Snakelike microfluidic mixer integrated with spoilers
By integrating a serpentine microfluidic mixer with turbulence deflectors, the serpentine bends and turbulence components are used to create Dean's vortex and chaotic convection within the microfluidic chip, solving the problem of low mixing efficiency in microfluidic chips and achieving efficient and low-energy fluid mixing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- LUDONG UNIVERSITY
- Filing Date
- 2026-03-19
- Publication Date
- 2026-05-05
AI Technical Summary
At the microfluidic chip scale, fluid mixing efficiency is low, reliance on long-channel molecular diffusion leads to low synthesis efficiency, and existing mixers have high energy consumption.
The system employs a combined structure integrating a serpentine mixing unit and a turbulence component. By creating a centrifugal velocity gradient through the serpentine bend and inducing local vortices through the turbulence component, it achieves stretching and folding of the fluid interface, accumulating mixing effects step by step to generate Dean's vortex and chaotic convection.
It achieves efficient mixing within micron-scale channels, shortens mixing time and channel length, reduces energy consumption, improves synthesis efficiency and integration, and features a compact and easy-to-operate structure.
Smart Images
Figure CN121972058A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of mixer technology, and more particularly to a serpentine microfluidic mixer with integrated baffles. Background Technology
[0002] Microfluidic mixing technology, using microfluidic chips as its core operating platform, is a cutting-edge technology based on the micrometer scale, enabling precise processing and manipulation of fluids within microchannels. This technology often uses microfabrication processes such as microchannels to control the flow and mixing of solutions, thereby efficiently completing various biochemical reactions. Common mixing mechanisms include turbulent motion and molecular diffusion. Turbulent mixing relies on the multi-scale vortex structure within the fluid, achieving rapid and efficient mixing of fluid components through the interaction between vortices. The formation of turbulence typically depends on conditions such as high Reynolds numbers, high energy input, or large gradients. However, when the system scale shrinks to the microfluidic chip level, volume limitations mean that the fluid is mostly in a laminar state, making it difficult to form effective turbulent effects. Therefore, most fluid mixing within microchannels relies on molecular diffusion. However, molecular diffusion requires sufficiently long channels to provide diffusion time, which often necessitates the design of lengthy channel structures in microfluidic chips, thus reducing the system's synthesis efficiency. Summary of the Invention
[0003] In view of this, to address the technical problem of low mixing efficiency at the microscale in existing technologies, this invention provides a serpentine microfluidic mixer with integrated turbulence deflectors. It employs a combined structure integrating serpentine mixing units and turbulence deflectors. Through the centrifugal velocity gradient formed by the serpentine bends, combined with the local vortices induced by the turbulence deflectors, it achieves stretching and folding of the fluid interface, accumulating mixing effects step by step. This results in Dean's vortices and chaotic convection during fluid flow, achieving highly efficient passive mixing without external energy input. It significantly enhances the mixing effect within micrometer-scale channels, greatly reducing mixing time and channel length compared to traditional methods relying on long channel diffusion. It also features a compact structure, simple operation, and no additional energy consumption, effectively improving the synthesis efficiency and integration of microfluidic systems.
[0004] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a serpentine microfluidic mixer with integrated baffles, comprising: Several serpentine mixing units connected in series have a serpentine curved flow channel structure with inlet and outlet channels. Different fluids flow into the confluence channel of the serpentine mixing unit through the inlet channel and merge to initially form parallel laminar flow. A turbulence-disrupting component is disposed at the bend of the serpentine mixing unit; At each bend of the serpentine mixing unit, the fluid is subjected to centrifugal force, which causes the fluid to form a velocity gradient. The turbulence component divides the fluid to generate local vortices. Each serpentine mixing unit repeats the process of fluid velocity gradient formation and vortex disturbance, accumulating the mixing effect step by step, so as to generate Dean's vortex and chaotic convection in the fluid flow process.
[0005] Compared with the prior art, the present invention has the following beneficial effects: High-efficiency mixing performance: The velocity gradient formed by the centrifugal force of the serpentine flow channel, combined with the local vortex induced by the turbulence plate, breaks the laminar flow state at the microscale, enhances the contact area and disturbance degree of the fluid interface, and achieves high-efficiency mixing.
[0006] Passive low-energy design: No external energy input such as sound field or magnetic field is required. It relies solely on the geometry of the flow channel itself to enhance mixing, simplifying the equipment structure and fundamentally avoiding the high energy consumption problem of active mixers.
[0007] Compact and easy to operate: Eliminating the need for complex external drive and control systems, the overall structure of the equipment is compact, the operation process is simplified, the technical requirements for operators are reduced, and it is easier to integrate and use.
[0008] Improved synthesis efficiency: Achieves good mixing effect with shorter channel length and mixing time, solving the problem of low synthesis efficiency caused by traditional microfluidic chips relying on long channel molecular diffusion. Attached Figure Description
[0009] Figure 1 This is an overall structural diagram of the present invention; Figure 2 This is a structural diagram of a serpentine mixer according to the present invention; Figure 3 This is a comparison chart showing the length effects of rectangular spoilers. The horizontal axis represents the number of micro-mixers. 45°, 0.15, and 0.2 represent the angle of the spoiler's central axis, the width of the spoiler, and the length of the spoiler's central axis, respectively. The units for 0.15 and 0.2 are (mm). Figure 4 This is a comparison chart showing the effect of the central axis angle of rectangular spoilers ranging from 0° to 75°. The horizontal axis represents the number of micro-mixers, where 0°~75° represents the angle of the central axis of the spoiler, and 0.15 represents the width of the spoiler, in mm. Figure 5This is a comparison chart showing the width effects of rectangular spoilers. The horizontal axis represents the number of micro-mixers. 45°, 0.15, and 0.2 represent the angle, width, and length of the spoiler's central axis, respectively. 45°, 0.05, and 0.2 represent the angle, width, and length of the spoiler's central axis, respectively. 45°, 0.08, and 0.2 represent the angle, width, and length of the spoiler's central axis, respectively. The units for 0.05, 0.08, 0.15, and 0.2 are (mm). In the diagram, 1 is the inlet channel; 2 is the confluence channel; 3 is the serpentine mixer; 4 is the mixing channel; 5 is the outlet channel; and 6 is the turbulence assemblies. Detailed Implementation
[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0011] This invention provides a serpentine microfluidic mixer with integrated baffles, comprising: Several serpentine mixing units connected in series have a serpentine curved flow channel structure, with an inlet channel 1 and an outlet channel 5. Different fluids flow into the confluence channel 2 of the serpentine mixing unit through independent inlet channels 1 and converge to initially form parallel laminar flow.
[0012] The flow-deflecting component 6 is located at the bend of the serpentine mixing unit. The simple serpentine mixing unit combined with the flow-deflecting component 6 forms an open flow channel structure.
[0013] The merged fluids enter the serpentine microfluidic mixer. At the bend of each stage of the serpentine mixing unit, the fluids are subjected to centrifugal force, accelerating along the outer wall and relatively slowing down on the inner side, thus creating a velocity gradient. The turbulence component 6 divides the fluid to generate local vortices, enhancing the stretching and folding of the fluid interface. Each stage of the serpentine mixing unit repeats the process of fluid velocity gradient formation and vortex disturbance, accumulating the mixing effect step by step. Finally, the uniformly mixed fluid is transported to the outlet through the outlet channel 5, realizing the generation of Dean's vortex and chaotic convection during the flow process.
[0014] like Figure 1-2 As shown, the present invention provides an exemplary embodiment of a serpentine microfluidic mixer with integrated baffles. The serpentine microfluidic mixer includes: an inlet, an inlet channel 1, a confluence channel 2, a serpentine mixing unit, baffles, and an outlet channel 5.
[0015] The serpentine mixing unit contains nine serpentine mixers 3, each serpentine mixer 3 having an inlet, an outlet and two turbulence components 6, with adjacent turbulence components 6 being staggered left and right.
[0016] The flow-disrupting component 6 is preferably a rectangular flow-disrupting plate. The tilt angle of the central axis of the rectangular flow-disrupting plate is preferably 45°. The length of the central axis is 200 μm, and the width of the rectangular flow-disrupting plate is 150 μm. Precise structural parameters optimize the flow-disrupting effect and maximize the stretching and folding of the fluid interface. The micron-level size is adapted to the scale of microfluidic systems, achieving efficient flow-disrupting within a limited space and avoiding the risk of flow channel blockage.
[0017] The turbulence-inducing component 6 is located inside the bend of the channel. When the solution bends, it is blocked by the turbulence-inducing plate and forms convection due to the centrifugal force of the bend. Due to the pressure difference change within the bend, local vortices are formed. Several serpentine mixing units are interconnected and linearly arranged. The fluid passes through each stage of the unit sequentially, repeatedly experiencing the formation of centrifugal velocity gradients and turbulence-inducing vortex disturbances, gradually improving the mixing uniformity. The linear arrangement ensures the continuity and stability of the fluid flow path and reduces flow resistance; the step-by-step cumulative mixing process allows for flexible adjustment of the number of units to adapt to different mixing accuracy requirements.
[0018] The bends in the serpentine mixing unit's flow channel cause abrupt changes in fluid direction. Fluid that originally flowed along the mixing channel 4 was forced to collide with the concave wall and then flow back along the convex wall. This collision and reversal directly disrupted the initial distribution of the fluid layer. The turbulence component 6 creates a local low-pressure zone behind it, attracting fluids from both sides to converge and collide towards the center, further refining the fluid interface. The change in flow channel width generates a lateral velocity gradient, causing relative motion between fluids in different regions, thus creating shear collisions at the interface and accelerating the fusion of the two fluids.
[0019] In this invention, the inlet channel 1 is T-shaped, with a first inlet and a second inlet. Different fluids enter through the first and second inlets and then converge into the confluence channel 2. The inlet channel 1 delivers different fluids through two independent inlets, allowing the fluids to flow in parallel within the confluence channel 2, forming a stable parallel laminar flow state. This lays the foundation for efficient mixing in the mixing channel 4 of the subsequent serpentine mixing unit. This achieves precise separation and initial merging of the two fluids, avoiding uneven reactions caused by premature mixing. The T-shaped structure simplifies fluid input control, reduces operational complexity, and facilitates integration into an automated delivery system.
[0020] For example, the first inlet can be used to deliver a nucleic acid mixture suspension, and the second inlet can be used to deliver a liposome encapsulation solution. Both the confluence channel 2 and the outlet channel 5 are straight structures and are arranged coaxially. This ensures the stability of the fluid flow before entering the serpentine mixing unit and after mixing, reducing additional resistance and flow loss caused by abrupt changes in flow direction. The coaxial straight structure reduces fluid flow resistance, reduces energy loss, and improves overall flow efficiency; the stable flow state avoids interference from fluid disturbances on the mixing effect, ensuring the consistency and repeatability of the mixing process.
[0021] The dimensions of the confluence channel 2, inlet channel 1, outlet channel 5, turbulence-inducing component 6, and serpentine mixing unit are all in the micrometer range. During operation, different fluids flow into the confluence channel 2 through the inlet channel 1 for initial confluence, and then enter the serpentine mixing unit. Within the serpentine mixing unit, the fluids rotate and flow along the sidewalls in the turning channels, and are subject to velocity and flow rate differences caused by the turbulence-inducing components. Since the channel width is not uniform throughout, the fluids collide during the confluence process, thus achieving efficient mixing. This process is repeated in the continuously connected serpentine mixers 3, and the finally mixed fluid is transported to the outlet through the outlet channel 5. This invention, through the above structure, achieves excellent mixing results in a shorter channel length and mixing time, significantly improving synthesis efficiency.
[0022] The technical solution provided by this invention, through its unique serpentine curved flow channel structure, induces Dean's vortex and chaotic convection during fluid flow, effectively breaking the laminar flow state at the microscale and significantly enhancing the contact area and disturbance degree between fluid interfaces, thereby achieving highly efficient mixing performance. Because it adopts a passive working mechanism, relying entirely on the geometric structure of the flow channel itself to enhance mixing, it requires no external energy input such as sound fields or magnetic fields. This not only simplifies the equipment configuration but also fundamentally avoids the high energy consumption problem commonly found in active mixers. Furthermore, eliminating the complex external drive and control system makes the overall equipment structure compact, greatly simplifies the operation process, reduces the technical requirements for operators, and facilitates integration and use.
[0023] To ensure the optimal technical effect of this invention, the parameters of the rectangular spoiler have been screened and verified, such as... Figure 3 As shown, the mixing efficiency is best when the length of the central axis of the turbulence component 6 is 200 μm, because the increase in length causes the change in pressure difference within the flow channel to form local eddies. Figure 4 As shown, the mixing efficiency is good when the angle of the central axis of the turbulence component 6 is 45° in the range of 0° to 75°, because if the angle is too small or too large, it is impossible to generate vortices and convection in the flow channel. Figure 5 As shown, the mixing efficiency is high when the width of the turbulence component 6 is 0.15, but if the width is too small, sufficient mixing cannot be achieved.
[0024] Compared with the existing serpentine mixer 3, the serpentine mixer 3 of the present invention has significant improvements in mixing efficiency, mixing uniformity, and mixing length. It can achieve thorough mixing of solutions within a shorter mixing distance and effectively reduce flow resistance. The overall mixing performance is significantly better than that of the existing serpentine mixer 3. Through the improvement and optimization of the serpentine channel structure, the technical defects of the existing serpentine mixer 3, such as low mixing efficiency and long mixing path, are overcome, resulting in outstanding technical effects and significant technological progress.
[0025] The above description is merely a preferred embodiment of the present invention. However, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention should be covered within the scope of protection of the present invention.
Claims
1. A serpentine microfluidic mixer with integrated baffles, characterized in that, include: Several serpentine mixing units connected in series have a serpentine curved flow channel structure with inlet and outlet channels. Different fluids flow into the confluence channel of the serpentine mixing unit through the inlet channel and merge to initially form parallel laminar flow. A turbulence-disrupting component is disposed at the bend of the serpentine mixing unit; At each bend of the serpentine mixing unit, the fluid is subjected to centrifugal force, which causes the fluid to form a velocity gradient. The turbulence component divides the fluid to generate local vortices. Each serpentine mixing unit repeats the process of fluid velocity gradient formation and vortex disturbance, accumulating the mixing effect step by step, so as to generate Dean's vortex and chaotic convection in the fluid flow process.
2. The serpentine microfluidic mixer with integrated baffles according to claim 1, characterized in that, The turbulence-disrupting component is a rectangular turbulence-disrupting plate. The tilt angle of the central axis of the rectangular turbulence-disrupting plate is 45°-50°, the length of the central axis of the rectangular turbulence-disrupting plate is 200μm, and the width of the rectangular turbulence-disrupting plate is 150μm.
3. The serpentine microfluidic mixer with integrated baffles according to claim 1, characterized in that, Several of the serpentine hybrid units are arranged linearly.
4. The serpentine microfluidic mixer with integrated baffles according to claim 1, characterized in that, The liquid inlet channel is T-shaped and has a first liquid inlet and a second liquid inlet.
5. The serpentine microfluidic mixer with integrated baffles according to any one of claims 1-4, characterized in that, Both the liquid outlet channel and the confluence channel are linear structures and are arranged coaxially.