Enhanced micro-mixing unit and micro-fluidic mixer

Abstract

The utility model discloses an enhanced micro-mixing unit and a microfluidic mixer, and belongs to the technical field of microfluidics. The microfluidic mixer comprises an inlet flow channel, at least one contraction-expansion mixing flow channel and an outlet flow channel which are arranged in series, the inlet flow channel comprises a collecting flow channel; the contraction-expansion mixing flow channel comprises one enhanced micro-mixing unit or at least two enhanced micro-mixing units which are arranged in series; the mixing chamber is defined by an upper wall, a lower wall and symmetrically arranged side walls and used for mixing circulating feed liquid, the mixing chamber comprises a turbulent flow structure, and the turbulent flow structure comprises a fan-shaped retaining wall in a fan shape in the direction perpendicular to the feed liquid circulating direction and at least one pair of L-shaped protrusions in an L shape; by introducing the L-shaped bulge structures, the number of the serial micro-mixing units is reduced, the length of the whole flow channel is shortened, and efficient mixing of micro-fluids is completed under the condition of smaller volume dosage, so that the consumption of reagents is effectively reduced.

Description

TECHNICAL FIELD

[0001] The application relates to an enhanced micro-mixing unit and a micro-fluidic mixer, and belongs to the technical field of micro-fluidics. BACKGROUND

[0002] The micro-fluidic mixer is a mixing device realized on a micro-fluidic technology platform, which can quickly and uniformly mix two or more different fluids under micro-scale conditions. The channel size of the micro-fluidic mixer is usually in the range of microns to millimeters, and the internal fluid flow is usually in a laminar flow state rather than a traditional turbulent flow. Therefore, a specific flow channel design is needed to promote the mixing of different fluids. Existing research shows that T-Y type micro-mixers, obstacle type micro-mixers and Tesla valve type micro-mixers have good functions in promoting fluid mixing. However, these traditional micro-mixer structures are simple and have uniform inner and outer diameters, and these characteristics result in low mixing efficiency, so it is usually necessary to lengthen the channel length or connect multiple micro-mixing units in series to improve the mixing efficiency.

[0003] The patent with the publication number CN117732385A is a typical technology for lengthening the channel length by connecting multiple micro-mixing units in series. The technical solution shows that connecting multiple micro-mixing units containing obstacles or baffles can better improve the mixing efficiency, but due to the limitation of the series structure, there are problems such as large fluid sample amount and high reagent consumption. In addition, as the volume of the micro-fluidic mixer increases, the manufacturing process cost further increases. UTILITY MODEL CONTENT

[0004] In order to solve the problem of "long micro-channel structure of the series structure, resulting in large amount of mixed fluid, which is difficult to meet the micro-fluidic production of expensive samples" in the prior art, the application provides a design scheme of an enhanced micro-mixing unit and a micro-fluidic mixer. By introducing an L-shaped protruding structure, the number of series micro-mixing units is reduced, the length of the overall flow channel is shortened, and efficient mixing of micro-fluids is realized with less volume, thereby effectively reducing the consumption of reagents.

[0005] According to a first aspect of the application, an enhanced micro-mixing unit is provided, which comprises:

[0006] a mixing chamber for mixing the flow of the material liquid, which is surrounded by an upper wall, a lower wall and symmetrically arranged side walls, and two ends of the mixing chamber along the flow direction of the material liquid are respectively a mixing chamber inlet and a mixing chamber outlet;

[0007] The mixing chamber comprises a turbulence structure, and the turbulence structure comprises a fan-shaped baffle wall in a fan shape perpendicular to the flow direction of the material liquid and at least one pair of L-shaped protrusions in an L shape.

[0008] The fan-shaped baffle is a protrusion formed on the upper wall and / or the lower wall of the mixing chamber, and the fan-shaped baffle separates the mixing chamber into symmetrical first and second flow channels; when the thickness of the protrusion or the sum of the protrusions of the upper and lower walls is equal to the depth of the mixing chamber, that is, the upper end surface of the fan-shaped baffle is tightly connected (integrally formed) with the upper wall of the mixing chamber, and the lower end surface of the fan-shaped baffle is tightly connected (integrally formed) with the lower wall of the mixing chamber.

[0009] The two ends of the first and second flow channels respectively converge at the mixing chamber inlet and the mixing chamber outlet.

[0010] The L-shaped protrusion is a protrusion formed on the upper wall and / or the lower wall of the mixing chamber, and each pair of L-shaped protrusions is symmetrically arranged in the first and second flow channels.

[0011] The L-shaped inflection point of the spoiler structure faces the direction of the mixing chamber inlet.

[0012] In this application, the meaning of the fan shape in the fan-shaped baffle refers to a general fan shape, also known as a curved triangle, that is, the arc side of the fan shape and the two sides of the fan shape can be part of a circular arc and a radius of the same circle, or part of a circular arc and a radius of different circles.

[0013] Optionally, the upper end surface and the lower end surface of the fan-shaped baffle are connected with the upper wall and the lower wall of the mixing chamber, respectively, and the fan-shaped baffle separates the mixing chamber into symmetrical first and second flow channels.

[0014] Optionally, the enhanced micro-mixing unit has one or more of the following features:

[0015] The width of the mixing chamber inlet is 0.5-2mm, and the depth is 0.5-2mm;

[0016] The width of the mixing chamber outlet is 0.5-2mm, and the depth is 0.5-2mm;

[0017] The maximum width of the mixing chamber is 3-6mm, the narrowest width is 0.5-2mm, the depth is 0.5-2mm, and the length is 8-10mm;

[0018] The height of the fan-shaped baffle is 0.5-2mm, the radius of the arc surface of the fan-shaped baffle is 1.9-2mm, the arc angle of the arc surface of the fan-shaped baffle is 100-140°, and the angular arc of the fan-shaped baffle is 40-80°;

[0019] Optionally, the fan-shaped baffle is a block with two planes and an arc surface as side edges, and the angular arc of the fan-shaped baffle refers to the included angle between the two planes of the fan-shaped baffle.

[0020] Optionally, the arc surface of the fan-shaped baffle wall faces the inflow direction of the mixed microfluid, and the vertex faces the outflow direction of the mixed microfluid.

[0021] The interval between each pair of L-shaped protrusions is 0.2-0.4 mm, the width of the L-shaped protrusion is 0.1-0.2 mm, the height is 0.5-1 mm, the length of the long side of the L-shaped protrusion is 1.6-1.8 mm, and the length of the short side is 0.5-0.7 mm.

[0022] Optionally, the flow disturbance structure includes 1-3 pairs of L-shaped structures.

[0023] Optionally, the flow disturbance structure includes a first pair of L-shaped structures arranged between the inlet of the mixing chamber and the fan-shaped baffle wall and / or a second pair of L-shaped structures arranged between the outlet of the mixing chamber and the fan-shaped baffle wall.

[0024] The short sides of the two L-shaped structures of the first pair of L-shaped structures are arranged opposite to each other, wherein the angle between the short side and the length direction of the mixing chamber is 40-50°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber inlet is 0.4-0.6 mm.

[0025] The long sides of the two L-shaped structures of the second pair of L-shaped structures are arranged opposite to each other, wherein the angle between the long side and the length direction of the mixing chamber is 50-60°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber outlet is 3-4 mm.

[0026] Optionally, the vertical distance between the end surface of the fan-shaped baffle wall close to one side of the inlet of the mixing chamber and the inlet of the mixing chamber is 2-3 mm.

[0027] Optionally, the side wall of the mixing chamber is an arc-shaped side wall, and the width of the mixing chamber is greater than the width of the inlet and outlet of the mixing chamber.

[0028] The mixing chamber is a part in the shape of an ellipse along the direction perpendicular to the flow direction of the material liquid, and the part in the shape of an ellipse is a shape obtained by symmetrically removing two end portions along the long axis direction of the ellipse;

[0029] The long axis of the ellipse is 10-15 mm, and the short axis is 3-6 mm.

[0030] According to a second aspect of the present application, a microfluidic mixer is provided, which comprises:

[0031] The inlet flow channel, at least one contraction-expansion mixing flow channel, and the outlet flow channel are arranged in series.

[0032] The inlet flow channel includes a collection flow channel, and at least two feeding flow channels are arranged at the inlet end of the collection flow channel.

[0033] The contraction-expansion mixed flow channel comprises one enhanced micro-mixing unit or at least two enhanced micro-mixing units arranged in series.

[0034] Optionally, the arrangement in series of the enhanced micro-mixing units means that two adjacent enhanced micro-mixing units are directly connected, i.e. the mixing chamber outlet of the enhanced micro-mixing unit relatively close to the inlet flow channel is connected to the mixing chamber inlet of the adjacent enhanced micro-mixing unit relatively far from the inlet flow channel, and the enhanced micro-mixing units are arranged in parallel and linearly.

[0035] The enhanced micro-mixing unit is selected from the enhanced micro-mixing units described above.

[0036] Optionally, the microfluidic mixer has one or more of the following features:

[0037] The width of the converging flow channel is 0.5-2 mm, the length is 5-11 mm, and the depth is 0.5-2 mm.

[0038] The width of each of the at least two feed flow channels is independently 0.5-2 mm, the length is independently 5-10 mm, and the depth is independently 0.5-2 mm.

[0039] The width of the outlet flow channel is 0.5-2 mm, the length is 5-20 mm, and the depth is 0.5-2 mm.

[0040] The contraction-expansion mixed flow channel comprises 10-30 enhanced micro-mixing units arranged in series.

[0041] Optionally, the contraction-expansion mixed flow channel comprises 10-15 enhanced micro-mixing units arranged in series.

[0042] Optionally, the inlet end of the converging flow channel is provided with two feed flow channels, i.e. a first feed flow channel and a second feed flow channel arranged at an angle of 90°.

[0043] Optionally, the microfluidic mixer comprises:

[0044] The inlet flow channel, the at least two contraction-expansion mixed flow channels, and the outlet flow channel are arranged in series.

[0045] The adjacent contraction-expansion mixed flow channels are connected by a turning flow channel.

[0046] The width of the turning flow channel is 0.5-2 mm, the length is 5-20 mm, and the depth is 0.5-2 mm.

[0047] In this application, the length of the turning flow channel refers to the outer circle length of the turning flow channel.

[0048] Optionally, the turning flow channel is used to realize the turning of the microfluidic mixer so that each contraction-expansion mixing flow channel is arranged in parallel.

[0049] Optionally, the enhanced micro mixing unit or the microfluidic mixer is prepared by a MEMS manufacturing process, 3D printing or a mechanical processing process, and has an integrated structure.

[0050] The microfluidic mixer provided in the application can be applied to the fields of pharmaceutical preparation research and development and continuous synthesis of new materials.

[0051] Specifically, for example, the pharmaceutical preparation research and development is one of a drug or a gene carrier selected from the group consisting of synthetic microcapsules, synthetic liposomes and synthetic lipid nanoparticles; the application not only improves the bioavailability of the drug or the gene, but also improves the efficiency and quality of the preparation research and development; for example, the continuous synthesis of new materials is selected from at least one of nanomaterial synthesis selected from the group consisting of emulsion synthesis, hydrogel microsphere synthesis and polymer synthesis. Through the control of flow rate and mixing conditions, the application can not only realize the synthesis of nanoparticles with different particle sizes and shapes, but also improve the production efficiency and reduce the energy consumption, so as to realize the sustainable development of material preparation.

[0052] The beneficial effects that can be produced by the application include:

[0053] The enhanced micro mixing unit and the microfluidic mixer provided in the application can destroy the laminar flow of the fluid by using the contraction-expansion mixing unit, induce secondary flow and vortex flow, and promote mixing. The design of the fan-shaped baffle can cause the fluid to be mixed multiple times in the tangential direction, promote efficient mixing, and the L-shaped protruding structure can further disturb the mixed microfluid and promote efficient mixing. By introducing the L-shaped structure, the number of serial micro mixing units is reduced, the length of the overall flow channel is shortened, efficient mixing of two microfluids is realized in a smaller volume, and the consumption of reagents is effectively reduced.

[0054] The microfluidic mixer has a small pressure drop at the inlet and outlet, has good stability, and is not easy to cause the mixer to break. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 FIG. 1 is a two-dimensional schematic diagram of a microfluidic mixer in the application.

[0056] Figure 2 FIG. 1 is a three-dimensional schematic diagram of a microfluidic mixer in the application.

[0057] Figure 3 FIG. 1 is a two-dimensional schematic diagram of a micro mixing unit in the application.

[0058] Figure 4 FIG. 1 is a three-dimensional schematic diagram of a micro mixing unit in the application.

[0059] Figure 5The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong.

[0060] Figure 6 The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong.

[0061] Figure 7 The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong.

[0062] Figure 8 The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong.

[0063] The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong. Figure 1 The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong.

[0064] The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong. Figure 1 The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong. Figure 6 The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong. The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong.DETAILED DESCRIPTION

[0065] The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong.

[0066] The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong.

[0067] The simulation graph of the microfluidic mixer of Example 1 of the present application has a simulation graph coordinate of 0 when Re = 1, which is because the velocity is too small to be displayed in the software, not because the identification is wrong.

[0068] According to an embodiment of the present application, the structural schematic diagram of the microfluidic mixer is shown in Figure 1 、 Figure 2

[0069] The inlet flow channel, at least one contraction-expansion mixing flow channel 3, and outlet flow channel 5 are arranged in series.

[0070] When the number of contraction-expansion mixing flow channels 3 is greater than 2, the adjacent contraction-expansion mixing flow channels 3 are connected through the turning flow channel 4.

[0071] The turning flow channel 4 is used to realize the turning of the microfluidic mixer so that each contraction-expansion mixing flow channel 3 is arranged in parallel.

[0072] The inlet flow channel comprises a collection flow channel 2, and the inlet end of the collection flow channel 2 is provided with at least two feeding flow channels 1;

[0073] The contraction-expansion mixing flow channel 3 comprises one enhanced micro-mixing unit 31 or at least two enhanced micro-mixing units 31 arranged in series;

[0074] The series arrangement of the enhanced micro-mixing units 31 means that the mixing chamber outlet of the enhanced micro-mixing unit relatively close to the inlet flow channel is connected to the mixing chamber inlet of the adjacent enhanced micro-mixing unit 31 relatively far from the inlet flow channel, and the enhanced micro-mixing units are arranged in parallel and linearly.

[0075] The structural schematic diagram of the enhanced micro-mixing unit 31 is shown in Figure 3 、 Figure 4 , which comprises:

[0076] A mixing chamber for mixing and flowing of the material liquid, which is surrounded by an upper wall, a lower wall and symmetrically arranged side walls, and the two ends of the mixing chamber along the material liquid flow direction are respectively a mixing chamber inlet and a mixing chamber outlet;

[0077] The mixing chamber comprises a flow disturbance structure, and the flow disturbance structure comprises a fan-shaped baffle wall 311 in the form of a fan shape perpendicular to the material liquid flow direction and at least one pair of L-shaped protrusions 312 in the form of an L shape;

[0078] The fan-shaped baffle wall 311 is a protrusion formed on the upper wall and / or the lower wall of the mixing chamber, and the fan-shaped baffle wall separates the mixing chamber into symmetric first and second flow channels 313 and 314; when the thickness of the protrusion or the sum of the protrusions of the upper and lower walls is equal to the depth of the mixing chamber, that is, the upper end surface of the fan-shaped baffle wall is closely connected (integrally formed) with the upper wall of the mixing chamber, and the lower end surface of the fan-shaped baffle wall is closely connected (integrally formed) with the lower wall of the mixing chamber.

[0079] The two ends of the first and second flow channels 313 and 314 respectively meet at the mixing chamber inlet and the mixing chamber outlet;

[0080] The L-shaped protrusion 312 is a protrusion formed on the upper wall and / or the lower wall of the mixing chamber, and each pair of L-shaped protrusions 312 is symmetrically arranged in the first and second flow channels 313 and 314;

[0081] The L-shaped inflection point of the flow disturbance structure is directed towards the mixing chamber inlet direction.

[0082] In one embodiment, the upper end surface and the lower end surface of the fan-shaped barrier wall 311 are connected to the upper wall and the lower wall of the mixing chamber, respectively, and the fan-shaped barrier wall 311 divides the mixing chamber into the first flow channel 313 and the second flow channel 314.

[0083] In one embodiment, the enhanced micro-mixing unit 31 or the micro-fluidic mixer is prepared by a MEMS manufacturing process, 3D printing or mechanical processing, and has an integrated structure.

[0084] In one embodiment, the width of the collection flow channel 2 is 0.5-2 mm, the length is 5-11 mm, and the depth is 0.5-2 mm.

[0085] In one embodiment, the width of each of the at least two feed flow channels 1 is independently 0.5-2 mm, the length is independently 5-10 mm, and the depth is independently 0.5-2 mm.

[0086] In one embodiment, the inlet end of the collection flow channel is provided with two feed flow channels, i.e., a first feed flow channel and a second feed flow channel arranged at an angle of 90°.

[0087] In one embodiment, the width of the outlet flow channel 5 is 0.5-2 mm, the length is 5-20 mm, and the depth is 0.5-2 mm.

[0088] In one embodiment, the contraction-expansion mixing flow channel 3 includes 10-30 enhanced micro-mixing units 31 arranged in series.

[0089] In one embodiment, the width of the inlet of the mixing chamber is 0.5-2 mm, and the depth is 0.5-2 mm.

[0090] In one embodiment, the width of the outlet of the mixing chamber is 0.5-2 mm, and the depth is 0.5-2 mm.

[0091] In one embodiment, the maximum width of the mixing chamber is 3-6 mm, the narrowest width is 0.5-2 mm, the depth is 0.5-2 mm, and the length is 8-10 mm.

[0092] In one embodiment, the width of the turning flow channel is 0.5-2 mm, the length is 5-20 mm, and the depth is 0.5-2 mm. In this embodiment, the length of the turning flow channel refers to the length of the outer circle of the turning flow channel.

[0093] In one embodiment, the height of the fan-shaped baffle 311 is 0.5-2 mm, the radius of the arc surface of the fan-shaped baffle 311 is 1.9-2 mm, the angle of the arc surface of the fan-shaped baffle 311 is 100-140°, and the angular arc of the fan-shaped baffle 311 is 40-80°.

[0094] In one embodiment, the fan-shaped baffle 311 is a block with two planes and an arc surface as side edges, and the angular arc of the fan-shaped baffle 311 refers to the angle between the two planes of the fan-shaped baffle.

[0095] In one embodiment, the arc surface of the fan-shaped baffle 311 faces the inflow direction of the mixed microfluid, and the vertex faces the outflow direction of the mixed microfluid.

[0096] In one embodiment, the distance between each pair of L-shaped protrusions 312 is 0.2-0.4 mm, the width of the L-shaped protrusion 312 is 0.1-0.2 mm, the height of the L-shaped protrusion 312 is 0.5-1 mm, the length of the long side of the L-shaped protrusion 312 is 1.6-1.8 mm, and the length of the short side of the L-shaped protrusion 312 is 0.5-0.7 mm.

[0097] In one embodiment, the turbulence structure includes 1-3 pairs of L-shaped structures.

[0098] In one embodiment, the turbulence structure includes a first pair of L-shaped structures arranged between the inlet of the mixing chamber and the fan-shaped baffle 311 and / or a second pair of L-shaped structures arranged between the outlet of the mixing chamber and the fan-shaped baffle 311.

[0099] In one embodiment, the two L-shaped structures of the first pair of L-shaped structures are arranged opposite to each other on one side of the short side, the angle between the short side and the length direction of the mixing chamber is 40-50°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber inlet is 0.4-0.6 mm.

[0100] In one embodiment, the two L-shaped structures of the second pair of L-shaped structures are arranged opposite to each other on one side of the long side, the angle between the long side and the length direction of the mixing chamber is 50-60°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber outlet is 3-4 mm.

[0101] In one embodiment, the vertical distance between the end surface of the fan-shaped baffle 311 close to the inlet side of the mixing chamber and the inlet of the mixing chamber is 2-3 mm.

[0102] In one embodiment, the side wall of the mixing chamber is an arc-shaped side wall, and the width of the mixing chamber is greater than the width of the inlet and outlet of the mixing chamber.

[0103] The mixing chamber is an oval-shaped part along the direction perpendicular to the flow direction of the feed liquid, and the oval-shaped part is a shape with two end parts symmetrically removed along the long axis direction of the oval shape;

[0104] The long axis of the oval shape is 10-15 mm, and the short axis is 3-6 mm. Embodiment 1

[0105] The structure of the microfluidic mixer is as shown in Figure 1 、 Figure 2 The microfluidic mixer is composed of an inlet flow channel, two contraction-expansion mixing flow channels 3 and an outlet flow channel 5 arranged in series, and adjacent contraction-expansion mixing flow channels 3 are connected through a turning flow channel 4, and each contraction-expansion mixing flow channel 3 is arranged in parallel.

[0106] The inlet flow channel includes a collection flow channel 2, and the inlet end of the collection flow channel 2 is symmetrically provided with a first feed flow channel 11 and a second feed flow channel 12 along the length direction of the collection flow channel 2, and the included angle between the first feed flow channel 11 and the second feed flow channel 12 is 90°.

[0107] The contraction-expansion mixing flow channel 3 is a plurality of enhanced micro mixing units 31 arranged in series.

[0108] The enhanced micro mixing units are arranged in parallel and straight, and the structure is as shown in Figure 3 、 Figure 4As shown, each enhanced micro-mixing unit 31 is composed of a mixing chamber for mixing flow-through liquid and a flow disturbing structure arranged in the mixing chamber, and is surrounded by an upper wall, a lower wall and symmetrically arranged side walls, two ends of the mixing chamber along the flow direction of the liquid are respectively a mixing chamber inlet and a mixing chamber outlet; the side wall of the mixing chamber is an arc-shaped side wall, the width of the mixing chamber is greater than the width of the mixing chamber inlet and the mixing chamber outlet; the mixing chamber is an oval-shaped part along the vertical direction of the flow direction of the liquid, and the oval-shaped part is a shape obtained by symmetrically removing two end parts along the long axis direction of the oval shape. The flow disturbing structure includes a fan-shaped baffle wall 311 which is fan-shaped along the vertical direction of the flow direction of the liquid, and two pairs of L-shaped protrusions 312 which are L-shaped; the fan-shaped baffle wall 311 is a protrusion formed on the lower wall of the mixing chamber, and the top surface of the protrusion is connected with the upper wall of the mixing chamber, the fan-shaped baffle wall 311 is a block with two planes and an arc surface as side edges, and the angular radian of the fan-shaped baffle wall 311 refers to the included angle between the two planes of the fan-shaped baffle. The arc surface of the fan-shaped baffle wall 311 faces the mixing microfluid flow direction, and the vertex faces the mixing microfluid flow direction, the fan-shaped baffle wall 311 divides the mixing chamber into symmetric first and second flow channels 313 and 314; the two end parts of the first and second flow channels 313 and 314 respectively converge at the mixing chamber inlet and the mixing chamber outlet; the L-shaped protrusions 312 are protrusions formed on the lower wall of the mixing chamber, and each pair of L-shaped protrusions 312 is symmetrically arranged in the first and second flow channels 313 and 314, and is respectively a first pair of L-shaped structures arranged between the mixing chamber inlet and the fan-shaped baffle wall 311 and a second pair of L-shaped structures arranged between the mixing chamber outlet and the fan-shaped baffle wall 311, the two L-shaped structures of the first pair of L-shaped structures are oppositely arranged on one side of the short side, and the two L-shaped structures of the second pair of L-shaped structures are oppositely arranged on one side of the long side, and the L-shaped inflection point of the flow disturbing structure faces the mixing chamber inlet direction.

[0109] The enhanced micro-mixing unit 31 and the microfluidic mixer are prepared by a 3D printing process and have an integrated structure.

[0110] In the embodiment, the size parameters of each structural part in the microfluidic mixer are as follows:

[0111] The width of the first and second inlet flow channels 11 and 12 is 2 mm, the length is 10 mm, and the depth is 2 mm;

[0112] The width of the collection flow channel 2 is 2 mm, the length is 11 mm, and the depth is 2 mm;

[0113] Each of the contraction-expansion mixing flow channels 3 includes 12 enhanced micro-mixing units 31 arranged in series;

[0114] The width of the turning flow channel 4 is 2 mm, the length is 17 mm (the length of the outer circle of the turning is 17 mm (arc radius 5.5 mm), and the length of the inner circle is 11 mm (arc radius 3.5 mm)), and the depth is 2 mm;

[0115] The width of the outlet flow channel 5 is 2 mm, the length is 13 mm, and the depth is 2 mm;

[0116] The width of the mixing chamber inlet is 2 mm, and the depth is 2 mm;

[0117] The width of the mixing chamber outlet is 2 mm, and the depth is 2 mm;

[0118] The maximum width of the mixing chamber is 6 mm, the narrowest width is 2 mm, the depth is 2 mm, and the length is 9.4 mm;

[0119] The mixing chamber is in the shape of an ellipse, with a major axis of 10 mm and a minor axis of 6 mm;

[0120] The height of the sector-shaped barrier wall 311 is 2 mm, the radius of the arc surface of the sector-shaped barrier wall 311 is 1.9 mm, the arc surface angle of the sector-shaped barrier wall 311 is 140°, and the angular arc of the sector-shaped barrier wall 311 is 50°;

[0121] The vertical distance between the end surface of the sector-shaped barrier wall 311 near the mixing chamber inlet and the mixing chamber inlet is 2.6 mm;

[0122] The distance between each pair of L-shaped protrusions 312 is 0.38 mm, the width of the L-shaped protrusion 312 is 0.2 mm, the height is 1 mm, the length of the long side of the L-shaped protrusion 312 is 1.8 mm, and the length of the short side is 0.7 mm;

[0123] The angle between the short side of the first pair of L-shaped structures and the length direction of the mixing chamber is 48°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber inlet is 0.5 mm;

[0124] The angle between the long side of the second pair of L-shaped structures and the length direction of the mixing chamber is 60°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber outlet is 3.3 mm. Example 2

[0125] The structure of the microfluidic mixer is the same as that of Example 1, except that some structure size parameters in the microfluidic mixer are different, which are as follows:

[0126] The width of the first and second feeding flow channels 11 and 12 is 2 mm, the length is 10 mm, and the depth is 1 mm;

[0127] The width of the collection flow channel 2 is 2 mm, the length is 11 mm, and the depth is 1 mm;

[0128] Each of the contraction-expansion mixed flow channels 3 comprises 12 enhanced micro-mixing units 31 arranged in series;

[0129] The width of the turning flow channel 4 is 2 mm, the length is 17 mm (the length of the outer circle of the turning is 17 mm (arc radius 5.5 mm), and the length of the inner circle is 11 mm (arc radius 3.5 mm)), and the depth is 1 mm;

[0130] The width of the outlet flow channel 5 is 2 mm, the length is 13 mm, and the depth is 1 mm;

[0131] The width of the mixing chamber inlet is 2 mm, and the depth is 1 mm;

[0132] The width of the mixing chamber outlet is 2 mm, and the depth is 1 mm;

[0133] The maximum width of the mixing chamber is 6 mm, the narrowest width is 2 mm, the depth is 1 mm, and the length is 9.4 mm;

[0134] The mixing chamber is in the shape of an ellipse, with a major axis of 10 mm and a minor axis of 6 mm; the height of the sector barrier wall 311 is 1 mm, the radius of the arc surface of the sector barrier wall 311 is 1.9 mm, the arc surface angle of the sector barrier wall 311 is 140°, and the angular arc of the sector barrier wall 311 is 50°;

[0135] The vertical distance between the end surface of the sector barrier wall 311 near the mixing chamber inlet side and the mixing chamber inlet is 2.6 mm;

[0136] The distance between each pair of L-shaped protrusions 312 is 0.38 mm, the width of the L-shaped protrusion 312 is 0.2 mm, the height is 0.5 mm, the length of the long side of the L-shaped protrusion 312 is 1.8 mm, and the length of the short side is 0.7 mm;

[0137] The angle between the short side of the first pair of L-shaped structures and the length direction of the mixing chamber is 48°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber inlet is 0.5 mm;

[0138] The angle between the long side of the second pair of L-shaped structures and the length direction of the mixing chamber is 60°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber outlet is 3.3 mm. Example 3

[0139] The structure of the microfluidic mixer is the same as that of Example 1, except that some structure size parameters in the microfluidic mixer are different, as follows:

[0140] The width of the first and second feed flow channels 11 and 12 is 2 mm, the length is 10 mm, and the depth is 2 mm;

[0141] The width of the gathering channel 2 is 2 mm, the length is 11 mm, and the depth is 2 mm;

[0142] Each of the contraction-expansion mixing channels 3 comprises 12 enhanced micro-mixing units 31 arranged in series;

[0143] The width of the turning channel 4 is 2 mm, the length is 17 mm (where the length refers to the length of the outer circle of the turning, which is 17 mm (arc radius 5.5 mm), and the length of the inner circle is 11 mm (arc radius 3.5 mm)), and the depth is 2 mm;

[0144] The width of the outlet channel 5 is 2 mm, the length is 13 mm, and the depth is 2 mm;

[0145] The width of the mixing chamber inlet is 2 mm, and the depth is 2 mm;

[0146] The width of the mixing chamber outlet is 2 mm, and the depth is 2 mm;

[0147] The maximum width of the mixing chamber is 6 mm, the narrowest width is 2 mm, the depth is 2 mm, and the length is 9.4 mm;

[0148] The mixing chamber is in the shape of an ellipse, with the major axis being 10 mm and the minor axis being 6 mm; the height of the sector-shaped barrier wall 311 is 1 mm, the radius of the arc surface of the sector-shaped barrier wall 311 is 1.9 mm, the arc surface angle of the sector-shaped barrier wall 311 is 140°, and the angular arc of the sector-shaped barrier wall 311 is 50°;

[0149] The vertical distance between the end surface of the sector-shaped barrier wall 311 near the mixing chamber inlet side and the mixing chamber inlet is 2.6 mm;

[0150] The distance between each pair of L-shaped protrusions 312 is 0.38 mm, the width of the L-shaped protrusion 312 is 0.2 mm, the height is 0.5 mm, the length of the long side of the L-shaped protrusion 312 is 1.8 mm, and the length of the short side is 0.7 mm;

[0151] The angle between the short side of the first pair of L-shaped structures and the length direction of the mixing chamber is 48°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber inlet is 0.5 mm;

[0152] The angle between the long side of the second pair of L-shaped structures and the length direction of the mixing chamber is 60°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber outlet is 3.3 mm. Comparative Example 1

[0153] The structure of the microfluidic mixer of Comparative Example 1 is designed with reference to the patent with publication number CN117732385A, and the same structure as that of Example 1 uses the same size parameters, except that the turbulence structure in the mixing chamber in the structure of Comparative Example 1 does not include an L-shaped protrusion in the shape of L.

[0154] Test Example

[0155] Example 1 as a typical example, flow rate simulation, pressure simulation test, and with Comparative Example 1 as a control test the pressure drop at the inlet and outlet of the microfluidic mixer in the presence and absence of the L-shaped protrusion. Specifically, the SpaceClaim software is used to build a three-dimensional solid model of the microfluidic mixer, and the ANSYS Meshing software is used to automatically mesh the three-dimensional model. The Fluent software is used to numerically simulate the mixed fluid in the microchannel. Without considering the effect of gravity, the laminar flow and mass transfer module are selected for numerical simulation, the velocity inlet boundary condition is used for the two inlets of the micro-mixer, the pressure outlet boundary condition is used for the outlet, and the no-slip boundary condition is used for all walls except the inlet and outlet. The density, dynamic viscosity and diffusion coefficient used in the simulation analysis are 1000 kg / m 3 , 0.001 Pa·s, 1×10 -11 m 2 / s, respectively. The mixed medium is selected to be anhydrous ethanol and deionized water, water flows into the first feed flow channel 11 and ethanol flows into the second feed flow channel 12. The mixing degree of the micro-mixing channel is usually represented by the mass fraction of ethanol component.

[0156] The specific liquid flow process is as follows: water enters the collection flow channel 2 through the first feed flow channel 11, ethanol enters the collection flow channel 2 through the second feed flow channel 12, and the water and ethanol laminar flow in the collection flow channel 2 undergoes preliminary mixing. The mixed medium continues to pass through the contraction-expansion mixing flow channel 3, and finally, the mixed microfluid of ethanol and water flows out of the microfluidic mixer through the outlet flow channel 5. The fan-shaped baffle in the contraction-expansion mixing flow channel 3 can cause multiple tangential mixing of the fluid, and the L-shaped protrusion structure can further disturb the mixed microfluid and accelerate the efficient mixing of water and ethanol.

[0157] The test results are as follows:

[0158] Velocity simulation analysis of the microfluidic mixer at different Reynolds numbers (Re). As can be seen from the drawings, the flow rate of the mixed microfluid of water and ethanol is strengthened after meeting the fan-shaped baffle structure, which can generate vortex flow in the micro-mixing unit, promote the rapid mixing between ethanol and water, and enhance the mass transfer effect; the flow rate of the mixed microfluid is slowed down after meeting the L-shaped protruding structure, which can generate secondary flow at the right angle position of the L-shaped protruding structure to accelerate the mixing between ethanol and water and enhance the mass transfer effect. In addition, the mixed microfluid can be effectively squeezed and stretched in the contraction-expansion mixing flow channel, and the laminar flow is converted into vortex flow, which enhances the collision between the mixed microfluids and further promotes the mixing of the microfluids.

[0159] Pressure simulation analysis of the microfluidic mixer at different Reynolds numbers (Re). As can be seen from the drawings, the pressure of the microfluidic mixer gradually decreases from the inlet to the outlet. As Re gradually increases, the inlet pressure of the microfluidic mixer gradually increases, but the outlet pressure eventually decreases to a consistent value.

[0160] Ethanol mass distribution cloud at the outlet of the microfluidic mixer at different Reynolds numbers (Re) and mixing index. In the drawings, the ethanol mass distribution cloud at the outlet under each Re condition is shown. The results show that as Re increases, the change in the speed of the two fluids will cause unbalanced collision when ethanol and water recombine, which will change the contact area between them and strengthen the mixing. The mixing index first decreases and then increases as the Reynolds number increases. Among them, under the condition of Re 50, the microfluidic mixer designed in the application can provide the highest efficient mixing performance.

[0161] Comparison of the overall pressure drop of the microfluidic mixer designed in the application and the microfluidic mixer of Comparative Example 1 at different Reynolds numbers (Re). The results show that as Re increases, the overall pressure drop of the microfluidic mixer is positively correlated with Re, and the overall pressure drop continuously increases as Re increases. In addition, under different Re conditions, the overall pressure drop of the microfluidic mixer of the application is significantly lower than that of the microfluidic mixer of Comparative Example 1. The results show that the microfluidic mixer of the application has better stability and is not prone to breaking, on the basis of providing efficient mixing function and reducing the amount of mixed fluid.

[0162] The above is only a few embodiments of the application, and does not limit the application in any form. Although the preferred embodiments are disclosed as above, they are not intended to limit the application. Any skilled person in the art can make some changes or modifications to the disclosed technical content without departing from the scope of the technical solution, which are equivalent to equivalent embodiments and belong to the scope of the technical solution.

Claims

1. An enhanced micromixing unit, characterized by The enhanced micro-mixing unit comprises: a mixing chamber for mixing flow-through liquid, which is surrounded by an upper wall, a lower wall and symmetrically arranged side walls, and two ends of the mixing chamber along the flow-through direction of the liquid are a mixing chamber inlet and a mixing chamber outlet respectively; the mixing chamber comprises a flow disturbance structure, which comprises a fan-shaped baffle wall along a fan shape perpendicular to the flow-through direction of the liquid and at least one pair of L-shaped protrusions in an L shape; the fan-shaped baffle wall is a protrusion formed on the upper wall and / or the lower wall of the mixing chamber, and the fan-shaped baffle wall divides the mixing chamber into symmetric first and second flow channels; two ends of the first and second flow channels respectively meet at the mixing chamber inlet and the mixing chamber outlet; the L-shaped protrusion is a protrusion formed on the upper wall and / or the lower wall of the mixing chamber, and each pair of L-shaped protrusions is symmetrically arranged in the first and second flow channels; the L-shaped inflection point of the flow disturbance structure is directed towards the mixing chamber inlet.

2. The enhanced micro-mixing unit of claim 1, wherein, The enhanced micro-mixing unit has one or more of the following characteristics: the width of the mixing chamber inlet is 0.5-2mm, and the depth is 0.5-2mm; the width of the mixing chamber outlet is 0.5-2mm, and the depth is 0.5-2mm; the maximum width of the mixing chamber is 3-6mm, the narrowest width is 0.5-2mm, the depth is 0.5-2mm, and the length is 8-10mm; the height of the fan-shaped baffle wall is 0.5-2mm, the radius of the arc surface of the fan-shaped baffle wall is 1.9-2mm, the angle of the arc surface of the fan-shaped baffle wall is 100-140°, and the angular arc of the fan-shaped baffle wall is 40-80°; the arc surface of the fan-shaped baffle wall is directed towards the inflow direction of the mixed microfluid, and the vertex is directed towards the outflow direction of the mixed microfluid; the distance between each pair of L-shaped protrusions is 0.2-0.4mm, the width of the L-shaped protrusion is 0.1-0.2mm, the height is 0.5-1mm, the length of the long side of the L-shaped protrusion is 1.6-1.8mm, and the length of the short side is 0.5-0.7mm.

3. The enhanced micro-mixing unit of claim 1, wherein, The flow disturbance structure comprises 1-3 pairs of L-shaped structures.

4. The enhanced micro-mixing unit of claim 3, wherein, The flow disturbance structure comprises a first pair of L-shaped structures arranged between the mixing chamber inlet and the fan-shaped baffle wall and / or a second pair of L-shaped structures arranged between the mixing chamber outlet and the fan-shaped baffle wall; the short sides of the two L-shaped structures of the first pair of L-shaped structures are oppositely arranged, the included angle between the short side and the length direction of the mixing chamber is 40-50°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber inlet is 0.4-0.6mm; the long sides of the two L-shaped structures of the second pair of L-shaped structures are oppositely arranged, the included angle between the long side and the length direction of the mixing chamber is 50-60°, and the vertical distance between the L-shaped inflection point and the end surface of the mixing chamber outlet is 3-4mm.

5. The enhanced micro mixing unit of claim 1, wherein, The vertical distance between the end surface of the side of the fan-shaped baffle wall close to the mixing chamber inlet and the mixing chamber inlet is 2-3mm.

6. The enhanced micro mixing element of claim 1, wherein, The side wall of the mixing chamber is an arc-shaped side wall, and the width of the mixing chamber is greater than the width of the mixing chamber inlet and the mixing chamber outlet; the mixing chamber is an oval-shaped part along the vertical direction of the flow-through direction of the liquid, and the oval-shaped part is a shape obtained by symmetrically removing two end parts along the long axis direction of the oval shape; The long axis of the ellipse is 10-15 mm, and the short axis is 3-6 mm.

7. A microfluidic mixer characterized by, The microfluidic mixer comprises: an inlet flow channel, at least one contraction-expansion mixing flow channel, and an outlet flow channel arranged in series; the inlet flow channel comprises a collection flow channel, and at least two feeding flow channels are arranged at the inlet end of the collection flow channel; the contraction-expansion mixing flow channel comprises one enhanced micro-mixing unit or at least two enhanced micro-mixing units arranged in series; the enhanced micro-mixing unit is selected from the enhanced micro-mixing unit according to any one of claims 1 to 6.

8. The microfluidic mixer of claim 7, wherein, The microfluidic mixer has one or more of the following characteristics: the width of the collection flow channel is 0.5-2 mm, the length is 5-11 mm, and the depth is 0.5-2 mm; the width of each of the at least two feeding flow channels is independently 0.5-2 mm, the length is independently 5-10 mm, and the depth is independently 0.5-2 mm; the width of the outlet flow channel is 0.5-2 mm, the length is 5-20 mm, and the depth is 0.5-2 mm.

9. The microfluidic mixer of claim 7, wherein, The contraction-expansion mixing flow channel comprises 10-30 enhanced micro-mixing units arranged in series.

10. The microfluidic mixer of claim 7, wherein, The microfluidic mixer comprises: an inlet flow channel, at least two contraction-expansion mixing flow channels, and an outlet flow channel arranged in series; the adjacent contraction-expansion mixing flow channels are connected through a turning flow channel; the width of the turning flow channel is 0.5-2 mm, the length is 5-20 mm, and the depth is 0.5-2 mm.

Images