Reciprocating flow mixing device based on Tesla valve

Abstract

The application discloses a reciprocating flow mixing device based on a Tesla valve, relates to the technical field of microfluidics, and can provide a device for realizing efficient reciprocating mixing of fluid. The device comprises: a mixing chip, which has a fluid flow channel inside, contains a mixing unit with a Tesla valve structure in the channel, and is provided with openings at both ends; a matching liquid path system is in communication with the openings of the mixing chip to form a closed loop for circulating flow of fluid, and the mixing chip is connected in series in the closed loop; a one-way driving source is connected to the matching liquid path system to provide a single-direction driving force for the fluid in the closed loop; under the condition that the driving direction of the one-way driving source is kept unchanged, the matching liquid path system changes the internal flow path communication state periodically, so that the fluid in the closed loop flows through the mixing chip in opposite directions alternately, the fluid forms reciprocating flow in the mixing unit, and the vortex effect caused by the difference in resistance of the Tesla valve in forward and reverse flow is utilized to realize mixing of the fluid.

Description

Technical Field

[0001] This application relates to the field of microfluidics, and more particularly to a reciprocating flow mixing device based on a Tesla valve. Background Technology

[0002] Microfluidics, with its significant advantages such as low reagent consumption, high mass and heat transfer efficiency, and ease of integration and automation, has been widely applied in fields such as biochemical analysis, point-of-care testing, drug screening, and microreaction process control. In these applications, fluid mixing is a fundamental and crucial step in achieving chemical reactions and bioassays, and its efficiency directly affects reaction rates, detection sensitivity, and result reproducibility. However, fluids within microscale channels are typically in a low Reynolds number state, exhibiting stable laminar flow with little turbulence. Under these conditions, mixing between different fluid components relies primarily on slow molecular diffusion mechanisms, resulting in long mixing distances, long processing times, and low efficiency, becoming a bottleneck restricting the overall performance and analytical throughput of microfluidic chips.

[0003] To overcome this limitation, various micro-mixing schemes have been developed in existing technologies, mainly divided into passive mixing and active mixing. Passive mixing increases the fluid contact area or induces local convection by setting obstacles, grooves, or using complex geometric configurations such as serpentine or spiral shapes within the flow channel. However, its effectiveness depends on the optimization of the flow channel structure and remains limited at extremely low flow rates. Active mixing, on the other hand, actively intervenes in the flow field using external energy sources such as electric fields, magnetic fields, sound fields, or pressure disturbances. While it can significantly improve mixing efficiency, it usually requires complex peripheral equipment, precise control timing, or high energy consumption, which is not conducive to the miniaturization, integration, and portability of the system.

[0004] Therefore, there is still a lack of a microfluidic mixing device that is compact, easy to control, and capable of achieving efficient reciprocating mixing of fluids under low flow conditions by combining the characteristics of the flow channel structure itself with the driving method. Summary of the Invention

[0005] This application provides a reciprocating flow mixing device based on a Tesla valve, which is a microfluidic mixing device with a compact structure and simple control. It can achieve efficient reciprocating mixing of fluids under low flow conditions by combining the characteristics of the flow channel structure itself with the driving method.

[0006] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, this application provides a reciprocating flow mixing device based on a Tesla valve, the device comprising: A mixing chip has a channel for fluid flow inside, the channel contains at least one mixing unit based on a Tesla valve structure, and the mixing chip has openings at both ends, which serve as ports for fluid inflow and outflow, respectively. A matching liquid circuit system is connected to the opening of the mixing chip to form a closed loop for fluid circulation, and the mixing chip is connected in series in the closed loop; A unidirectional drive source is connected to the matching fluid circuit system to provide a unidirectional driving force for the fluid within the closed loop; The matching fluid circuit system, while keeping the driving direction of the unidirectional drive source unchanged, periodically changes the flow path connection state inside it, so that the fluid in the closed loop flows through the mixing chip alternately in opposite directions, so that the fluid forms a reciprocating flow in the mixing unit, and the eddy current effect generated by the resistance difference of the Tesla valve in the forward and reverse flow is used to achieve the mixing of the fluid.

[0007] As one possible implementation, the mixing chip includes a flow channel layer, a sealing layer, and a base layer stacked sequentially from top to bottom; The channel and the mixing unit are disposed in the flow channel layer; The sealing layer is made of a hydrophobic flexible material and is used to seal the channel; The base layer is made of a rigid material and is used to provide structural support.

[0008] As one possible implementation, one of the mixing units includes: a connecting channel, and a first Tesla valve subunit and a second Tesla valve subunit that are centrally symmetrically distributed based on the connecting channel; Each of the Tesla valve sub-units includes, in sequence, a narrow straight flow channel, a flow splitting node, a wide straight flow channel, a narrow lateral flow channel, an arc-shaped flow channel, a confluence node, and a wide lateral flow channel; The narrow straight flow channel is connected to the wide straight flow channel and the narrow lateral flow channel via the flow splitting node, and the narrow straight flow channel and the wide straight flow channel are collinear. The wide straight flow channel is connected to the wide lateral flow channel via the arc-shaped flow channel and the confluence node in sequence, and the narrow lateral flow channel is connected to the confluence node, and the narrow lateral flow channel and the wide lateral flow channel are collinear.

[0009] As one possible implementation, one of the mixing units includes: a rhomboid connecting channel, and a first Tesla valve subunit, a second Tesla valve subunit, a third Tesla valve subunit, and a fourth Tesla valve subunit that are centrally symmetrically distributed about the center of the rhomboid connecting channel; The first Tesla valve subunit and the second Tesla valve subunit are mirror symmetrical about the transverse central axis. The wide lateral flow channels of the first Tesla valve subunit and the second Tesla valve subunit converge toward the center, forming two sides of one side of the rhomboid connecting flow channel. The narrow straight flow channels of the first Tesla valve subunit and the second Tesla valve subunit extend away from the rhomboid connecting flow channel and converge at one end. The first Tesla valve subunit and the second Tesla valve subunit are mirror-symmetrical about each other across the longitudinal axis of the center of the rhomboid connecting channel to obtain the fourth Tesla valve subunit and the third Tesla valve subunit, respectively.

[0010] As one possible implementation, the angle between the wide straight flow channels of the first Tesla valve subunit and the second Tesla valve subunit is 50°~90°; The angle between the wide lateral flow channels of the first Tesla valve subunit and the second Tesla valve subunit is 30°~70°; The width of the narrow straight flow channel and the narrow lateral flow channel is L1; The width of the wide straight flow channel, the arc flow channel and the wide lateral flow channel is L2, and the ratio of L1 to L2 is (1.5~2). The central angle corresponding to the arc-shaped flow channel is 150°~210°; The angle between the wide straight flow channel and the narrow lateral flow channel is 60°~100°.

[0011] As one possible implementation, multiple mixing units are arranged in series to form the main structure of the channel, and two adjacent mixing units are directly connected through the opening. The two ends of the flow channel layer are respectively connected to a left buffer cavity and a right buffer cavity, and the left buffer cavity and the right buffer cavity are respectively connected to the corresponding ends of the mixing chip; The radii of both the left and right buffer cavities are 1.5mm to 5.0mm. The length of the connection channel between the left and right buffer cavities and the end corresponding to the mixing chip is 1.0mm~3.0mm, and the width is 1.0mm~3.0mm.

[0012] As one possible implementation, the supporting hydraulic system includes a first two-way valve, a second two-way valve, a third two-way valve, a fourth two-way valve, a first three-way connector, a second three-way connector, a third three-way connector, a fourth three-way connector, and connecting pipes; The first interface of the first three-way connector is connected to the second interface of the second three-way connector through a first connecting pipe, and the first two-way valve is provided on the first connecting pipe; The first interface of the second three-way connector is connected to the second interface of the third three-way connector through a second connecting pipe, and the second two-way valve is provided on the second connecting pipe; The first interface of the third three-way connector is connected to the second interface of the fourth three-way connector through a third connecting pipe, and the third two-way valve is provided on the third connecting pipe; The first interface of the fourth three-way connector is connected to the second interface of the first three-way connector through a fourth connecting pipe to form the closed loop, and the fourth two-way valve is provided on the fourth connecting pipe.

[0013] As one possible implementation, one opening of the mixing chip is connected to the third interface of the first tee connector via a fifth connecting pipe; The other opening of the mixing chip is connected to the third interface of the third tee connector via the sixth connecting pipe; The unidirectional drive source is connected to the third interface of the fourth tee connector via the seventh connecting pipe; The third interface of the second three-way connector is connected to the external atmosphere or sample injection device through the eighth connecting pipe; The supporting fluid circuit system is configured to periodically switch valve states, causing the first two-way valve and the third two-way valve to alternately open or close with the second two-way valve and the fourth two-way valve, so that the fluid forms a reciprocating flow within the closed loop and the mixing chip.

[0014] As one possible implementation, the valves in the supporting hydraulic system are one of the following: solenoid valves, clamp valves, piezoelectric valves, or rotary valves, and can be switched in sequence through a control module; The unidirectional drive source is at least one of the following: mechanical drive device, electroosmotic drive device, acoustic drive device, thermal drive device, centrifugal drive device, capillary drive structure, magnetohydrodynamic drive device, and osmotic pressure drive device.

[0015] As one possible implementation, the hydrophobic flexible material of the sealing layer is one of polydimethylsiloxane, silicone rubber, fluororubber, or polyurethane; The rigid material of the flow channel layer and the base layer is one of glass, polymethyl methacrylate (PMMA), polycarbonate or metal. The flow channel layer is made by a patterning manufacturing process, which includes at least one of soft lithography, machining, laser processing, hot stamping, injection molding, additive manufacturing, wet etching, or dry etching.

[0016] The beneficial effects of the technical solutions provided in this application include at least the following: The reciprocating flow mixing device based on a Tesla valve provided in this application includes: a mixing chip with a channel for fluid flow inside, the channel containing at least one mixing unit based on a Tesla valve structure, the mixing chip having openings at both ends serving as inflow and outflow ports for fluid, respectively; a matching liquid circuit system connected to the openings of the mixing chip to form a closed loop for fluid circulation, the mixing chip being connected in series in the closed loop; and a unidirectional drive source connected to the matching liquid circuit system to provide a unidirectional driving force for the fluid in the closed loop. While maintaining the driving direction of the unidirectional drive source, the matching liquid circuit system periodically changes the flow path connection state within it, causing the fluid in the closed loop to alternately flow through the mixing chip in opposite directions, thus forming a reciprocating flow in the mixing unit. The mixing of the fluid is achieved by utilizing the eddy current effect generated by the resistance difference of the Tesla valve during forward and reverse flow.

[0017] This application connects the mixing chip in series in a closed loop formed by the matching liquid circuit system. By using a unidirectional drive source in conjunction with periodic flow path switching, the fluid can reciprocate within the chip channel. This eliminates the need for bidirectional pumps or coordinated control of multiple drive sources, resulting in a compact system structure, simple control logic, and reduced complexity and cost of the device.

[0018] Secondly, the mixing chip has a built-in mixing unit based on the Tesla valve structure in its channel. During the reciprocating flow, the fluid repeatedly experiences the resistance difference between the forward and reverse flows of the Tesla valve. Through self-impact, local vortices are formed, which effectively disrupt the laminar flow state at the microscale, significantly improving mixing efficiency and speed, shortening the time required to achieve the target mixing uniformity, and still achieving efficient mixing under low flow conditions.

[0019] Furthermore, as a highly modular universal mixing platform, the device's supporting liquid circuit system can be flexibly cascaded with the front-end sample injection module and the back-end detection module through standard interfaces. It is suitable for the mixing needs of various solution systems, has good compatibility and scalability, and can be widely used in biochemical analysis, point-of-care testing, and microreaction process control scenarios that require pre-mixing or incubation steps. Attached Figure Description

[0020] Figure 1 A schematic diagram of a reciprocating flow mixing device based on a Tesla valve provided in an embodiment of this application; Figure 2 A schematic diagram of a mixing chip provided in an embodiment of this application; Figure 3 A schematic diagram of a mixing unit provided in an embodiment of this application. Figure 1 ; Figure 4This is a schematic diagram of the structure of a Tesla valve subunit provided in an embodiment of this application; Figure 5 A schematic diagram of a mixing unit provided in an embodiment of this application. Figure 2 ; Figure 6 Simulation curve of the mixing effect of a mixing unit provided in an embodiment of this application.

[0021] Figure label: 1~ Unidirectional drive source; 21~First two-way valve, 22~Second two-way valve, 23~Third two-way valve, 24~Fourth two-way valve; 31~First tee connector, 32~Second tee connector, 33~Third tee connector, 34~Fourth tee connector; 41~First connecting pipe, 42~Second connecting pipe, 43~Third connecting pipe, 44~Fourth connecting pipe, 45~Fifth connecting pipe, 46~Sixth connecting pipe, 47~Seventh connecting pipe, 48~Eighth connecting pipe; 5~Mixing chip, 51~Flow channel layer, 52~Sealing layer, 53~Base layer, 511~Mixing unit, 512~Buffer cavity; 5111~First Tesla valve subunit, 5112~Second Tesla valve unit, 5113~Connecting flow channel, 5114~Rhomboid connecting flow channel; 51111~Narrow straight flow channel, 51112~Flow splitting node, 51113~Wide straight flow channel, 51114~Arc-shaped flow channel, 51115~Narrow lateral flow channel, 51116~Wide lateral flow channel. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0023] Hereinafter, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0024] In addition, the use of “based on” or “according to” implies openness and inclusivity, because processes, steps, calculations or other actions “based on” or “according to” one or more conditions or values ​​can in practice be based on additional conditions or values ​​beyond those conditions.

[0025] This application provides a reciprocating flow mixing device based on a Tesla valve, such as... Figure 1 As shown, the device includes: The mixing chip 5 has a channel for fluid flow inside, and the channel contains at least one mixing unit 511 based on a Tesla valve structure. The mixing chip 5 has openings at both ends, which serve as ports for fluid inflow and outflow, respectively. A matching liquid circuit system is connected to the opening of the mixing chip 5 to form a closed loop for fluid circulation, and the mixing chip 5 is connected in series in the closed loop; A unidirectional drive source 1 is connected to the matching liquid circuit system to provide a unidirectional driving force for the fluid in the closed loop; While keeping the driving direction of the unidirectional drive source 1 unchanged, the supporting liquid circuit system periodically changes the flow path connection state inside it, so that the fluid in the closed loop flows through the mixing chip 5 alternately in opposite directions, so that the fluid forms a reciprocating flow in the mixing unit 511, and the eddy current effect generated by the resistance difference of the Tesla valve in the forward and reverse flow is used to achieve the mixing of the fluid.

[0026] It is understood that this application provides a reciprocating flow mixing device based on a Tesla valve. The core concept of this device is to connect a mixing chip 5 with a built-in Tesla valve structure into a closed loop with switchable flow direction. Under the premise of keeping the driving source driving in a single direction unchanged, the reciprocating flow of fluid within the chip can be achieved simply by changing the connection path inside the loop.

[0027] Specifically, the device comprises three main parts: a mixing chip 5, a matching liquid circuit system, and a unidirectional drive source 1.

[0028] The mixing chip 5 is the core site for fluid mixing. It contains channels for fluid flow, each containing at least one mixing unit 511 based on a Tesla valve structure. A Tesla valve, also known as a Tesla diode, is a passive fluid element with no moving parts. Its asymmetrical geometry results in low resistance and smooth flow when the fluid flows in the forward direction, but in the reverse direction, some fluid is guided to lateral branches and forms a backflow that impacts the main flow, generating strong local eddies and thus significant flow resistance. This application utilizes this difference in resistance between forward and reverse flow and the self-impacting eddy effect generated during reverse flow to achieve enhanced fluid mixing. The mixing chip 5 has openings at both ends, serving as inflow and outflow ports for the fluid, respectively.

[0029] The matching liquid circuit system is key to achieving flow direction switching. It connects to the opening of the mixing chip 5, forming a closed loop for fluid circulation, and the mixing chip 5 is connected in series within this closed loop. A unidirectional drive source 1 is connected to this matching liquid circuit system, and its function is to continuously provide a driving force in one direction to the fluid in the closed loop. Here, "unidirectional" means that the output direction of the drive source remains unchanged throughout the mixing process, such as continuous suction or continuous pushing.

[0030] The most significant feature of this device is that, while the driving direction of the unidirectional drive source 1 remains constant, the accompanying liquid circuit system periodically changes the flow path connectivity state within its internal flow path (e.g., through the alternating switching of valve groups) to alter the overall circulation direction of the fluid in the closed loop. When the flow path is in the first connectivity state, the fluid flows clockwise (or in the first direction) through the mixing chip 5 under the drive of the unidirectional drive source 1; when the flow path switches to the second connectivity state, the fluid also flows counterclockwise (or in the opposite second direction) through the mixing chip 5 under the drive of the unidirectional drive source 1. This periodic switching causes the fluid to form a reciprocating flow in the mixing unit 511 of the mixing chip 5. In each round trip, the fluid experiences both forward smooth flow and reverse vortex impact from the Tesla valve structure, thereby efficiently disrupting the laminar flow state at the microscale and achieving rapid and uniform mixing.

[0031] The reciprocating flow mixing device based on a Tesla valve provided in this application features a significantly simplified structure. It eliminates the complex design of traditional reciprocating flow systems that require bidirectional pumps or multiple drive sources, relying solely on a single unidirectional drive source and a fluid circuit system that can switch between two states to drive the fluid to reciprocate within the chip. This not only reduces hardware costs and system size but also greatly simplifies the control logic, requiring only periodic switching signals, thus laying a solid foundation for the device's integration, portability, and automation.

[0032] Optional, such as Figure 2As shown, the mixing chip 5 includes a flow channel layer 51, a sealing layer 52 and a base layer 53 stacked sequentially from top to bottom; The channel and the mixing unit 511 are disposed on the flow channel layer 51; the sealing layer 52 is made of a hydrophobic flexible material and is used to seal the channel; the base layer 53 is made of a rigid material and is used to provide structural support.

[0033] This layered design assigns the three functions of fluid channel construction, sealing, and support to different material layers, each performing its own function, thus optimizing the manufacturing process and overall performance.

[0034] The fluid flow channels and the mixing unit 511 based on the Tesla valve structure are both patterned on the flow channel layer 51. As the core functional layer of the chip, the flow channel layer 51 is preferably made of a rigid material to ensure the accuracy of the microstructure pattern and the stability of its dimensions. The sealing layer 52, located below the flow channel layer 51, is made of a hydrophobic flexible material. Its primary function is to adhere to the lower surface of the flow channel layer 51, achieving reliable sealing of the channels and preventing liquid leakage. Secondly, the flexible material can undergo slight deformation under certain pressure, better conforming to the plane of the flow channel layer 51 and compensating for minor processing unevenness. More importantly, its hydrophobic properties effectively suppress liquid column breakage or discontinuity caused by shear stress when the liquid flows in narrow channels, improving flow stability and reducing frictional resistance between the fluid and the wall, thus reducing overall flow resistance. The base layer 53, located at the bottom, is made of a rigid material, providing robust structural support for the entire chip and ensuring that the chip does not bend or be damaged when subjected to fastening pressure and pipeline connection stress. The flow channel layer 51, sealing layer 52 and base layer 53 can be clamped and fixed by through fastening screws or other detachable connection methods.

[0035] The mixing chip 5 provided in this application employs a simple, low-cost, and reliable chip packaging solution. The three-layer structure allows for independent surface treatments (such as hydrophobic treatment) of the flow channel layer 51 and the sealing layer 52 to optimize their respective performance without affecting other layers. The combination of the rigid base and the flexible sealing layer 52 achieves excellent sealing performance while ensuring structural strength. Simultaneously, this detachable stacked structure facilitates chip disassembly, cleaning, and reassembly, supporting reusable scenarios and reducing long-term operating costs.

[0036] In one possible implementation, such as Figure 3As shown, one of the mixing units 511 includes: a connecting channel 5113, and a first Tesla valve sub-unit 5111 and a second Tesla valve sub-unit 5112 that are centrally symmetrically distributed based on the connecting channel 5113; each Tesla valve sub-unit includes a narrow straight channel 51111, a flow splitting node 51112, a wide straight channel 51113, a narrow lateral channel 51115, an arc-shaped channel 51114, a confluence node, and a wide lateral channel 51116 connected in sequence; wherein, the narrow straight channel... 51111 is connected to the wide straight flow channel 51113 and the narrow lateral flow channel 51115 via the branching node 51112, and the narrow straight flow channel 51111 and the wide straight flow channel 51113 are collinear; the wide straight flow channel 51113 is connected to the wide lateral flow channel 51116 via the arc-shaped flow channel 51114 and the confluence node, and the narrow lateral flow channel 51115 is connected to the confluence node, and the narrow lateral flow channel 51115 and the wide lateral flow channel 51116 are collinear.

[0037] The above describes a basic implementation of the mixing unit 511. The mixing unit 511 consists of a connecting channel 5113, and a first Tesla valve sub-unit 5111 and a second Tesla valve sub-unit 5112 that are centrally symmetrically distributed based on the connecting channel 5113. This symmetrical design is key to achieving efficient bidirectional mixing.

[0038] Specifically, such as Figure 4As shown, each Tesla valve subunit contains a complete Tesla valve flow channel structure, which consists of: a narrow straight flow channel 51111, a flow splitting node 51112, a wide straight flow channel 51113, a narrow lateral flow channel 51115, an arc-shaped flow channel 51114, a confluence node, and a wide lateral flow channel 51116. Its working principle is as follows: when fluid flows into the narrow straight flow channel 51111 (defined as the reverse direction of this subunit), at the flow splitting node 51112, part of the fluid, due to inertia, flows forward along the collinear wide straight flow channel 51113 and enters the arc-shaped flow channel 51114, while the other part of the fluid enters the narrow lateral flow channel 51115. Although the wide straight flow channel 51113 is in the same direction as the incoming flow and has a larger width, the total path is longer due to the presence of the arc-shaped flow channel 51114, increasing the flow resistance and causing the flow resistance of the two paths to become equal, thus effectively splitting the fluid. The two fluid streams eventually collide and merge at the confluence node, creating a vortex that disrupts the laminar flow and produces efficient local mixing. When fluid flows in from the wide straight channel 51113 (defined as the forward direction of this sub-unit), at the confluence node, the narrow lateral channel 51115 flows in the same direction as the incoming flow and has a short path. Although its channel width is smaller than that of the curved channel 51114 and the wide straight channel 51113, its overall flow resistance is smaller, causing most of the fluid to flow through the narrow lateral channel 51115, with only a small amount of fluid entering the curved channel 51114 and the wide straight channel 51113, resulting in a negligible flow splitting effect. The vortex formed when the two fluid streams finally merge at the splitting node 51112 is weak, resulting in low mixing efficiency. This asymmetrical mixing state affects the application of this structure in micro-mixing units. This application addresses this by arranging two identical sub-units symmetrically about the center, ensuring that regardless of which end the fluid enters from, the flow is forward for one sub-unit and reverse for the other. Therefore, macroscopically, as long as the fluid flows through the mixing unit 511, there will always be a sub-unit inside that is experiencing reverse flow to generate eddies, thereby achieving bidirectional and efficient mixing.

[0039] The microstructure of the basic functional unit of the mixing chip 5 provided above cleverly utilizes the inherent asymmetric flow resistance characteristics of the Tesla valve and organizes it into a centrally symmetrical layout, achieving bidirectional mixing capability. This unit structure is simple, with well-defined parameters, making it easy to precisely manufacture and replicate using microfabrication processes.

[0040] In another possible implementation, such as Figure 5As shown, one of the mixing units 511 includes: a rhomboid connecting channel 5114, and a first Tesla valve sub-unit 5111, a second Tesla valve sub-unit 5112, a third Tesla valve sub-unit, and a fourth Tesla valve sub-unit that are centrally symmetrically distributed about the center of the rhomboid connecting channel 5114; the first Tesla valve sub-unit 5111 and the second Tesla valve sub-unit 5112 are mirror symmetrical about the lateral central axis, and the wide lateral channels 51 of the first Tesla valve sub-unit 5111 and the second Tesla valve sub-unit 5112 are... 116 converge towards the center, forming two sides of one side of the rhomboid connecting channel 5114. The narrow straight channels 51111 of the first Tesla valve sub-unit 5111 and the second Tesla valve sub-unit 5112 extend away from the rhomboid connecting channel 5114 and converge at one end. After the first Tesla valve sub-unit 5111 and the second Tesla valve sub-unit 5112 are mirror-symmetrical through the longitudinal axis of the center of the rhomboid connecting channel 5114, the fourth Tesla valve sub-unit and the third Tesla valve unit are obtained respectively.

[0041] Similarly, each of the Tesla valve subunits includes a narrow straight flow channel 51111, a flow branching node 51112, a wide straight flow channel 51113, a narrow lateral flow channel 51115, an arc-shaped flow channel 51114, a confluence node, and a wide lateral flow channel 51116 connected in sequence; wherein, the narrow straight flow channel 51111 is connected to the wide straight flow channel 51113 and the narrow lateral flow channel 51115 via the flow branching node 51112, and the narrow straight flow channel 51111 and the wide straight flow channel 51113 are collinear; the wide straight flow channel 51113 is connected to the wide lateral flow channel 51116 via the arc-shaped flow channel 51114 and the confluence node, and the narrow lateral flow channel 51115 is connected to the confluence node, and the narrow lateral flow channel 51115 and the wide lateral flow channel 51116 are collinear.

[0042] Figure 5 The mixing unit 511 shown is another preferred implementation, which is more refined in structure and has higher mixing efficiency. Figure 5 The structural design of the mixing unit 511 shown makes the fluid flow path highly symmetrical and uniform. Regardless of the direction from which the fluid flows into the mixing unit 511, it first splits into two sub-units, experiencing different flow states in each sub-unit, and finally generating strong convection and disturbance when converging at the diamond-shaped connecting channel 5114 or at the end. The diamond-shaped connecting channel 5114 itself acts as a concentrated mixing zone, providing space for collision and fusion of fluids from different directions.

[0043] This application further increases the complexity and symmetry of the internal flow channels by introducing a rhomboid connecting channel 5114 and a double-mirror symmetrical four-sub-cell layout. This not only multiplies the number and intensity of local vortices generated by the fluid within the cell, but also provides additional collision mixing space in the central rhomboid region, resulting in a significant improvement in the mixing efficiency of the mixing unit 511 during a single pass compared to the two-cell version, enabling it to reach a homogeneous mixing state more quickly.

[0044] Optional, such as Figure 5 As shown, the angle between the wide straight flow channels 51113 of the first Tesla valve subunit 5111 and the second Tesla valve subunit 5112 is 50°~90°; the angle between the wide lateral flow channels 51116 of the first Tesla valve subunit 5111 and the second Tesla valve subunit 5112 is 30°~70°; the width of the narrow straight flow channel and the narrow lateral flow channel is L1, and the width of the wide straight flow channel, the arc flow channel and the wide lateral flow channel is L2, and the ratio of L1 to L2 is (1.5~2); the central angle corresponding to the arc flow channel is 150°~210°; the angle between the wide straight flow channel and the narrow lateral flow channel is 60°~100°.

[0045] Specifically, the width of the narrow straight flow channel 51111 and the narrow lateral flow channel 51115 can be 0.5mm to 2.0mm; the width of the wide straight flow channel 51113, the arc-shaped flow channel 51114 and the wide lateral flow channel 51116 can be 1.0mm to 3.0mm.

[0046] Preferably, the angle between the wide straight flow channels 51113 of the first Tesla valve subunit 5111 and the second Tesla valve subunit 5112 is 70°; the angle between the wide lateral flow channels 51116 of the first Tesla valve subunit 5111 and the second Tesla valve subunit 5112 is 50°; the width of the narrow straight flow channel 51111 and the narrow lateral flow channel 51115 is 1.0 mm; the width of the wide straight flow channel 51113, the arc flow channel 51114, and the wide lateral flow channel 51116 is 1.5 mm; the central angle corresponding to the arc flow channel 51114 is 180°, and the angle between the wide straight flow channel and the narrow lateral flow channel is 80°. Products manufactured using this preferred parameter combination... Figure 5 The mixing unit 511 shown exhibited the best mixing efficiency and pressure drop balance in the experiment.

[0047] This application provides a directly reproducible quantitative basis for implementing the application by clearly defining the preferred range of key flow channel structural parameters. This ensures that the mixing unit 511 manufactured according to these parameters can stably and effectively generate the expected eddy mixing effect, avoiding problems such as low mixing efficiency or excessive flow resistance caused by improper parameters.

[0048] Optional, such as Figure 5 As shown, multiple mixing units 511 are arranged in series to form the main structure of the channel. Adjacent mixing units 511 are connected to each other through the end joints. The two ends of the flow channel layer 51 are respectively connected to a left buffer cavity 512 and a right buffer cavity 512. The left buffer cavity 512 and the right buffer cavity 512 are respectively connected to the corresponding ends of the mixing unit 511. The radius of the left buffer cavity 512 and the right buffer cavity 512 is 1.5mm~5.0mm. The length of the connection channel between the left buffer cavity 512 and the right buffer cavity 512 and the corresponding end of the mixing chip 5 is 1.0mm~3.0mm, and the width is 1.0mm~3.0mm.

[0049] It is understood that this application provides an extended description of the macroscopic layout and transition structure of the 5-channel mixing chip. To achieve thorough mixing, multiple mixing units 511 are typically arranged in a straight line in series, collectively forming the main structure of the internal channels of the chip. Two adjacent mixing units 511 are directly connected through openings at their ends, forming a continuous and structurally repeating mixing path. In addition to being arranged in a straight line in series, the multiple mixing units 511 can also be designed in a serpentine arrangement or a circular array arrangement, depending on the actual situation; this application does not specifically limit this arrangement.

[0050] At both ends of the extension direction of the flow channel layer 51, i.e., at the beginning and end of the array of series mixing units 511, there are left buffer cavities 512 and right buffer cavities 512, respectively. These two buffer cavities 512 are relatively spacious circular or near-circular spaces. They are respectively connected to the outermost opening of the mixing chip 5 through a short connecting channel.

[0051] The design of the buffer chamber 512 is of great significance. When fluid suddenly enters the wide buffer chamber 512 from a narrow pipe or chip opening, the flow velocity distribution is readjusted, preventing the formation of an overly directional jet that directly impacts the first mixing unit 511, thus ensuring the stability of the flow upon entering the mixing region. During the switching moments of reciprocating flow, the buffer chamber 512 also serves to store energy and stabilize pressure, making the flow direction switch smoother. The design of the connecting channel between the buffer chamber 512 and the opening provides a physical transition, facilitating stable connection of external pipelines and further regulating the flow pattern.

[0052] This application constructs a scalable and flow-stable mixing platform through a "series arrangement" and the addition of a "buffer cavity 512" design. The series arrangement allows the mixing path to be extended as needed, thereby increasing the overall mixing effect and meeting the requirements of different mixing difficulties. The introduction of the buffer cavity 512 optimizes the flow field at the inlet and outlet, protects the internal fine flow channel structure, and improves the operational stability and reliability of the device during repeated flow direction switching.

[0053] Optionally, the supporting hydraulic system includes a first two-way valve 21, a second two-way valve 22, a third two-way valve 23, a fourth two-way valve 24, a first three-way connector 31, a second three-way connector 32, a third three-way connector 33, a fourth three-way connector 34, and connecting pipes. The first interface of the first three-way connector 31 is connected to the second interface of the second three-way connector 32 via a first connecting pipe 41, on which a first two-way valve 21 is installed; the first interface of the second three-way connector 32 is connected to the second interface of the third three-way connector 33 via a second connecting pipe 42, on which a second two-way valve 22 is installed; the first interface of the third three-way connector 33 is connected to the second interface of the fourth three-way connector 34 via a third connecting pipe 43, on which a third two-way valve 23 is installed; the first interface of the fourth three-way connector 34 is connected to the second interface of the first three-way connector 31 via a fourth connecting pipe 44, on which a fourth two-way valve 24 is installed. In this way, the four three-way connectors, through their respective "first interface" and "second interface" and four sections of connecting pipe with valves, are sequentially connected end-to-end, forming a loop that can be segmented and switched on and off by the four valves.

[0054] This loop is the physical basis for the flow direction switching of this device. The four valves are divided into two groups: the first and third valves form one group, and the second and fourth valves form the other. When one group is open and the other is closed, the loop is opened as a path through the chip in a specific direction (e.g., clockwise); conversely, it is opened as a path through the chip in the opposite direction. This application utilizes a loop flow path constructed with four simple two-way valves and four three-way connectors, replacing complex multi-position rotary valves or expensive bidirectional pumps. The accompanying fluid system has good structural symmetry, facilitating standardized and modular assembly, and also making it easy to locate and replace components in case of failure.

[0055] Optionally, one opening of the mixing chip 5 is connected to the third interface of the first three-way connector 31 via a fifth connecting pipe 45; the other opening of the mixing chip 5 is connected to the third interface of the third three-way connector 33 via a sixth connecting pipe 46; the unidirectional drive source 1 is connected to the third interface of the fourth three-way connector 34 via a seventh connecting pipe 47; and the third interface of the second three-way connector 32 is connected to the external atmosphere or a sample injection device via an eighth connecting pipe 48. The supporting liquid circuit system is configured to periodically switch the valve states, so that the first two-way valve 21 and the third two-way valve 23 are alternately opened or closed with the second two-way valve 22 and the fourth two-way valve 24, so that the fluid forms a reciprocating flow in the closed loop and the mixing chip 5.

[0056] In practical operation, when the unidirectional drive source 1 (e.g., set to negative pressure suction mode) is activated, and in conjunction with the valve state switching, sample injection and reciprocating mixing can be completed. For example, opening the first and third valves and closing the second and fourth valves, the negative pressure generated by the drive source acts on one end of the mixing chip 5 through the fourth three-way connector 34, the opened third connecting pipe 43 (third valve), the third three-way connector, and the sixth connecting pipe, drawing the sample into the eighth connecting pipe 48 connected to the second three-way connector 32. The sample flows counterclockwise through the mixing chip 5 along the opened first connecting pipe 41 (first valve), the first three-way connector, and the fifth connecting pipe. Conversely, closing the first and third valves and opening the second and fourth valves changes the direction of the negative pressure, and the fluid is drawn into the other end of the chip, achieving reverse flow. By periodically switching these two valve states, the reciprocating flow of fluid within the mixing chip 5 is achieved. This connection method organically integrates all components into one unit and clearly defines the connection positions of the injection port, drive interface, and chip, making the operation process of the device standardized: from injection to mixing, and then to possible discharge, it can be completed automatically through the timing control of the valve, making the operation extremely convenient.

[0057] Optionally, the valve in the supporting liquid circuit system is one of a solenoid valve, a pinch valve, a piezoelectric valve, or a rotary valve, and can be switched in sequence through a control module; the unidirectional drive source 1 is at least one of a mechanical drive device, an electroosmotic drive device, an acoustic drive device, a thermal drive device, a centrifugal drive device, a capillary drive structure, a magnetohydrodynamic drive device, or an osmotic pressure drive device.

[0058] Specifically, regardless of the driving principle used, any valve that possesses both on and off states and can respond to electrical signals for timing control is acceptable. Preferably, these valves can all achieve precise timing switching control through a single control module (such as a microcontroller, embedded system, or host computer program). For unidirectional drive source 1, any valve capable of providing stable, continuous, and unidirectional fluid driving force can, in principle, serve as the drive source for this device. Depending on different application requirements (such as flow rate, accuracy, cost, portability, etc.), developers can flexibly select the most suitable valve and pump type.

[0059] Optionally, the hydrophobic flexible material of the sealing layer 52 is one of polydimethylsiloxane, silicone rubber, fluororubber, or polyurethane; these materials not only have natural hydrophobicity, but also have low elastic modulus, enabling gasket-free sealing through slight deformation, and have good biocompatibility.

[0060] The rigid material of the flow channel layer 51 and the base layer 53 is one of glass, polymethyl methacrylate (PMMA), polycarbonate, or metal. These materials have high mechanical strength, good dimensional stability, can withstand operating pressure without deformation, and can be formed by various precision machining techniques. Preferably, the flow channel layer 51 and the base layer 53 are made of PMMA, and the sealing layer 52 is made of silicone rubber, which balances optical transparency, processing convenience, and cost.

[0061] The flow channel layer 51 is manufactured using a patterning process, which includes at least one of soft lithography, machining, laser processing, thermoforming, injection molding, additive manufacturing, wet etching, or dry etching. The choice of process depends on the required precision, batch size, and cost budget. For example, CNC machining or 3D printing can be used for small-batch prototype verification; for mass production, injection molding or thermoforming are more cost-effective options.

[0062] In some optional embodiments, to further improve the hydrophobic properties of the flow channel and suppress liquid column breakage or discontinuity during fluid flow, the lower surface of the flow channel layer 51 and the upper surface of the sealing layer 52 can be treated with hydrophobicity. Specifically, this hydrophobic treatment can be achieved by vapor deposition of perfluorodecyltrichloromethane. An exemplary process parameter is as follows: 0.5 μL of perfluorodecyltrichloromethane is placed together with the flow channel layer 51 and the sealing layer 52 in a vacuum-sealed environment, the temperature is set to 95°C, and the deposition time is 15 minutes. Through this treatment, a nanoscale hydrophobic molecular layer can be formed on the surface, effectively reducing the frictional resistance between the fluid and the channel wall, so that the fluid maintains a stable and continuous transport state during reciprocating flow.

[0063] In some alternative embodiments, the flow channel layer 51, the sealing layer 52, and the base layer 53 are detachably connected by through-hole fastening screws. Using screw fastening not only provides uniform and controllable clamping force, ensuring a tight fit between the sealing layer 52 and the flow channel layer 51 for reliable sealing, but also facilitates chip disassembly, cleaning, and reassembly, supports device reuse, and reduces long-term operating costs.

[0064] In some optional embodiments, the openings at both ends of the flow channel layer 51 adopt a through-thread structure, and are connected to the matching liquid circuit system through an external threaded connector that mates with the internal thread structure. The use of threaded connection can ensure the airtightness of the interface, prevent liquid leakage or gas ingress, thereby ensuring the formation of a continuous and stable pressure gradient throughout the device, providing a guarantee for the controllable reciprocating flow of the fluid.

[0065] In some optional embodiments, the inner diameter of each connecting pipe in the supporting fluid system is between 1 mm and 3 mm. This range of inner diameters balances a small internal volume to reduce dead volume with moderate flow resistance to reduce the load on the drive source. The material of the connecting pipes can be any of silicone, polyvinyl chloride, polyethylene, polyurethane, polytetrafluoroethylene, or polyetheretherketone, depending on factors such as the chemical properties of the fluid being transported and the required operating pressure.

[0066] The reciprocating flow mixing device based on a Tesla valve provided in this application can achieve mixing of various solution systems. Furthermore, compared with existing technologies, this application exhibits excellent solution system compatibility; solutions of different viscosities, different volume ratios, and complex solutions containing biomolecules can all achieve thorough mixing in the reciprocating flow. It features a compact structure and small size; through the synergistic design of an integrated annular liquid path and a bidirectional Tesla valve mixing chip 5, the device size is reduced while ensuring the mixing system throughput, overcoming the problem of the large size of traditional unidirectional mixing systems. The use of a Tesla valve instead of a traditional serpentine flow channel utilizes self-impact to generate eddies, improving mixing efficiency and shortening mixing time. The bidirectional Tesla valve mixing chip 5 has a three-layer structure. The design ensures the system's sealing effect, structural rigidity, and portability, while facilitating low-cost patterned manufacturing of the flow channel layer 51. It also facilitates disassembly, assembly, and cleaning, supporting reusable scenarios. The control logic is simple, requiring no complex programming or precise pressure regulation. Fluid injection and reciprocating flow can be achieved through periodic switching between two states. It is highly scalable, serving as a universal mixing platform with a highly modular design that can be adapted to various injection and detection modules. It can be applied to scenarios such as antigen-antibody specific binding, aptamer specific binding, nucleic acid hybridization, enzymatic reactions, and nanomaterial synthesis.

[0067] The following examples use a solution to be mixed, consisting of magnetic microparticles coated with streptavidin, biotin-labeled anti-NT-proBNP mouse monoclonal antibody, ruthenium complex-labeled anti-NT-proBNP sheep monoclonal antibody, and standard samples, as a model system to illustrate the structure, operation, and mixing effect of the Tesla valve-based reciprocating flow mixing device provided in this application.

[0068] With the unidirectional pneumatic pump in negative pressure mode, the solution consisting of magnetic microparticles coated with streptavidin, biotin-labeled anti-NT-proBNP mouse monoclonal antibody, ruthenium complex-labeled anti-NT-proBNP sheep monoclonal antibody, and standard sample is mixed by periodically switching between the two states of the four two-way valves.

[0069] NT-proBNP is a key biomarker for the early diagnosis and prognostic assessment of heart failure. Its high-sensitivity detection is an important clinical application of electrochemiluminescence immunoassay technology, providing important support for the rapid diagnosis and efficacy monitoring of cardiovascular diseases such as heart failure.

[0070] Specifically, 35 μL of magnetic microparticles coated with streptavidin at a concentration of 0.75 mg / mL, 60 μL of biotin-labeled anti-NT-proBNP mouse monoclonal antibody at a concentration of 1.5 mg / mL, 60 μL of ruthenium complex-labeled anti-NT-proBNP sheep monoclonal antibody at a concentration of 1.5 mg / mL, and 45 μL of standard sample were fed into the mixing chip 5 through the eighth connecting pipe 48. At 37°C, the reciprocating flow direction was switched at a flow rate of 300 μL / s for 15 s cycles, with multiple incubation time gradients set. After incubation, the mixture was removed from the chip and injected into a standard electrochemiluminescence detection device. A constant potential of 2.3 V was applied between the working electrode and the reference electrode of the three-electrode system, with an excitation time of 10 s, and the luminescence intensity was measured.

[0071] To verify the mixing efficiency, the same solution ratio was subjected to reciprocating flow mixing and incubation, as well as isothermal static incubation, using this device. The luminescence intensity of the two groups at different incubation times was compared. The results showed that the luminescence intensity of the reciprocating flow mixing device based on the Tesla valve in this application tended to stabilize at 3.5 min, while the luminescence intensity of the isothermal static group tended to stabilize at 9 min. The final stable luminescence intensity values ​​of the two groups were approximately equal. This indicates that the reciprocating flow mixing device based on the Tesla valve can effectively improve the mixing efficiency.

[0072] The mixing experiment of the above-mentioned NT-proBNP antigen-antibody system shows that the device provided in this application has effective mixing ability. It is a more efficient, faster and simpler modular integrated liquid mixing device, which can be applied to a variety of rapid detection scenarios that require a pre-incubation step.

[0073] To further verify the enhanced effect of the Tesla valve flow channel structure on fluid mixing in the device of this application, computational fluid dynamics was used to simulate and evaluate the mixing performance of a single mixing unit 511, and compared it with a straight-flow channel of equal length with the same total flow channel length.

[0074] The simulation software used was COMSOL Multiphysics. The working medium was set to water, with the following physical properties: density ρ = 998 kg / m³, and kinetic viscosity μ = 0.89 × 10⁻⁶. -3 The concentration was set at kg / (m·s), and the temperature was set at 298.15 K. The diffusion coefficient of the solute in the medium was set at 5 × 10⁻⁶. -11 m 2 The flow model uses a laminar flow model, and the mass transfer process uses a dilute mass transfer model. The inlet boundary condition is set as a velocity inlet with a velocity of 0.0083 m / s, and the flow state is fully developed. The outlet boundary condition is set as a pressure outlet with an outlet pressure of atmospheric pressure. The mesh is set to a "finer" level to ensure simulation accuracy. To form an initial concentration gradient, the inlet region is divided into four equal channels, with the first and third inlet channels (counting from top to bottom) injecting a concentration of 1 mol / m³. 3 The solute was injected at a concentration of 0 mol / m³ into the second and fourth inlet channels. 3 The solute. The mixing effect is as follows: Figure 6 As shown, the quantitative evaluation index of the mixing effect is the mixing degree, which is defined as the coefficient of variation of the concentration values ​​at each point on the outlet section. The higher the mixing degree value, the more uniform the mixing.

[0075] according to Figure 6 It can be seen that, under the condition of a single pass without reciprocating flow (0 mixing cycles), the mixing degree of the Tesla valve channel reaches 71.5%, while the mixing degree of the constant-length straight channel is only 9.5%. This indicates that the Tesla valve structure can generate a significant mixing enhancement effect through self-impacting eddies in a single flow. With the increase of the number of reciprocating mixing cycles, the mixing degree of the Tesla valve channel increases rapidly, reaching 90.0% after 12 reciprocating flows and 98.0% after 32 flows, essentially achieving complete mixing. In contrast, the mixing degree of the constant-length straight channel increases extremely slowly; even after 32 reciprocating flows, the mixing degree only increases to 19.0%.

[0076] The simulation results above fully demonstrate that the mixing unit 511 based on the Tesla valve structure used in this application can significantly outperform the traditional direct-flow structure under the same flow conditions by utilizing the resistance difference between forward and reverse flows and the self-impacting vortex effect generated during reverse flow, thereby greatly improving the fluid mixing efficiency and mixing speed.

[0077] In summary, in the field of microfluidics, traditional serpentine flow mixing devices struggle to adequately disrupt the laminar flow state of the solution to be mixed, resulting in low mixing efficiency per unit length and poor mixing performance. Secondly, the unidirectional flow design limits the residence time and interaction opportunities of the fluid within a confined space, failing to fully utilize the spatial structure. Furthermore, devices with reciprocating flow capabilities typically rely on two opposing power sources for coordinated drive, leading to complex structures and significant control challenges, which hinders system miniaturization and integration. Additionally, traditional mixing devices often exist as independent units, making effective cascading with sample introduction or detection modules difficult, thus limiting the development of practical devices for rapid on-site detection and restricting overall application scenarios.

[0078] The mixing device developed based on the Tesla valve transfers its flow-stopping principle to the mixing application scenario. It makes full use of the mechanical action of the liquid itself. Without the need for additional external magnetic or electric fields, it achieves passive and efficient mixing by forming local strong eddies and disrupting the laminar flow state.

[0079] The core advantage of the mixing chip 5 and the matching liquid circuit system working together is that it can utilize the inherent asymmetric flow characteristics of the Tesla valve to continuously generate local self-impact and eddy current disturbances when the fluid flows through the valve unit in both the forward and reverse directions. This significantly extends the effective mixing path and interaction time of the fluid within a limited space, fully tapping the spatial potential of the flow channel structure itself and breaking through the limitation of insufficient space utilization in traditional unidirectional flow.

[0080] In addition, the supporting liquid circuit system, through the structural design of the annular flow path and the three-way connector, does not require changing the working state of the pump. It only requires periodically switching the working states of two two-way valves to realize operations such as sample injection, reciprocating flow mixing and extraction. This not only reduces the overall size and operating cost of the device, but also makes it possible for integrated detection and miniaturization and chip design.

[0081] In addition, the mixing chip 5 and the matching liquid circuit system adopt a modular design, which not only realizes the compact integration of the mixing unit 511 itself, but also enables rapid cascading with the sample injection module and detection module through a standard interface, forming a complete analysis link from sample preprocessing to signal output. This overcomes the limitation of traditional mixing devices that are difficult to work in conjunction with other functional units, and expands its application scenarios in real-time detection and resource-constrained environments.

[0082] Specifically, the mixing chip 5 adopts a three-layer structure design. By combining a rigid support structure with a flexible sealing structure, it avoids the potential risks of gas and liquid leakage in the system, avoids the processing of hollow structures, reduces processing difficulty and cost, improves the versatility of the device, and provides convenience for mass production.

[0083] In addition, the processing plane of the flow channel layer 51 and the opposite sealing layer 52 plane are hydrophobically treated, which effectively suppresses the liquid column breakage or discontinuity caused by shear stress during the fluid movement and improves the flow stability of the liquid phase. At the same time, this treatment method also reduces the frictional resistance between the fluid and the channel wall, which greatly reduces the overall flow resistance of the bidirectional Tesla valve mixing chip 5, ensuring that the fluid can maintain a stable and continuous delivery state during the reciprocating flow.

[0084] 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.

[0085] The above embodiments merely illustrate 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 invention patent. 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 protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A reciprocating flow mixing device based on a Tesla valve, characterized in that, The device includes: A mixing chip has a channel for fluid flow inside, the channel contains at least one mixing unit based on a Tesla valve structure, and the mixing chip has openings at both ends, which serve as ports for fluid inflow and outflow, respectively. A matching liquid circuit system is connected to the opening of the mixing chip to form a closed loop for fluid circulation, and the mixing chip is connected in series in the closed loop; A unidirectional drive source is connected to the matching fluid circuit system to provide a unidirectional driving force for the fluid within the closed loop; The matching fluid circuit system, while keeping the driving direction of the unidirectional drive source unchanged, periodically changes the internal flow path connection state, so that the fluid in the closed loop flows through the mixing chip alternately in opposite directions, so that the fluid forms a reciprocating flow in the mixing unit, and the eddy current effect generated by the resistance difference of the Tesla valve in the forward and reverse flow is used to achieve fluid mixing. The mixing chip includes a flow channel layer, a sealing layer and a base layer stacked from top to bottom; The channel and the mixing unit are disposed in the flow channel layer; The sealing layer is made of a hydrophobic flexible material and is used to seal the channel; The base layer is made of a rigid material and is used to provide structural support; Multiple mixing units are arranged in series to form the main structure of the channel, and two adjacent mixing units are directly connected through the opening. The two ends of the flow channel layer are respectively connected to a left buffer cavity and a right buffer cavity, and the left buffer cavity and the right buffer cavity are respectively connected to the corresponding ends of the mixing chip; The supporting hydraulic system includes a first two-way valve, a second two-way valve, a third two-way valve, a fourth two-way valve, a first three-way connector, a second three-way connector, a third three-way connector, a fourth three-way connector, and connecting pipes; The first interface of the first three-way connector is connected to the second interface of the second three-way connector through a first connecting pipe, and the first two-way valve is provided on the first connecting pipe; The first interface of the second three-way connector is connected to the second interface of the third three-way connector through a second connecting pipe, and the second two-way valve is provided on the second connecting pipe; The first interface of the third three-way connector is connected to the second interface of the fourth three-way connector through a third connecting pipe, and the third two-way valve is provided on the third connecting pipe; The first interface of the fourth three-way connector is connected to the second interface of the first three-way connector through a fourth connecting pipe to form the closed loop, and the fourth two-way valve is provided on the fourth connecting pipe.

2. The apparatus according to claim 1, characterized in that, One of the mixing units includes: a connecting flow channel, and a first Tesla valve subunit and a second Tesla valve subunit that are centrally symmetrically distributed based on the connecting flow channel; Both the first Tesla valve subunit and the second Tesla valve subunit include a narrow straight flow channel, a flow splitting node, a wide straight flow channel, a narrow lateral flow channel, an arc-shaped flow channel, a confluence node, and a wide lateral flow channel connected in sequence. The narrow straight flow channel is connected to the wide straight flow channel and the narrow lateral flow channel via the flow splitting node, and the narrow straight flow channel and the wide straight flow channel are collinear. The wide straight flow channel is connected to the wide lateral flow channel via the arc-shaped flow channel and the confluence node in sequence, and the narrow lateral flow channel is connected to the confluence node, and the narrow lateral flow channel and the wide lateral flow channel are collinear.

3. The apparatus according to claim 1, characterized in that, One of the mixing units includes: a rhomboid connecting channel, and a first Tesla valve subunit, a second Tesla valve subunit, a third Tesla valve subunit, and a fourth Tesla valve subunit that are centrally symmetrically distributed about the center of the rhomboid connecting channel; The first Tesla valve subunit and the second Tesla valve subunit are mirror symmetrical about the transverse central axis. The wide lateral flow channels of the first Tesla valve subunit and the second Tesla valve subunit converge toward the center, forming two sides of one side of the rhomboid connecting flow channel. The narrow straight flow channels of the first Tesla valve subunit and the second Tesla valve subunit extend away from the rhomboid connecting flow channel and converge at one end. The first Tesla valve subunit and the second Tesla valve subunit are mirror-symmetrical about each other across the longitudinal axis of the center of the rhomboid connecting channel to obtain the fourth Tesla valve subunit and the third Tesla valve subunit, respectively.

4. The apparatus according to claim 3, characterized in that, The angle between the wide straight flow channels of the first Tesla valve subunit and the second Tesla valve subunit is 50°~90°; The angle between the wide lateral flow channels of the first Tesla valve subunit and the second Tesla valve subunit is 30°~70°; The width of the narrow straight flow channel and the narrow lateral flow channel of the first Tesla valve subunit and the second Tesla valve subunit is L1; The width of the wide straight flow channel, the arc flow channel, and the wide lateral flow channel of the first Tesla valve subunit and the second Tesla valve subunit is L2, and the ratio of L1 to L2 is 1.5~2. The central angle corresponding to the arc-shaped flow channel is 150°~210°; The angle between the wide straight flow channel and the narrow lateral flow channel is 60°~100°.

5. The apparatus according to claim 1, characterized in that, The radii of both the left and right buffer cavities are 1.5mm to 5.0mm. The length of the connection channel between the left and right buffer cavities and the end corresponding to the mixing chip is 1.0mm~3.0mm, and the width is 1.0mm~3.0mm.

6. The apparatus according to claim 1, characterized in that, One opening of the mixing chip is connected to the third interface of the first tee connector via a fifth connecting pipe. The other opening of the mixing chip is connected to the third interface of the third tee connector via the sixth connecting pipe; The unidirectional drive source is connected to the third interface of the fourth tee connector via the seventh connecting pipe; The third interface of the second three-way connector is connected to the external atmosphere or sample injection device through the eighth connecting pipe; The supporting fluid circuit system is configured to periodically switch valve states, causing the first two-way valve and the third two-way valve to alternately open or close with the second two-way valve and the fourth two-way valve, so that the fluid forms a reciprocating flow within the closed loop and the mixing chip.

7. The apparatus according to claim 1, characterized in that, The valves in the supporting hydraulic system are one of the following: solenoid valves, pinch valves, piezoelectric valves, or rotary valves, and can be switched in sequence through a control module. The unidirectional drive source is at least one of the following: mechanical drive device, electroosmotic drive device, acoustic drive device, thermal drive device, centrifugal drive device, capillary drive structure, magnetohydrodynamic drive device, and osmotic pressure drive device.

8. The apparatus according to claim 1, characterized in that, The hydrophobic flexible material of the sealing layer is one of polydimethylsiloxane, silicone rubber, fluororubber, or polyurethane. The rigid material of the flow channel layer and the base layer is one of glass, polymethyl methacrylate, polycarbonate or metal; The flow channel layer is made by a patterning manufacturing process, which includes at least one of soft lithography, machining, laser processing, hot stamping, injection molding, additive manufacturing, wet etching, or dry etching.

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