Self-powered spacer fabric based on electromagnetic induction and method of making same

Abstract

The application provides a self-powered interval fabric based on electromagnetic induction and a preparation method thereof. The self-powered interval fabric based on electromagnetic induction is obtained by mixing an elastic polymer and magnetic particles in proportion, loading the mixture on one side of the interval fabric, forming a magnetic layer, and simultaneously sewing a conductive fiber in a loop shape on the side of the interval fabric opposite to the magnetic layer to form a conductive coil. Through the above method, when the obtained self-powered interval fabric based on electromagnetic induction is compressed or tapped, the conductive coil on both sides of the interval fabric can be made to approach or move away from the magnetic layer, so that the magnetic flux in the conductive coil changes, an induced electromotive force is generated, the self-power supply of the flexible sensing fabric is realized, and sufficient electrical signal changes can be generated only through human actions or external forces under the condition that no external power supply equipment is needed, so as to be used for sensing and monitoring.

Description

Technical Field

[0001] This invention relates to the field of flexible sensing fabric technology, and in particular to a self-powered spacer fabric based on electromagnetic induction and its preparation method. Background Technology

[0002] Currently, flexible sensing technology is developing rapidly and is gradually being applied in fields such as personal health monitoring, human-computer interaction, and soft robotics. However, this technology requires external power supply / storage devices (such as batteries), which limits its application range, lifespan, and lightweight design. Therefore, self-powering of flexible sensing devices is crucial.

[0003] Electromagnetic induction is the phenomenon where a change in magnetic flux through a closed loop induces an electromotive force. First discovered by Faraday, this phenomenon led to the emergence of self-generating devices based on electromagnetic induction, which gradually became an important energy harvesting method. However, in current self-generating devices, the conductive coils and magnets are mostly made of rigid materials, are heavy, and lack flexibility and elasticity, making them difficult to integrate with flexible sensor components.

[0004] Furthermore, most existing flexible sensors based on electromagnetic induction are designed as separate units. For example, patent CN111636130A discloses a flexible fabric for swinging electromagnetic induction power generation, its production method, and its application. This patent utilizes the electromagnetic induction effect of the human body to convert the mechanical energy generated during arm swinging / walking into electrical energy by setting magnetic yarn fabric and conductive coil fabric on the surfaces of two relatively swinging parts. However, the magnetic fabric and conductive coil fabric formed in this way are separate and can only be applied to two different surfaces with relative swinging, which limits its practical application scenarios.

[0005] In view of this, it is necessary to design an improved self-powered fabric based on electromagnetic induction, so that the same fabric has both a magnetic layer and a conductive coil, in order to solve the above problems. Summary of the Invention

[0006] To address the shortcomings of the existing technology, the present invention aims to provide a self-powered spacer fabric based on electromagnetic induction and its preparation method. The present invention involves placing conductive coils and magnetic layers on opposite sides of the spacer fabric. Compressing or patting the fabric causes the conductive coils and magnetic layers to move closer or further apart, thereby changing the magnetic flux within the conductive coils and generating an induced electromotive force, thus achieving self-powering of the flexible sensing fabric.

[0007] To achieve the above objectives, the present invention provides a method for preparing a self-powered spacer fabric based on electromagnetic induction, comprising the following steps:

[0008] S1. After mixing the pretreated elastic polymer with magnetic particles in a predetermined ratio, the mixture is loaded onto one side of the spacer fabric. After shaping and magnetization, a magnetic layer is formed on one side of the spacer fabric.

[0009] S2. Conductive fibers are sewn in a loop onto the side of the spacer fabric opposite to the magnetic layer to obtain a self-powered spacer fabric based on electromagnetic induction.

[0010] As a further improvement of the present invention, the spacer fabric includes a top layer and a bottom layer formed by interlocking yarn loops, and a spacer yarn located between the top layer and the bottom layer;

[0011] The method for preparing the spacer fabric includes: knitting yarns into loops using a knitting process and connecting them interlocking to obtain the top layer and the bottom layer; and alternately connecting the top layer and the bottom layer in a looping manner in the vertical direction to form multiple spacer yarns that provide support.

[0012] As a further improvement of the present invention, the thickness of the spacer fabric is 1 to 10 cm; the thickness of the magnetic layer is 0.5 to 5 mm.

[0013] As a further improvement of the present invention, in step S1, the mass ratio of the elastic polymer to the magnetic particles is 80:20 to 20:80.

[0014] As a further improvement of the present invention, in step S1, the magnetization process is as follows: the shaped fiber to be magnetized is placed under a voltage of 1500-3000V and magnetized for 1 to 2000ms.

[0015] As a further improvement of the present invention, in step S1, the pretreatment operation of the elastic polymer is: dissolving the granules of the elastic polymer in a solvent.

[0016] As a further improvement of the present invention, in step S1, the elastic polymer includes any one of polyvinyl alcohol, polyurethane, polydimethylsiloxane, polymethylvinylsiloxane, polypropylene, polyolefin and styrene polymer.

[0017] As a further improvement of the present invention, in step S1, the magnetic particles include any one of neodymium iron boron magnetic powder, neodymium nickel cobalt magnetic powder, iron oxide magnetic powder, chromium dioxide magnetic powder, and cobalt-iron oxide magnetic powder.

[0018] As a further improvement of the present invention, in step S2, the conductive fiber includes any one of carbon fiber, graphene fiber, carbon nanotube fiber, silver-plated fiber, copper-plated fiber, gold-plated fiber, aluminum-plated fiber, iron-plated fiber, copper fiber, silver fiber, gold fiber, aluminum fiber, and iron fiber.

[0019] The present invention also provides a self-powered spacer fabric based on electromagnetic induction, which is prepared by any of the above technical solutions and includes a spacer fabric, a magnetic layer disposed on one side of the spacer fabric, and a conductive coil disposed on the side of the spacer fabric opposite to the magnetic layer.

[0020] The beneficial effects of this invention are:

[0021] 1. The method for preparing a self-powered spacer fabric based on electromagnetic induction provided by this invention involves mixing an elastic polymer with magnetic particles in a specific ratio and loading the mixture onto one side of a spacer fabric to form a magnetic layer. Simultaneously, conductive fibers are sewn in a circular pattern onto the side of the spacer fabric opposite to the magnetic layer to form a conductive coil, thereby obtaining a self-powered spacer fabric based on electromagnetic induction. Based on the structure of this spacer fabric, by compressing or beating the fabric, the relative distance between the two sides of the spacer fabric bearing the conductive coil and the magnetic layer changes, causing the conductive coil and the magnetic layer to move closer or further apart. This, in turn, changes the magnetic flux in the conductive coil, generating an induced electromotive force, thus achieving self-powering of the flexible sensing fabric.

[0022] 2. On the one hand, this invention fully enhances the magnetism of the magnetic layer through magnetization treatment, thereby increasing the magnetic induction intensity of the fabric. On the other hand, by designing a method for preparing the spacer fabric, it is possible to obtain a spacer fabric that is easy to deform and has good resilience, so that it can produce a large deformation after being subjected to external force, thereby increasing the change in magnetic flux in the conductive coil, and allowing it to rebound quickly after the external force is removed, further increasing the rate of change of magnetic flux, thereby generating sufficient electrical signal changes for sensing and monitoring, and improving the sensitivity of the monitoring.

[0023] 3. The self-powered spacer fabric based on electromagnetic induction provided by this invention integrates power supply and sensing on the fabric and clothing. Utilizing the flexibility of ordinary fibers and the elasticity of the magnetic layer and spacer fabric, it can be bent and rebound at will, making it easy for the human body to wear. Moreover, it does not require the use of external power supply equipment such as batteries. It can generate electrical signals through human body movements and external forces, and has a wide range of application prospects. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the self-powered spacer fabric based on electromagnetic induction provided by the present invention from one viewpoint.

[0025] Figure 2 This is a structural schematic diagram of the self-powered spacer fabric based on electromagnetic induction provided by the present invention from another perspective.

[0026] Figure 3 This is a photograph of the spacer fabric prepared in Example 1.

[0027] Figure 4A schematic diagram of the structure of the self-powered fabric based on electromagnetic induction provided for Comparative Example 2.

[0028] Figure 5 The voltage change detection results for Example 1 caused by deformation are shown.

[0029] Figure 6 The voltage change detection results for Comparative Example 1 caused by deformation are shown.

[0030] Figure 7 The voltage change detection results for Comparative Example 2 are shown below.

[0031] Figure Labels

[0032] 10-Spacer fabric; 11-Top layer; 12-Bottom layer; 13-Spacer yarn; 20-Magnetic layer; 30-Conductive coil. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0035] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0036] This invention provides a method for preparing a self-powered spacer fabric based on electromagnetic induction, comprising the following steps:

[0037] S1. After mixing the pretreated elastic polymer with magnetic particles in a predetermined ratio, the mixture is loaded onto one side of the spacer fabric. After shaping and magnetization, a magnetic layer is formed on one side of the spacer fabric.

[0038] S2. Conductive fibers are sewn in a loop onto the side of the spacer fabric opposite to the magnetic layer to obtain a self-powered spacer fabric based on electromagnetic induction.

[0039] By compressing or beating the prepared self-powered spacer fabric based on electromagnetic induction in the above manner, the conductive coils and magnetic layers located on both sides of the spacer fabric can be brought closer or further apart, thereby changing the magnetic flux in the conductive coils and generating an induced electromotive force. This enables the flexible sensing fabric to be self-powered, and sufficient electrical signal changes can be generated by human movement or external force without the need for external power supply equipment, so as to be used for sensing and monitoring.

[0040] Specifically, the spacer fabric includes a top layer and a bottom layer formed by interlocking yarn loops, and a spacer yarn located between the top layer and the bottom layer;

[0041] The method for preparing the spacer fabric includes: knitting yarns into loops using a knitting process and connecting them interlocking to obtain the top layer and the bottom layer; and alternately connecting the top layer and the bottom layer in a looping manner in the vertical direction to form multiple spacer yarns that provide support.

[0042] The yarns used to prepare the top and bottom layers are one or more of cotton, polyester, nylon, carbon fiber, and glass fiber; the yarns used to prepare the spacer yarns are one or more of polyester, nylon, acrylic, iron wire, copper wire, glass fiber, and carbon fiber; and the thickness of the spacer fabric is preferably 1 to 10 cm.

[0043] The spacer fabric produced by the above method is flexible, lightweight, and breathable. Based on this spacer fabric, a self-powered spacer fabric based on electromagnetic induction can respond sensitively to actions such as slapping and twisting without requiring an external power supply. Due to the robust structure of the spacer fabric itself, the output electrical signal of the self-powered spacer fabric is more stable, which is beneficial for decoupling and analyzing the electrical signal in downstream applications.

[0044] More specifically, in step S1, the purpose of the pretreatment of the elastic polymer is to form a liquid phase that can be uniformly mixed with the magnetic particles. Specific pretreatment methods include dissolving the elastic polymer granules in a solvent, or preparing a polymer solution by mixing the main agent and the curing agent. The selection of the solvent, main agent, and curing agent is determined according to the type of elastic polymer, with the aim of enabling the elastic polymer to form a liquid phase that can be fully mixed with the magnetic particles; this invention does not limit this selection. The shaping treatment method in step S1 can also be freely selected according to the type of elastic polymer, with the aim of enabling the polymer to cure and set.

[0045] In step S1, the thickness of the magnetic layer can be adjusted by controlling the amount of elastic polymer and magnetic particles loaded on the surface of the spacer fabric; preferably, the thickness of the magnetic layer is 0.5 to 5 mm. This setting maintains the softness and lightweight properties of the fabric, while the thickness range can accommodate an appropriate amount of magnetic particles, ensuring that the magnetic field strength of the magnetic layer provides a sufficiently large electrical signal response to the conductive coil.

[0046] In step S1, the mass ratio of the elastic polymer to the magnetic particles is 80:20 to 20:80; the magnetization treatment involves placing the shaped fiber to be magnetized under a voltage of 1500-3000V for 1-2000ms. With this setup, the resulting magnetic fibers possess both good elasticity and high magnetic induction intensity.

[0047] Preferably, the elastic polymer includes any one of polyvinyl alcohol, polyurethane, polydimethylsiloxane, polymethylvinylsiloxane, polypropylene, polyolefins, and styrene polymers. The magnetic particles include any one of neodymium iron boron magnetic powder, neodymium nickel cobalt magnetic powder, iron oxide magnetic powder, chromium dioxide magnetic powder, and cobalt-iron oxide magnetic powder. The conductive fibers include any one of carbon fiber, graphene fiber, carbon nanotube fiber, silver-plated fiber, copper-plated fiber, gold-plated fiber, aluminum-plated fiber, iron-plated fiber, copper fiber, silver fiber, gold fiber, aluminum fiber, and iron fiber.

[0048] This invention also provides a self-powered spacer fabric based on electromagnetic induction, which is prepared by the above-described technical solution, and its structural schematic diagram is shown below. Figure 1 , Figure 2 As shown, it specifically includes a spacer fabric 10, a magnetic layer 20 disposed on one side of the spacer fabric, and a conductive coil 30 disposed on the side of the spacer fabric opposite to the magnetic layer 20; wherein, the spacer fabric 10 includes a top layer 11 and a bottom layer 12 formed by interlocking yarn coils, and a spacer yarn 13 located between the top layer 11 and the bottom layer 12.

[0049] The following describes the self-powered spacer fabric based on electromagnetic induction and its preparation method provided by the present invention with reference to specific embodiments.

[0050] Example 1

[0051] This embodiment provides a method for preparing a self-powered spacer fabric based on electromagnetic induction, including the following steps:

[0052] S1. Preparation of spacer fabric: Polyester yarns are knitted into loops and interlocked to form a top layer and a bottom layer; Acrylic yarns are alternately connected to the top layer and bottom layer in a loop-like manner in the vertical direction to form multiple spacer yarns that provide support.

[0053] A physical image of the spacer fabric produced in this embodiment is shown below. Figure 3 As shown, its thickness is 1cm.

[0054] S2. According to the instructions, the purchased polydimethylsiloxane silicone elastomer was mixed with solutions A and B at a mass ratio of 10:1 to obtain uncured polydimethylsiloxane silicone elastomer. Neodymium iron boron magnetic powder was added simultaneously to form a mixture, which was then poured into a mold. The lower side of the spacer fabric was then brought into contact with the mixture, allowing the mixture to be loaded onto the lower side of the spacer fabric. The mixture was dried at 80°C for 2 hours for curing and shaping. The cured and shaped fibers to be magnetized were then magnetized at 2000V for 20ms to obtain a spacer fabric with a magnetic layer loaded on the lower side. The mass ratio of polydimethylsiloxane to neodymium iron boron magnetic powder was 20:80, and the thickness of the magnetic layer was 2mm.

[0055] S3. Conductive fibers (copper fibers) are sewn in a loop onto the upper side of the spacer fabric to obtain a self-powered spacer fabric based on electromagnetic induction.

[0056] Comparative Examples 1-2

[0057] Comparative Examples 1 and 2 respectively provide a method for preparing a self-powered fabric based on electromagnetic induction. Compared with Example 1, Comparative Example 1 does not perform magnetization treatment in step S1, and Comparative Example 2 does not use spacer fabric. Instead, the mixture of elastic polymer and magnetic particles is directly shaped and magnetized in a mold to form a magnetic layer. Then, copper fibers are directly fixed in a loop on the surface of the magnetic layer (its structural schematic diagram is shown in Figure 1). Figure 4 As shown in the figure, the remaining steps are the same as in Example 1, and will not be repeated here.

[0058] The voltage changes of the self-energized fabrics based on electromagnetic induction prepared in Example 1 and Comparative Examples 1-2 were detected as a result of deformation. Figures 5-7 As shown.

[0059] The test results show that the signal strength of Example 1 is approximately three times that of Comparative Example 1. The magnetization process significantly enhances the voltage generated by the fabric. By increasing the magnetic field strength of the fabric, the induced electromotive force generated can be increased. Under the same force, the electrical signal output is stronger and more stable, which is beneficial for the reception and analysis of the backend signal. Compared with Comparative Example 2, Example 1 has a greater advantage in signal strength. Under the same pressing force, the displacement of the vertical distance between the fabric in Example 1 is better than that of the mixture of elastic polymer and magnetic particles in Comparative Example 2. The larger change in magnetic flux per unit time is positively correlated with the generation of induced electromotive force. Therefore, Example 1 has a higher voltage peak. At the same time, the stable structure and integrated design of the fabric can ensure the long-term stable application of the present invention. Compared with Comparative Example 2, the coil in Example 1 is combined with the fabric. Due to the regularity of the fabric structure, the coil can be neatly arranged in the interwoven structure through sewing, which can effectively reduce the difference between individual products and ensure the stability of product performance.

[0060] Examples 2-5

[0061] Examples 2-5 provide a method for preparing a self-powered spacer fabric based on electromagnetic induction. Compared with Example 1, in Example 2, only the mass ratio of elastic polymer to magnetic particles is adjusted to 50:50; in Example 3, only the mass ratio of polydimethylsiloxane to neodymium iron boron magnetic powder is adjusted to 80:20; in Example 4, only the thickness of the magnetic layer is adjusted to 1 mm; and in Example 5, only the thickness of the spacer fabric is adjusted to 3 cm. The remaining steps are the same as in Example 1 and will not be repeated here.

[0062] Testing showed that the self-energized spacer fabrics based on electromagnetic induction prepared in Examples 2-5 all generated strong voltage changes with deformation. Compared with Example 1, due to the reduction in magnetic particle content, the magnetic field strength generated by the magnetic layer decreased, and the electromagnetic induced electromotive force generated by the action triggering conductive coil moving away / approaching decreased. Therefore, the voltage signal strength in Examples 2 and 3 showed a gradually decreasing trend. In Example 4, the thickness of the magnetic layer decreased, and the overall flexibility of the fabric was improved to some extent. However, the overall reduction in magnetic particle content led to a decrease in the induced electromotive force, resulting in a decrease in the collected electrical signal strength. In Example 5, the increase in the thickness of the spacer fabric increased the vertical displacement range of the fabric. However, the magnetic field range of the magnetic layer was limited, and the conductive fibers farther from the magnetic layer could not sense changes in magnetic flux. The sensing performance for small forces was weak, thus hindering the output and analysis of electrical signals.

[0063] In summary, this invention provides a self-powered spacer fabric based on electromagnetic induction and its preparation method. This invention involves mixing an elastic polymer with magnetic particles in a specific ratio and loading the mixture onto one side of a spacer fabric to form a magnetic layer. Simultaneously, conductive fibers are sewn in a circular pattern onto the side of the spacer fabric opposite the magnetic layer to form conductive coils, thus obtaining a self-powered spacer fabric based on electromagnetic induction. By compressing or beating the prepared self-powered spacer fabric based on electromagnetic induction, the conductive coils on both sides of the spacer fabric and the magnetic layer can be brought closer or further apart, causing a change in the magnetic flux in the conductive coils and generating an induced electromotive force. This achieves self-powering of the flexible sensing fabric, allowing sufficient electrical signal changes to be generated solely through human movement or external force for sensing and monitoring without the need for external power supply equipment.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a self-powered spacer fabric based on electromagnetic induction, characterized in that, Includes the following steps: S1. After mixing the pretreated elastic polymer with magnetic particles in a predetermined ratio, the mixture is loaded onto one side of the spacer fabric. After shaping and magnetization, a magnetic layer is formed on one side of the spacer fabric. S2. The conductive fibers are sewn in a loop onto the side of the spacer fabric opposite to the magnetic layer to obtain a self-powered spacer fabric based on electromagnetic induction. The spacer fabric includes a top layer and a bottom layer formed by interlocking yarn loops, and a spacer yarn located between the top layer and the bottom layer; The method for preparing the spacer fabric includes: knitting yarns into loops using a knitting process, and then connecting them to each other to obtain the top layer and the bottom layer; The yarns are alternately connected in a loop in the vertical direction between the top layer and the bottom layer to form multiple spacer yarns that provide support.

2. The method for preparing the self-powered spacer fabric based on electromagnetic induction according to claim 1, characterized in that: The thickness of the spacer fabric is 1 to 10 cm; the thickness of the magnetic layer is 0.5 to 5 mm.

3. The method for preparing a self-powered spacer fabric based on electromagnetic induction according to claim 1, characterized in that: In step S1, the mass ratio of the elastic polymer to the magnetic particles is 80:20 to 20:

80.

4. The method for preparing a self-powered spacer fabric based on electromagnetic induction according to claim 1, characterized in that: In step S1, the magnetization process is as follows: the shaped fiber to be magnetized is placed under a voltage of 1500-3000V and magnetized for 1-2000ms.

5. The method for preparing a self-powered spacer fabric based on electromagnetic induction according to claim 1, characterized in that: In step S1, the pretreatment operation of the elastic polymer is to dissolve the elastic polymer granules in a solvent.

6. The method for preparing a self-powered spacer fabric based on electromagnetic induction according to claim 1, characterized in that: In step S1, the elastic polymer includes any one of polyvinyl alcohol, polyurethane, polydimethylsiloxane, polymethylvinylsiloxane, polypropylene, polyolefin and styrene polymer.

7. The method for preparing a self-powered spacer fabric based on electromagnetic induction according to claim 1, characterized in that: In step S1, the magnetic particles include any one of neodymium iron boron magnetic powder, neodymium nickel cobalt magnetic powder, iron oxide magnetic powder, chromium dioxide magnetic powder, and cobalt-iron oxide magnetic powder.

8. The method for preparing a self-powered spacer fabric based on electromagnetic induction according to claim 1, characterized in that: In step S2, the conductive fiber includes any one of carbon fiber, graphene fiber, carbon nanotube fiber, silver-plated fiber, copper-plated fiber, gold-plated fiber, aluminum-plated fiber, iron-plated fiber, copper fiber, silver fiber, gold fiber, aluminum fiber, and iron fiber.

9. A self-powered spacer fabric based on electromagnetic induction, characterized in that: Prepared by any of the preparation methods described in claims 1-8; It includes a spacer fabric, a magnetic layer disposed on one side of the spacer fabric, and a conductive coil disposed on the spacer fabric on the side opposite to the magnetic layer.

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