One-way moisture conducting bionic fabric and method of making same

Abstract

The application provides a one-way moisture-conducting bionic fabric and a preparation method thereof, and the one-way moisture-conducting bionic fabric comprises a fabric base body, the fabric base body comprises a skin layer, a directional conducting layer and a moisture diffusion layer from inside to outside in sequence; the skin layer is composed of hydrophobic fiber bundles with a first surface energy; the directional conducting layer comprises a plurality of asymmetric bionic micro-channels arranged in an array, the micro-channels penetrate through the skin layer and the directional conducting layer; the longitudinal section of the micro-channels is in a conical structure, the large end is towards the skin layer, and the small end is towards the moisture diffusion layer; the moisture diffusion layer is composed of hydrophilic fiber bundles with a second surface energy, and the second surface energy is greater than the first surface energy. The application introduces the bionic micro-channels with geometric asymmetric characteristics into the fabric structure, and combines the surface energy gradient design between the skin layer and the moisture diffusion layer, so that a liquid water self-driven transmission mechanism based on Laplace pressure difference is constructed at a micro level.

Description

Technical Field

[0001] This application belongs to the field of functional textile technology, specifically relating to a unidirectional moisture-wicking biomimetic fabric and its preparation method. Background Technology

[0002] With the continuous development of the global economy and the increasing demands for comfort in outdoor sports, competitive sports, and special occupations, textile fabrics with efficient moisture management functions are crucial for ensuring the body's thermal and moisture balance and physiological health. Their performance evolution and structural innovation are therefore particularly important. Traditional quick-drying fabrics primarily achieve their protective function by providing basic moisture-wicking capabilities. However, they have not yet provided a completely ideal, systematic solution for the actual needs of users under different exercise intensities and complex environments, especially the balance between the efficiency of sweat directional migration and the dryness of the skin.

[0003] The current mainstream functional moisture-wicking fabric technologies can be mainly divided into two categories: The first is physical moisture-wicking fabrics based on fiber cross-section modification, where the wicking force mainly comes from the capillary effect (wicking) generated by the irregular grooves formed on the fiber surface. This type of fabric increases the specific surface area of ​​the fibers, using microchannels to guide liquid sweat from the skin side to the outer layer of the fabric. Its advantages include mature technology, good breathability, and relatively controllable cost, playing an important role in assisting perspiration wicking under normal wearing conditions. However, the wicking force provided by this type of fabric is symmetrical. Because capillary action is bidirectional, when the outer fabric reaches saturation or the external humidity is high, sweat easily seeps back to the skin side through micropores under capillary pressure equilibrium, resulting in a noticeable stickiness and coldness, affecting the wearer's thermal comfort. The second category is chemically treated, immersion gradient fabrics, which typically use hydrophilic or hydrophobic finishing agents to create different surface energy gradients on the inner and outer sides of the fabric. Such solutions improve the unidirectional transfer performance of water to some extent, but when dealing with extreme situations of heavy sweating, the driving force for liquid water migration is relatively singular, and the functional stability of chemical coatings often faces the challenge of performance degradation after repeated washing.

[0004] However, with the increasing diversification of water sports and outdoor activities and people's higher pursuit of intelligent and self-driving equipment, the inherent limitations of the aforementioned technical solutions that rely on passive capillary action or simple wetting gradients are gradually becoming apparent. This is especially true given the new demands for high-speed, self-driven sweat migration to balance multiple performance indicators, where the bottlenecks are particularly prominent. Specifically, the moisture-wicking design of traditional fabrics is often forced to compromise between penetration speed and unidirectional isolation: if larger pore sizes are designed to increase moisture transfer speed, the risk of backflow of moisture from the outer layer increases; if a tight weave structure is used to prevent backflow, then in windless or high-humidity environments, relying solely on passive capillary action is insufficient to achieve high-speed, active sweat migration, leading to sweat accumulation on the skin surface. Furthermore, there is room for improvement in optimizing the sweat evaporation efficiency of traditional fabrics. If moisture cannot quickly spread and form a very thin water film on the outer layer of the fabric, excessively high humidity in localized areas will significantly reduce the evaporation rate, thus limiting the overall drying performance of the fabric.

[0005] Ultimately, the wicking materials and structures used in existing quick-drying fabrics rely on physical mechanisms that drive liquid water migration, making their wicking efficiency highly susceptible to environmental factors. This static or passive regulatory characteristic means that their response speed in managing moisture is less than optimal when faced with the sudden surge of sweat generated during high-intensity exercise, especially in complex scenarios requiring continuous, unidirectional, and self-driven moisture transfer. Furthermore, even attempts to achieve unidirectional moisture wicking through multi-layer composites or adding external functional layers often introduce additional thickness, reduce breathability, or increase the complexity of the manufacturing process. Moreover, these solutions deviate from the fundamental requirement of achieving active moisture management through the fabric's own biomimetic structure. It is crucial to recognize that demanding a higher standard for the "self-driven unidirectional pump" structure in functional fabrics means breaking through the boundaries of traditional fiber weaving and endowing the fabric with the ability to generate Laplace pressure differences at the microscopic level using geometric asymmetry, thereby regulating its macroscopic droplet transport characteristics. This is precisely the key technological bottleneck in existing wicking technologies that still requires in-depth exploration and systematic breakthroughs. Summary of the Invention

[0006] This application provides a one-way moisture-wicking bionic fabric and its preparation method to solve the technical problems of existing moisture-wicking fabrics having a bottleneck in response speed when dealing with the instantaneous large amount of sweat generated by high-intensity exercise, as well as insufficient moisture-wicking power and easy back-seepage of sweat to the skin side in complex environments.

[0007] To solve the above-mentioned technical problems, one technical solution adopted in this application is: a unidirectional moisture-wicking biomimetic fabric, comprising:

[0008] The fabric matrix consists of a skin-adhering layer, a directional conductive layer, and a moisture diffusion layer from the inside out.

[0009] The skin-adhesive layer is composed of hydrophobic fiber bundles with a first surface energy; the directional conduction layer contains multiple asymmetric biomimetic microchannels distributed in an array, and the microchannels penetrate the skin-adhesive layer and the directional conduction layer; the longitudinal section of the microchannels is conical, with the large end facing the skin-adhesive layer and the small end facing the moisture diffusion layer; the moisture diffusion layer is composed of hydrophilic fiber bundles with a second surface energy, which is greater than the first surface energy.

[0010] Furthermore, the hydrophobic fiber bundles used in the skin-adhesive layer are at least one of polypropylene fiber, polytetrafluoroethylene fiber, and polydimethylsiloxane modified polyester fiber; the cross-section of the hydrophobic fiber bundles has an irregular structure, including triangular, cross-shaped, or multi-leaf-shaped structures.

[0011] Furthermore, the surface of the hydrophobic fiber bundle is distributed with microgrooves extending along the fiber axis; the thickness of the skin layer is 0.25-0.35 mm, and an interconnected micron-scale pore network is formed inside the skin layer.

[0012] Furthermore, the directional conductive layer is composed of a nanofiber membrane formed by electrospinning, and the nanofiber membrane is made of at least one of polyvinylidene fluoride, polyacrylonitrile, or thermoplastic polyurethane; the fiber diameter of the nanofiber membrane is 200-500 nm.

[0013] Furthermore, the inner wall of the asymmetric biomimetic microchannel has a micro-nano composite rough structure, which is composed of inorganic nanoparticles deposited on the inner wall of the channel and a polymer binder.

[0014] Furthermore, the inorganic nanoparticles are selected from at least one of silicon dioxide, alumina, and titanium dioxide; the polymeric binder is selected from at least one of polyurethane, acrylic resin, and fluorocarbon resin.

[0015] Furthermore, the thickness of the micro-nano composite rough structure is 30-50 nm; the inner wall of the asymmetric biomimetic microchannel is grafted with a hydrophilic molecular chain layer, and the grafting density of the hydrophilic molecular chain layer increases in a gradient from the skin-adhering layer side to the moisture diffusion layer side.

[0016] Furthermore, the moisture diffusion layer has a three-dimensional porous network structure, and the average pore size of the three-dimensional porous network structure is smaller than the opening diameter of the asymmetric biomimetic microchannel on one side of the moisture diffusion layer.

[0017] Furthermore, multiple asymmetric biomimetic microchannels are distributed in an equilateral triangular array, a square array, or a regular hexagonal array within the plane of the directional conduction layer.

[0018] Another technical solution adopted in this application is: a method for preparing a unidirectional moisture-wicking biomimetic fabric, comprising:

[0019] S1. Preparation of skin-adhesive layer substrate: Select hydrophobic fibers of preset specifications, form a skin-adhesive layer substrate with preset thickness and porosity through knitting, weaving or non-woven processes, and perform plasma cleaning treatment on its surface to remove surface impurities.

[0020] S2. Preparation of precursor for directional conductive layer: Using electrospinning technology, a polymer solution is spun under preset voltage, preset receiving distance and preset flow rate conditions to form a nanofiber film on a collecting device; the nanofiber film serves as the precursor for directional conductive layer;

[0021] S3. Interlayer composite: The moisture diffusion layer substrate, the directional conduction layer precursor, and the skin-adhesive layer substrate are stacked in a preset order and pressed together by a hot-pressing composite device under preset pressure, preset temperature, and preset time conditions to form a composite fabric blank.

[0022] S4. Construction of asymmetric biomimetic microchannels: A high-energy beam processing device is used to process composite fabric blanks, and asymmetric perforation is performed from the skin layer side to the moisture diffusion layer side according to preset array parameters and geometric parameters; the energy intensity, pulse frequency and scanning speed of the high-energy beam processing device are dynamically adjusted according to the thermophysical properties of the material.

[0023] S5. Functional modification of the inner wall: The composite fabric preform with microchannels is placed in a reaction chamber containing a modifier, and a micro-nano composite rough structure or wettability gradient layer is formed on the inner wall of the asymmetric biomimetic microchannel by vapor deposition or microfluidic infusion process.

[0024] S6. Post-treatment: The functionalized fabric is heat-set at a predetermined temperature, followed by washing and drying to obtain a unidirectional moisture-wicking biomimetic fabric.

[0025] The beneficial effects of this application are as follows: By introducing biomimetic microchannels with geometrically asymmetric features into the fabric structure and combining them with the surface energy gradient design between the skin-contact layer and the moisture diffusion layer, a self-driven liquid water transport mechanism based on the Laplace pressure difference is constructed at the microscopic level. This mechanism utilizes the difference in the radius of curvature at both ends of the conical channel to generate asymmetric additional pressure, driving droplets to actively and rapidly migrate from the hydrophobic side to the hydrophilic side, effectively breaking through the bottleneck of moisture-wicking dynamics caused by the passive capillary action of traditional fabrics. At the same time, the high hydrophobicity of the skin-contact layer and the geometric isolation effect of the asymmetric channel together constitute a physical barrier for moisture back-permeation, maintaining a dry state on the skin side even when the outer layer is saturated or in a high-humidity environment. In addition, the high hydrophilicity and three-dimensional porous structure of the moisture diffusion layer promote the rapid spread of moisture on the outer layer, increasing the effective evaporation area of ​​liquid water. Combined with the self-driven pumping function of the directional conduction layer, efficient management of the entire chain of sweat from generation and migration to evaporation is achieved, significantly improving thermal and humid comfort in high-intensity sports scenarios. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments.

[0027] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0028] This invention provides a unidirectional moisture-wicking biomimetic fabric, which is a multi-layered composite structure comprising, from the inside out, a skin-adhering layer, a directional conductive layer, and a moisture-diffusing layer. The directional conductive layer is disposed between the skin-adhering layer and the moisture-diffusing layer, and its interior contains multiple asymmetric biomimetic microchannels arranged in a predetermined array. Each asymmetric biomimetic microchannel penetrates both the skin-adhering layer and the directional conductive layer. The longitudinal section of the microchannel exhibits an asymmetric conical structure, with the larger end of the cone facing the skin-adhering layer and the smaller end facing the moisture-diffusing layer. The inner wall of the microchannel undergoes precise physical structural design and chemical modification, enabling liquid moisture to migrate directionally from the skin-adhering layer to the moisture-diffusing layer under the influence of the Laplace pressure difference generated by the difference in curvature radii at both ends of the channel.

[0029] The skin-adhesive layer, serving as the interface in direct contact with human skin, is precisely woven from bundles of highly hydrophobic and low thermal conductivity synthetic fibers. The synthetic fiber material is at least one of polypropylene fiber, polytetrafluoroethylene fiber, or polydimethylsiloxane-modified polyester fiber. In one specific embodiment, the skin-adhesive layer uses a unit area mass of 110 gm³. -2Polypropylene fibers, prepared using a double-knitted structure, ensure excellent physical barrier properties under static conditions. To further enhance its hydrophobic properties, the cross-section of the skin-adhesive layer fibers is designed with a cross-shaped structure, and the fiber surface is distributed with axially extending microgrooves. This structural design increases the effective specific surface area of ​​the fibers, ensuring that the static contact angle between the skin-adhesive layer and liquid water remains stably above 140°. After shear stress treatment, the thickness of the skin-adhesive layer is typically controlled between 0.25 and 0.35 mm, forming an interconnected micron-scale pore network with an average pore size of 45 μm.

[0030] The directional transport layer is crucial for achieving self-driven sweat transport. It consists of a series of independent, geometrically asymmetric biomimetic microchannels arranged in a high-precision array. Each asymmetric biomimetic microchannel has a micro-nano composite rough structure on its inner wall, formed by inorganic nanoparticles deposited on the channel's inner wall and a polymeric binder. In one embodiment, the asymmetric biomimetic microchannel exhibits a truncated conical structure, designed to utilize the difference in opening diameters at both ends of the channel to construct an asymmetric wetting interface.

[0031] Specifically, the pore size of the microchannels is precisely controlled at 150 μm at the large end on the skin-adhesive layer side and 60 μm at the small end on the moisture diffusion layer side, while the cone angle of the channel walls is strictly limited to between 15° and 25°. This geometric configuration and pore size ratio design maximizes the additional pressure difference between the leading and trailing edges of the droplet after it enters the channel, thereby achieving active pumping of liquid sweat. At the same time, it ensures that when water undergoes phase change evaporation in the moisture diffusion layer, the capillary resistance to its backflow into the skin-adhesive layer is significantly increased.

[0032] The matrix material for the directional conductive layer is a special electrospun nanofiber membrane, in which the nanofibers have a diameter distribution between 200-500 nm, exhibiting high porosity and excellent flexibility. This nanofiber membrane is prepared from polyvinylidene fluoride (PVDF) via electrospinning, ensuring high crystallinity and chemical stability, resulting in a tensile strength of 25 MPa and an elongation at break exceeding 150%.

[0033] To further enhance the moisture-wicking efficiency of the microchannels and achieve anisotropic control of the wettability gradient, a layer of hydrophilic molecular chains of a specific density is uniformly grafted onto the inner wall of the microchannels. The hydrophilic monomers are selected from acrylamide or hydroxyethyl methacrylate, and their grafting density on the inner wall increases gradient from the skin-adhesive layer to the moisture diffusion layer. This wettability gradient effectively reduces the resistance of the droplet's advance angle when the microchannel is wetted by liquid water, while simultaneously guiding it to undergo high-speed, irreversible volume migration along the axial direction. This dual enhancement mechanism of geometry and wettability not only improves the fabric's response speed under instantaneous heavy perspiration but also significantly reduces the risk of functional failure under saturated ambient humidity. Furthermore, to ensure the stability of the channel's inner wall structure, 5% by mass of nano-silica particles are doped into the micro-nano composite rough structure. These particles undergo a cross-linking reaction with a silane coupling agent and a polymer binder, forming a uniform and dense protective film on the inner wall of the channel. The thickness of this protective film is precisely controlled between 30 and 50 nm. This coating not only imparts microscopic roughness to the inner wall, but also effectively coordinates the driving force generated by geometric asymmetry by increasing surface free energy, thereby ensuring the moisture-wicking stability of the fabric after long-term washing cycles.

[0034] In one specific embodiment, to further enhance the fabric's adaptability under different exercise intensities, a specific proportion of shape memory polymers (SMPs) are uniformly coated on the opening edges of some microchannels in the directional conductive layer. The coated SMPs account for 1.5% of the total mass of the directional conductive layer. The glass transition temperature ($T_{\text{g}}$) of the SMPs is precisely designed and set at 35°C. When human movement generates heat, causing the skin's microenvironment temperature to exceed 35°C, the SMPs are in their rubbery state, increasing the mobility of the molecular chain segments, thereby causing the microchannel opening diameter to expand by approximately 15%. This dynamic increase in pore size directly leads to an increase in the flow cross-section of the microchannels under the same perspiration volume, thus enabling the fabric to have a higher perspiration flux. This characteristic is crucial for heat dissipation and dehumidification in high-intensity competitive sports or high-temperature work environments. Conversely, when the ambient temperature is below 35 °C, the SMPs revert to their glassy state, restricting the movement of molecular chain segments. This allows the microchannels to maintain their initial geometry, thereby preserving basic moisture permeability and preventing convective heat transfer from cold external air through the channels. By integrating this temperature response mechanism, this invention, based on geometric self-driving, further achieves intelligent optimization of moisture-wicking performance under different physiological metabolic levels.

[0035] In one implementation, multiple asymmetric biomimetic microchannels were precisely integrated and arranged using high-energy beam processing technology to form a regular two-dimensional hexagonal array. The center-to-center distance between two adjacent microchannels was strictly controlled at 800 μm to ensure the stability of the channel geometry when the fabric is bent or stretched. The oriented conductive layer nanofiber membrane could be independently prepared in advance using electrospinning technology. This process was carried out under controlled temperature and humidity to ensure the uniformity of fiber diameter. The prepared PVDF solution was then used at 1.2 mL h... -1 The flow rate is injected into the nozzle, and spinning is performed under a 20 kV DC high voltage. The collected nanofiber film is sent to the lamination station to be composited with the skin-adhesive layer and the moisture diffusion layer.

[0036] This application also provides a method for preparing a unidirectional moisture-wicking biomimetic fabric, including the following steps: S1. Preparing a skin-adhesive substrate: Selecting hydrophobic fibers of a preset specification, forming a skin-adhesive substrate with a preset thickness and porosity through knitting, weaving or non-woven processes, and performing plasma cleaning treatment on its surface to remove surface impurities;

[0037] S2. Preparation of precursor for directional conductive layer: Using electrospinning technology, a polymer solution is spun under preset voltage, preset receiving distance and preset flow rate conditions to form a nanofiber film on a collecting device; the nanofiber film serves as the precursor for directional conductive layer;

[0038] S3. Interlayer composite: The moisture diffusion layer substrate, the directional conduction layer precursor, and the skin-adhesive layer substrate are stacked in a preset order and pressed together by a hot-pressing composite device under preset pressure, preset temperature, and preset time conditions to form a composite fabric blank.

[0039] S4. Construction of asymmetric biomimetic microchannels: A high-energy beam processing device is used to process composite fabric blanks, and asymmetric perforation is performed from the skin layer side to the moisture diffusion layer side according to preset array parameters and geometric parameters; the energy intensity, pulse frequency and scanning speed of the high-energy beam processing device are dynamically adjusted according to the thermophysical properties of the material.

[0040] S5. Functional modification of the inner wall: The composite fabric preform with microchannels is placed in a reaction chamber containing a modifier, and a micro-nano composite rough structure or wettability gradient layer is formed on the inner wall of the asymmetric biomimetic microchannel by vapor deposition or microfluidic infusion process.

[0041] S6. Post-treatment: The functionalized fabric is heat-set at a predetermined temperature, followed by washing and drying to obtain a unidirectional moisture-wicking biomimetic fabric.

[0042] In step S4, the high-energy beam processing device is one of an ultraviolet laser processing system, a femtosecond laser processing system, or an electron beam processing system; by adjusting the spatial position of the laser focus and the energy distribution gradient, an asymmetric hole with a predetermined taper is formed inside the composite fabric.

[0043] In step S5, the modifier includes a silane coupling agent, a hydrophilic monomer, and an initiator; under preset light or heat initiation conditions, the hydrophilic monomer undergoes an in-situ polymerization reaction on the inner wall of the asymmetric biomimetic microchannel to form a molecular chain layer with wetting enhancement function.

[0044] In step S1, the gas environment used for the plasma cleaning process is oxygen, argon, or a mixture thereof; the plasma processing power is set to a preset power value, and the processing time is set to a preset duration.

[0045] In step S2, the concentration of the polymer solution is controlled within a preset percentage range, and the solvent is selected from at least one of dimethylformamide, acetone, or ethanol; the ambient humidity during the spinning process is controlled within a preset humidity range.

[0046] In step S3, the surface of the pressure roller of the hot-pressing composite device is coated with an elastic silicone layer to control the pressure uniformity during the pressing process; the hot-pressing temperature is set near the softening point of the nanofiber film.

[0047] After interlayer lamination, a femtosecond laser processing system is used to punch holes in the composite fabric. The laser's center wavelength is 1030 nm, pulse width is 280 fs, and repetition frequency is set to 100 kHz. By adjusting the spatial trajectory and energy distribution of the laser focus, holes of a predetermined taper are formed inside the fabric. Specific processing parameters include a laser scanning speed of 500 mm / s. -1 The single-pulse energy is 15 μJ, and the number of scans is 5. This process ensures that the channel opening edges are neat and free of hot melt zones, maintaining the overall flexibility of the fabric.

[0048] After processing, the composite fabric requires internal wall functionalization modification. The modification solution is a mixed solution containing 2% nano-silica dispersion and 1% aqueous polyurethane. The solution is introduced into the microchannels using microfluidic infusion technology to ensure that the coating completely covers the inner wall of the channel. The composite pressing process is carried out on a continuous lamination production line, where temperature, pressure, and time are precisely controlled.

[0049] Specifically, the hot-pressing temperature was set at 125℃, the pressing pressure at 0.8 MPa, and the pressing time at 45 s. These conditions aim to locally soften the nanofibers of the directional conductive layer and allow them to interlock with the fibers of each layer, forming a strong, non-delaminating interface with good air permeability. The moisture diffusion layer is composed of highly hydrophilic and highly absorbent cotton fibers or hydrophilic modified polyester fibers, with a thickness ranging from 0.40 mm. This layer has a three-dimensional porous network structure, with an average pore size smaller than the opening diameter of the asymmetric biomimetic microchannels on one side of the moisture diffusion layer. The main function of the moisture diffusion layer is to provide a rapid lateral diffusion space for moisture delivered from the channels, allowing it to quickly spread on the outer layer of the fabric to form an ultra-thin water film, thereby significantly improving the evaporation rate. Furthermore, the surface of the moisture diffusion layer is further treated with low-temperature plasma technology to introduce hydrophilic functional groups such as carboxyl or hydroxyl groups. This treatment not only reduces the resistance to moisture spreading on the outer layer but also utilizes capillary suction to synergize with the pumping function of the microchannels, optimizing the overall drying performance of the fabric.

[0050] In a specific application scenario, the unidirectional moisture-wicking biomimetic fabric of this invention can be further integrated with a micro-flexible electrochemical sensor unit array. These sensor units can provide real-time monitoring data on the composition of sweat or physiological parameters on the skin surface. The sensor unit array includes ion-selective electrodes and a glucose oxidase sensor, which are integrated in a flexible array within the micropores between the skin-adhesive layer and the directional conductive layer. The sensors output corresponding electrical signals by monitoring changes in electrolyte concentration or metabolites in sweat. The micro-channel array is integrated with an ultra-low-power signal conditioning circuit, which uses a guide as a continuous sampling channel for sweat, ensuring that the sensor surface is always in contact with fresh sweat samples and can be used to evaluate the real-time feedback of the fabric's moisture-wicking effect. The sensor is packaged on a flexible PCB substrate with a thickness of only 0.15 mm.

[0051] As a highly optimized embodiment of the present invention, the unidirectional moisture-wicking biomimetic fabric can be customized in its microchannel distribution density during manufacturing, based on the differences in perspiration rates in different parts of the body. For example, in the underarm and back core areas of a sweatshirt, to provide maximum perspiration efficiency, a higher density (25 microchannels per square centimeter) or a larger pore size (200 μm at the large end) of microchannels can be used. In pressure-bearing areas of the limbs, to prevent the channels from closing under pressure, the elastic modulus of the channel wall material can be selectively increased. This regionalized structural design, achieved through precise control of the geometric parameters and arrangement logic of the microchannels, further optimizes the overall performance of the fabric, significantly improving the wearer's thermo-moisture regulation experience while maintaining high comfort.

[0052] To further illustrate the technical effects of the present invention, an embodiment and a comparative example are provided below for comparison.

[0053] Example 1: Using the unidirectional moisture-wicking biomimetic fabric of the present invention

[0054] In a specific production batch, a unidirectional moisture-wicking biomimetic fabric conforming to the present invention was produced. The skin-adhesive layer uses 110 gm -2 Polypropylene fibers with a static water contact angle of 142°. The directional conductive layer is a PVDF nanofiber membrane with a fiber diameter of 350 nm. The asymmetric microchannels have a large-end pore diameter of 150 μm and a small-end pore diameter of 60 μm, with an array center-to-center distance of 800 μm. The inner wall of the channel is deposited with a SiO2 nanoparticle modification layer with a thickness of 40 nm. The moisture diffusion layer is made of hydrophilic modified polyester with a static water contact angle of 25°. The layers are bonded together using a hot-pressing process at 125 ℃, 0.8 MPa, and for 45 s.

[0055] Comparative Example 1: A moisture-wicking fabric without an asymmetric microchannel structure was prepared with the same material composition as Example 1, but the difference was that the directional conductive layer did not have asymmetric conical microchannels; instead, it used a common cylindrical symmetrical microporous structure. All other material parameters, fiber specifications, and lamination processes remained consistent with Example 1.

[0056] Several performance tests were conducted on the fabric samples prepared in Example 1 and Comparative Example 1, including the one-way moisture wicking index (MMT test), the liquid water dynamic transfer index, the drying rate, and the functional retention rate after washing. The test results are shown in Table 1.

[0057] Table 1 shows a comparison of the test results between the examples and the comparative examples.

[0058]

[0059] As shown in Table 1, the unidirectional moisture-wicking biomimetic fabric prepared in Example 1 significantly outperforms Comparative Example 1 in several key performance indicators. The unidirectional moisture-wicking index of Example 1 reaches 680%, far exceeding the 215% of Comparative Example 1, demonstrating that the Laplace pressure difference generated by the asymmetric conical channel can provide moisture-wicking power far exceeding passive capillary action. Regarding water re-permeability, Example 1 exhibits extremely low re-permeability (< 5 mg), while Comparative Example 1, lacking geometric isolation, shows significant re-permeability after water saturation. More importantly, the drying rate of Example 1 is increased by approximately 80%, indicating a highly efficient synergistic effect formed by the active pumping of the directional conduction layer and the high-speed spreading of the moisture diffusion layer. Furthermore, in terms of washing stability, Example 1 retains 4.2% of its functionality after 50 standard washes, while the performance of Comparative Example 1 declines significantly, further confirming the structural stability of the inner wall micro / nano composite coating and laser-processed pores.

[0060] In summary, this invention introduces biomimetic microchannels with geometrically asymmetric features into the fabric composite structure, and combines an inner wall wettability gradient with a surface energy step design to achieve self-driven, unidirectional transport of liquid sweat from the skin side to the outer layer. This invention effectively solves the technical bottleneck of existing fabrics in dealing with sweat accumulation and backflow during high-intensity exercise, significantly improving the wearer's dryness and comfort and the product's intelligence level while ensuring high breathability.

[0061] The unidirectional moisture-wicking biomimetic fabric of the present invention has the characteristics of precise preparation, stable function and strong dynamic response, providing a systematic moisture management solution for functional clothing, medical dressings and special protective equipment.

[0062] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A unidirectional moisture-wicking biomimetic fabric, characterized in that, include: The fabric matrix comprises, from the inside out, a skin-adhering layer, a directional conductive layer, and a moisture diffusion layer; The skin-adhesive layer is composed of hydrophobic fiber bundles with a first surface energy; the directional conductive layer includes multiple asymmetric biomimetic microchannels arranged in an array, the microchannels penetrating the skin-adhesive layer and the directional conductive layer; the longitudinal section of the microchannels is conical, with the larger end facing the skin-adhesive layer and the smaller end facing the moisture diffusion layer; The moisture diffusion layer is composed of hydrophilic fiber bundles with a second surface energy greater than the first surface energy.

2. The unidirectional moisture-wicking biomimetic fabric according to claim 1, characterized in that, The hydrophobic fiber bundles used in the skin-adhesive layer are at least one of polypropylene fiber, polytetrafluoroethylene fiber, and polydimethylsiloxane modified polyester fiber; the cross-section of the hydrophobic fiber bundles has an irregular structure, including triangular, cross-shaped, or multi-leaf-shaped structures.

3. The unidirectional moisture-wicking biomimetic fabric according to claim 2, characterized in that, The surface of the hydrophobic fiber bundle is distributed with microgrooves extending along the fiber axis; the thickness of the skin layer is 0.25-0.35 mm, and the interior of the skin layer is formed with an interconnected micron-sized pore network.

4. The unidirectional moisture-wicking biomimetic fabric according to claim 1, characterized in that, The directional conductive layer is composed of a nanofiber membrane formed by electrospinning, and the nanofiber membrane is made of at least one of polyvinylidene fluoride, polyacrylonitrile, or thermoplastic polyurethane; the fiber diameter of the nanofiber membrane is 200-500 nm.

5. The unidirectional moisture-wicking biomimetic fabric according to claim 4, characterized in that, The inner wall of the asymmetric biomimetic microchannel has a micro-nano composite rough structure, which is composed of inorganic nanoparticles deposited on the inner wall of the channel and a polymer binder.

6. The unidirectional moisture-wicking biomimetic fabric according to claim 5, characterized in that, The inorganic nanoparticles are selected from at least one of silicon dioxide, aluminum oxide, and titanium dioxide; the polymer binder is selected from at least one of polyurethane, acrylic resin, and fluorocarbon resin.

7. The unidirectional moisture-wicking biomimetic fabric according to claim 5, characterized in that, The thickness of the micro-nano composite rough structure is 30-50 nm; the inner wall of the asymmetric biomimetic microchannel is grafted with a hydrophilic molecular chain layer, and the grafting density of the hydrophilic molecular chain layer increases in a gradient from the skin-adhering layer side to the moisture diffusion layer side.

8. A unidirectional moisture-wicking biomimetic fabric according to claim 7, characterized in that, The moisture diffusion layer has a three-dimensional porous network structure, and the average pore size of the three-dimensional porous network structure is smaller than the opening diameter of the asymmetric biomimetic microchannel on one side of the moisture diffusion layer.

9. A unidirectional moisture-wicking biomimetic fabric according to claim 8, characterized in that, Multiple asymmetric biomimetic microchannels are distributed in an equilateral triangular array, a square array, or a regular hexagonal array within the plane of the directional conductive layer.

10. A method for preparing the unidirectional moisture-wicking biomimetic fabric according to any one of claims 1-9, characterized in that, include: S1. Preparation of skin-adhesive layer substrate: Select hydrophobic fibers of preset specifications, form a skin-adhesive layer substrate with preset thickness and porosity through knitting, weaving or non-woven processes, and perform plasma cleaning treatment on its surface to remove surface impurities. S2. Preparation of the precursor for the directional conductive layer: Using electrospinning technology, a polymer solution is spun under preset voltage, preset receiving distance and preset flow rate conditions to form a nanofiber film on a collecting device; The nanofiber film serves as a precursor for the directional conductive layer; S3. Interlayer lamination: The moisture diffusion layer substrate, the directional conductive layer precursor, and the skin-adhesive layer substrate are stacked in a preset order and pressed together by a hot-pressing lamination device under preset pressure, preset temperature, and preset time conditions to form a composite fabric blank. S4. Construction of asymmetric biomimetic microchannels: A high-energy beam processing device is used to process the composite fabric blank, and asymmetric perforation is performed from the skin-adhesive layer side to the moisture diffusion layer side according to preset array parameters and geometric parameters; the energy intensity, pulse frequency and scanning speed of the high-energy beam processing device are dynamically adjusted according to the thermophysical properties of the material. S5. Functional modification of the inner wall: The composite fabric preform with microchannels is placed in a reaction chamber containing a modifier, and a micro-nano composite rough structure or wettability gradient layer is formed on the inner wall of the asymmetric biomimetic microchannel by vapor deposition or microfluidic infusion process. S6. Post-processing: The functionalized fabric is subjected to heat setting at a predetermined temperature, followed by washing and drying to obtain the finished unidirectional moisture-wicking biomimetic fabric.

Images