Three-dimensional laminar flow miniature mixer

Abstract

The embodiment of the invention relates to a three-dimensional laminar flow micro mixer which comprises an inlet unit, an outlet unit and a plurality of periodically arranged micro separation and exchange units located between the inlet unit and the outlet unit, and the micro separation and exchange units are sequentially connected end to end. An inlet and an outlet of the miniature separation and exchange unit are connected through three torsion runners, laminar fluid is divided by the three torsion runners at the inlet, exchange and rearrangement of separated fluid are achieved through the three torsion runners, so that separation and exchange of the fluid are completed, and finally a new laminar fluid distribution form is formed at the outlet. And the fluid on the cross section is in two-dimensional distribution. According to the invention, rapid mixing of laminar fluid is realized by means of separation and exchange of the torsion flow channel, the structure is simple, the laser direct writing processing technology is compatible, large-scale preparation can be realized, and the device has important application in the fields of medicine, chemical industry, detection and the like.

Description

Technical Field

[0001] This invention relates to the field of micro mixers, and more particularly to a three-dimensional laminar flow micro mixer. Background Technology

[0002] In fields such as chemical synthesis, biomedical analysis, environmental monitoring, and nucleic acid sequencing, achieving rapid and uniform mixing of materials is crucial. Microfluidic systems, due to their ability to efficiently mix fluids within limited spaces, significantly save space and cost while improving reaction safety, have become an important technological platform for achieving this goal. However, due to limitations in channel size and fluid velocity, fluids are typically in a laminar flow state, resulting in mixing relying primarily on molecular diffusion and relatively low mixing efficiency. As the core component of microfluidic systems, micromixers bear the critical function of rapid and uniform fluid mixing. Therefore, to meet the stringent requirements for mixing performance in high-throughput applications, the structure of micromixers must be specifically designed and optimized. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a three-dimensional laminar flow micro mixer that solves the problem of fluid mixing in microfluidic systems under high throughput conditions. It enables efficient, rapid, and uniform mixing of liquid-liquid, gas-liquid, and gas-gas media within a limited space. This mixer features a compact structure, small space occupation, and excellent pressure resistance, providing a reliable solution for rapid and uniform mixing in high-throughput applications.

[0004] To achieve the above objectives, the present invention provides a three-dimensional laminar flow micro-mixer, comprising: an inlet unit 1, an outlet unit 3, and at least one micro-separation and exchange unit 2 disposed between the inlet unit 1 and the outlet unit 3; wherein,

[0005] The inlet unit 1 is used to introduce two fluids to be mixed, and the outlet of the inlet unit 1 is connected to the inlet of the first micro-separation and exchange unit 2.

[0006] The micro separation and exchange unit 2 is provided with an inlet 24 and an outlet 25, as well as a plurality of torsional channels connecting the inlet 24 and the outlet 25. The torsional channels are configured to separate, exchange and rearrange the incoming laminar fluid in three-dimensional space to increase the contact interface and concentration gradient between the fluids, thereby forming a laminar fluid pattern with more layers and more uniform distribution at the outlet 25 of the micro separation and exchange unit than at the inlet 24.

[0007] The outlet unit 3 is used to discharge the mixed fluid, and the inlet of the outlet unit 3 is connected to the outlet of the last micro-separation and exchange unit 2.

[0008] Preferably, the number of torsion channels connecting the inlet 24 and the outlet 25 in the micro separation and exchange unit 2 is three, including a first torsion channel 21, a second torsion channel 22 and a third torsion channel 23.

[0009] More preferably, at the inlet 24 of the micro-separation and exchange unit 2, the inlets of the three torsion channels are arranged sequentially in the transverse direction, wherein the inlet heights of the first torsion channel 21, the second torsion channel 22 and the third torsion channel 23 are equal, the inlet widths of the first torsion channel 21 and the third torsion channel 23 are equal, and both are 1 / 2 of the inlet width of the second torsion channel 22.

[0010] More preferably, at the outlet 25 of the micro-separation and exchange unit 2, the outlet of the second torsional channel 22 is located on the upper layer, and the outlets of the first torsional channel 21 and the third torsional channel 23 are located on the lower layer, arranged symmetrically from left to right, and the two outlets are arranged symmetrically with the upper-layer outlet along the vertical axis; wherein, the outlet heights of the first torsional channel 21, the second torsional channel 22 and the third torsional channel 23 are equal, and the outlet widths of the first torsional channel 21 and the third torsional channel 23 are equal, and both are 1 / 2 of the outlet width of the second torsional channel 22.

[0011] More preferably, the inlets and outlets of the first torsion channel 21, the second torsion channel 22, and the third torsion channel 23 are all rectangular, and the inlet and outlet dimensions are different.

[0012] Preferably, the number of micro-separation and switching units 2 is n, where n≥1, and all micro-separation and switching units 2 are periodically connected in series from beginning to end.

[0013] Further preferably, after processing by n micro-separation and exchange units 2, the number of laminar flow distribution layers of the fluid increases according to a recursive law, wherein the recursive law is as follows:

[0014]

[0015] Among them, a n This represents the actual number of alternating distribution layers after the nth unit.

[0016] Preferably, the mixer is suitable for rapid and uniform mixing of liquid-liquid, liquid-gas, or gas-gas media.

[0017] Preferably, the inlet unit 1 has a T-shaped structure with two inlets at the top and an end outlet 13 connected to the micro-separation and exchange unit 2, for merging two different fluids to form an initial left-right side-by-side laminar flow.

[0018] Preferably, the outlet unit 3 has an L-shaped structure, with an inlet 31 connected to the micro separation and exchange unit 2, a final outlet 32, and a linear narrowing flow channel connecting the inlet 31 and the outlet 32, for guiding and converging the mixed fluid output.

[0019] This invention provides a three-dimensional laminar flow micromixer that periodically separates and exchanges fluids through a torsional channel, resulting in a two-dimensional distribution of the laminar fluid cross-section. This significantly improves fluid mixing efficiency. The slender rectangular micro-separation and exchange unit configuration facilitates large-scale parallel integration and provides the ability to flexibly expand the throughput of the microfluidic system. Its superior mixing performance effectively enhances the sensitivity and efficiency of biomonitoring. This design offers a high-throughput, high-safety material mixing solution for chemical synthesis, and thanks to standard three-dimensional fabrication, the device also exhibits good consistency and repeatability. Attached Figure Description

[0020] Figure 1 A schematic diagram of a three-dimensional laminar flow micro-mixer structure is provided for an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a mixer structure with three micro-separation and exchange units provided in an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of an entry unit structure provided in an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of a micro-separation switching unit structure provided in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of an outlet unit structure provided in an embodiment of the present invention. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] Figure 1 A schematic diagram of a three-dimensional laminar flow micro-mixer structure is provided for an embodiment of the present invention, as shown below. Figure 1 As shown, the three-dimensional laminar flow micro mixer of this embodiment includes an inlet unit 1, an outlet unit 3, and at least one micro separation and exchange unit 2 disposed between the inlet unit 1 and the outlet unit 3. These parts are connected end to end through internal flow channels to form a complete fluid mixing path. The structure of each part of the three-dimensional laminar flow micro mixer is described below.

[0027] Inlet unit 1 is used to introduce two fluids to be mixed and initially arrange them into a laminar flow state. The outlet of inlet unit 1 is connected to the inlet of the first micro-separation and exchange unit 2. The fluids to be mixed enter the micro-separation and exchange unit from the outlet of inlet unit 1. In a preferred embodiment, see [reference needed]. Figure 3 The inlet unit 1 has a T-shaped structure with two circular inlets (11, 12) at the top and an end outlet 13 connected to the micro separation and exchange unit 2. It is used to merge two different fluids to form an initial left-right side-by-side laminar flow. The inlet unit 1 in this embodiment has a simple and reliable structure and can provide a stable and symmetrical initial flow pattern for the subsequent separation and exchange process.

[0028] The micro separation and exchange unit 2 is provided with an inlet 24 and an outlet 25, as well as multiple torsional channels connecting the inlet 24 and the outlet 25. The torsional channels are configured to separate, exchange, and rearrange the incoming laminar fluid in three-dimensional space to increase the contact interface and concentration gradient between the fluids, thereby forming a laminar fluid pattern with more layers and a more uniform distribution at the outlet 25 of the micro separation and exchange unit than at the inlet 24.

[0029] In some preferred embodiments, the miniature separation and exchange unit 2 has three torsional channels connecting the inlet 24 and the outlet 25, including a first torsional channel 21, a second torsional channel 22, and a third torsional channel 23. These three channels are arranged in a staggered manner in space to jointly complete the division, spatial exchange, and rearrangement of the inflowing fluid. The inlet 24 is divided into three parts by the three torsional channels. At the inlet 24 of the miniature separation and exchange unit 2, the inlets of the three torsional channels are arranged sequentially in the transverse direction. The inlet geometry (e.g., rectangular) of the first torsional channel 21 and the third torsional channel 23 located on both sides is exactly the same. The inlet heights of the first torsional channel 21, the second torsional channel 22, and the third torsional channel 23 are equal, and the inlet widths of the first torsional channel 21 and the third torsional channel 23 are equal, both being half the inlet width of the second torsional channel 22. After passing through the first torsion channel 21 and the third torsion channel 23, the fluid is amplified by left and right exchange and compressed vertically, flowing towards the lower layer of the outlet 25. The laminar fluid in the second torsion channel 22 is amplified horizontally and compressed vertically, flowing towards the upper layer of the outlet 25, and converges with the first torsion channel 21 and the third torsion channel 23 at the outlet 25 to form a new laminar fluid distribution.

[0030] Furthermore, at the outlet 25 of the micro-separation exchange unit 2, there is one outlet in the upper layer and two outlets in the lower layer. The outlet of the second torsional flow channel 22 is located in the upper layer, and the outlets of the first torsional flow channel 21 and the third torsional flow channel 23 are located in the lower layer. The two outlets in the lower layer are symmetrical from left to right and are arranged symmetrically with the upper layer outlets along the vertical axis. The outlet heights of the first torsional flow channel 21, the second torsional flow channel 22 and the third torsional flow channel 23 are equal, and the outlet widths of the first torsional flow channel 21 and the third torsional flow channel 23 are equal, and are both 1 / 2 of the outlet width of the second torsional flow channel 22.

[0031] Furthermore, the inlets and outlets of the first torsional flow channel 21, the second torsional flow channel 22, and the third torsional flow channel 23 are all rectangular, and the inlet and outlet dimensions are different, thereby realizing the vertical compression and horizontal rotation of the fluid within the flow channel, and thus completing the division, spatial position exchange, and rearrangement of the inflowing fluid.

[0032] It should be noted that the number of the above-mentioned micro-separation and switching units 2 is n, n≥1, and all micro-separation and switching units 2 are periodically connected in series from end to end. The inlet of the first micro-separation and switching unit 2 is connected to the inlet unit 1, and the outlet of the last micro-separation and switching unit 2 is connected to the outlet unit 3.

[0033] After being processed by n micro-separation and exchange units 2, the number of laminar flow distribution layers of the fluid increases according to a recursive law, which is as follows:

[0034]

[0035] Among them, a n This represents the actual number of alternating distribution layers after the nth unit.

[0036] The core working mechanism of this mixer lies in achieving three-dimensional spatial division and exchange of fluid through a twisting flow channel. Its enhanced mixing primarily stems from the following effects:

[0037] Enhanced convection: Twisting the flow channel forces the fluid to change its direction and position in three-dimensional space, breaking the pure laminar interface.

[0038] Interface proliferation: Each separation exchange unit divides the inflowing fluid layer and rearranges it into more layers at the outlet, exponentially increasing the contact interface between different fluids.

[0039] Concentration gradient optimization: By exchanging fluid layers that are originally close to the wall and have a slower flow rate, the fluid layer is periodically exchanged to the high shear zone in the center of the channel. At the same time, the high concentration gradient region is placed in the center of the flow field, making full use of the synergistic effect of diffusion and convection to significantly improve mixing efficiency.

[0040] The outlet unit 3 is used to discharge the mixed fluid, and the inlet of the outlet unit 3 is connected to the outlet of the last micro-separation and exchange unit 2.

[0041] In some preferred embodiments, the outlet unit 3 has an L-shaped structure, with a circular inlet 31 connected to the micro separation and exchange unit 2, a final outlet 32, and a linear narrowing flow channel connecting the inlet 31 and the outlet 32, for guiding and converging the mixed fluid output.

[0042] The mixer provided in this application embodiment is suitable for rapid and uniform mixing of liquid-liquid, liquid-gas, or gas-gas media in high-throughput microfluidic systems. It can be widely used in fields such as biomedical detection, chemical synthesis, drug screening, environmental analysis, and microreactors, and is especially suitable for occasions requiring high-throughput and high-uniformity mixing.

[0043] To better understand the present invention, specific embodiments are described below.

[0044] In this embodiment, three micro-separation switching units 2 are connected in series as an example.

[0045] Using ultrafast laser-assisted chemical etching technology, Figure 2 The solid structure in the image is obtained by scanning and directly writing inside the quartz glass using an ultrafast laser, followed by selective etching inside the quartz glass. Figure 2 The hollow structure becomes the flow channel.

[0046] See Figure 2 and Figure 3 Inlet unit 1, where two circular holes 11 and 12 are the first fluid inlet 11 and the second fluid inlet 12. The first inlet 11 enters fluid b, and the second inlet 12 enters fluid a. At outlet 13, a single layer of laminar fluid with a left-right distribution of ab will be formed.

[0047] See Figure 2 and Figure 4 The micro-separation and exchange unit 2 has an inlet 24 connected to the outlet 13 of the inlet unit 1. The inlet 24 and outlet 25 are connected through a first torsion channel 21, a second torsion channel 22, and a third torsion channel 23. The inlet 24 is divided into three parts by the three torsion channels. The inlet heights of the first torsion channel 21, the second torsion channel 22, and the third torsion channel 23 are the same, and the inlet width of the torsion channel 23 is the same as that of the torsion channel 21, which is half the inlet width of the torsion channel 22. The laminar fluid entering the micro-separation and exchange unit 2 from the inlet unit 1 is divided into three parts at the inlet 24. During the flow through their respective channels:

[0048] First torsional flow channel 21 and third torsional flow channel 23: Fluid a in the first torsional flow channel 21 and fluid b in the third torsional flow channel 23 exchange and amplify left and right, and are compressed vertically, flowing to the lower right and lower left sides of the outlet 25 respectively. Specifically, within the flow channels, not only is the fluid guided forward, but the three-dimensional torsional geometry also causes the fluid to exchange left and right positions. That is, fluid a from the left is transported to the lower right side of the outlet 25 after passing through flow channel 21; fluid b from the right is transported to the lower left side of the outlet 25 after passing through flow channel 23. At the same time, the change in the flow channel cross-section causes the fluid to be compressed vertically (up and down).

[0049] The second torsional flow channel 22: the laminar fluid in the middle is distributed in an ab shape. It is amplified to the left and right and compressed to the top and bottom as it flows towards the outlet 25. Its main function is to make the fluid in the middle part moderately widen in the horizontal direction and be compressed in the vertical direction, so that it eventually flows smoothly to the upper center position of the outlet 25.

[0050] Finally, the second torsional flow channel 22 converges with torsional flow channels 21 and 23 at outlet 25 to form a new laminar flow, which is a two-layer alternating distribution, in the form of... This process achieves the separation and exchange of laminar fluids, allowing the three fluids to reconverge at the outlet section 25, forming a new laminar flow distribution pattern with an increased number of layers.

[0051] The above describes the fluid mixing process in the first micro-separation and exchange unit, Unit 2. As the fluid flows forward, it is distributed as follows: The laminar fluid enters the second micro-separation and exchange unit, where it is again separated and exchanged at its inlet 24 through three torsion channels, with torsion channel 21 being... The distributed laminar fluid is in the torsional flow channel 23. The laminar fluid is uniformly distributed in the torsional flow channel 22. The fluid, after passing through three torsional channels, converges at outlet 25, forming a laminar fluid distribution. Since the fluid distribution is the same in the two middle layers, the actual distribution is a three-layer alternating distribution.

[0052] Based on the separation and exchange law of micro-separation and exchange unit 2, after passing through the third micro-separation and exchange unit, the actual distribution of the laminar fluid at the outlet is as follows: The fluid exhibits a 6-layer distribution. As can be seen from the above process, with each additional micro-separation and exchange unit 2, the number of laminar distribution layers increases according to a definite mathematical law. Without considering inter-substance diffusion, after n micro-separation and exchange units, the actual number of alternating distribution layers is a. n The actual number of distribution layers is:

[0053] a1 = 2,

[0054] For example:

[0055] After passing through the first unit: a1 = 2 layers

[0056] After the second unit: a2 = 2a1 - 1 = 3 layers

[0057] After the 3rd unit: a3 = 2a2 = 6 layers

[0058] Similarly, users can flexibly select the number of units n (n≥1) in series according to the diffusion coefficient of the target fluid, the required mixing uniformity, and the allowable pressure drop, so as to achieve continuous control from basic mixing to highly uniform mixing.

[0059] See Figure 2 and Figure 5 The outlet 25 of the tail-end micro separation and exchange unit 2 is connected to the inlet 31 of the outlet unit 3. After passing through a compression channel, the fluid is finally discharged from the outlet 32.

[0060] This invention provides a three-dimensional laminar flow micro-mixer that transforms the cross-sectional distribution of laminar fluid from a one-dimensional to a two-dimensional distribution through the separation, exchange, and recombination of micro-separation and exchange units. Furthermore, by exchanging the flow through the torsional channels within the micro-separation and exchange units, the slower-velocity boundary layer is moved to the laminar boundary, resulting in a high-concentration gradient field and a high-velocity field distributed in the middle of the flow channel. This further utilizes convection diffusion and the concentration gradient field to improve mixing efficiency. Depending on the specific material properties and fluid flux requirements, the number of micro-separation and exchange units can be periodically expanded between the inlet and outlet units to meet specific mixing requirements.

[0061] Compared with existing technologies, the three-dimensional laminar flow micro mixer provided by this invention utilizes three torsion channels of the micro separation and exchange unit to actively divide, exchange and rearrange the laminar fluid in three-dimensional space, so that the distribution of the laminar fluid cross-section changes from a one-dimensional distribution to a two-dimensional distribution. Then, through the cascading effect of several periodically arranged micro separation and exchange units, the number of fluid contact interface layers increases, and the high concentration gradient region is continuously introduced into the high shear zone in the center of the channel. By making full use of the synergistic effect of convection and diffusion, the fluid can be rapidly and uniformly mixed within a short channel distance.

[0062] In this invention, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0063] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0064] In the description herein, the terms "a specific embodiment," "some embodiments," "one embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0065] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A three-dimensional laminar flow micro-mixer, characterized in that, The three-dimensional laminar flow micro-mixer includes an inlet unit (1), an outlet unit (3), and at least one micro-separation and exchange unit (2) disposed between the inlet unit (1) and the outlet unit (3); wherein, The inlet unit (1) is used to introduce two fluids to be mixed, and the outlet of the inlet unit (1) is connected to the inlet of the first micro-separation and exchange unit (2). The micro separation and exchange unit (2) is provided with an inlet (24) and an outlet (25), and a plurality of twisted flow channels connecting the inlet (24) and the outlet (25); the twisted flow channels are configured to separate, exchange and rearrange the incoming laminar fluid in three-dimensional space to increase the contact interface and concentration gradient between the fluids, thereby forming a laminar fluid pattern with more layers and more uniform distribution at the outlet (25) of the micro separation and exchange unit than at the inlet (24); The outlet unit (3) is used to discharge the mixed fluid, and the inlet of the outlet unit (3) is connected to the outlet of the last micro-separation and exchange unit (2).

2. The three-dimensional laminar flow micro-mixer according to claim 1, characterized in that, The miniature separation and exchange unit (2) has three torsion channels connecting the inlet (24) and the outlet (25), including a first torsion channel (21), a second torsion channel (22) and a third torsion channel (23).

3. The three-dimensional laminar flow micro-mixer according to claim 2, characterized in that, At the inlet (24) of the micro-separation exchange unit (2), the inlets of the three twisted channels are arranged in the transverse direction. The inlet heights of the first twisted channel (21), the second twisted channel (22) and the third twisted channel (23) are equal, and the inlet widths of the first twisted channel (21) and the third twisted channel (23) are equal, and both are 1 / 2 of the inlet width of the second twisted channel (22).

4. The three-dimensional laminar flow micro-mixer according to claim 2 or 3, characterized in that, At the outlet (25) of the micro-separation exchange unit (2), the outlet of the second torsion channel (22) is located on the upper layer, and the outlets of the first torsion channel (21) and the third torsion channel (23) are located on the lower layer, arranged symmetrically from left to right, and the two outlets are arranged symmetrically with the upper-layer outlet on the vertical axis; wherein, the outlet heights of the first torsion channel (21), the second torsion channel (22) and the third torsion channel (23) are equal, and the outlet widths of the first torsion channel (21) and the third torsion channel (23) are equal, and both are 1 / 2 of the outlet width of the second torsion channel (22).

5. The three-dimensional laminar flow micro-mixer according to claim 4, characterized in that, The inlets and outlets of the first torsion channel (21), the second torsion channel (22), and the third torsion channel (23) are all rectangular, and the inlet and outlet dimensions are different.

6. The three-dimensional laminar flow micro-mixer according to claim 1, characterized in that, The number of micro-separation and switching units (2) is n, n≥1, and all micro-separation and switching units (2) are periodically connected in series from beginning to end.

7. The three-dimensional laminar flow micromixer according to claim 6, characterized in that, After being processed by n micro-separation and exchange units (2), the number of laminar flow distribution layers of the fluid increases according to a recursive law, which is as follows: Among them, a n This represents the actual number of alternating distribution layers after the nth unit.

8. The three-dimensional laminar flow micro-mixer according to claim 1, characterized in that, The mixer is suitable for rapid and uniform mixing of liquid-liquid, liquid-gas, or gas-gas media.

9. The three-dimensional laminar flow micro-mixer according to claim 1, characterized in that, The inlet unit (1) is a T-shaped structure with two inlets (11, 12) at the top and an end outlet (13) connected to the micro-separation and exchange unit (2) for merging two different fluids to form an initial left-right side-by-side laminar flow.

10. The three-dimensional laminar flow micro-mixer according to claim 1, characterized in that, The outlet unit (3) has an L-shaped structure, with an inlet (31) connected to the micro separation and exchange unit (2), a final outlet (32), and a linear narrowing channel connecting the inlet (31) and the outlet (32) for guiding and converging the mixed fluid output.

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