A directional fluid transport structure

Abstract

The application discloses a directional fluid transportation structure, belonging to the field of fluid transportation, and can solve the problem that the existing directional fluid transportation structure has poor applicability in the case that the shape of a fluid bearing object is complex or special, and is easy to deform in the bending process, thereby causing fluid transportation failure. The substrate layer of the directional fluid transportation structure is made of a material with good plasticity; the fluid channel layer includes at least two channel walls; the at least two channel walls are made of a material with good plasticity, are arranged at intervals on the substrate layer, and form a micro-fluid channel between the adjacent two channel walls; the channel wall is arranged with an opening recessed from the top surface to the bottom surface along the length direction; and the contact angle of the hydrophilic layer is less than 20°, and the hydrophilic layer is arranged on the surface of the micro-fluid channel. The application can be applied to fluid bearing objects with different shapes through deformation such as bending or stretching, and the micro-fluid channel can always keep unobstructed and have good fluid transportation capacity.

Description

Technical Field

[0001] This application relates to the field of fluid transport technology, and in particular to a directional fluid transport structure. Background Technology

[0002] In recent years, with the continuous development of interface science and technology, directional fluid transport technology has attracted widespread attention. It has excellent application prospects, such as being widely used in heat transfer, condensation, water collection and microfluidic transport, and is expected to achieve even wider applications in the future.

[0003] In the field of heat transfer, directional fluid transport technology enables efficient and rapid heat exchange. By optimizing fluid flow paths and heat transfer efficiency, it can significantly improve the heat transfer performance of equipment, providing new solutions for efficient energy utilization, contributing to solving energy and environmental problems, and providing technical support for the development of green energy. In the field of condensation, efficient directional fluid transport can effectively refresh condensation surfaces, thereby significantly enhancing heat exchange and improving condensation efficiency. In the field of water collection, directional fluid transport technology can effectively collect captured micro-droplets, providing a new approach to solving the global water shortage problem. This allows directional fluid transport technology to be applied to seawater desalination and wastewater treatment, creating safer and purer drinking water resources for humanity. In the field of microfluidic transport, directional fluid transport technology is of great significance for achieving precise control of micro-volume fluids. This gives directional fluid transport technology broad application prospects in real life, such as biomedicine, chemical analysis, and medical diagnostics. For example, through microfluidic transport technology, precise manipulation and analysis of fluids including blood, sweat, and urine can be achieved, opening new avenues for life science research.

[0004] Directional fluid transport technology, driven by the release of fluid surface energy, achieves directional fluid transfer without consuming any external energy, demonstrating low power consumption and high efficiency. However, directional fluid transport structures still face many challenges. Currently, the shapes of fluid-carrying objects in directional fluid transport are more complex, and existing directional fluid transport structures have high rigidity, making them less suitable for complex or irregularly shaped fluid-carrying objects, thus limiting their application areas. Furthermore, existing fluid transport structures are prone to deformation during bending, leading to fluid transport failure. Summary of the Invention

[0005] This application provides a directional fluid transport structure that solves the problem that existing directional fluid transport structures are poorly applicable to situations where the fluid-carrying object has a complex or irregular shape, and are prone to deformation during bending, leading to fluid transport failure.

[0006] To achieve the above objectives, the technical solution of this invention is as follows:

[0007] In a first aspect, embodiments of the present invention provide a directional fluid transport structure, including a substrate layer, a fluid channel layer, and a hydrophilic layer;

[0008] The substrate layer is made of a material with good plasticity;

[0009] The fluid channel layer includes at least two channel walls;

[0010] At least two of the channel walls are made of a material with good plasticity and are spaced apart on the substrate layer, forming a microfluidic channel between two adjacent channel walls;

[0011] The channel wall is provided with an array of openings along its length that are recessed from the top to the bottom.

[0012] The hydrophilic layer has a contact angle of less than 20° and is disposed on the surface of the microfluidic channel.

[0013] In conjunction with the first aspect, in one possible implementation, the substrate layer is one of aluminum, copper, and iron;

[0014] And / or, the channel wall is one of plastic, silicone rubber, aluminum, copper, and iron;

[0015] And / or, the hydrophilic layer is one or a combination of hydrophilic silica, tannic acid and polyvinyl alcohol.

[0016] In conjunction with the first aspect, in one possible implementation, the directional fluid transport structure further includes a transition connection layer;

[0017] The transition connection layer is disposed between the substrate layer and the fluid channel layer and is configured to connect the substrate layer and the fluid channel layer.

[0018] In conjunction with the first aspect, in one possible implementation, the cross-section of the microfluidic channel along the direction perpendicular to the fluid flow includes a first inverted trapezoid, a first inverted triangle, a semicircle, a first shape, and a second shape;

[0019] In the top-down direction, the first shape is a second inverted trapezoid and a rectangle connected in sequence, and the second shape is a third inverted trapezoid and a circle connected in sequence.

[0020] In conjunction with the first aspect, in one possible implementation, each of the microfluidic channels has a similar cross-section perpendicular to the fluid flow direction, and the cross-sectional area remains constant or gradually increases from the first end to the second end.

[0021] In conjunction with the first aspect, in one possible implementation, the shape of the microfluidic channel projected onto the substrate layer is a straight line, a curve, or a mixture of straight lines and curves.

[0022] In conjunction with the first aspect, in one possible implementation, at least two of the microfluidic channels have the same or different depths.

[0023] In conjunction with the first aspect, in one possible implementation, the shape of the opening is a second inverted triangle.

[0024] Secondly, another embodiment of the present invention provides a method for preparing a directional fluid transport structure, used to prepare the above-mentioned directional fluid transport structure, comprising:

[0025] At least two spaced-apart channel walls are fabricated, forming a microfluidic channel between two adjacent channel walls to obtain a fluid channel layer; wherein, the channel walls are made of a material with good plasticity and have openings arranged along the length direction that are recessed from the top to the bottom.

[0026] A hydrophilic layer with a contact angle of less than 20° is formed on the surface of the microfluidic channel;

[0027] The fluid channel layer having the hydrophilic layer is disposed on a substrate layer made of a material with good plasticity.

[0028] In conjunction with the second aspect, in one possible implementation, before depositing the fluid channel layer having the hydrophilic layer on a substrate layer made of a material with good plasticity, the method further includes:

[0029] A transition connection layer is provided on the substrate layer, and the fluid channel layer having the hydrophilic layer is disposed on the transition connection layer.

[0030] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0031] The directional fluid transport structure provided in this application firstly fabricates at least two spaced-apart channel walls, forming a microfluidic channel between adjacent channel walls to obtain a fluid channel layer. The channel walls are made of a material with good plasticity and have openings arranged along their length, recessed from the top to the bottom. A hydrophilic layer with a contact angle of less than 20° is formed on the surface of the microfluidic channel. The fluid channel layer with the hydrophilic layer is then placed on a substrate layer made of a material with good plasticity. For fluid-carrying objects with complex or irregular shapes, the directional fluid transport structure can adapt to different shapes of fluid-carrying objects through deformations such as bending or stretching. The openings in the channel walls can deform and disperse external forces, avoiding unnecessary stress concentration. Furthermore, under the action of the hydrophilic layer, the microfluidic channel maintains its unobstructed flow and excellent fluid transport capacity after deformation, without affecting the normal transport of fluid substances. This increases the adaptability and reliability of the directional fluid transport structure, making its application fields wider. Moreover, the substrate layer is made of a material with good plasticity, which allows the substrate layer to deform. The substrate layer and the fluid channel layer bend and deform synchronously. Under the action of the substrate layer, the deformed fluid channel layer can be guaranteed to maintain its bent shape stably for a long time, thus ensuring stability during use. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 Schematic diagram of the directional fluid transport structure provided in the first embodiment of this application Figure 1 ;

[0034] Figure 2 This is a schematic diagram of a directional fluid transport structure provided in the second embodiment of this application;

[0035] Figure 3 Schematic diagram of the structure of the fluid channel layer provided in the embodiments of this application Figure 1 ;

[0036] Figure 4 Schematic diagram of the structure of the fluid channel layer provided in the embodiments of this application Figure 2 ;

[0037] Figure 5 Schematic diagram of the directional fluid transport structure provided in the first embodiment of this application Figure 2 ;

[0038] Figure 6A physical image of the directional fluid transport structure prepared according to a specific embodiment of this application;

[0039] Figure 7 This is a photograph showing the directional fluid transport structure prepared according to a specific embodiment of this application transporting liquid against gravity and rapidly draining it during the maximum throughput test.

[0040] Icons: 1-Substrate layer; 2-Fluid channel layer; 21-Channel wall; 22-Microfluidic channel; 23-Opening; 3-Transition connection layer. Detailed Implementation

[0041] 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, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0043] Please refer to Figures 1-3 As shown, an embodiment of the present invention provides a directional fluid transport structure, including a substrate layer 1, a fluid channel layer 2, and a hydrophilic layer.

[0044] The substrate layer 1 is made of a material with good plasticity (deformability), so that the substrate layer 1 can be deformed.

[0045] The fluid channel layer 2 includes at least two channel walls 21. Both channel walls 21 are made of a material with good plasticity (deformability) and are spaced apart on the substrate layer 1. Microfluidic channels 22 are formed between adjacent channel walls 21, and the microfluidic channels 22 are trench-shaped. The fluid channel layer 2 and the substrate layer 1 have the same projected outline on the plane.

[0046] The channel wall 21 is arrayed with recessed openings 23 from the top to the bottom along its length. When the fluid-carrying object has a complex or irregular shape, these openings 23 can deform to disperse external forces, avoiding unnecessary stress concentration. Thus, when the directional fluid transport structure adapts to the shape of the fluid-carrying object, the channel wall 21 can adaptively deform, effectively preventing deformation of the microfluidic channel 22 during bending. Therefore, when the directional fluid transport structure is adapted to use fluid-carrying objects with complex or irregular shapes, it ensures that the microfluidic channel 22 maintains its unobstructed flow and excellent fluid transport capacity during bending or stretching, without affecting the normal transport of fluid substances. Based on this deformable characteristic, the shape of the fluid channel can be changed according to the actual application scenario to suit different shapes of fluid-carrying objects, transmission purposes, and transmission lines, resulting in good performance and durability.

[0047] The hydrophilic layer has a contact angle of less than 20° and is disposed on the surface of the microfluidic channel 22 (not shown in the figure). Under the action of the hydrophilic layer, the microfluidic channel 22 can still accommodate fluid substances under bending, stretching and other deformations, and maintain the fluid transport function. This enables the fluid substances to be transported from one location to another, achieving rapid transport and increasing the adaptability and reliability of the directional fluid transport structure.

[0048] like Figure 3 As shown, the cross-section of the microfluidic channel 22 along the direction perpendicular to the fluid flow includes a first inverted trapezoid (e.g., Figure 3 (a) shows the first inverted triangle (V-shaped, as shown in the image). Figure 3 (b) shown), semi-circular (as shown in) Figure 3 (c) shows the first shape and the second shape. In the top-to-bottom direction, the first shape is a second inverted trapezoid and a rectangle connected in sequence (as shown in [example]). Figure 3 (d) shows that the second shape is a third inverted trapezoid and a circle connected in sequence (as shown in d). Figure 3 (e) is shown.

[0049] For example, when the cross-section of the microfluidic channel 22 perpendicular to the fluid flow direction is a first inverted trapezoid, the sidewalls of the two adjacent channel walls 21 forming the first inverted trapezoid and the bottom surface of the microfluidic channel 22 are all provided with a hydrophilic layer. When the cross-section of the microfluidic channel 22 perpendicular to the fluid flow direction is a first inverted triangle, the sidewalls of the two adjacent channel walls 21 forming the first inverted triangle are provided with a hydrophilic layer. When the cross-section of the microfluidic channel 22 perpendicular to the fluid flow direction is a semicircle, the bottom surface of the semicircle is provided with a hydrophilic layer. When the cross-section of the microfluidic channel 22 perpendicular to the fluid flow direction is a first shape, the sidewalls of the two adjacent channel walls 21 forming the first shape and the bottom surface of the microfluidic channel 22 are all provided with a hydrophilic layer. When the cross-section of the microfluidic channel 22 perpendicular to the fluid flow direction is a second shape, the sidewalls of the two adjacent channel walls 21 forming the second shape and the bottom surface of the microfluidic channel 22 are all provided with a hydrophilic layer.

[0050] In microfluidic systems, fluid flow is typically laminar and can be accurately described by the Poisson's equations. The flow characteristics of fluid in microchannels are significantly influenced by the channel's cross-sectional shape, which is crucial for the design of microfluidic devices. When the cross-section of the microfluidic channel 22 perpendicular to the fluid flow direction is a first inverted triangle, the fluid velocity flowing through the microfluidic channel 22 is faster. This phenomenon can be explained by fluid dynamics theory: the microfluidic channel 22 with a first inverted triangle cross-section has a lower Poisson's number, typically exhibiting lower flow resistance. Therefore, its resistance to the fluid is smaller, resulting in a higher flow rate and thus a higher average velocity under the same pressure drop.

[0051] Furthermore, from a mathematical perspective, the relationship between flow rate and channel shape can be expressed by the following formula:

[0052]

[0053] Where: Q is the flow rate, A is the cross-sectional area of ​​the microfluidic channel 22, ΔP is the pressure drop, μ is the fluid viscosity, L is the length of the microfluidic channel 22, and the coefficient k directly reflects the influence of the shape of the microfluidic channel 22 on the flow resistance. For the microfluidic channel 22 with a first inverted triangle cross-section, its k value is smaller, which means that under the same other conditions, the flow rate Q will be larger, and thus its average flow velocity will be higher. Calculations based on fluid dynamics theory show that the flow rate of the first inverted triangle microfluidic channel 22 can be significantly higher than that of channels with other shapes.

[0054] When the cross-section of the microfluidic channel 22 perpendicular to the fluid flow direction is a first inverted trapezoid and a semicircle, its shape is closer to that of a capillary, and the fluid velocity flowing through the microfluidic channel 22 is more uniform and stable. This is because the geometry of the first inverted trapezoid and semicircle reduces the corner effect, and the fluid velocity changes less within the cross-section, similar to laminar flow behavior in a capillary. Specifically, the velocity distribution of the microfluidic channel 22 with a semicircular cross-section is a symmetrical parabola. If the microfluidic channel 22 with a first inverted trapezoidal cross-section is further approached to a rectangle, the velocity distribution in the width direction is more uniform.

[0055] In microfluidic systems, fluid flow is typically laminar and can be accurately described by the Poiseuille equation. For applications requiring stable flow, such as precise analysis or uniform mixing, microfluidic channels 22 with cross-sections of the first inverted trapezoid and semi-circular shape offer superior performance; while for applications requiring high flow rates, microfluidic channels 22 with cross-sections of the first inverted triangle may be more suitable.

[0056] In summary, when the cross-section is the first inverted triangle, the flow resistance is small due to the lower Poisson number, and the fluid velocity is faster; while when the cross-section is the first inverted trapezoid or semi-circle, its shape is closer to that of a capillary tube, and the flow velocity is more uniform and stable, which is suitable for application scenarios that require stable flow.

[0057] Of course, the cross-sections of multiple microfluidic channels 22 in the same directional fluid delivery structure perpendicular to the fluid flow direction can be the same or different. For example Figure 3 Figures (a) to (e) show schematic diagrams of multiple microfluidic channels 22 of the same directional fluid delivery structure with identical cross-sections perpendicular to the fluid flow direction.

[0058] The directional fluid transport structure provided in this application firstly fabricates at least two spaced-apart channel walls 21, forming a microfluidic channel 22 between adjacent channel walls 21, resulting in a fluid channel layer 2. The channel walls 21 are made of a material with good plasticity and have openings 23 arranged along their length, recessed from the top to the bottom. A hydrophilic layer with a contact angle of less than 20° is formed on the surface of the microfluidic channel 22. The fluid channel layer 2 with the hydrophilic layer is then placed on a substrate layer 1 made of a material with good plasticity. For fluid-carrying objects with complex or irregular shapes, the directional fluid transport structure can adapt to different shapes of fluid-carrying objects through deformations such as bending or stretching. The openings 23 on the channel walls 21 can deform and disperse external forces, avoiding unnecessary stress concentration. Furthermore, under the action of the hydrophilic layer, the microfluidic channel 22 can always maintain unobstructed flow and good fluid transport capacity after deformation of the directional fluid transport structure, without affecting the normal transport of fluid substances. This increases the adaptability and reliability of the directional fluid transport structure, making its application fields more extensive. Moreover, the substrate layer 1 is made of a material with good plasticity, which allows the substrate layer 1 to deform. The substrate layer 1 and the fluid channel layer 2 achieve bending deformation simultaneously. Under the action of the substrate layer 1, the deformed fluid channel layer 2 can be guaranteed to maintain a bent shape stably for a long time, and has stability during use.

[0059] The directional fluid transport structure of this application embodiment is a deformable structural interface for rapid liquid transport. Together with the flexible microfluidic channel 22 constructed from the hydrophilic layer, it possesses high throughput, high flow rate, and even anti-gravity directional transport capabilities. The fabrication process is simple, easy to industrialize, and its application is flexible, enabling its use in various scenarios.

[0060] Optionally, the substrate layer 1 is an alloy made of one or more of aluminum, copper, and iron, or a mixture of these metals, possessing good plasticity and deformability. Aluminum has low density, making it easy to shape and form, and exhibits good ductility and ease of processing. Copper has excellent plasticity, ease of processing, and moderate resistance to deformation. Iron has high strength, high toughness, and good machinability. Therefore, aluminum, copper, and iron have strong deformability.

[0061] And / or, the channel wall 21 is made of one of plastic, silicone rubber, aluminum, copper, and iron, or other alloys with good plasticity and deformability. Preferably, the fluid channel layer 2 is made of metal, such as aluminum, copper, iron, or an alloy. Based on the flexibility of the metal, the microfluidic channel 22 can maintain a stable state after the channel wall 21 is bent and deformed. The back of the channel wall 21 is adhered to the metal, allowing the microfluidic channel 22 to bend and maintain its bent shape stably for a long time after bending, without easily returning to its original state. This enhances the stability and practicality of the structure, greatly improving the performance and durability of the directional fluid transport structure in complex application scenarios.

[0062] And / or, the hydrophilic layer is one or a combination of hydrophilic silica, tannic acid, and polyvinyl alcohol. Hydrophilic silica possesses advantages such as excellent hydrophilicity, uniform particle size distribution, and high specific surface area. Tannic acid has advantages such as strong hydrophilicity. Polyvinyl alcohol possesses advantages such as good hydrophilicity, biodegradability, biocompatibility, heat resistance, and corrosion resistance.

[0063] like Figure 1 and Figure 5 As shown, the directional fluid transport structure provided in this embodiment of the invention further includes a transition connection layer 3. The transition connection layer 3 is disposed between the substrate layer 1 and the fluid channel layer 2, and is configured to connect the substrate layer 1 and the fluid channel layer 2. The transition connection layer 3 is made of materials such as 502 glue or 704 glue. Connecting the deformable substrate layer 1 to the fluid channel layer 2 by adhesive bonding can improve the connectivity between the substrate layer 1 and the fluid channel layer 2. When both the fluid channel layer 2 and the deformable substrate are made of metal, the substrate layer 1 and the fluid channel layer 2 can also be connected by welding.

[0064] Each microfluidic channel 22 has a similar cross-section perpendicular to the fluid flow direction, and the cross-sectional area remains constant from the first end to the second end (e.g., ...). Figure 1 As shown, multiple microfluidic channels 22 are arranged in parallel or gradually increase in size (i.e., fan-shaped).

[0065] Optionally, the shape of the microfluidic channel 22 projected onto the substrate layer 1 is a straight line (e.g., Figure 1 (as shown) or curves (such as) Figure 2 (As shown) or a mixture of straight lines and curves, depending on the user's needs.

[0066] Figure 3 Furthermore, the depth h of at least two microfluidic channels 22 can be the same or different. When the depth of the microfluidic channels 22 is the same, the flow rate of fluid through each microfluidic channel 22 is basically the same, such as... Figure 3 As shown in (a) to (e), the channel depth can be set to approximately 1 mm to 4 mm. If there is a difference in depth h between at least two microfluidic channels 22, such as Figure 4In (a) to (c), the fluid flux will vary depending on the changes in the channel geometry (including arc length S, width w, etc.). By adjusting the channel depth, the flow rate in the directional fluid transport structure can be precisely controlled to meet the requirements of fluid injection rate or total transport volume in different applications.

[0067] The relationship between fluid flux q and channel geometry parameters can be described as follows:

[0068]

[0069] In the formula: q is the fluid flux (i.e., the volume of liquid passing through the channel per unit time); γ is the liquid surface tension; μ is the liquid viscosity; θ is the static contact angle between the liquid and the sidewall of the microfluidic channel 22; S is the arc length of the microfluidic channel 22, which can be understood as the perimeter of the cross-section of the microfluidic channel 22 (i.e., the length of the surface that can be wetted along the flow direction); and θ is the width at the widest point of the microfluidic channel 22. As the depth h of the microfluidic channel 22 increases, the arc length S tends to increase accordingly, thereby increasing the effective wetting area in contact with the liquid and ultimately significantly improving the fluid flux q. Conversely, if the depth of the microfluidic channel 22 is reduced, the fluid flux can be reduced, achieving finer flow control. Based on this characteristic, this invention, by setting microfluidic channels 22 of different depths in the same microfluidic system, can achieve differentiated adjustment of the fluid velocity or flow rate in each microfluidic channel 22 without changing the planar distribution of the microfluidic channels 22.

[0070] like Figure 1 , Figure 2 and Figure 5 As shown in (b) and (c), the shape of the opening 23 is a second inverted triangle, a design with significant structural advantages. The geometric characteristic of the second inverted triangular opening 23, wider at the top and narrower at the bottom, makes it particularly suitable for applications in the microfluidic channel 22. When fluid flows through the microfluidic channel 22, the second inverted triangular opening 23 effectively controls the fluid flow path, preventing liquid from overflowing from the sidewalls. More importantly, when the microfluidic channel 22 is subjected to bending or tensile stress, these second inverted triangular openings 23 can flexibly adapt to deformations in different directions. Especially when the channel bends inward, the second inverted triangular notch gradually closes as the degree of bending increases, forming an adaptive sealing mechanism, further ensuring the side sealing of the microfluidic channel 22 and effectively preventing leakage. This dynamic sealing characteristic is a unique advantage of the second inverted triangular opening 23, enabling the microfluidic channel 22 to maintain good fluid transport performance under various deformation conditions.

[0071] Of course, the shape of the opening 23 can also be rectangular, semi-circular, or linear.

[0072] Rectangular opening 23: Although the rectangular opening 23 is relatively simple to manufacture, due to the lack of a top-wide and bottom-narrow structural characteristic, the connection between its bottom and the channel wall is too wide, causing liquid to easily overflow from the opening 23 when the microfluidic channel 22 is bent or stretched. In addition, the right-angled edges of the rectangle are prone to forming stress concentration points, which may generate microcracks during repeated bending, affecting the structural integrity and service life of the channel wall.

[0073] Semicircular opening 23: While the semicircular opening 23 avoids stress concentration, similar to the rectangular opening 23, its bottom connection with the channel wall is wider, unlike the narrow connection point formed by the second inverted triangle. This means that when the system deforms, the liquid can easily overflow from the opening 23, failing to meet the requirements of high-sealing microfluidic applications.

[0074] Linear notches: This shape is the simplest to manufacture, but its application is relatively limited. When the microfluidic channel 22 bends outward, the linear notch opens appropriately, providing some deformation space; however, when the microfluidic channel 22 bends inward, this notch will cause compression and overlap, which may lead to wrinkling or even damage to the material of the channel wall 21. Due to the lack of an effective geometric structure to control the degree of opening 23, the linear notch may experience unpredictable deformation during long-term use, reducing the stability and reliability of the microfluidic system.

[0075] Comprehensive analysis shows that the second inverted triangular opening 23 exhibits significant advantages in several aspects. Its top-wide, bottom-narrow structure not only effectively controls liquid flow and prevents leakage, but its self-closing characteristic during inward bending also provides additional sealing protection. In contrast, rectangular and semi-circular openings 23 are prone to liquid overflow due to their excessively wide bottom connections, while simple cuts are only suitable for outward bending, not inward bending. Therefore, the second inverted triangular opening 23 is an ideal choice for the sidewall slotting of the microfluidic channel 22, providing excellent structural adaptability while ensuring fluid delivery efficiency, allowing the microfluidic channel 22 to maintain a stable and reliable working state under various deformation conditions.

[0076] Preferably, such as Figure 5 As shown in (b), the height of the second inverted triangle is half the height of the channel wall 21. This height design achieves a balance between ensuring structural integrity and functionality. When the height of the opening 23 of the second inverted triangle is controlled at half the height of the channel wall 21, sufficient stress relief space is provided without excessively weakening the overall strength of the channel wall.

[0077] If the height of the opening 23 of the second inverted triangle is too shallow, for example, only a quarter or less of the height of the channel wall 21, although more wall material is retained and the overall structural strength is enhanced, the deformation space provided by the opening 23 is limited. In this case, when the microfluidic channel 22 is bent or stretched, the shallow opening cannot effectively disperse the stress, causing the stress to remain concentrated at the top and bottom connection of the opening 23. In long-term use, these stress concentration areas are prone to fatigue cracks, eventually leading to structural failure. In addition, the shallow opening cannot close fully when the microfluidic channel 22 bends inward, failing to leverage the adaptive sealing advantage of the second inverted triangle.

[0078] Conversely, if the opening 23 of the second inverted triangle is too deep, for example, equal to the height of the sidewall, while it can provide greater deformation space and better stress dispersion, it also introduces new problems. An excessively deep opening 23 significantly reduces the effective support material of the channel wall, lowering the overall structural strength. More seriously, when the microfluidic channel 22 is under pressure, an excessively deep opening 23 is prone to excessive deformation due to insufficient sidewall material, causing liquid to overflow from the edges of the opening 23. Especially under high flow rate or high pressure operating conditions, the risk of liquid overflow increases significantly, affecting the reliability and accuracy of the system.

[0079] When the height of the second inverted triangle opening 23 is half the height of the channel wall 21, the opening area is large enough to effectively disperse the stress generated by bending and stretching, preventing structural damage caused by stress concentration. Simultaneously, sufficient wall material is retained to provide necessary support and strength, preventing excessive deformation of the channel wall under operating pressure. Furthermore, this moderately high opening 23 can close appropriately when the microfluidic channel 22 bends inward, forming an effective adaptive seal, while not losing control of the fluid due to excessive opening when bending outward. Moreover, to adapt to different application requirements and operating conditions, the width and angle of the opening 23 can be appropriately adjusted while maintaining the opening height at half the height of the channel wall 21. For example, in areas requiring higher flexibility, the top width of the opening 23 can be slightly increased; while in areas requiring higher strength, the angle of the opening 23 can be appropriately reduced to increase material retention. This flexible parameter adjustment allows the inverted triangle opening 23 design to better adapt to the requirements of various specific application scenarios.

[0080] The directional fluid transport structure provided in this invention can be used for rapid liquid transport, and can be applied in scenarios such as fluid transfer, collection of tiny droplets in mist and steam, and low-energy drainage. When using the directional fluid transport structure of this invention for rapid liquid transport, its application scenarios are rich and diverse, including directional liquid transport along curved paths, liquid flow transport, and rapid drainage. Due to the high-throughput characteristics of this directional fluid transport structure, it can transport large amounts of liquid in a short time. Therefore, the practicality and scalability of this application will enable its widespread application in multiple fields, such as steam harvesting, environmental protection, and energy.

[0081] This application investigates the effects of parameters such as material surface wettability, channel depth, and channel width on the velocity and flux of directional fluid transport, and further optimizes these parameters to obtain a directional transport channel that combines high flux, high velocity, and even anti-gravity performance. Through in-depth research on the effects of parameters such as material surface wettability, material flexibility, and durability on directional fluid transport performance, bendability, and the impact of bend on transport efficiency, these parameters are further optimized, resulting in a channel that combines high-fluidity directional transport with flexible bending capabilities.

[0082] Multiple integrated superhydrophilic microfluidic channels 22 are made flexible and combined with a flexible substrate layer 1 to achieve high flow rate, large throughput, and versatility in microfluidic transport. By combining the flexible microfluidic channels 22 with the deformable substrate layer 1, the microfluidic transport device can be bent into the required shape and fixed in a simple step, thus adapting to various complex application scenarios. Using existing microfabrication techniques, microfluidic transport channels with complex structures can be fabricated in a simple manner. This method not only reduces the fabrication difficulty but also improves fabrication accuracy and efficiency, providing convenience for practical applications.

[0083] This application describes a method for optimizing fluid transport performance by precisely controlling geometric parameters based on the surface wettability of hydrophilic materials. By fully considering key factors such as surface tension and viscosity of the directional fluid transport structure and utilizing existing microfabrication techniques, the fabrication of microfluidic transport channels with complex structures can be achieved in a simple process. This not only improves fluid transport performance but also reduces energy consumption and cost, and increases system efficiency.

[0084] Another embodiment of the present invention provides a method for preparing a directional fluid transport structure, which is used to prepare the above-mentioned directional fluid transport structure, comprising:

[0085] At least two spaced-apart channel walls 21 are fabricated, forming microfluidic channels 22 between adjacent channel walls 21, thus obtaining a fluid channel layer 2. The channel walls 21 are made of a material with good plasticity and have openings 23 arranged in a recessed pattern from the top to the bottom along their length. Specifically, at least two spaced-apart channel walls 21 are fabricated by folding, die stamping, lathe grinding, splicing, or mold casting, forming microfluidic channels 22 of specific shape and size between adjacent channel walls 21, thus forming the fluid channel layer 2.

[0086] A hydrophilic layer with a contact angle of less than 20° is fabricated on the surface of the microfluidic channel 22. Specifically, the hydrophilic layer with a contact angle of less than 20° is fabricated on the surface of the microfluidic channel 22 through surface activation treatments such as chemical etching, physical polishing, or coating. The superhydrophilic nature of the hydrophilic layer allows the liquid to spread rapidly upon contact with the microfluidic channel 22, reducing flow resistance and thus achieving more efficient and controllable liquid transport. To ensure the transport effect of the prepared directional fluid transport structure, the contact angle of the hydrophilic layer is less than 20°.

[0087] A fluid channel layer 2 with a hydrophilic layer is disposed on a substrate layer 1 made of a material with good plasticity.

[0088] Furthermore, before depositing the fluid channel layer 2 with a hydrophilic layer onto the substrate layer 1 made of a material with good plasticity, the method further includes:

[0089] A transition connection layer 3 is disposed on the substrate layer 1, and a fluid channel layer 2 with a hydrophilic layer is disposed on the transition connection layer 3. After the prefabricated superhydrophilic deformable microfluidic channel 22 is completed, the substrate layer 1 is connected to the substrate layer 1 through the transition connection layer 3 to ensure the stability and functionality of the overall structure. When rapid liquid transport is required on different surface structures, the directional fluid transport structure can achieve efficient liquid transport and control by adjusting the shape and size of the microfluidic channel 22 and the deformation of the substrate layer 1.

[0090] Currently, it is extremely difficult to construct large-scale interfaces with special wettability. Commonly used construction methods include 3D printing and mask etching, but these methods all have limitations, making it difficult to fabricate complex structures and fine features. This not only limits the application range of directional fluid transport interfaces but also hinders their application in microfluidics, biomedicine, and other fields. The method for fabricating directional fluid transport structures provided in this application can achieve the fabrication of directional fluid transport structures with complex structures and fine features.

[0091] The present invention will now be described with reference to the accompanying drawings. Unless otherwise specified, the experimental reagents used in the following specific embodiments are all conventional biochemical reagents. Unless otherwise specified, the experimental methods described are all conventional methods. Specific Implementation

[0093] The fabrication method of the directional fluid transport structure includes the following steps:

[0094] By casting a mold, a mixture of silicone rubber and curing agent is poured into a prefabricated model to create at least two spaced channel walls 21. A microfluidic channel 22 is formed between two adjacent channel walls 21, resulting in a fluid channel layer 2. The channel walls 21 are made of a material with good plasticity and have an array of openings 23 that are recessed from the top to the bottom along the length direction. The cross section of the microfluidic channel 22 perpendicular to the fluid flow direction is a first inverted triangle. After curing, the microfluidic channel 22 is removed to prepare a model of the fluid channel layer 2. The specific dimensional parameters of the microfluidic channel 22 are shown in Table 1 below.

[0095] Table 1. Size parameters of microchannels

[0096] P1 10 1 ≈20 P2 10 1.5 ≈20 P3 10 2 ≈20

[0097] A hydrophilic layer with a contact angle of approximately 0° is formed on the surface of the microfluidic channel 22 using a hydrophilic material. The hydrophilic material can be formed by directly treating the surface of the microfluidic channel 22, or by pasting or coating it onto the surface. In this embodiment, hydrophilic silica is selected as the hydrophilic material. This result indicates that the hydrophilic layer has low surface energy, which promotes liquid wetting and spreading, thereby effectively improving the fluid properties of the microfluidic channel 22.

[0098] A transition connection layer 3 is disposed on the substrate layer 1, and a fluid channel layer 2 with a hydrophilic layer is disposed on the transition connection layer 3 to obtain a directional fluid transport structure for rapid liquid transport. A physical diagram of the directional fluid transport structure is shown below. Figure 6 As shown.

[0099] like Figure 7 As shown, after appropriate bending, the prepared directional fluid transport structure is inserted into the water tank, with one end inside the tank and the other end exposed. Simultaneously, the height of the outer end is lower than the inner end, thus utilizing the capillary force and siphon effect of the channel to rapidly and continuously transfer the liquid inside the tank to the outside without requiring any external energy input.

[0100] like Figure 7As shown in the test, for a 50ml water tank, the directional fluid transport structure of this invention can quickly achieve anti-gravity transport, and the liquid can be completely drained in just 6 seconds. Therefore, this invention can not only play an important role in various liquid transport scenarios, but also solve the problems of slow transport speed, low overall transport throughput, unstable flow rate, and insufficient flow rate in traditional liquid transport processes, improving the efficiency and stability of liquid transport, making its application more widespread and able to meet the needs of certain specific fields.

[0101] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0102] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A directional fluid transport structure, characterized in that, It includes a substrate layer, a fluid channel layer, a hydrophilic layer, and a transition connection layer; The transition connection layer is disposed between the substrate layer and the fluid channel layer and is configured to connect the substrate layer and the fluid channel layer; The substrate layer is made of a material with good plasticity; The fluid channel layer includes at least two channel walls; At least two of the channel walls are made of a material with good plasticity and are spaced apart on the substrate layer, forming a microfluidic channel between two adjacent channel walls; Each of the microfluidic channels has a similar cross-section perpendicular to the fluid flow direction, and the cross-sectional area remains constant or gradually increases from the first end to the second end; the cross-section of the microfluidic channel perpendicular to the fluid flow direction includes a first inverted trapezoid, a first inverted triangle, a semicircle, a first shape, and a second shape; in the direction from top to bottom, the first shape is a second inverted trapezoid and a rectangle connected in sequence, and the second shape is a third inverted trapezoid and a circle connected in sequence; The channel wall is provided with an array of openings that are recessed from the top to the bottom along its length; the shape of the openings is a second inverted triangle; the height of the second inverted triangle is half the height of the channel wall; The hydrophilic layer has a contact angle of less than 20° and is disposed on the surface of the microfluidic channel.

2. The directional fluid transport structure according to claim 1, characterized in that, The substrate layer is one of aluminum, copper, and iron; And / or, the channel wall is one of plastic, silicone rubber, aluminum, copper, and iron; And / or, the hydrophilic layer is one or a combination of hydrophilic silica, tannic acid and polyvinyl alcohol.

3. The directional fluid transport structure according to claim 1, characterized in that, The shape of the microfluidic channel projected onto the substrate layer is a straight line, a curve, or a mixture of straight lines and curves.

4. The directional fluid transport structure according to claim 1, characterized in that, At least two of the microfluidic channels may have the same or different depths.

5. A method for preparing a directional fluid transport structure, characterized in that, For preparing the directional fluid transport structure according to any one of claims 1 to 4, comprising: At least two spaced-apart channel walls are fabricated, forming a microfluidic channel between two adjacent channel walls to obtain a fluid channel layer; wherein, the channel walls are made of a material with good plasticity and have openings arranged along the length direction that are recessed from the top to the bottom. A hydrophilic layer with a contact angle of less than 20° is formed on the surface of the microfluidic channel; The fluid channel layer having the hydrophilic layer is disposed on a substrate layer made of a material with good plasticity.

6. The method for preparing the directional fluid transport structure according to claim 5, characterized in that, Before depositing the fluid channel layer having the hydrophilic layer on a substrate layer made of a material with good plasticity, the method further includes: A transition connection layer is provided on the substrate layer, and the fluid channel layer having the hydrophilic layer is disposed on the transition connection layer.

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