Microfluidic chip and microfluidic device

Abstract

This invention provides a microfluidic chip and a microfluidic device, wherein the microchannel includes at least two input channels, a mixing channel, and an output channel. The at least two input channels converge at the inlet of the mixing channel, and the outlet of the mixing channel connects to the output channel. The mixing channel has a widened region connected to the inlet. Of the first and second sidewalls on either side of the widened region, the first sidewall faces the inlet, and the second sidewall extends downstream from the inlet, gradually moving away from the first sidewall to form the widened region. Therefore, this embodiment, through its improved mixing channel, can achieve high mixing efficiency while reducing or even eliminating microchannel clogging problems, thus improving preparation efficiency and continuity.

Description

Technical Field

[0001] This invention relates to the field of microfluidics, and more particularly to a microfluidic chip and a microfluidic device. Background Technology

[0002] Microfluidics is a fluid manipulation technology based on microfabrication processes. It enables fluid transport, mixing, reaction, separation, or detection within microchannels at the micrometer or nanometer scale, and is widely used in fields such as chemical synthesis, biomedical detection, energy catalysis, and new material preparation. This technology can miniaturize traditional laboratory reactions and synthesis operations into microfluidic chips, achieving miniaturized, automated, and controllable experimental environments.

[0003] In the preparation of target products such as micron and nanomaterials, microfluidic chips have become an important means of preparing high-quality materials due to their advantages such as uniform reaction, thorough mixing, and precise parameter control. Existing microfluidic chips generally include multiple input channels, mixing channels, and output channels. Fluids of different chemical materials enter the fluid processing channels through the input channels and react to generate the target product.

[0004] However, in related technologies, due to the chemical properties of certain components or formulations, substances may precipitate and accumulate during the preparation process, resulting in microchannel blockage. This may lead to the failure of the microchannel system and affect the product preparation efficiency.

[0005] Therefore, how to solve the problem of microchannel blockage is a technical problem that urgently needs to be solved in the field of microfluidic chip design.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] In view of the problems in the prior art, the purpose of this invention is to provide a microfluidic chip and a microfluidic device, which overcomes the difficulties of the prior art and can solve the technical problem of microchannel blockage in related technologies.

[0008] This disclosure provides a microfluidic chip, which includes microchannels;

[0009] The microchannel includes at least two input channels, a mixing channel, and an output channel. The at least two input channels converge into the inlet of the mixing channel, and the outlet of the mixing channel is connected to the output channel.

[0010] The mixing channel has a widened area connected to the feed inlet. Among the first sidewall and the second sidewall on both sides of the widened area, the first sidewall faces the feed inlet, and the second sidewall extends downstream from the feed inlet and gradually away from the first sidewall to form the widened area with the first sidewall.

[0011] Optionally, the first sidewall extends downstream from the first end connected to the feed inlet to the second end, and the second sidewall extends downstream from the third end connected to the feed inlet to the fourth end, so as to form a widening area with the first sidewall.

[0012] The curvature of the second sidewall at the third end is greater than the curvature of the first sidewall at the first end.

[0013] Optionally, the second sidewall includes a body segment and an extension segment;

[0014] The second sidewall extends downstream from the third end connected to the feed inlet to the fourth end through the body section, so as to form a widening area with the first sidewall.

[0015] The extension section extends downstream from the fourth end to the fifth end, along the centerline of the feed inlet, with the fifth end and the feed inlet located on either side of the second end.

[0016] Optionally, the second sidewall transitions seamlessly from the main body section to the extension section, making the second sidewall a concave arc surface.

[0017] Optionally, the fifth end is located on the center line of the feed inlet, or the second end and the first end are located on opposite sides of the center line of the feed inlet, and the fifth end and the second end are located on opposite sides of the center line of the feed inlet.

[0018] Optionally, a first protruding structure is formed at the second end, and a second protruding structure is formed at the fifth end, with the first protruding structure and the second protruding structure forming a vortex channel opposite each other.

[0019] Optionally, the first protruding structure has a first beak portion that bends downstream, and the second protruding structure has a second beak portion that bends upstream, with the first beak portion and the second beak portion forming a vortex channel.

[0020] Optionally, the first sidewall and the body section at least partially overlap in a direction perpendicular to the centerline of the feed inlet.

[0021] Optionally, the first sidewall is formed with a concave structure facing the feed inlet along the centerline direction of the feed inlet.

[0022] Optionally, the depth of the mixing channel is greater than the depth of the input channel.

[0023] Optionally, the bottom of the feed inlet is a ramp that slopes downward from the bottom of the input channel toward the bottom of the mixing channel.

[0024] Optionally, the mixing channel includes at least two widening zones, with adjacent widening zones connected end to end, wherein the first sidewall of the upstream widening zone is connected to the second sidewall of the downstream widening zone, and the second sidewall of the upstream widening zone is connected to the first sidewall of the downstream widening zone.

[0025] A second aspect of this disclosure provides a microfluidic device comprising a microfluidic chip according to any of the above embodiments and a pump connected to each input channel. The pump is used to pump chemical materials into the corresponding input channels, so that different chemical materials in at least two input channels are mixed in a mixing channel to obtain a target product.

[0026] Optionally, the pump is a peristaltic pump.

[0027] The microfluidic chip and microfluidic device proposed in this disclosure have the following advantages:

[0028] The second sidewall extends downstream from the feed inlet, gradually moving away from the first sidewall to form a widening zone. This creates a gradually widening structure in the mixing channel at the feed inlet, causing the cross-sectional width of the mixing channel to gradually change along the flow direction of the chemical materials, forming an asymmetric widening channel. During the preparation process, the chemical materials enter the mixing channel from the feed inlet, i.e., from the relatively narrow feed inlet into the widening zone. Compared to traditional microchannel structures, because the second sidewall is gradually separated from the first sidewall, the flow path of the chemical materials in the widening zone is smoother, avoiding the backflow dead zone that is easily formed in symmetrical widening structures, effectively reducing and solving the clogging problem of microchannels, and improving preparation efficiency. At the same time, this asymmetric extension design causes the chemical materials to impact the first sidewall, forming a lateral secondary flow towards the second sidewall. The gradual extension of the second sidewall induces eddies and shear effects, significantly enhancing the perturbation effect at the interface between chemical materials, promoting efficient mixing, reaction, or particle formation of multiple chemical materials, thereby improving the preparation efficiency and product quality of the target product.

[0029] Therefore, this embodiment, through its improved mixing channel, can achieve high mixing efficiency while reducing or even eliminating the clogging problem of microchannels, thereby improving preparation efficiency and continuity. It is suitable for various applications such as chemical reactions, bioanalysis, and drug synthesis.

[0030] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0031] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0032] Figure 1 A perspective view of a microfluidic chip provided by an embodiment of this disclosure is shown;

[0033] Figure 2 exhibit Figure 1 The front view of the microfluidic chip shown;

[0034] Figure 3 for Figure 1 A magnified schematic diagram of region S1 in the microfluidic chip shown.

[0035] Figure 4 for Figure 2 A magnified schematic diagram of region S2 in the microfluidic chip shown;

[0036] Figure 5 This illustration shows an architecture diagram of a microfluidic device provided by an embodiment of the present disclosure. Detailed Implementation

[0037] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0038] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore, repeated descriptions of them will be omitted.

[0039] In related technologies, microchannels use smaller channel cross-sections to make chemical materials mix more thoroughly. However, excessively small channel cross-sections can exacerbate microchannel blockage and cause the microfluidic system to fail prematurely. At the same time, smaller channel cross-sections can easily lead to increased fluid resistance and a sudden increase in pressure, which places higher demands on equipment hardware and greatly increases the difficulty and cost of scale-up production.

[0040] To address these issues, related technologies have attempted to widen the mixing channels. However, while simply widening the channels may alleviate fluid blockage, it can also lead to insufficient mixing of chemical materials, resulting in poor quality of the final product.

[0041] This disclosure proposes an improved microfluidic chip designed to solve the problem of chemical material or product blockage in microchannels, while also taking into account the mixing efficiency of chemical materials in microchannels.

[0042] Figure 1 A perspective view of a microfluidic chip provided by an embodiment of this disclosure is shown. Figure 2 for Figure 1 The front view of the microfluidic chip shown is for reference. Figure 1 and Figure 2The microfluidic chip provided in this embodiment includes a microchannel 10, which includes at least two input channels 11, a mixing channel 12 and an output channel 13. The at least two input channels 11 converge into the inlet A1 of the mixing channel 12, and the outlet A2 of the mixing channel 12 is connected to the output channel 13.

[0043] Figure 3 for Figure 1 An enlarged view of region S1 shown. Figure 4 for Figure 2 An enlarged view of region S2 is shown below. Figure 3 and Figure 4 As shown, the mixing channel 12 has a widening region 120 connected to the feed inlet A1. Among the first sidewall 121 and the second sidewall 122 on both sides of the widening region 120, the first sidewall 121 faces the feed inlet A1, and the second sidewall 122 extends downstream from the feed inlet A1 and gradually moves away from the first sidewall 121 to form the widening region 120 with the first sidewall 121. This results in the mixing channel 12 forming a gradually widening structure at the feed inlet A1. This structure causes the cross-sectional width of the mixing channel 12 to gradually change along the flow direction of the chemical material, forming an asymmetrical widening channel.

[0044] During the preparation process, fluid chemical materials enter the mixing channel 12 through the feed inlet A1, that is, from the relatively narrow feed inlet A1 into the widened region 120. Compared with the traditional microfluidic chip mixing structure, this asymmetric expansion design causes the chemical materials to impact the first sidewall 121, forming a lateral secondary flow towards the second sidewall 122. The asymmetric extension of the second sidewall 122 induces eddies and shear effects, significantly enhancing the perturbation effect at the interface between chemical materials. This promotes the efficient mixing, reaction, or particle formation of various chemical materials, thereby improving the preparation efficiency and product quality of the target product.

[0045] Meanwhile, since the second sidewall 122 is arranged gradually away from the first sidewall 121, the flow path of chemical materials in the widened area 120 is smoother, avoiding the backflow dead zone that is easily formed in the symmetrical widened structure, effectively reducing the clogging problem of the microchannel 10 and improving the mixing efficiency.

[0046] Therefore, this embodiment, through the improved mixing channel 12, can reduce or even eliminate the clogging problem of the microchannel while achieving high mixing efficiency, thereby improving preparation efficiency and continuity, and is suitable for various applications such as chemical reactions, biological analysis and drug synthesis.

[0047] The microfluidic chip of this embodiment is suitable for various applications such as chemical reactions, biological analysis, and drug synthesis. The chemical materials can be in the form of gases and / or liquids, and are applicable to mixed scenarios including, but not limited to, low-viscosity solutions, high-viscosity solutions, and suspensions containing particles.

[0048] In this embodiment, the microfluidic chip can be formed by bonding PDMS (polydimethylsiloxane) to a glass substrate, or by using SU-8 photolithography mold combined with thermoforming technology to form a precise sidewall profile. The input channel 11, mixing channel 12, and output channel 13 can be integrally micro-etched within the microfluidic chip body and connected to an external sample injection system via through-holes.

[0049] In this disclosure, such as Figure 3 and Figure 4 As shown, the first sidewall 121 and the second sidewall 122 extend downstream from the feed inlet A1 to jointly define the widened area 120.

[0050] Specifically, the first sidewall 121 extends from the first end 2a connected to the feed inlet A1 to the second end 2b, and the second sidewall 122 extends from the third end 2c connected to the feed inlet A1 to the fourth end 2d. The first sidewall 121 and / or the second sidewall 122 form an angle at the feed inlet A1, so that the width of the mixing channel 12 gradually increases in the downstream direction.

[0051] The curvature of the second sidewall 122 at the third end 2c is greater than that of the first sidewall 121 at the first end 2a. This results in a more abrupt curvature of the second sidewall 122 near the feed inlet A1, introducing asymmetric flow disturbances in the initial stage of the chemical material entering the mixing channel 12. This promotes stronger shear forces and eddy current disturbances in the widened region 120. In other words, the second sidewall 122 near the feed inlet A1 exhibits a more pronounced arc-shaped expansion, while the first sidewall 121 is relatively gentle. This difference in curvature causes the two streams of chemical material entering the mixing channel 12 to generate different shear rates and pressure distributions in the flow field, thus forming a controllable lateral velocity component. This helps to disrupt the laminar interface between the two fluids, improve mixing efficiency, and reduce the risk of chemical material or product accumulation on the channel wall.

[0052] In one implementation, such as Figure 4 As shown, the first sidewall 121 has a concave structure 20 facing the inlet A1 along the centerline L direction. In this way, the chemical material entering from the input channel 11 directly impacts the concave structure 20, generating enhanced lateral secondary flow and eddy current disturbance. Specifically, the concave structure 20 guides the fluid to generate a rotating flow, further stretching and folding the fluid interface. Compared to flat or convex sidewalls, this significantly enhances the mixing efficiency between chemical materials, making it particularly suitable for processing high-viscosity materials or suspensions containing particles.

[0053] In addition, the concave structure 20 combined with the asymmetric extension of the second sidewall 122 enhances the asymmetric flow field of the widened region 120, prolongs the vortex residence time, and reduces the risk of flow channel blockage.

[0054] Optionally, the concave structure 20 may be an arc-shaped concave surface or other irregular concave surfaces.

[0055] In alternative implementations, such as Figure 3 and Figure 4 As shown, the second sidewall 122 includes a body section 1221 and an extension section 1222. The second sidewall 122 extends downstream from the third end 2c connected to the feed port A1 through the body section 1221 to the fourth end 2d, and together with the first sidewall 121, defines the widening region 120.

[0056] Extension 1222 continues downstream from the fourth end 2d to the fifth end 2e. Along the centerline L1 of the feed inlet A1 ( Figure 3 (Not shown) When viewed from the direction of the fifth end 2e and the feed inlet A1 are located on both sides of the second end 2b, that is, the second sidewall 122 continues to extend downstream after the widening area 120, thus expanding the function of the second sidewall 122.

[0057] In the above embodiment, the main body section 1221 maintains the initial asymptotic expansion of the widening region 120 to guide the chemical material to initially form a transverse secondary flow. The further extension of the extension section 1222 to the fifth end 2e enhances the asymmetric disturbance of the downstream flow field, prolongs the eddy residence time, and promotes the continuous processing of the chemical material. This design allows the chemical material to maintain a certain transverse flow tendency after passing through the widening region 120, preventing the fluid from re-layering due to channel symmetry after mixing. The extension section 1222 can be considered a kind of "inertial extension region," which improves the continuity and stability of mixing by extending the effective distance of the chemical material disturbance.

[0058] Optionally, by combining the curvature design above, the overall asymmetry of the widened region 120 is ensured, further optimizing the disturbance effect at the interface between chemical materials, making it suitable for high-viscosity materials or suspensions containing particles.

[0059] In this disclosure, such as Figure 4 As shown, the transition of the second sidewall 122 from the main body segment 1221 to the extension segment 1222 is a non-discontinuous structure, that is, there are no broken lines or abrupt changes at the junction of the two segments, forming a continuous and smooth curved surface transition. Optionally, the curvature change of this transition region is continuous and differentiable, so that the second sidewall 122 as a whole has an inwardly concave arc surface shape.

[0060] This concave arc surface can be achieved through grayscale photolithography or two-step PDMS replication. Its geometric features cause the chemical material to form curved streamlines along the wall direction when flowing near the second sidewall 122, further exacerbating the flow field asymmetry. Through this uninterrupted arc surface transition, the energy loss of local eddies can be effectively reduced, the formation position of the turbulence zone can be stabilized, and thus more controllable mixing performance can be obtained.

[0061] Optionally, the transition from the main body segment to the extension segment can also be an intermittent structure. Optionally, the second sidewall can also be a non-concave arcuate shape, such as consisting of multiple square wall surfaces connected end to end; this embodiment does not limit its shape.

[0062] In alternative implementations, such as Figure 4 As shown, the extension 1222 of the second sidewall 122 terminates at the fifth end 2e. Under different design conditions, the position of the fifth end 2e can have two forms:

[0063] In one form, the fifth end 2e is located on the center line L of the feed inlet A1, that is, the end of the extension 1222 is aligned with the mainstream direction of the chemical material, in order to obtain symmetrical disturbance and balanced eddy current distribution.

[0064] In another configuration, the second end 2b and the first end 2a are located on opposite sides of the centerline L of the inlet A1, and the fifth end 2e and the second end 2b are located on opposite sides of the centerline L of the inlet A1. In other words, after passing through the widened area 120 formed by the body section 1221, the extension section 1222 of the second sidewall 122 continues to extend downstream in an arc shape, and the fifth end 2e and the second end 2b are distributed on opposite sides of the centerline L of the inlet A1 in a staggered manner.

[0065] The aforementioned structure characterizes the spatial offset of the extension section 1222: the extension section 1222 not only extends along the mainstream fluid direction (downstream), but also crosses the centerline L of the inlet A1 laterally, achieving a "contralateral outward extension" of the flow channel morphology. Through this arc-shaped staggered layout, the second sidewall 122 forms an asymmetric guiding interface in the flow field, allowing the mainstream fluid from the inlet A1 to be further guided to the other side of the centerline L after passing through the widening zone 120, inducing a stable lateral circulation structure. This allows the mixing range of the chemical materials to continue to expand downstream, strengthening the interface re-stratification and entrainment effect, thereby further improving the mixing effect.

[0066] In this disclosure, such as Figure 3 and Figure 4 As shown, a first protruding structure 31 is formed at the second end 2b, and a second protruding structure 32 is formed at the fifth end 2e. The first protruding structure 31 and the second protruding structure 32 are arranged opposite to each other and together define a local vortex channel S.

[0067] In this embodiment, the relative distribution of the first protruding structure 31 and the second protruding structure 32 restricts and stabilizes the main vortex generated by the chemical material after passing through the widened region 120 in the downstream region, thereby forming a local circulation region. This vortex channel S, by limiting the rotation path of the chemical material in the local space, prolongs the residence time of the reactants in the mixing channel 12, allowing the material to be repeatedly entrained and redistributed at the microscale, significantly improving mixing uniformity and chemical reaction conversion rate.

[0068] This structure can also reduce the peak flow velocity in the mainstream region, mitigate shear instability caused by uneven flow velocity, and maintain stable flow characteristics in the channel even under high flow rate operation. It is suitable for processing particulate materials, such as the preparation of lipid nanoparticles.

[0069] In this disclosure, such as Figure 3 and Figure 4 As shown, the first protruding structure 31 may have a first beak portion 31a that bends downstream, and the second protruding structure 32 may have a second beak portion 32a that bends upstream. The spacing and bending direction of the vortex channels S formed by the first beak portion 31a and the second beak portion 32a together determine the intensity and shape of the local vortex.

[0070] When the chemical material enters the region from the widened region 120, it is guided by the first beak section 31a and the second beak section 32a, forming a distinct shear layer and a reflux nucleus between the two beak sections. This structure, by forming a local circulating flow channel, further extends the mixing path and residence time of the material, allowing the vortex to maintain a high energy density in the downstream region, thereby enhancing the turbulent mixing effect.

[0071] By designing the bending angle and protruding length of the first beak portion 31a and the second beak portion 32a, controllable disturbance of the flow field can be achieved for different fluid systems, which is suitable for multiphase mixing, high viscosity liquids or application scenarios where the reaction rate is limited by interface diffusion.

[0072] In alternative implementations, such as Figure 4 As shown, the first sidewall 121 and the body segment 1221 at least partially overlap in a direction perpendicular to the centerline L of the feed inlet A1. Specifically, the first sidewall 121 extends downstream from the first end 2a connected to the feed inlet A1 and also has a lateral extension in a direction perpendicular to the centerline L of the feed inlet A1, such that the first sidewall 121 at least partially overlaps with the feed inlet A1 and the body segment 1221 of the second sidewall 122 in this direction, with the first end 2a and the second end 2b located on both sides of the centerline L of the feed inlet A1.

[0073] The aforementioned overlapping design not only ensures that the first sidewall 121 faces the inlet A1 to guide the chemical material to impact and form a transverse secondary flow, but also further constrains the fluid path by overlapping with the body section 1221, enhancing local shear force and eddy current disturbance. The overlapping area between the first sidewall 121 and the body section 1221 causes the chemical material to experience a more complex asymmetric flow field within the widened region 120, prolonging the time for fluid interface stretching and folding, thereby improving mixing efficiency and reducing the risk of material accumulation.

[0074] In one implementation, such as Figure 3 As shown, in the microfluidic chip, the depth of the mixing channel 12 is greater than the depth of the input channel 11. By increasing the depth of the mixing channel 12, the overall volume of the mixing channel 12 can be significantly increased, allowing the chemical material to have a longer residence path and a larger flow space within the mixing channel 12. This increases the residence time of the chemical material within the mixing channel 12, thereby enhancing the lateral diffusion and longitudinal convection intensity of the chemical material and improving the mixing effect. In other words, this depth difference design not only creates abrupt changes in the local velocity and pressure fields but also improves the overall capacity for chemical material mixing and energy dissipation efficiency through the increase in spatial volume.

[0075] In addition, the aforementioned enhanced design reduces fluid resistance by increasing the cross-sectional area of ​​the flow channel, thereby reducing the risk of chemical material accumulation and blockage, making it suitable for continuous production applications, such as nanoparticle preparation.

[0076] Optionally, a feed inlet A1 is provided between the input channel 11 and the mixing channel 12. At the bottom of the feed inlet A1 is a ramp 30, which extends downwards from the input channel 11 toward the bottom of the mixing channel 12. The ramp 30 extends downwards along the flow direction from the bottom of the input channel 11 to the bottom of the mixing channel 12.

[0077] The ramp 30 allows the chemical material to undergo a smooth depth transition before entering the mixing channel 12, which avoids local backflow or bubble accumulation caused by abrupt structural changes, and also creates a velocity gradient that is conducive to disturbance when entering the mixing channel 12.

[0078] Furthermore, the ramp 30 smoothly connects the bottom of the input channel 11 and the mixing channel 12 at the feed inlet A1 position. Combined with the deepening design of the mixing channel 12, it eliminates dead corners that may be formed due to abrupt changes in depth, effectively solving the problem of accumulation or retention of chemical materials at the turning point. It is particularly suitable for scenarios containing particulate suspensions or high-viscosity materials.

[0079] Compared to the shallow structure of the input channel 11, the deeper design of the mixing channel 12 in the longitudinal direction can create a "volume expansion and suction" effect at the feed inlet A1. That is, the chemical material is accelerated and submerged due to the sinking of the bottom of the channel, thereby generating shear stratification and vortices between different laminar flows. Combined with the guiding effect of the bottom slope 30, the fluid entering the mixing channel 12 is disturbed in both the longitudinal and horizontal directions, thereby promoting the spatial cross-linking and mixing of multiphase fluids or component liquids.

[0080] The above design ensures that fluids of different components are rapidly stretched, dispersed and mixed at multiple scales after entering the mixing channel 12, making the mixing process more uniform and controllable, especially suitable for complex fluid systems containing high-viscosity liquids or particulate suspensions.

[0081] In this disclosure, such as Figure 3 and Figure 4 As shown, the mixing channel 12 includes at least two widening zones 120 (two widening zones are shown in the figure, namely 120a and 120b), with adjacent widening zones 120 connected end-to-end along the fluid flow direction. Each widening zone 120 is defined by a corresponding first sidewall 121 and a second sidewall 122, wherein the first sidewall 121 of the upstream widening zone 120a is connected to the second sidewall 122 of the downstream widening zone 120b at its downstream end; simultaneously, the second sidewall 122 of the upstream widening zone 120a is connected to the first sidewall 121 of the downstream widening zone 120b at its downstream end. This forms an "interlaced" sidewall connection structure, causing adjacent widening zones 120 to alternate in the sidewall direction.

[0082] Specifically, in this embodiment, the connecting region between the upstream widening region 120a and the downstream widening region 120b can be considered as a transition neck. The width of this neck region is smaller than the maximum width of the two adjacent widening regions 120, so that the fluid generates a local contraction effect when flowing through the neck. As the fluid enters the next widening region 120, the cross-sectional area increases again, forming a continuous "contraction-expansion" flow pattern. Through this periodic geometric perturbation, transverse shear, secondary flow, and local vortices can be periodically induced within the fluid, thereby significantly improving the mixing intensity.

[0083] In another alternative embodiment, two adjacent widening zones (120a, 120b) are arranged in a mirror image in planar shape, that is, the first sidewall 121 of the upstream widening zone 120a corresponds to the second sidewall 122 of the downstream widening zone 120b, and the second sidewall 122 of the upstream widening zone 120a corresponds to the first sidewall 121 of the downstream widening zone 120b. This mirrored connection allows the fluid to alternately deflect its flow direction when flowing through different widening zones 120, causing the main flow line to continuously bend and cross, enhancing the breaking and re-coiling effect of the fluid interface.

[0084] Furthermore, by setting multiple widening zones 120 (e.g., two-stage, three-stage, or multi-stage structures), the overall flow channel length and mixing energy distribution can be flexibly adjusted according to different mixing requirements. For example, the first-stage widening zone at the inlet A1 can be mainly used to break the inlet laminar interface, enabling the two fluids to achieve initial entrainment; subsequent widening zones can achieve deep remixing and flow field re-disturbance through staggered sidewall layouts and different curvature designs, thereby obtaining higher mixing uniformity.

[0085] In terms of effectiveness, the multi-level widening region structure can form more complex flow paths within a limited chip size compared to the single-level structure, enabling the fluid to generate multi-scale disturbances and vortex superposition in space. It is particularly suitable for scenarios such as reaction control, chemical synthesis or biochemical detection where high mixing uniformity is required.

[0086] This disclosure also provides a microfluidic device. Figure 5 The diagram illustrates the architecture of the microfluidic device, which includes a microfluidic chip 100 and a pump 200. The microfluidic chip 100 can be any of the microfluidic chips described in the above embodiments. Figure 5 The module structure is used to represent this, and the specific structure can be referred to the above implementation method, which will not be described in detail here.

[0087] In this process, each pump 200 corresponds one-to-one with an input channel 11 in the microfluidic chip 100. Each pump 200 is used to pump chemical materials into the corresponding input channel 11, so that different chemical materials in at least two input channels 11 are mixed in the mixing channel 12 to obtain the target product.

[0088] Based on the mixing channel design in the microfluidic chip 100, the microfluidic device can achieve chemical material mixing while reducing channel blockage, improving preparation efficiency and the quality of the target product.

[0089] In one embodiment, pump 200 can be a peristaltic pump. Because peristaltic pumps are valveless pumps, the chemical material does not directly contact the pump body, avoiding interaction or contamination between the chemical material and the pump body material. This makes them particularly suitable for highly active chemical reagents, nanoparticle suspensions, and biological agents.

[0090] However, due to the small size of the microchannels, the peristaltic pump output pressure is insufficient, making it prone to clogging of the feed inlet or mixing channel. The widened region design, extended section design, and asymmetric vortex channel structure of the mixing channel in the microfluidic chip provided in this disclosure can disperse local velocity peaks, reduce local pressure concentration and dead zones, effectively avoid clogging, and maintain fluid disturbance and mixing effect.

[0091] Therefore, by using the microfluidic chip in this embodiment, the problem of chemical material blockage is actively solved, allowing the peristaltic pump to stably deliver materials even at low pressure. Thus, this solution achieves the advantages of a peristaltic pump that combines low pump pressure, high stability, and high mixing uniformity.

[0092] Furthermore, by adjusting the pump speed and flow rate of the peristaltic pump, the transverse secondary flow and eddies formed by the chemical materials in the widened and extended sections can be controlled, thereby further improving the mixing uniformity and product quality.

[0093] Therefore, the microfluidic device of this embodiment overcomes the problem of clogging caused by the low pressure output of the peristaltic pump itself by combining microfluidic chip structure optimization with peristaltic pump, and achieves high mixing efficiency, low clogging risk and high stability in the preparation of nanomaterials or chemical materials.

[0094] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A microfluidic chip, characterized in that, Including microchannels; The microchannel includes at least two input channels, a mixing channel, and an output channel. The at least two input channels converge into the inlet of the mixing channel, and the outlet of the mixing channel is connected to the output channel. The mixing channel has a widened area connected to the feed inlet. In the first sidewall and the second sidewall on both sides of the widened area, the first sidewall faces the feed inlet, and the second sidewall extends downstream from the feed inlet and gradually away from the first sidewall to form the widened area with the first sidewall. The first sidewall extends downstream from the first end connected to the feed inlet to the second end, and the second sidewall extends downstream from the third end connected to the feed inlet to the fourth end to form the widened area with the first sidewall, and extends downstream from the fourth end to the fifth end along the centerline direction of the feed inlet, with the fifth end and the feed inlet located on both sides of the second end. The second end has a first protruding structure, and the fifth end has a second protruding structure. The first protruding structure and the second protruding structure form a vortex channel opposite to each other.

2. The microfluidic chip according to claim 1, characterized in that, The curvature of the second sidewall at the third end is greater than the curvature of the first sidewall at the first end.

3. The microfluidic chip according to claim 2, characterized in that, The second sidewall includes a body segment and an extension segment; The second sidewall extends downstream from the third end connected to the feed inlet to the fourth end through the body section to form the widened area with the first sidewall; The extension segment extends downstream from the fourth end to the fifth end.

4. The microfluidic chip according to claim 3, characterized in that, The second sidewall transitions seamlessly from the body segment to the extension segment, resulting in a concave arc surface.

5. The microfluidic chip according to claim 3, characterized in that, The fifth end is located on the center line of the feed inlet, or the second end and the first end are located on opposite sides of the center line of the feed inlet, and the fifth end and the second end are located on opposite sides of the center line of the feed inlet.

6. The microfluidic chip according to claim 5, characterized in that, The first protruding structure has a first beak portion that bends downstream, and the second protruding structure has a second beak portion that bends upstream, the first beak portion and the second beak portion forming the vortex channel.

7. The microfluidic chip according to claim 3, characterized in that, The first sidewall and the body segment at least partially overlap in a direction perpendicular to the centerline of the feed inlet.

8. The microfluidic chip according to claim 1, characterized in that, The first sidewall has a concave structure facing the feed inlet along the centerline direction of the feed inlet.

9. The microfluidic chip according to claim 1, characterized in that, The depth of the mixing channel is greater than the depth of the input channel.

10. The microfluidic chip according to claim 9, characterized in that, The bottom of the feed inlet is a ramp, which extends downwards from the input channel toward the bottom of the mixing channel.

11. The microfluidic chip according to claim 1, characterized in that, The mixing channel includes at least two widening zones, with two adjacent widening zones connected end to end. The first sidewall of the upstream widening zone is connected to the second sidewall of the downstream widening zone, and the second sidewall of the upstream widening zone is connected to the first sidewall of the downstream widening zone.

12. A microfluidic device, characterized in that, The invention includes a microfluidic chip according to any one of claims 1-11 and a pump connected to each of the input channels, the pump being used to pump chemical materials into the corresponding input channels, so that different chemical materials in at least two of the input channels are mixed in the mixing channel to obtain the target product.

13. The microfluidic device according to claim 12, characterized in that, The pump is a peristaltic pump.

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