal force, the liquid level no longer rises, and the gas is no longer compressed. Although during the process of reaching force equilibrium, the air pressure drives the first liquid 200 in the air pressure chamber 130 to flow from the fluid outlet of the air pressure chamber 130 into the second fluid channel 150, the radial distance of the bend 153 is smaller than the radial distance of the fluid outlet of the air pressure chamber 130. Therefore, as long as the radial distance of the bend 153 is sufficiently smaller than the radial distance of the fluid outlet of the air pressure chamber 130, the gas pressure will not be able to overcome the centrifugal force and fluid resistance on the liquid column in the second fluid channel 150. Consequently, the liquid front cannot cross the bend 153 and thus cannot flow to the downstream chamber 120. Thus, the first liquid 200 is blocked in the upstream chamber 110 at this time. For ease of description, the small amount of first liquid 200 in the air pressure chamber 130, the first fluid channel 140, and the second fluid channel 150 is temporarily ignored; therefore, this state is the closed valve state. When it is necessary for the first liquid 200 to be completely discharged from the upstream chamber 110, that is, when the valve needs to be opened, the first centrifugal force increases to the second centrifugal force. At this point, the original pressure balance in the pressure chamber 130 is broken, and the first liquid 200 flows further into the pressure chamber 130 while the gas is further compressed. However, when the gas pressure rises to a certain level, it is sufficient to allow the liquid in the second fluid channel 150 to overcome centrifugal force, causing the liquid front in the second fluid channel 150 to cross the bend 153 and continue to flow radially outward. At this point, the valve is opened. Therefore, the upstream chamber 110, the first fluid channel 140, the pressure chamber 130, and the second fluid channel 150 form a smooth liquid flow path. The first liquid 200 in the upstream chamber 110 can flow into the downstream chamber 120 until the liquid level in the pressure chamber 130 is lower than the fluid outlet of the pressure chamber 130, at which point the liquid stops flowing, and the first liquid 200 in the upstream chamber 110 is completely discharged.

[0068] As another method, when the gas pressure in the pressure chamber 130 reaches force equilibrium with the first centrifugal force, the first centrifugal force decreases to the third centrifugal force. At this point, the gas in the pressure chamber 130 loses its force equilibrium state and expands. Since the third centrifugal force is less than the first centrifugal force, the centrifugal force on the liquid in the second fluid channel 150 decreases. The gas pressure generated by the gas expansion drives the liquid in the second fluid channel 150 to flow towards the bend 153 and then across the bend 153 in a radially outward direction, at which point the valve opens. During the flow of liquid in the second fluid channel 150, the liquid level in the pressure chamber 130 decreases. However, by setting the radial distance of the fluid outlet of the pressure chamber 130, the liquid level can be kept above the fluid outlet during this process, preventing the liquid in the second fluid channel 150 from being disconnected from the liquid in the pressure chamber 130. Since the radial distance of the fluid inlet of the pressure chamber 130 is greater than the radial distance of the fluid outlet, the liquid in the first fluid channel 140 remains connected to the liquid in the pressure chamber 130 during the gas expansion process.

[0069] As can be seen from the above description, compared with the liquid handling device proposed in CN107949437A, the valve device 100 proposed in the embodiments of this application is less prone to liquid flow interruption and is more conducive to the complete discharge of liquid from the upstream chamber 110. When the valve is opened, the upstream chamber 110, the first fluid channel 140, the pneumatic chamber 130 and the second fluid channel 150 form a smooth liquid flow path. If centrifugal motion continues, the first liquid 200 in the upstream chamber 110 can flow into the downstream chamber 120 until the liquid level in the pneumatic chamber 130 is lower than the fluid outlet of the pneumatic chamber 130, at which point the liquid stops flowing, and the first liquid 200 in the upstream chamber 110 is also completely discharged.

[0070] It can be seen that, compared with capillary siphon valves, spring valves proposed in CN212868723U, and phase change valves proposed in CN101070927B, the valve device 100 proposed in the embodiments of this application is independent of the hydrophilicity or hydrophobicity of the material surface of the test carrier 400, does not require a special valve processing step after the test carrier 400 is manufactured, and does not require any external device assistance for valve closing and opening. Therefore, it is easier to mass-produce, easier to save costs, and has longer-lasting stability and operability.

[0071] In biomedical testing and inspection, multiple reaction steps are often involved, which may require the same valve to be repeatedly opened and closed, i.e., the valve must be reusable. As mentioned above, after the liquid in the upstream chamber 110 is completely drained, only the pressure chamber 130, the downstream chamber 120, and the first fluid channel 140 in the valve device 100 contain liquid. If a second liquid is introduced into the upstream chamber 110 at this time, because there is gas between the fluid outlet of the upstream chamber 110 and the liquid front in the first fluid channel 140, the second liquid 300 cannot flow into the first fluid channel 140 under a lower centrifugal force, such as the fourth centrifugal force. Therefore, the second liquid 300 in the upstream chamber 110 can be trapped in the upstream chamber 110 to complete the reaction. When it is necessary to drain the second liquid 300, the centrifugal force is increased to the fifth centrifugal force. At this time, the second liquid 300 flows into the first fluid channel 140, while the gas in it escapes into the upstream chamber 110 through the fluid outlet. As a result, the liquid level in the pressure chamber 130 will gradually rise. Obviously, similar to the method of intercepting and discharging the first liquid 200 described above, the same method can still be used to control the opening of the valve device 100, thereby controlling the complete discharge of the second liquid 300 from the upstream chamber 110. The valve device 100 proposed in the embodiments of this application uses the relationship between the centrifugal force on the liquid and the gas pressure in the pressure chamber 130 to control the opening and closing of the valve. Therefore, theoretically, the valve device 100 described in the embodiments of this application can be reused an unlimited number of times. Thus, compared to capillary tubes, siphon valves, and phase change valves, the valve device 100 proposed in the embodiments of this application is more compatible with a wide variety of biochemical reaction processes.

[0072] The following will continue to combine Figures 1 to 15 This application describes the specific application of the valve device.

[0073] like Figure 1 and Figure 4 As shown, the valve device 100 includes an upstream chamber 110 having a first fluid outlet 141; a pneumatic chamber 130 having a first fluid inlet 142 and a second fluid outlet 151; and a downstream chamber 120 having a second fluid inlet 152. The first fluid outlet 141 is located radially inward from the first fluid inlet 142; the first fluid inlet 142 is located radially outward from the second fluid outlet 151. A first fluid passage 140 connects the first fluid outlet 141 and the first fluid inlet 142; a second fluid passage 150 connects the second fluid outlet 151 and the second fluid inlet 152. The second fluid passage 150 includes a bend 153 that bends radially inward, the radial distance of which is smaller than the radial distance of the second fluid outlet 151.

[0074] A first liquid 200 is introduced into the upstream chamber 110, such as... Figure 6 and Figure 7 As shown, when the test carrier 400 rotates centrifugally with a first centrifugal force, the first liquid 200 flows into the pressure chamber 130 through the first fluid channel 140, and the gas in the pressure chamber 130 is discharged from the second fluid outlet 151. As the centrifugation time increases, the liquid level in the pressure chamber 130 gradually rises and at a certain moment exceeds the second fluid outlet 151. Thereafter, as the liquid level rises, the gas in the pressure chamber 130 is no longer discharged but is captured and compressed within the pressure chamber 130, and the gas pressure gradually increases. When the gas pressure in the pressure chamber 130 reaches force equilibrium with the first centrifugal force, the liquid level stops rising, and the gas is no longer compressed. Although the gas pressure drives the first liquid 200 in the gas pressure chamber 130 to flow from the second fluid outlet 151 into the second fluid channel 150 during the process of reaching force equilibrium, the radial distance of the bend 153 is smaller than the radial distance of the second fluid outlet 151. Therefore, as long as the radial distance of the bend 153 is sufficiently smaller than the radial distance of the second fluid outlet 151, the gas pressure will not be able to overcome the centrifugal force and fluid resistance experienced by the liquid column in the second fluid channel 150. Consequently, the liquid front cannot pass through the bend 153. Figure 8 As shown. It can be seen that the first liquid 200 is currently trapped in the upstream chamber 110. For ease of description, the small amount of the first liquid 200 in the pressure chamber 130, the first fluid channel 140, and the second fluid channel 150 is temporarily ignored; therefore, this state is the valve closed state. When it is necessary to completely discharge the first liquid 200 from the upstream chamber 110, that is, when the valve needs to be opened, the first centrifugal force rises to the second centrifugal force. At this time, the original pressure balance in the pressure chamber 130 is broken, and the first liquid 200 flows further into the pressure chamber 130 while the gas is further compressed. However, when the gas pressure rises to a certain level, the gas pressure is sufficient to allow the liquid in the second fluid channel 150 to overcome centrifugal force and fluid resistance, causing the liquid front in the second fluid channel 150 to cross the bend 153 and continue to flow radially outward. At this time, the valve is opened, as shown... Figure 9 As shown. Therefore, the upstream chamber 110, the first fluid channel 140, the pneumatic chamber 130, and the second fluid channel 150 form a smooth liquid flow path. The first liquid 200 in the upstream chamber 110 can flow into the downstream chamber 120 until the liquid level in the pneumatic chamber 130 is lower than the second fluid outlet 151, at which point the liquid flow stops, and the first liquid 200 in the upstream chamber 110 is also completely discharged. Figure 10 and 13 As shown.

[0075] Another method for controlling valve opening is described below, such as... Figures 6 to 8As shown, when the air pressure in the air pressure chamber 130 reaches force balance with the first centrifugal force, the first centrifugal force is reduced to the third centrifugal force. At this time, the gas in the air pressure chamber 130 loses its force balance state and the gas will expand. Since the third centrifugal force is less than the first centrifugal force, the centrifugal force on the liquid in the second fluid channel 150 decreases. The gas pressure generated by the gas expansion will drive the liquid in the second fluid channel 150 to flow towards the bend 153 and then flow radially outward past the bend 153. At this time, the valve opens, as... Figure 11 As shown. During the liquid flow in the second fluid channel 150, the liquid level in the pressure chamber 130 decreases. However, by setting the radial distance of the second fluid outlet 151, the liquid level can be ensured not to fall below the fluid outlet during this process, preventing the liquid in the second fluid channel 150 from becoming disconnected from the liquid in the pressure chamber 130. Since the radial distance of the first fluid inlet 142 is greater than the radial distance of the second fluid outlet 151, the liquid in the first fluid channel 140 remains connected to the liquid in the pressure chamber 130 during gas expansion. When the valve is opened, the upstream chamber 110, the first fluid channel 140, the pressure chamber 130, and the second fluid channel 150 form a smooth liquid flow path, as shown. Figure 11 As shown, if the centrifugal motion continues, the first liquid 200 in the upstream chamber 110 can flow into the downstream chamber 120. Figure 12 As shown, the liquid stops flowing when the liquid level in the pressure chamber 130 is lower than the second fluid outlet 151. At this time, the first liquid 200 in the upstream chamber 110 is also completely discharged. Figure 13 As shown.

[0076] Another method for controlling valve opening is further described below: After the first liquid 200 is completely discharged, the valve device 100 is reused to control the flow of the second liquid 300. Specifically, after the first liquid 200 is completely discharged, only the pneumatic chamber 130, the downstream chamber 120, and the first fluid passage 140 in the valve device 100 contain liquid. The second liquid 300 is then introduced into the upstream chamber 110. Figure 14 As shown, due to the presence of gas between the first fluid outlet 141 and the liquid front in the first fluid channel 140, the second liquid 300 cannot flow into the first fluid channel 140 under a lower centrifugal force, such as the fourth centrifugal force. Therefore, the second liquid 300 in the upstream chamber 110 can be trapped in the upstream chamber 110 to complete the reaction. When it is necessary to discharge the second liquid 300, the centrifugal force is increased to the fifth centrifugal force. At this time, the second liquid 300 flows into the first fluid channel 140, while the gas in it escapes through the first fluid outlet 141 to the upstream chamber 110. Thus, the liquid level in the pressure chamber 130 will gradually rise, and the gas will begin to be captured and compressed in the pressure chamber 130 at a certain moment, eventually reaching a state of equilibrium between the pressure and the fifth centrifugal force, as shown. Figure 15As shown. At this time, the state of valve device 100 is similar to the state of valve device 100 when the gas pressure and the first centrifugal force reach equilibrium during the interception of the first liquid 200, as... Figure 12 As shown. Therefore, by opening the valve in the same way as in the above embodiment, the second liquid 300 can be completely discharged from the upstream chamber 110 and finally flow into the downstream chamber 120 through the second fluid inlet 152. For more complex liquid control, such as a third liquid, a fourth liquid, or more liquids, the above embodiment can be used as a reference, and will not be described again.

[0077] It should be noted that other embodiments of this application also include valve devices, microfluidic chips, and methods for controlling liquid flow formed by combining the technical features of the above embodiments. By improving the positional relationship between the inlet and outlet ports of the pressure chamber, liquid flow interruption is less likely to occur, which is more conducive to the complete discharge of liquid from the upstream chamber. Moreover, it is not necessary to accurately calculate the internal pressure of the pressure chamber and the liquid flow relationship between the inlet and outlet ports of the pressure chamber before designing the valve device, which greatly improves the versatility of the product. Furthermore, compared with traditional capillary siphon valves, spring valves, and phase change valves, the valve device described in this application is independent of the hydrophilicity or hydrophobicity of the material surface, does not require a special valve processing step after the carrier is manufactured, and the closing and opening of the valve does not require any external device assistance. Therefore, it is easier to mass-produce, easier to save costs, and easier to use. It has longer-lasting stability and operability and is more compatible with a wide variety of biochemical reaction processes.

[0078] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. A valve device (100) applied in a carrier (400) having a rotation center (410), characterized in that, The valve device (100) includes an upstream chamber (110), a downstream chamber (120), a pneumatic chamber (130), a first fluid passage (140), and a second fluid passage (150). The upstream chamber (110) is sequentially connected to the downstream chamber (120) through the first fluid channel (140), the pneumatic chamber (130) and the second fluid channel (150). The fluid inlet of the pneumatic chamber (130) that communicates with the first fluid channel (140) has a greater radial distance from the rotation center (410) relative to the fluid outlet of the pneumatic chamber (130) that communicates with the second fluid channel (150). The first fluid outlet (141) of the first fluid channel (140) that communicates with the upstream chamber (110) is located at the position of the maximum radial distance between the upstream chamber (110) and the rotation center (410), and is set according to the rotation direction of the carrier (400) or the valve device (100) to adapt to the effect of the Coriolis force on the fluid during rotation. The second fluid channel (150) is provided with a connected curved section (153) and a conveying section (154). The curved section (153) is connected to the pneumatic chamber (130) through the second fluid outlet (151), and the conveying section (154) is connected to the downstream chamber (120) through the second fluid inlet (152). The minimum radial distance between the curved section (153) and the rotation center (410) is less than the radial distance between the second fluid outlet (151) and the rotation center (410). Furthermore, the position of the pneumatic chamber (130) and the second fluid outlet (151) forms a ramp-shaped guide channel, so that when the valve device (100) is in the open state, the liquid in the second fluid channel (150) and the liquid in the pneumatic chamber (130) remain in communication, so as to release the liquid in the pneumatic chamber (130) into the second fluid channel (150) to the maximum extent. The sloping guide channel is located at the maximum radial distance between the pressure chamber (130) and the rotation center (410) and forms a smooth surface and a partial spherical surface to cooperate with the Coriolis force during rotation and reduce resistance, so that the liquid in the pressure chamber (130) flows out.

2. The valve device (100) according to claim 1, characterized in that, By setting the minimum radial distance between the bend (153) of the second fluid channel (150) and the rotation center (410), the centrifugal force required for the fluid in the pneumatic chamber (130) to enter the downstream chamber (120) through the second fluid channel (150) is limited.

3. The valve device (100) according to claim 1, characterized in that, According to the rotation direction of the carrier (400) or the valve device (100), the first fluid channel (140) and the second fluid channel (150) are respectively disposed on both sides of the pneumatic chamber (130).

4. The valve device (100) according to any one of claims 1 to 3, characterized in that, The upstream chamber (110) and the downstream chamber (120) are respectively used to connect the pressure balance chamber of the carrier (400).

5. The valve device (100) according to any one of claims 1 to 3, characterized in that, The upstream chamber (110) and the downstream chamber (120) are respectively provided with air outlets that connect to the atmospheric environment.

6. The valve device (100) according to any one of claims 1 to 3, characterized in that, One of the upstream chamber (110) and the downstream chamber (120) is provided with an air outlet connected to the atmospheric environment. The upstream chamber (110) and the downstream chamber (120) are connected by an additional flow channel, and the additional flow channel has a smaller radial distance relative to the maximum liquid level of the upstream chamber (110).

7. A microfluidic chip, characterized in that, Includes the valve device (100) and the carrier (400) as described in any one of claims 1 to 6.

8. A method for controlling liquid flow using a valve device, characterized in that, The method of controlling liquid flow using the valve device (100) as described in any one of claims 1 to 6 includes the steps of: A measured amount of the first liquid (200) is placed in the upstream chamber (110); Driven by the preset first centrifugal force, the valve device (100) rotates, and the first liquid (200) in the upstream chamber (110) is driven by the centrifugal force to flow into the pneumatic chamber (130) through the first fluid channel (140), so that the liquid volume in the pneumatic chamber (130) gradually increases, and the gas in the pneumatic chamber (130) is gradually discharged from the second fluid channel (150); When the liquid level in the pressure chamber (130) exceeds the fluid outlet of the pressure chamber (130), the gas in the pressure chamber (130) is restricted from being discharged through the bend (153) of the second fluid channel (150), and as the liquid level rises, the gas in the pressure chamber (130) is compressed, and the pressure gradually increases. When the air pressure in the air pressure chamber (130) reaches force balance with the first centrifugal force, the liquid level in the air pressure chamber (130) no longer rises, forming a valve closed state; Driven by a preset second centrifugal force, the first liquid (200) in the pneumatic chamber (130) overcomes the restriction of the bend (153) and flows into the downstream chamber (120), forming a valve open state. The flow stops when the liquid level in the pneumatic chamber (130) is lower than the fluid outlet of the pneumatic chamber (130), so that the first liquid (200) in the upstream chamber (110) is completely discharged.

9. The method for controlling liquid flow using a valve device according to claim 8, characterized in that, The second centrifugal force is greater than the first centrifugal force, so that the air pressure in the air pressure chamber (130) increases to the point that the first liquid (200) in the air pressure chamber (130) overcomes the restriction of the bend (153) and flows into the downstream chamber (120); or, The second centrifugal force is less than the first centrifugal force, so that the air pressure in the air pressure chamber (130) decreases. Under the action of gas expansion, the first liquid (200) in the air pressure chamber (130) overcomes the restriction of the bend (153) and flows into the downstream chamber (120). At the same time, during the gas expansion process, the liquid in the first fluid channel (140) is always in communication with the liquid in the air pressure chamber (130), and the liquid in the second fluid channel (150) is always in communication with the liquid in the air pressure chamber (130).

10. The method for controlling liquid flow using a valve device according to claim 8, characterized in that, By adjusting the rotation speed, the valve device (100) is controlled to open and close at least twice.

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