Multistage micro-fluidic chip and chip production mold

Abstract

The utility model relates to the technical field of microfluidics, and discloses a multi-stage micro-fluidic chip, which at least comprises a first-stage collision fluid channel and a second-stage collision fluid channel, and a mixing channel of the upper-stage fluid channel is arranged as a premixing fluid channel of the lower-stage fluid channel; the first-stage collision fluid channel comprises a first premixed fluid channel and a second premixed fluid channel, a first-stage fluid collision channel is arranged between the first premixed fluid channel and the second premixed fluid channel, and the first-stage fluid collision channel enters the second-stage premixed fluid channel after collision; a second-stage fluid collision channel is arranged between the third premixing fluid channel and the fourth premixing fluid channel, and the second-stage fluid collision channel enters the mixing channel after collision. The multi-stage micro-fluidic chip has the advantages of high mixing efficiency, low shear damage, easiness in integrated packaging and batch manufacturing and the like, and the micro-fluid mixing performance and the system practicability are remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of microfluidic chip technology, specifically to a multi-level microfluidic chip and a chip manufacturing mold. Background Technology

[0002] Microfluidics, as an emerging technology for processing micro-volume fluids, boasts significant advantages such as low reagent consumption, rapid reaction rates, high heat and mass transfer efficiency, and ease of integration and automated control. In fields such as biomedical analysis, chemical synthesis, environmental monitoring, and life science research, microfluidics demonstrates immense application value and economic benefits due to its high throughput control capabilities and precise reaction condition management.

[0003] In microfluidic systems, mixers are key components for achieving thorough mixing of multiphase or multicomponent fluids. Depending on different design requirements, common microfluidic mixer structures include T-shaped, Y-shaped, cross-shaped, staggered herringbone structures, and network structures composed of several annular or helical channels. These structures, through different geometric shapes and flow characteristic designs, enable the mixing of two-phase or multiphase fluids in microscale channels, thus facilitating the preparation of nanoparticles, the synthesis of compounds, or chemical / biological reactions.

[0004] Taking the most commonly used T-type structure as an example, it typically consists of a simple three-way pipe. The two-phase fluids enter from both inlets, undergo initial mixing in a straight pipe section of the same size, and then exit from the third pipe to enter subsequent processes or testing units. Currently, this structure has the following main drawbacks in practical applications:

[0005] 1. The mixing efficiency is low and the reagent waste is serious. Because the two-phase fluids flow in parallel at a high linear velocity in a straight pipe, there is a lack of sufficient shear and vortex action, resulting in an unsatisfactory mixing effect. It is often necessary to increase the flow rate or perform multi-stage mixing, which further aggravates the consumption and waste of reagents.

[0006] 2. The piping connection is complicated and the integration is low. Traditional T-type mixers rely on external pipes and joints to connect the input and output interfaces, which not only increases the difficulty of system assembly and debugging, but also hinders subsequent modular integration and rapid on-site deployment.

[0007] Therefore, there is an urgent need for a microfluidic mixer structure that combines high-efficiency mixing performance with easy integration characteristics, in order to further improve the overall performance and practicality of microfluidic systems. Utility Model Content

[0008] This invention provides a multi-level microfluidic chip. Through an innovative structural design that combines graded premixing and graded collision, this multi-level microfluidic chip combines multiple advantages such as high-efficiency mixing, low shear damage, easy integration and packaging, and mass production, significantly improving the microfluidic mixing performance and system practicality.

[0009] The present invention solves the above-mentioned technical problems through the following technical solution:

[0010] A multi-level microfluidic chip, the chip including at least a first-level collision fluid path and a second-level collision fluid path, wherein the mixing channel of the upper-level fluid path is set as the premixed fluid channel of the lower-level fluid path;

[0011] The primary collision fluid pathway includes a first premixed fluid channel and a second premixed fluid channel. A primary fluid collision channel is provided between the first premixed fluid channel and the second premixed fluid channel. After collision in the primary fluid collision channel, the fluid enters the secondary premixed fluid channel.

[0012] The secondary collision fluid pathway includes a third premixed fluid channel and a fourth premixed fluid channel, wherein the third premixed fluid channel is connected to the primary fluid collision channel; a secondary fluid collision channel is provided between the third premixed fluid channel and the fourth premixed fluid channel, and the fluid enters the mixing channel after collision in the secondary fluid collision channel.

[0013] In a specific embodiment, the injection ports of the same level premixed fluid channels are at the same horizontal plane, and the pipe diameters of the premixed fluid channels are the same, that is, the injection ports of the first premixed fluid channel and the second premixed fluid channel are at the same horizontal plane, and the injection ports of the third premixed fluid channel and the fourth premixed fluid channel are at the same horizontal plane.

[0014] In a specific embodiment, the primary fluid collision channel is located between the first premixed fluid channel and the second premixed fluid channel; the primary fluid collision channel includes a fluid acceleration section and a fluid collision section, with the two ends of the collision channel connected to the premixed fluid channel being the fluid acceleration section and the middle part being the fluid collision section; the diameter of the fluid acceleration section gradually decreases from the premixed fluid channel to the fluid collision section, and the collision channel is symmetrically arranged on both sides.

[0015] In a specific embodiment, the starting ends of the third and fourth premixed fluid channels are located on the same horizontal plane, and the starting end of the mixing channel is provided with an arc-shaped flow-slowing bend, after which a horizontal flow path extends; the secondary fluid collision channel includes a fluid acceleration section and a fluid collision section, with the two ends of the collision channel connected to the premixed fluid channel being the fluid acceleration section, and the middle part being the fluid collision section; the diameter of the fluid acceleration section gradually decreases from the premixed fluid channel to the fluid collision section, and the collision channel is symmetrically arranged on both sides.

[0016] In one specific embodiment, a mixing channel extends from the secondary fluid collision channel, and an outlet is provided at the end of the mixing channel.

[0017] In a specific embodiment, the chip includes an upper cover and a lower cover, with fluid channels provided at corresponding positions on the upper cover and the lower cover, and the upper cover and the lower cover are interlocked to form a multi-level microfluidic chip; the surfaces of the upper cover and the lower cover are provided with injection ports and discharge ports.

[0018] The production mold for injection molding multi-stage microfluidic chips includes a front mold and a rear mold. The front mold is provided with a glue injection port that extends through the front mold and connects to the mold groove. The surface of the rear mold has mold grooves with upper and lower covers. The grooves are symmetrically arranged and an S-shaped glue injection channel is provided between the grooves.

[0019] In one specific embodiment, the front mold and the rear mold are provided with hot and cold runners that penetrate the mold body on the side.

[0020] In one specific embodiment, the front mold has threaded holes at its four corners for mounting onto a mold frame or hot press, and one corner of the front mold is chamfered.

[0021] In one specific embodiment, a plurality of anti-foolproof cylinders are provided in the mold groove of the rear mold, and the rear mold is provided with garbage nail holes along the outer edge of the mold groove.

[0022] This technical solution introduces multi-stage (at least two-stage) collision premixing and mixing pathways on the basis of single-stage collision mixing, thereby achieving progressively enhanced collision and mixing of fluids within the microchannel, and has the following main beneficial effects:

[0023] 1. Staged premixing and progressively enhanced mixing improve mixing efficiency. The first-stage collision pathway completes the initial premixing, while the second-stage collision pathway further enhances the shear and turbulence effects, enabling two-phase or multi-component fluids to achieve more thorough and uniform mixing after two high-intensity collisions, significantly improving mixing efficiency. This is especially suitable for systems with high viscosity or high reaction kinetic requirements.

[0024] The step-by-step design avoids the energy consumption and turbulence control problems caused by a single large-flow collision, while taking into account fluid shear and residence time, which is conducive to the full diffusion and reaction of various components at the microscale.

[0025] 2. The premixed flow path and the mixing flow path are organically connected to reduce stagnation and dead zones. The mixing channel of the previous stage is directly used as the premixing channel of the next stage. External interfaces and pipeline connections are eliminated, reducing fluid stagnation and dead zones at the connection points and reducing stratification caused by uneven shearing.

[0026] The combined design of the curved, gentle flow bend and the smooth flow path effectively balances the pressure inside the flow channel before entering the secondary collision stage, suppresses the inlet vortex, and ensures that the colliding flow stream is stable and symmetrical, laying the foundation for efficient mixing.

[0027] 3. The collision channels are symmetrical and have a stepped diameter reduction, resulting in uniform and controllable acceleration. The diameter of the "fluid acceleration section" at both ends of each collision channel gradually decreases from the premixed flow channel to the "fluid collision section". Under the symmetrical structure, controlled jet acceleration is generated, allowing the flow stream to obtain maximum kinetic energy conversion at the collision center, thereby enhancing shear and turbulence intensity.

[0028] 4. The inlet is horizontally arranged and the pipe diameter is consistent to ensure symmetrical introduction of fluids of the same level. The injection ports of the premixed fluid channels of the same level are located on the same horizontal plane and the pipe diameter is consistent to ensure that the fluids have the same pressure drop and flow velocity when entering the collision channel, so as to achieve symmetrical dynamic conditions during collision and avoid uneven mixing or channel deviation caused by inlet imbalance.

[0029] Horizontal arrangement facilitates chip planar design and packaging, and improves compatibility with external delivery systems (such as pump tubes and samplers).

[0030] 5. Modular top / bottom cover interlocking packaging, easy for mass production and integration. The top and bottom covers are etched or molded at their respective positions to form a complete fluid passage, and precise alignment and sealing are achieved through interlocking. No additional pipe connections are required, simplifying the assembly process and reducing the risk of leakage.

[0031] This packaging method facilitates integration with peripheral components such as electrodes, optical detection units, valves, and heating / cooling modules, and has good modular expansion potential, making it suitable for the industrial mass production of microfluidic chips. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0033] Figure 1 The diagram shown is a schematic of the structure of a microfluidic chip.

[0034] Figure 2 The diagram shows the upper and lower cover structures of a microfluidic chip.

[0035] Figure 3 The diagram shown is a schematic representation of the fluid collision channel.

[0036] Figure 4 The diagram shown is a schematic of multiphase mixing in a primary collision fluid path.

[0037] Figure 5 The diagram shows the structure of the rear mold. Figure 1 ;

[0038] Figure 6 The diagram shows the structure of the rear mold. Figure 2 ;

[0039] Figure 7 The diagram shows the structure of the front mold. Figure 1 .

[0040] In the attached diagram: 1-Upper cover; 2-Lower cover; 3-First premixed fluid channel; 4-Second premixed fluid channel; 5-Third premixed fluid channel; 6-Fourth premixed fluid channel; 7-Arc-shaped slow-flow bend; 8-Horizontal flow section;

[0041] 9- Primary collision fluid passage; 10- Secondary collision fluid passage; 11- Acceleration section; 12- Collision section; 13- Rear mold; 14- Front mold; 15- S-shaped injection channel; 16- Foolproof cylinder; 17- Waste nail hole; 18- Hot and cold runners; 19- Injection port; 20- Fifth premixed fluid passage. Detailed Implementation

[0042] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0043] The following description, in conjunction with the accompanying drawings, illustrates a specific embodiment of the present invention, "a microfluidic chip," but the invention is not limited to this embodiment.

[0044] Example 1

[0045] The specific structure of the microfluidic chip is as follows:

[0046] The chip consists of two parts: an upper cover 1 and a lower cover 2. Fluid passage grooves are formed in corresponding positions on the upper cover 1 and the lower cover 2, and they are encapsulated by a bump-and-contact fitting without the need for additional adhesives.

[0047] The upper and lower cover surfaces are provided with an injection port and an outlet port. The injection port of the upper cover corresponds to the inlet of the first and second premixed fluid passages 4, and the outlet port of the lower cover corresponds to the outlet port at the end of the mixing channel.

[0048] This chip structure is a multi-stage collision structure. This embodiment provides a two-stage structure, and other multi-phase or multi-stage structures can be expanded according to this embodiment.

[0049] Primary collision fluid pathway 9:

[0050] The injection ports of the first premixed fluid channel 3 (inlet A) and the second premixed fluid channel 4 (inlet B) are on the same horizontal plane and have the same pipe diameter. The same-stage injection achieves symmetrical dynamic conditions, so that the kinetic energy of their collisions is consistent, and the fluid mixing is more complete.

[0051] This embodiment also includes a variant in which the primary collision fluid passage 9 includes two or more mixing fluid passages, such as... Figure 4 As shown, it includes a first premixed fluid channel 3 (inlet A), a second premixed fluid channel 4 (inlet B), and a fifth premixed fluid channel 20 (inlet E).

[0052] The first premixed fluid channel 3 (inlet A) and the second premixed fluid channel 4 (inlet B) are symmetrically arranged, and the fifth premixed fluid channel 20 (inlet E) is located in the middle of the first and second premixed fluid channels. The inlets of the three channels are at the same horizontal plane and have the same pipe diameter. After the fluids in the three channels pass through the constricted pipe, they collide and mix at the confluence. This is suitable for fluids that require vigorous mixing. After passing through the first-stage fluid collision channel, the fluids enter the mixing channel, where the pipe diameter increases. This allows for instantaneous pressure release, which can alleviate the pressure on the front-end pump, valve, and pipeline, and reduce the risk of leakage.

[0053] The primary fluid collision channel is located between the first and second premixed fluid channels 4, and includes fluid acceleration sections 11 at both ends and a fluid collision section 12 in the middle:

[0054] The diameter of the fluid acceleration section 11 gradually decreases from 200µm to 80µm; the collision section 12 is a tubular structure with a diameter of 80µm.

[0055] The collision channels are symmetrically arranged on both sides. The flow streams achieve maximum kinetic energy conversion at the collision center, completing the initial premixing. After the collision, the fluid enters the downstream secondary premixed fluid channel.

[0056] Secondary collision fluid pathway 10:

[0057] The third premixed fluid channel 5 (inlet C) is directly connected to the first-stage fluid collision channel, and its injection port is at the same horizontal plane as the fourth premixed channel 6 (inlet D), with the same pipe diameter.

[0058] An arc-shaped flow-slowing bend 7 (radius 250µm) is set between the inlet C, D and the secondary collision channel, and combined with the subsequent advection section 8 to balance the pressure and suppress eddies.

[0059] The structure of the second-stage fluid collision channel is similar to that of the first stage:

[0060] The diameter of the fluid acceleration section 11 was reduced from 200µm to 60µm;

[0061] The collision section 12 has a diameter of 60µm; it is symmetrical on both sides.

[0062] After the collision, they enter the mixing channel, which has an outlet E at the end.

[0063] The specific structure of the injection molding die is as follows:

[0064] Front mold 14 (moving mold): The center of the mold surface has a glue injection port 19, which leads to the S-shaped glue injection channel 15; M6 threaded holes are provided at the four corners for mold frame or hot press installation, one corner of which is cut at 45°; hot and cold runners 18 are arranged on the side, and the hot and cold runners are interleaved to ensure the mold temperature is 70℃±2℃.

[0065] Rear mold 13 (fixed mold): The surface of the rear mold has upper cover mold groove and lower cover mold groove. The grooves are symmetrically arranged, and their dimensions correspond to the thickness of the upper and lower covers of the chip and the width of the channel.

[0066] An S-shaped injection channel 15 is provided between the grooves, and several anti-foolproof cylinders 16 (Ø2 mm) are arranged in the mold groove. Waste nail holes 17 are provided along the outer edge of the groove to facilitate chip removal.

[0067] After demolding and post-processing, the mold is opened after cooling and solidification, and the preform is taken out through the ejector mechanism; the flash is removed, the preform is cleaned, and plasma activation is performed; after the upper and lower covers are fitted and aligned, a small amount of pressure is applied and heated (80℃, 2min) to complete the encapsulation.

[0068] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0069] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-level microfluidic chip, characterized in that, The chip includes at least a primary collision fluid path and a secondary collision fluid path, wherein the mixing channel of the primary fluid path is set as the premixed fluid path of the secondary fluid path; The primary collision fluid pathway includes a first premixed fluid channel and a second premixed fluid channel. A primary fluid collision channel is provided between the first premixed fluid channel and the second premixed fluid channel. After collision in the primary fluid collision channel, the fluid enters the secondary premixed fluid channel. The secondary collision fluid pathway includes a third premixed fluid channel and a fourth premixed fluid channel, wherein the third premixed fluid channel is connected to the primary fluid collision channel; a secondary fluid collision channel is provided between the third premixed fluid channel and the fourth premixed fluid channel, and the fluid enters the mixing channel after collision in the secondary fluid collision channel.

2. The multi-stage microfluidic chip according to claim 1, characterized in that, The injection ports of the same level premixed fluid channels are at the same horizontal plane, and the pipe diameters of the premixed fluid channels are the same. That is, the injection ports of the first premixed fluid channel and the second premixed fluid channel are at the same horizontal plane, and the injection ports of the third premixed fluid channel and the fourth premixed fluid channel are at the same horizontal plane.

3. The multi-level microfluidic chip according to claim 2, characterized in that, The primary fluid collision channel is located between the first premixed fluid channel and the second premixed fluid channel. The primary fluid collision channel includes a fluid acceleration section and a fluid collision section. The two ends of the collision channel are connected to the premixed fluid channel as fluid acceleration sections, and the middle part is the fluid collision section. The diameter of the fluid acceleration section gradually decreases from the premixed fluid channel to the fluid collision section, and the two sides of the collision channel are symmetrically arranged.

4. The multi-stage microfluidic chip according to claim 3, characterized in that, The starting ends of the third and fourth premixed fluid channels are located on the same horizontal plane, and the starting end of the mixing channel is provided with an arc-shaped slow-flow bend, after which a horizontal flow path extends; the secondary fluid collision channel includes a fluid acceleration section and a fluid collision section, with the two ends of the collision channel connected to the premixed fluid channel being the fluid acceleration section, and the middle part being the fluid collision section; the diameter of the fluid acceleration section gradually decreases from the premixed fluid channel to the fluid collision section, and the collision channel is symmetrically arranged on both sides.

5. The multi-stage microfluidic chip according to claim 3 or 4, characterized in that, The primary and secondary collision fluid pathways include, but are not limited to, having only two premixed fluid channels at the same level.

6. The multi-stage microfluidic chip according to claim 4, characterized in that, A mixing channel extends from the secondary fluid collision channel, and a discharge port is provided at the end of the mixing channel.

7. The multi-stage microfluidic chip according to claim 6, characterized in that, The chip includes an upper cover and a lower cover, with fluid channels provided at corresponding positions on the upper and lower covers. The upper and lower covers are interlocked to form a multi-level microfluidic chip. Injection ports and discharge ports are provided on the surfaces of the upper and lower covers.

8. A production mold for injection molding the multi-stage microfluidic chip according to any one of claims 1-6, characterized in that, The production mold includes a front mold and a rear mold. The front mold is provided with an injection port that extends through the front mold and connects to the mold groove. The surface of the rear mold has mold grooves with upper and lower covers. The grooves are symmetrically arranged, and an S-shaped injection channel is provided between the grooves.

9. The production mold according to claim 8, characterized in that, The front mold and the rear mold are provided with hot and cold runners that penetrate the mold body on the side.

10. The production mold according to claim 9, characterized in that, The rear mold has several anti-foolproof cylinders in the mold groove, and the rear mold has garbage nail holes along the outer edge of the mold groove.

Images