Large-pitch fiber actuator and preparation method thereof, fabric and manufacturing method and application thereof

Abstract

The application provides a large-pitch fiber actuator and a preparation method thereof, a fabric and a manufacturing method and application thereof. The preparation method comprises the following steps: providing functional fibers and template fibers, the functional fibers having artificial muscle driving characteristics; plying and twisting or plying and braiding the functional fibers and the template fibers to form plied fibers, the functional fibers and the template fibers being in close contact; performing heat setting treatment on the plied fibers to shape the functional fibers into a spiral appearance; and dissolving or decomposing and removing the template fibers to obtain the large-pitch fiber actuator. The template fibers are removed in the way of "sacrificial template", so that the template is removed without physical extraction, and continuous and low-cost preparation can be realized. Meanwhile, the preparation method is easy to realize fabricization, the template fibers can be removed through simple physical or chemical means after the fabric is formed, the deformation of the large-pitch functional fibers caused by the braiding process can be avoided, and the fabric jamming phenomenon caused by the spiral structure of the initial fibers during braiding can also be avoided.

Description

Technical Field

[0001] This invention belongs to the field of artificial muscle technology, specifically relating to a large-pitch fiber actuator and its preparation method, fabric and its manufacturing method and application. Background Technology

[0002] With the rapid development of fields such as flexible actuation, intelligent bionics, wearable electronics, and soft robotics, the construction of lightweight, flexible, and woven integrated artificial muscle actuators based on fibers has gradually become an important technological direction to replace traditional rigid actuators. Compared with traditional metal drive motors, large-pitch muscle fiber actuators have advantages such as light weight, large deformation, easy miniaturization, adaptability to complex curved surfaces, and good compatibility with fabric systems. They have shown good application potential in rehabilitation assistive devices, human-computer interaction devices, and micro-drive systems. How to construct fiber drive structures that combine large contraction stroke, high output power, high stability, and continuous fabrication capability has become an important research direction in this field.

[0003] Among existing fiber actuator structures, the helical configuration is one of the most widely used structural forms because it can effectively transform the microscopic volume changes and torsional responses of fiber materials under stimuli such as heat, electricity, light, and solvents into macroscopic axial contraction and elongation behaviors. Compared with tightly wound self-crescendo structures, large-pitch helical fibers have a larger helical spacing and axial release space, which can significantly reduce the constraint between adjacent helical units. This allows the fiber to undergo a more complete untwisting, contraction, and recovery process when subjected to external stimuli, thereby achieving a larger contraction stroke and higher output power. Therefore, the large-pitch helical structure is considered one of the key configurations for improving the performance of fiber actuators and an important foundation for achieving high-performance engineering applications.

[0004] To obtain large-pitch helical fibers, existing technologies typically employ methods such as mechanical stretching training, external mandrel winding, and multi-strand fiber extraction to control the helical structure. While these methods can increase fiber pitch and improve driving behavior to some extent, they often suffer from complex processes, numerous operational steps, poor structural consistency, and difficulty in continuous implementation. For example, invention patent CN116949629A discloses a highly elastic helical conductive fiber and its preparation method and application. This patent involves pre-stretching elastic polymer filaments and winding them onto the surface of a threaded screw, followed by high-temperature heat setting and annealing to form a stable helical structure. Finally, conductive materials are polymerized in situ on the surface or impregnated with a conductive liquid to obtain a helical fiber with conductive properties. This method utilizes the synergistic effect of stretching and heat treatment to promote the orderly arrangement of molecular chains and eliminate residual stress within the fiber, thereby producing a helical conductive fiber with good elasticity, mechanical strength, and electrical stability.

[0005] US Patent US2024 / 0263361 A1 and Zhang et al.'s paper in Science, "Mandrel-free fabrication of giant spring-index and stroke muscles for diverse applications," both involve using multiple fibers to act as "temporary mandrels" to form a stranded structure, followed by heat setting to extract the target fiber from the stranded structure. While this method avoids the high cost associated with traditional external mandrels, the "stranding-setting-extraction" process does not clearly separate the template and functional roles at the material level. Structural support and final drive are often shared by the same type of fiber, making it difficult to separately optimize template and drive performance. This also limits the process's ability to be extended to different material combinations and complex configurations.

[0006] Furthermore, this method may face problems such as tension fluctuations, difficulty in synchronous control, and poor product performance consistency during continuous and stable production. In particular, since the template fiber needs to be extracted and removed, it is difficult to achieve continuous preparation. Therefore, it still has certain limitations in continuous and large-scale preparation. At the same time, this preparation method faces the problem of how to extract the template fiber when making fabrics, making it difficult to apply to fabrics. Summary of the Invention

[0007] The main objective of this invention is to provide a large-pitch fiber actuator and its preparation method, fabric and its manufacturing method and application, so as to overcome the shortcomings of the prior art.

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a large-pitch fiber actuator, comprising: Functional fibers and template fibers are provided, wherein the functional fibers have artificial muscle-driving properties; The functional fibers and template fibers are twisted or woven together to form a ply fiber, in which the functional fibers and template fibers are in close contact. The twisted fibers are heat-set to shape the functional fibers into a helical morphology. The template fibers are dissolved or decomposed to remove them, thereby obtaining a large-pitch fiber actuator.

[0009] Secondly, the present invention also provides a continuous large-pitch fiber actuator prepared by the above-described preparation method.

[0010] Thirdly, the present invention also provides a method for manufacturing a fabric with a driving function, comprising: Functional fibers and template fibers are provided, wherein the functional fibers have artificial muscle-driving properties; The functional fibers and template fibers are twisted or braided together to form twisted fibers; At least the plyed fibers are used to construct the fabric precursor; The fabric precursor is subjected to heat setting treatment to fix the functional fibers into a spiral morphology; The template fibers are dissolved or decomposed to remove them, thereby obtaining a fabric with driving function.

[0011] Fourthly, the present invention also provides a fabric with driving function obtained by the above-described manufacturing method.

[0012] Fifthly, the present invention also provides the application of the above-mentioned large-pitch fiber actuator or the above-mentioned fabric in wearable drive devices.

[0013] Compared with the prior art, the beneficial effects of the present invention include at least the following: The method for preparing a large-pitch fiber actuator provided by this invention involves twisting or weaving template fibers and functional fibers together to form tightly bonded stranded fibers. The template fiber serves as the pitch support for the functional fibers, and after a shaping treatment, it fixes the large-pitch morphology. The template fiber is removed by "sacrificing the template," avoiding physical extraction to remove the template, thus enabling continuous and low-cost preparation. At the same time, this preparation method is easy to fabricate. After the fabric is formed, the template fiber can be removed by simple physical or chemical means. It also avoids deformation of the large-pitch functional fibers caused by the weaving process and avoids fabric jamming caused by direct sewing of helical fibers.

[0014] The above description is merely an overview of the technical solution of the present invention. In order to enable those skilled in the art to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described below in conjunction with detailed drawings. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a continuous preparation process of large-pitch helical fibers provided in a typical embodiment of the present invention; Figure 2 These are photographs documenting the polyvinyl alcohol fiber removal process in a typical embodiment of the present invention. Figure 3 These are photographs documenting the process of obtaining helical fibers with different pitches through continuous preparation in a typical embodiment of the present invention. Figure 4 This is a photograph of a typical embodiment of the present invention, showing spiral fibers of different twists obtained through continuous preparation. Figure 5 This is a comparative test diagram of the driving performance of four strands of silver-plated nylon fibers with different pitches provided in a typical embodiment of the present invention; Figure 6 This is a comparative test diagram of the driving performance of four strands of silver-plated nylon fibers with different twists, provided in a typical embodiment of the present invention. Figure 7 This is a test diagram of the driving quantity and driving rate of four strands of silver-plated nylon under different currents and loads, provided in a typical embodiment of the present invention. Figure 8 This is a typical embodiment of the present invention, providing test diagrams of the driving force and contraction work of four-strand silver-plated nylon with different pitches under different loads; Figure 9 This is a test diagram of the cyclic drive performance of four strands of silver-plated nylon provided in a typical embodiment of the present invention; Figure 10 This is a photograph of a large-pitch fiber prepared by twisting different functional fibers with polyvinyl alcohol, provided in a typical embodiment of the present invention. Figure 11 This is a comparative test chart of the driving performance of different large-pitch functional fibers provided in a typical embodiment of the present invention; Figure 12 This is a photograph of a composite material of polyvinyl alcohol fiber and silver-plated nylon fiber with different number of strands, provided in a typical embodiment of the present invention. Figure 13 This is a photograph of a composite material of silver-plated nylon fiber and polyvinyl alcohol fiber with different strand numbers, provided in a typical embodiment of the present invention. Figure 14 These are photographs of different weaving structures of silver-plated nylon fiber and polyvinyl alcohol fiber provided in a typical embodiment of the present invention. Figure 15 This is a photograph of a large-pitch fiber coated with a polydimethylsiloxane film, provided in a typical embodiment of the present invention. Figure 16 These are photographs of the fabrics from which all polyvinyl alcohol fibers have been removed, provided in a typical embodiment of the present invention. Figure 17 This is a photograph of a fabric with half of the polyvinyl alcohol fibers removed, along with a test diagram of its driving performance, provided in a typical embodiment of the present invention. Figure 18This is a photograph of a fabric with one-quarter of the polyvinyl alcohol fibers removed, along with a test diagram of its driving performance, provided in a typical embodiment of the present invention. Detailed Implementation

[0017] The existing technologies have the following main drawbacks: 1) The twist of the fibers cannot be controlled. Appropriate twist helps to enhance fiber strength, but it also affects the stability and repeatability of the overall driving performance. 2) Manual twisting and "training" processes are inefficient and have poor repeatability, making it difficult to achieve large-scale continuous fabrication of uniform helical structures. 3) The pitch is difficult to control precisely, resulting in large fluctuations in driving performance, which makes it difficult to meet the requirements for response stability in practical applications. 4) Existing spindleless large-pitch fabrication methods are still relatively complex, and the final structure is easily disturbed during the extraction process, which is not conducive to achieving stable continuous fabrication. 5) The fabricated fiber actuators cannot simultaneously possess large driving volume and high work capacity. 6) The helical structure of the initial fibers causes fabric jamming, and the compatibility with complex fiber structures and patterned devices is insufficient, making it impossible to fabricate programmable deformable fabrics and three-dimensional patterned structures. 7) Existing technologies lack green design for the structure release process and have not formed a complete process route based on mild media, low-pollution treatment, and sustainable manufacturing.

[0018] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate the technical solution, its implementation process, and its principles.

[0019] Many 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 different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0020] This invention addresses the problems of existing methods for fabricating large-pitch fiber actuators, such as complex separation processes, susceptibility to disturbance of the final structure, insufficient environmental friendliness, limited material compatibility, weak universality of complex structures, and insufficient continuous fabrication capability. It proposes a method for fabricating large-pitch fiber actuators based on template fiber removal. This method involves composite design of functional fibers capable of driving action with selectively removable template fibers to form a composite helical structure. After heat setting to stabilize the overall configuration, common physical or chemical methods, rather than mechanical extraction methods, are used to release the initial helical winding stress without directly damaging the target functional fibers, significantly increasing the fiber pitch and ultimately obtaining a structurally stable large-pitch fiber actuator.

[0021] Meanwhile, this invention aims to establish a green, environmentally friendly, low-pollution, and sustainable template removal path, eliminating the need for complex mechanical extraction during template release, reducing the environmental burden during process implementation, and improving process gentleness. It also constructs a multi-material system preparation method applicable to different combinations of template fibers and different driving polymer fibers, enabling the separation of template and driving functions at the material level, thereby improving the flexibility of material selection and process scalability. Furthermore, this invention provides a universal process that can be extended to various complex fiber configurations such as large-pitch helical structures, non-prestressed secondary helical structures, braided structures, and multi-strand co-twisted and ply-stranded structures. The resulting helical structures exhibit good stability, the entire process chain is clear, and continuous preparation is possible, meeting the practical needs of high-performance fiber actuators in flexible actuation and engineering applications.

[0022] Based on the above technical concept, the present invention first provides a method for preparing a large-pitch fiber actuator, which includes the following steps: Functional fibers and template fibers are provided, wherein the functional fibers have artificial muscle-driving properties; The functional fibers and template fibers are twisted or woven together to form a ply fiber, in which the functional fibers and template fibers are in close contact. The twisted fibers are heat-set to shape the functional fibers into a helical morphology. The template fibers are dissolved or decomposed to remove them, thereby obtaining a large-pitch fiber actuator.

[0023] To achieve the above technical solution, several points should generally be noted: First, under the heat setting treatment conditions matched to the functional fibers, the template fibers should not experience significant property degradation, such as melting; second, the selected method and conditions for dissolving or decomposing the template fibers should not cause significant damage to the functional fibers.

[0024] In the above technical solution, the template fiber, as the helical template of the functional fiber, plays a fixing role during the heat setting process. It can achieve precise control of the helical pitch by utilizing its own diameter, thus obtaining a large-pitch fiber actuator with uniform and controllable morphology and strong continuity.

[0025] Specifically, in some embodiments, the functional fibers and template fibers have a preset twist; When performing the ply twisting or ply weaving, the helical direction of the functional fiber and the template fiber is consistent with the direction of the preset twist.

[0026] In the above embodiments, both the functional fiber and the template fiber have twist, and the twisting direction of both fibers is consistent with the helical direction (both clockwise or both counterclockwise). This creates a mechanical balance, counteracting the torque caused by the twisting of the functional fiber, resulting in better linearity of the twisted fiber and reducing the difficulty of the process. Of course, the twist of the two fibers is usually similar, but the stress caused by twisting will vary depending on the fiber material and diameter. The specific twist can be adjusted adaptively, and this invention does not impose specific limitations on this. Ultimately, the goal should be to achieve mechanical balance.

[0027] Furthermore, compared to untwisted template fibers, template fibers with a predetermined twist (especially template fibers formed by twisting multiple finer sub-fibers together) can accelerate the dissolution or decomposition removal process. For example, during dissolution removal, the initial dissolution can cause the template fibers to untwist to a certain extent, resulting in loosening of the helical winding. This allows the fibers to spontaneously untwist away from the functional fibers, thereby accelerating removal through spontaneous movement. Of course, this does not mean that the feasible methods of the present invention are limited to this. Even using solid untwisted fibers, as long as sufficient dissolution or decomposition removal can be ensured, the same objective can be achieved.

[0028] Regarding specific materials, in some embodiments, when the removal method of the template fiber is selected as dissolution, the material of the template fiber includes any one or more combinations of polyvinyl alcohol, sodium alginate, PEG, PVP, cellulose acetate, and PLA, but is not limited to these.

[0029] The preferred embodiment described above uses a solvent method to remove the template fiber. The template fiber is not limited to water-soluble polyvinyl alcohol fiber; other selectively removable template materials can be selected based on the functional fiber's tolerance and post-processing conditions. The template material can be a water-soluble template fiber, such as sodium alginate fiber or some PEG fibers; it can also be an organic solvent-removable template fiber, such as ethanol-removable PVP fibers, acetone-removable cellulose acetate fibers, and PLA fibers removable by organic solvents such as chloroform, dichloromethane, or dioxane; it can also be a thermally decomposable or melt-removable temporary template fiber. Any template material that can be selectively removed and release helical winding stress during post-processing without significantly damaging the main structure of the functional fiber can be used as an alternative embodiment of the present invention.

[0030] In some embodiments, the functional fiber includes any one or a combination of two or more of metal composite polymer fibers, conductive polymer fibers, and carbon-based composite fibers.

[0031] In some embodiments, the preparation method further includes the following steps: When a protective layer is used to cover a portion of the stranded fiber, the template fiber within the segment of the protective layer is retained during the dissolution or decomposition removal of the template fiber.

[0032] The above technical solution can achieve patterned preparation by coating a protective layer (or forming a protective layer by other means, such as vapor deposition). Especially for fabric applications, after weaving, a protective layer can be used to shield certain areas in a patterned manner, and only the template fibers in the remaining areas can be removed, thus achieving programmable patterned drive.

[0033] This invention also provides a continuous large-pitch fiber actuator prepared by the above-described method.

[0034] Furthermore, the preparation method provided by this invention can be combined with a fabrication method; that is, the embodiments of this invention also provide a method for manufacturing a fabric with a driving function, which includes the following steps: Functional fibers and template fibers are provided, wherein the functional fibers have artificial muscle-driving properties; The functional fibers and template fibers are twisted or braided together to form twisted fibers; At least the plyed fibers are used to construct the fabric precursor; The fabric precursor is subjected to heat setting treatment to fix the functional fibers into a spiral morphology; The template fibers are dissolved or decomposed to remove them, thereby obtaining a fabric with driving function.

[0035] In some implementations, the manufacturing method specifically includes the following steps: Provide base fabric; The ply fibers are woven into the base fabric by stitching to form the fabric precursor.

[0036] This invention also provides a fabric with driving function obtained by the above manufacturing method.

[0037] Based on the above technical solutions, the embodiments of the present invention also provide the application of the large-pitch fiber actuator provided in any of the above embodiments or the fabric provided in any of the above embodiments in wearable drive devices.

[0038] The technical solution of the present invention will be further described in detail below through several embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only for illustrating the present invention and do not limit the scope of the present invention.

[0039] Example 1 1) Preparation method, mainly including the following steps: Step 1: Pre-twisting treatment before plying functional base fibers and polyvinyl alcohol fibers First, prepare two types of fiber materials: take silver-plated nylon fiber as an example, use it as a functional fiber, and use water-soluble polyvinyl alcohol fiber as a sacrificial template. Apply the set twist to the two fibers in the same direction using a twisting machine.

[0040] Step 2: Continuous fiber preparation using a tension closed-loop control system. like Figure 1 As shown, silver-plated nylon fibers and polyvinyl alcohol fibers, which have been twisted separately, are fixed on two pay-off shafts. A synchronously rotating twisting motor performs a twisting operation, causing the two fibers to twist into a stable composite helical structure under axial tension. During this process, it is important to ensure that the direction of twisting is consistent with the direction of pre-twisting of the two fibers to guarantee the consistency and stability of the formed structure.

[0041] Step 3: High-temperature annealing and heat setting to fix the composite spiral structure Will Figure 1 The composite spiral fibers, after being twisted together, undergo annealing and heat setting. Under high temperature, the silver-plated nylon fibers undergo molecular chain rearrangement and structural shaping, while the polyvinyl alcohol fibers serve only as a support template at the annealing temperature, ensuring the formation of the composite spiral structure.

[0042] Step 4: Dissolve the sacrificial template to obtain large-pitch helical fibers. like Figure 1 As shown, composite spiral fibers, heat-set by high-temperature annealing, are introduced into an overflow tank filled with water. A digitally displayed constant-temperature water bath is installed at the bottom of the overflow tank. The dissolution rate of polyvinyl alcohol (PVA) fibers can be adjusted by regulating the water temperature, which is positively correlated with the water temperature. During this process, the PVA fibers automatically peel off the structural system, leaving only the already-formed silver-plated nylon large-pitch spiral fiber structure. To ensure complete dissolution and structural integrity, parameters such as the length of the overflow tank, the fiber flow rate, and the water temperature must be properly set and controlled. Finally, the fibers are reciprocated and wound up using a take-up device to complete the continuous production of large-pitch spiral fibers in batches.

[0043] 2) Experimental results: Figure 2 It is the process of removing polyvinyl alcohol fibers from water; Figure 3 It is a spiral fiber with different pitches that is continuously prepared by using the "sacrificial template method" to produce four strands of silver-plated nylon fiber and polyvinyl alcohol fiber of different specifications. Figure 4 It involves combining four strands of silver-plated nylon fiber with polyvinyl alcohol fiber of the same specification. The twist of the four strands of silver-plated nylon fiber can be controlled by the "sacrificial template method" to obtain spiral fibers with large pitch and different twists. Figure 5The relationship between fiber shrinkage and p / d ratio under different applied stress conditions was shown. The applied voltage was 25 V and the current was 0.6 A. The curves show that the fiber shrinkage performance significantly improves with increasing p / d ratio. The shrinkage of different samples initially increases and then decreases with increasing applied stress, indicating the existence of an optimal load range. The fiber with p / d = 1.42 exhibits the best driving performance, reaching a maximum shrinkage of 41.78% under an applied stress of 2.1 MPa. When the p / d ratios are 1.16, 0.97, 0.86, and 0.77, the corresponding maximum shrinkages are 36.2%, 29.1%, 27.8%, and 26.9%, respectively.

[0044] Figure 6 This study compares the driving performance of four strands of silver-plated nylon fibers with different twists under a 25 V voltage and a 0.5 A current, while maintaining a pre-twist of 300 turns·m for the polyvinyl alcohol fibers. -1 Under constant conditions, as the pre-twist of the silver-plated nylon fiber increases, the overall driving force of the fiber shows an increasing trend, indicating that the degree of pre-twist before the formation of the helical structure is positively correlated with the final driving performance. When the pre-twist of the silver-plated nylon fiber is 300 turns m... -1 350 turns m -1 400 turns m -1 450 turns·m -1 and 500 turns·m -1 At that time, the maximum driving amount of the helical fiber was 8.43% (0.7 MPa), 17.59% (1.4 MPa), 31.89% (1.4 MPa), 32.06% (1.4 MPa) and 34.92% (2.1 MPa), respectively.

[0045] Figure 7 The left figure shows the maximum shrinkage and average shrinkage rate of the large-pitch fiber actuator under different currents under a stress of 0.3N (2.1 MPa); the right figure shows the maximum shrinkage and average shrinkage rate of the fiber under different applied stresses at a current of 1.5 A. Figure 8 It can be seen that the maximum work done by the large-pitch fiber actuators with p / d ratios of 1.42 and 0.77 is 1.42 J g, respectively. -1 and 1.06J g -1 . Figure 9 The large-pitch fiber actuator, under a stress of 0.7 MPa, showed no significant decrease in driving force after 1000 cycles and could still maintain more than 30%.

[0046] Figure 10Polyester, polyethylene, and spandex fibers were selected as functional fibers and plyed with polyvinyl alcohol fibers to prepare large-pitch fibers. The final morphologies of the plyed fibers, the fibers after annealing and heat setting, and the fibers after removing the polyvinyl alcohol fibers were shown sequentially. It can be seen that different functional fibers can be plyed with polyvinyl alcohol fibers, heat-set, and then the sacrificial template is removed to prepare large-pitch helical fibers. This indicates that this method is not only applicable to a single material system, but also has good applicability and universality to different types of functional fibers, and can be used to prepare large-pitch helical fibers of different materials.

[0047] Figure 11 Under a load of 0.01 N, the driving performance of different large-pitch functional fibers increased from 30 ℃ to 137 ℃. Polyester fiber (PET) showed the most outstanding driving performance, with a maximum driving amount of 51.2%; nylon fiber (PA) and polyethylene fiber (PE) had maximum driving amounts of 22.6% and 20.8%, respectively; spandex fiber (SP) had the lowest driving amount of 9.3%.

[0048] This result demonstrates that by combining the "sacrificial template method" with a continuous fabrication process, large-pitch fiber actuators can be fabricated efficiently without requiring "muscle training" to open the fiber pitch. Furthermore, the twist and pitch of the large-pitch helical fiber can be controlled. This method also has good applicability to fiber materials, not only applicable to a single type of fiber but also extending to large-pitch structural components made of various functional fiber materials. Therefore, this method has greater application potential and engineering promotion value.

[0049] Figure 12 It is a large-pitch fiber actuator made of silver-plated nylon fiber with a diameter of 425μm and polyvinyl alcohol fiber with a diameter of 361μm, using different numbers of polyvinyl alcohol fibers respectively; Figure 13 It is a process of preparing by plying together silver-plated nylon fibers of different numbers and one polyvinyl alcohol fiber; Figure 14 This demonstrates the braided structure of multiple silver-plated nylon fibers and polyvinyl alcohol fibers, fully illustrating that the method is applicable to braided structures and multi-strand fiber co-twisted and ply-ply structures.

[0050] It should be noted that the preferred process parameters adopted in this embodiment are not applicable to all embodiments. Depending on the fiber material and diameter, the appropriate twist, temperature, spiral parameters and other conditions should be different. When implementing this invention, those skilled in the art should not be limited to the specific parameter range in the embodiment, but should determine the preferred parameter range through condition experiments based on the guidance of the implementation of this invention.

[0051] Example 2 This embodiment, based on embodiment 1, implements segmented driving behavior.

[0052] Figure 15 The process involves partially coating a polydimethylsiloxane film onto fibers prepared by continuous twisting, and then removing the unprotected polyvinyl alcohol fibers by water dissolution, thereby achieving shrinkage in specific areas (for example, in a woven structure, protecting one area and removing the template fibers in another area to achieve patterning drive).

[0053] Example 3 This embodiment is based on Embodiment 1 and implements a fabric-based technical solution.

[0054] Figure 16 The optical image shows how the fabric was created by sewing plied fibers onto the fabric and then immersing it in water to remove all the polyvinyl alcohol fibers, thus enabling the fabric to be fabricated.

[0055] Figure 17 The fabric was immersed in water to remove all the polyvinyl alcohol fibers on the side in contact with water, while the other side was left intact. Then, an electrothermal drive test was performed under a current of 0.5A and a load of 0.8N. It can be seen that the deformation of the fabric can reach about 15%.

[0056] Figure 18 The fabric is placed on a table, and water is added to a specific location using a dropper to remove the polyvinyl alcohol fibers that have come into contact with water. The fabric is then subjected to an electrothermal drive test under a current of 0.5A and a load of 0.8N, and the fabric deformation can reach approximately 9%.

[0057] The above results provide a solution for manufacturing smart garments driven by large-pitch fiber actuators and programmable-driven deformable fabrics using industrial sewing equipment.

[0058] Example 4 Based on Example 1, this embodiment prepares various large-pitch fiber actuators by replacing the template material.

[0059] In this embodiment, the sacrificial template fiber is not limited to water-soluble polyvinyl alcohol fiber. Other selectively removable template materials can be selected based on the functional fiber's tolerance and post-processing conditions. The template material can be a water-soluble template fiber, such as sodium alginate fiber or some PEG fibers; it can also be an organic solvent-removable template fiber, such as ethanol-removable PVP fibers, acetone-removable cellulose acetate fibers, and PLA fibers removable by organic solvents such as chloroform, dichloromethane, or dioxane. Any template material that can be selectively removed and release helical winding stress during post-processing without significantly damaging the main structure of the functional fiber can be used as an alternative embodiment of the present invention. Example 5 Based on Example 1, this embodiment prepares various large-pitch fiber actuators by replacing the removal of the sacrificial template.

[0060] In addition to water dissolution, this embodiment can remove the sacrificial template by thermal decomposition. For example, a biodegradable template material with a thermal decomposition temperature lower than the thermal stability temperature of the silver-plated nylon fiber (such as a thermally degradable polymer fiber, but with a thermal decomposition temperature higher than the temperature of the heat setting treatment) can be selected to cause thermal decomposition or thermal evaporation of the template material. This allows the template to be removed without damaging the structure of the silver-plated nylon fiber, while retaining a stable large-pitch helical structure.

[0061] Besides using high-temperature tube furnaces for high-temperature tempering and heat setting, infrared heating, hot air circulation heating, oil bath heating, or microwave heating can also be used for heat setting of helical fibers to achieve molecular chain rearrangement and helical structure stabilization. In addition, photo-induced pyrolysis can also be used as an equivalent alternative.

[0062] Example 6 Based on Example 1, this embodiment prepares various large-pitch fiber actuators by using different functional fiber materials.

[0063] In this embodiment, the functional fiber material is not limited to silver-plated nylon fiber. Other fiber materials capable of forming a helical drive structure can be selected based on differences in driving method, mechanical properties, heat resistance, conductivity, dielectric properties, and application scenarios. The functional fiber can be polymer fiber, composite polymer fiber, conductive polymer fiber, carbon fiber, or other fiber materials capable of achieving a driving function.

[0064] The polymer functional fibers include, but are not limited to: nylon fibers, spandex fibers, polyimide fibers, aramid fibers, polyethylene fibers, ultra-high molecular weight polyethylene fibers, polyacrylonitrile fibers, polyvinylidene fluoride fibers, polydimethylsiloxane fibers, polytetrafluoroethylene fibers, polyester fibers, polyethylene terephthalate fibers, polypropylene fibers, polyurethane fibers, polylactic acid fibers, polyetheretherketone fibers, polyphenylene sulfide fibers, liquid crystal polymer fibers, polyvinyl chloride fibers, polyvinyl alcohol acetal fibers, polymethyl methacrylate fibers, thermoplastic elastomer fibers, and their blends, composites, or modified fibers.

[0065] The carbon material functional fibers include, but are not limited to: carbon nanotube fibers, carbon fibers, graphene fibers, reduced graphene oxide fibers, carbon nanotube / polymer composite fibers, carbon fiber / polymer composite fibers, graphene / polymer composite fibers, and other conductive, thermally responsive, or electrochemically responsive fibers constructed based on carbon materials.

[0066] The functional fibers can also be surface-metallized, conductively coated, or composite-modified fiber materials, including but not limited to silver-plated fibers, copper-plated fibers, nickel-plated fibers, conductive polymer-coated fibers, carbon-coated fibers, and metal / polymer composite fibers. The specific material selection of the functional fibers can be adjusted according to the driving mode of the target artificial muscle, such as thermal driving, electrothermal driving, electrochemical driving, dielectric driving, humidity driving, or multi-field coupling driving.

[0067] Any fiber material that can maintain its basic structural integrity during the pre-twisting, twisting, heat setting, and subsequent sacrificial template removal processes described in this invention, and achieve a driving effect after forming a large-pitch helical configuration, should be considered as an alternative implementation of the functional fiber material of this invention.

[0068] Through the above embodiments, it is clear that the embodiments of the present invention employ the "sacrificial template method" to prepare large-pitch fiber actuators. This involves composite design of functional fibers and selectively removable template fibers, applying twist to each fiber and then twisting them together to form a composite helical structure. The overall configuration is then stabilized through annealing and heat setting. Finally, the water-soluble template fibers are dissolved and removed using room-temperature water, thereby releasing the initial winding stress within the helical structure and significantly increasing the fiber pitch, directly obtaining a structurally stable large-pitch fiber actuator. The core idea of ​​this invention is to utilize sacrificial template fibers to construct a temporary support and constraint structure, which is then gently removed after heat setting to avoid complex disassembly or mechanical extraction of the target functional fibers themselves. Therefore, this method is not limited to the specific material combination of silver-plated nylon fibers and polyvinyl alcohol fibers, but can be further extended to other functional fiber and removable template fiber systems. By changing the functional fiber material, the type and specifications of the sacrificial template, the pre-twisting parameters, and the plying method, large-pitch fiber actuators suitable for different driving modes, structural configurations, and application scenarios can be constructed, giving the invention strong versatility, platform potential, and engineering promotion value.

[0069] The advantages of the above technical solution include at least the following: 1. By selecting different types and specifications of sacrificial template fibers and combining the pre-twisting parameters and ply twisting parameters of functional fibers, the pitch, twist, and final structural morphology of the fiber actuator can be precisely controlled to meet different application requirements.

[0070] 2. By removing the water-soluble sacrificial template with room temperature water after heat setting, the residual stress in the helical structure can be effectively released, the pitch can be significantly increased, and a relaxed and stable large pitch structure can be directly formed, avoiding the traditional training process.

[0071] 3. The template removal process does not require complex mechanical dissociation, extraction or organic solvent treatment, making the process path simpler. This reduces process complexity, time cost and preparation loss, and helps improve the yield and structural consistency of the finished product.

[0072] 4. This method uses a water-soluble template removal pathway, with mild processing conditions, and has the advantages of being green, environmentally friendly, low-pollution, and sustainable, making it more suitable for the process development needs of large-scale preparation.

[0073] 5. The fiber actuator obtained by the present invention can not only obtain a large driving amount, but also maintain good structural stability and work capacity, which is conducive to meeting the application requirements of high-performance flexible actuation devices.

[0074] 6. The manufacturing process chain is clear and can be connected with units such as continuous unwinding, continuous pre-twisting, continuous plying and twisting, continuous heat setting, continuous water bath template removal, and continuous winding, which has the potential to achieve continuous and batch manufacturing.

[0075] 7. This method has good versatility and scalability. It is not only applicable to multi-material systems composed of different functional fibers and different sacrificial template fibers, but can also be extended to various complex configurations such as large-pitch helical structures, non-prestressed secondary helical fiber structures, braided structures, and multi-strand fiber co-twisted and stranded structures.

[0076] 8. This method can also be combined with hand weaving, sewing machines or other industrial equipment to selectively remove template fibers after the ply-stranded fibers are woven or patterned, thereby preparing fabrics or three-dimensional patterned structures with programmable deformation capabilities, expanding the application range of fiber actuators in smart fabrics and flexible devices.

[0077] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a large-pitch fiber actuator, characterized in that, include: Functional fibers and template fibers are provided, wherein the functional fibers have artificial muscle-driving properties; The functional fibers and template fibers are twisted or woven together to form a ply fiber, in which the functional fibers and template fibers are in close contact. The twisted fibers are heat-set to shape the functional fibers into a helical morphology. The template fibers are dissolved or decomposed to remove them, thereby obtaining a large-pitch fiber actuator.

2. The preparation method according to claim 1, characterized in that, The functional fibers and template fibers have a preset twist. When performing the ply twisting or ply weaving, the helical direction of the functional fiber and the template fiber is consistent with the direction of the preset twist.

3. The preparation method according to claim 1, characterized in that, When the removal method of the template fiber is selected as dissolution, the material of the template fiber includes any one or a combination of two or more of polyvinyl alcohol, sodium alginate, PEG, PVP, cellulose acetate, and PLA.

4. The preparation method according to claim 1, characterized in that, The functional fibers include any one or a combination of two or more of the following: metal composite polymer fibers, conductive polymer fibers, and carbon material-based composite fibers.

5. The preparation method according to claim 1, characterized in that, Also includes: When a protective layer is used to cover a portion of the stranded fiber, the template fiber within the segment of the protective layer is retained during the dissolution or decomposition removal of the template fiber.

6. A continuous large-pitch fiber actuator prepared by the preparation method according to any one of claims 1-5.

7. A method for manufacturing a fabric with a driving function, characterized in that, include: Functional fibers and template fibers are provided, wherein the functional fibers have artificial muscle-driving properties; The functional fibers and template fibers are twisted or braided together to form twisted fibers; At least the plyed fibers are used to construct the fabric precursor; The fabric precursor is subjected to heat setting treatment to fix the functional fibers into a spiral morphology; The template fibers are dissolved or decomposed to remove them, thereby obtaining a fabric with driving function.

8. The manufacturing method according to claim 7, characterized in that, Specifically, it includes: Provide base fabric; The ply fibers are woven into the base fabric by stitching to form the fabric precursor.

9. A fabric with a driving function obtained by the manufacturing method according to any one of claims 7-8.

10. The application of the large-pitch fiber actuator of claim 6 or the fabric of claim 9 in a wearable actuation device.

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