Polyurethane fiber with magnetoelastic effect and fabric

Abstract

The utility model relates to a polyurethane fiber and fabric with magnetoelastic effect, the polyurethane fiber with magnetoelastic effect has a core-shell structure, the diameter is 400-600 [mu] m, the core layer is made of polyurethane containing magnetic particles, and the shell layer is made of polyurethane without magnetic particles; the flexible and wearable magnetic sensing fabric comprises base cloth, and magnetic sensing fibers and conductive wires which are respectively fixed on the base cloth, or the flexible wearable magnetic sensing fabric is of a warp and weft woven structure, the warp and the weft are independently selected from one or more of the magnetic sensing fibers and the conductive wires, and the warp and the weft are neither the conductive wires nor the magnetic sensing fibers at the same time; the magnetic sensing fiber is the polyurethane fiber with the magnetoelastic effect. According to the utility model, the magnetoelastic effect is realized in the flexible fiber; when the magnetic sensing fabric for flexible wearing is applied to the field of flexible wearing, the influence of body sweat or a water environment on a device can be effectively avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of magnetic sensing and relates to polyurethane fiber and fabric with magnetoelastic effect. Background Art

[0002] Flexible sensing materials are key components in the field of smart materials and wearable technologies. They provide innovative solutions for a variety of applications by combining sensing functions with soft, elastic and stretchable physical properties. Flexible sensing materials have great potential in the field of wearable devices and health monitoring. They can be integrated into clothing, watch straps, patches or shoes to monitor physiological parameters such as heart rate, blood pressure, body temperature, sweat composition in real time, and provide support for user health management and disease prevention. The development of flexible sensing materials has promoted the innovation of smart textiles, which not only provide comfort and beauty, but also sense, respond and adapt to their environment or user needs. For example, the thermal insulation of clothing can be automatically adjusted according to temperature changes, or the health of athletes can be monitored by analyzing biochemical indicators in sweat. Flexible sensors can be used to develop more natural and intuitive human-computer interaction interfaces, such as flexible touch screens, wearable controllers and smart home systems. These materials can detect touch, pressure, and even bending and stretching, creating a more humane and flexible interactive experience. Flexible sensing materials are essential for the development of soft robots and smart prostheses. They enable robots and prostheses to not only simulate the softness and flexibility of human limbs, but also sense the external environment and applied forces, providing more natural and precise control; flexible sensing materials can also be used in environmental monitoring, such as air quality detection, water quality monitoring and soil analysis. Their softness and lightness make it easy to integrate into various environments, and even develop degradable or environmentally friendly sensors to reduce the impact on the environment.

[0003] Magnetic fiber is a common flexible sensing material. For example, patent CN114062480A embeds magnetic fibers into composite materials, and by measuring the electrical signal response of the magnetic fibers under different energy impacts, the relationship between composite material damage and electrical signal changes can be established. Patent CN114061436A attaches or implants magnetic fiber sensors into the object to be tested, and measures the change in the curvature of the object to be tested by monitoring the impedance change of the magnetic fiber sensor during the service process. Patent CN114061435A connects sleeve electrodes at both ends of the magnetic fiber to enable the device to have a highly sensitive micro-strain monitoring capability, which can realize real-time monitoring of micro-strain of structural parts. However, the development of magnetic sensing fibers in the above-mentioned public patents is all for detecting material damage or strain, and does not involve the development of magnetic sensing fibers that can be used for flexible, wearable, self-powered sensing.

[0004] The document (Soft fibers with magnetoelasticity for wearable electronics. Nat Commun 2021, 12, 6755) mentions that NdFeB magnetic powder is mixed into silicone rubber, and a flexible magnetic sensing fiber is prepared by mechanical extrusion molding. After weaving it with conductive yarn, it can be used for stress sensing. The development of magnetic sensing fibers in this document is limited by the type of materials used and the preparation method. The modulus of the obtained magnetic sensing fiber is too small and the diameter is too large. It can only be used in weaving processes and cannot be used in other textile processes, which limits the wider application of magnetic sensing fibers in the field of flexible wearables.

[0005] Since water does not affect the change of magnetic field, magnetic sensing has the characteristic of intrinsic waterproofness. Therefore, applying magnetic sensing fibers to the field of flexible wearables can effectively avoid the influence of body sweat or water environment on the device.

[0006] Therefore, it is of great significance to study a polyurethane fiber and fabric with magnetoelastic effect that can be used for flexible wearables and is suitable for a variety of textile processes to solve the problems existing in the existing technology. Utility Model Content

[0007] The utility model aims to solve the problems existing in the prior art and provide a polyurethane fiber and fabric with magnetoelastic effect.

[0008] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0009] A polyurethane fiber with magnetoelastic effect, which is a core-shell structure, wherein the core layer is polyurethane containing magnetic particles, and the shell layer is polyurethane without magnetic particles;

[0010] The diameter of the polyurethane fiber having the magnetoelastic effect is 400 to 600 μm.

[0011] As the preferred technical solution:

[0012] In the polyurethane fiber with magnetoelastic effect as described above, the magnetic particles are neodymium iron boron powder modified by tetraethyl silicate (TEOS) and γ-aminopropyltriethoxysilane (KH550).

[0013] In the polyurethane fiber with magnetoelastic effect as described above, the particle size of the magnetic particles is 3 to 8 μm.

[0014] The specific steps of the preparation method of the polyurethane fiber with magnetoelastic effect are as follows:

[0015] (1) adding 5-10 g of tetraethyl silicate to a mixed solution of deionized water and anhydrous ethanol in a mass ratio of 1:1, and then adding 0.5-1 g of a dilute sulfuric acid solution (the mass ratio of sulfuric acid to water is 1:40-50), and magnetically stirring to completely hydrolyze the tetraethyl silicate to obtain a clear tetraethyl silicate hydrolysis solution;

[0016] Wherein, the mass ratio of tetraethyl silicate to a mixed solution of deionized water and anhydrous ethanol in a mass ratio of 1:1 is 1:2-4;

[0017] (2) adding 5 to 15 g of NdFeB into a mixed solution of deionized water and anhydrous ethanol in a mass ratio of 1:3, and mechanically stirring the mixed solution of NdFeB to disperse the NdFeB in the mixed solution of deionized water and anhydrous ethanol to obtain a NdFeB dispersion;

[0018] Wherein, the mass ratio of NdFeB to the mixed solution of deionized water and anhydrous ethanol in a mass ratio of 1:3 is 1 to 3:8;

[0019] (3) adding the tetraethyl silicate hydrolyzate solution obtained in step (1) and the NdFeB dispersion obtained in step (2) into a round-bottom flask, and reacting them under a heating condition of 50 to 70° C. with mechanical stirring for 6 to 8 hours, so that a condensation reaction of silicate occurs to form a silicon dioxide protective layer on the surface of the NdFeB particles;

[0020] Wherein, the volume ratio of tetraethyl silicate hydrolyzate solution to NdFeB dispersion is 1:2;

[0021] (4) After the reaction in step (3) is completed, the NdFeB is taken out from the reaction solution using a magnet, washed repeatedly with deionized water and anhydrous ethanol, and then dried in an oven, and then the NdFeB is fully ground to obtain NdFeB@SiO2;

[0022] (5) Anhydrous ethanol and deionized water are prepared into an ethanol solution in a mass ratio of 4:1, and then KH550 is added, and stirred with a glass rod for 10 to 20 minutes to uniformly disperse KH550 in the ethanol solution to obtain a KH550 solution; then the NdFeB@SiO2 particles of step (4) are added to the above KH550 solution while stirring, and then stirred with a glass rod to make the NdFeB@SiO2 particles and the KH550 solution fully contact, and then allowed to stand for 10 to 20 minutes, and then placed in a blast drying oven, dried at 60° C. for 60 hours, taken out and ground into powder, to obtain KH550 / NdFeB@SiO2;

[0023] The addition amount of KH550 is 2-5% of the mass of NdFeB@SiO2; the mass ratio of KH550 to ethanol solution is 1:80-200;

[0024] (6) adding polyurethane pellets (manufacturer: BASF, Germany, product number: Elastollan S85A11) into N,N-dimethylformamide, and dissolving under magnetic stirring at room temperature for 10 to 15 hours to obtain a polyurethane solution with a mass concentration of 20 to 30%;

[0025] (7) adding the KH550 / NdFeB@SiO2 prepared in step (5) to the polyurethane solution prepared in step (6) to prepare a mixed solution of KH550 / NdFeB@SiO2 and polyurethane in a mass ratio of 1 to 4:1;

[0026] (8) using the polyurethane solution prepared in step (6) as the shell component, and the mixed solution of KH550 / NdFeB@SiO2 and polyurethane prepared in step (7) as the core component for coaxial wet spinning, using deionized water as a coagulation bath, and then respectively undergoing post-stretching and winding with a stretching ratio of 1.125 to 1.5 times, taking out the fiber and drying it at room temperature to finally obtain a shell-core structure TPU-NdFeB@TPU fiber with a polyurethane shell layer and a polyurethane core layer of KH550 / NdFeB@SiO2, that is, a polyurethane fiber with a magnetoelastic effect;

[0027] Among them, the shell model of the coaxial needle is 14G, the core model is 18G, the polyurethane solution is extruded through the shell needle, and the mixed solution of KH550 / NdFeB@SiO2 and polyurethane is extruded through the core needle. The extrusion speed is 150μl / min; the winding speed is 180-240cm / min; an infrared heating lamp is placed between the post-stretching device and the fiber winding device to evaporate some of the residual N,N-dimethylformamide and water in the fiber;

[0028] (9) Using a magnetizer, the TPU-NdFeB@TPU fiber prepared in step (8) is magnetized to obtain a polyurethane fiber with a magnetoelastic effect.

[0029] The thickness of the shell-core layer of the finally prepared polyurethane fiber with magnetoelastic effect is 1:14-18.

[0030] The utility model provides a polyurethane fiber with magnetoelastic effect. The preparation method is not limited to coaxial wet spinning, and can also be prepared by melt spinning and other methods.

[0031] The utility model also provides a flexible wearable magnetic sensing fabric, comprising a base fabric and magnetic sensing fibers and conductive wires respectively fixed on the base fabric;

[0032] The magnetic sensing fiber is the polyurethane fiber with magnetoelastic effect as described above.

[0033] As the preferred technical solution:

[0034] In the flexible wearable magnetic sensing fabric as described above, the magnetic sensing fibers and the conductive lines are located on the same side or on the front and back sides of the base fabric, and the relative positions of the magnetic sensing fibers and the conductive lines are parallel or perpendicular to each other.

[0035] In the flexible wearable magnetic sensing fabric as described above, the magnetic sensing fibers and the conductive threads are fixed on the base fabric by sewing.

[0036] The utility model also provides a magnetic sensing fabric for flexible wearability, which is a warp and weft woven structure, wherein the warp and weft are independently selected from one or more of magnetic sensing fibers and conductive threads, and the warp and weft are neither conductive threads nor magnetic sensing fibers at the same time;

[0037] The magnetic sensing fiber is the polyurethane fiber with magnetoelastic effect as described above.

[0038] In the flexible wearable magnetic sensing fabric as described above, the conductive wire is a metal coated fiber, a conductive metal wire, a carbon material coated fiber, a conductive polymer coated fiber or a composite material coated fiber.

[0039] In the flexible wearable magnetic sensing fabric as described above, the conductive thread is a silver-coated nylon yarn (which is a specific metal-coated fiber).

[0040] Beneficial effects:

[0041] (1) The magnetoelastic effect of the prior art usually exists in rigid metals or alloys. The polyurethane fiber with magnetoelastic effect of the utility model realizes the magnetoelastic effect in flexible fibers, and its magnetic coupling is stronger than that of traditional rigid materials;

[0042] (2) The utility model is a kind of magnetic sensing fabric for flexible wearable. Since the magnetic field can penetrate water and the strength loss is negligible, the polyurethane fiber with magnetoelastic effect has intrinsic waterproofness. Applying the polyurethane fiber with magnetoelastic effect to the field of flexible wearable can effectively avoid the influence of body sweat or water environment on the device; and the application range is wide. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a side view of a core-shell structured polyurethane fiber with magnetoelastic effect according to Example 1;

[0044] Figure 2 is a front view of a core-shell structure polyurethane fiber with magnetoelastic effect according to Example 1;

[0045] Figure 3 is a stereoscopic diagram of a core-shell structure polyurethane fiber with magnetoelastic effect according to Example 1;

[0046] Figure 4 A magnetic sensing fabric for flexible wearable use prepared by a computer sewing machine in Example 2;

[0047] Figure 5 A magnetic sensing fabric for flexible wearable use prepared by a computer sewing machine in Example 3;

[0048] Figure 6 The present invention is a flexible wearable magnetic sensing fabric prepared by warp and weft weaving in Example 4;

[0049] Figure 7 is a graph of the current output signal of the fabric sample of Example 2 under 1000 cycles of 40N pressure test, and the frequency of pressure application is 1 Hz;

[0050] Figure 8 yes Figure 7 The test starts with a 10s current output;

[0051] Fig. 9 yes Figure 7 The current output of 10s after the test is completed;

[0052] Fig.10 is a surface SEM image of the polyurethane fiber with magnetoelastic effect of Example 1;

[0053] Fig.11 is a cross-sectional SEM image of the polyurethane fiber with magnetoelastic effect of Example 1;

[0054] Among them, 1-shell layer, 2-core layer, 3-base fabric, 4-polyurethane fiber with magnetoelastic effect, 5-silver-plated nylon yarn. DETAILED DESCRIPTION

[0055] The present invention is further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

[0056] Example 1

[0057] A polyurethane fiber having a magnetoelastic effect, such as Figures 1 to 3 , 10-11, which are core-shell structures, the core layer 2 is polyurethane containing magnetic particles, and the shell layer 1 is polyurethane without magnetic particles; the shell-core layer thickness ratio is 1:15;

[0058] The magnetic particles are neodymium iron boron powder modified by tetraethyl silicate and γ-aminopropyltriethoxysilane; the particle size of the magnetic particles is 3 to 8 μm;

[0059] The diameter of the polyurethane fiber having the magnetoelastic effect is 400 to 600 μm.

[0060] The above-mentioned method for preparing the polyurethane fiber with magnetoelastic effect comprises the following specific steps:

[0061] (1) adding 7.5 g of tetraethyl silicate to a mixed solution of deionized water and anhydrous ethanol in a mass ratio of 1:1, and then adding 0.6 g of a dilute sulfuric acid solution (the mass ratio of sulfuric acid to water is 1:40), and magnetically stirring for 10 min to obtain a tetraethyl silicate hydrolysis solution;

[0062] Wherein, the mass ratio of tetraethyl silicate to a mixed solution of deionized water and anhydrous ethanol in a mass ratio of 1:1 is 3:8;

[0063] (2) adding 10 g of NdFeB into a mixed solution of deionized water and anhydrous ethanol in a mass ratio of 1:3, and mechanically stirring to disperse the NdFeB in the mixed solution of deionized water and anhydrous ethanol to obtain a NdFeB dispersion;

[0064] Wherein, the mass ratio of NdFeB to the mixed solution of deionized water and anhydrous ethanol in a mass ratio of 1:3 is 1:4;

[0065] (3) adding the tetraethyl silicate hydrolyzate solution obtained in step (1) and the NdFeB dispersion obtained in step (2) into a round-bottom flask, and reacting them under mechanical stirring at 60° C. for 6 hours to cause a condensation reaction of silicate and form a silicon dioxide protective layer on the surface of the NdFeB particles;

[0066] Wherein, the volume ratio of tetraethyl silicate hydrolyzate solution to NdFeB dispersion is 1:2;

[0067] (4) After the reaction in step (3) is completed, the NdFeB is taken out from the reaction solution using a magnet, washed repeatedly with deionized water and anhydrous ethanol, and then dried in an oven, and then the NdFeB is fully ground to obtain NdFeB@SiO2;

[0068] (5) Anhydrous ethanol and deionized water are prepared into an ethanol solution in a mass ratio of 4:1, and then KH550 is added, and stirred with a glass rod for 10 minutes to uniformly disperse KH550 in the ethanol solution to obtain a KH550 solution; then the NdFeB@SiO2 particles of step (4) are added to the KH550 solution while stirring, and then stirred with a glass rod to make the NdFeB@SiO2 particles and the KH550 solution fully contact, let it stand for 5 minutes, and then place it in a forced air drying oven, dry it at 60°C for 60 hours, take it out and grind it into powder to obtain KH550 / NdFeB@SiO2;

[0069] The addition amount of KH550 is 2% of the mass of NdFeB@SiO2; the mass ratio of KH550 to ethanol solution is 1:200;

[0070] (6) adding polyurethane pellets (manufacturer: BASF, Germany, product number: Elastollan S85A11) into N,N-dimethylformamide, and dissolving under magnetic stirring at room temperature for 10 hours to obtain a polyurethane solution with a mass concentration of 25%;

[0071] (7) adding the KH550 / NdFeB@SiO2 prepared in step (5) to the polyurethane solution prepared in step (6) to prepare a mixed solution of KH550 / NdFeB@SiO2 and polyurethane in a mass ratio of 4:1;

[0072] (8) using the polyurethane solution prepared in step (6) as the shell layer component, and the mixed solution of KH550 / NdFeB@SiO2 and polyurethane prepared in step (7) as the core layer component for coaxial wet spinning, using deionized water as the coagulation bath, and then respectively stretching at a stretching ratio of 1.125 times and winding to finally obtain a shell-core structure TPU-NdFeB@TPU fiber with a shell layer of polyurethane and a core layer of polyurethane and KH550 / NdFeB@SiO2;

[0073] The polyurethane solution was extruded through a 14G needle, and the mixed solution of KH550 / NdFeB@SiO2 and polyurethane was extruded through an 18G needle. The extrusion speed was 150μl / min. The winding speed was 180cm / min.

[0074] (9) Using a magnetizer, the TPU-NdFeB@TPU fiber prepared in step (8) is magnetized to obtain a polyurethane fiber with a magnetoelastic effect.

[0075] Example 2

[0076] A magnetic sensing fabric for flexible wearable, such as Figure 4As shown, it includes a base fabric 3 and magnetic sensing fibers and conductive wires respectively fixed on the base fabric 3;

[0077] The size of the primary fabric (cotton) is 2.5×2.5cm;

[0078] The magnetic sensing fiber is the polyurethane fiber 4 with magnetoelastic effect of Example 1;

[0079] The magnetic sensing fiber and the conductive line are located on the same side of the base fabric, and the relative positions of the magnetic sensing fiber and the conductive line are perpendicular to each other;

[0080] The conductive thread is silver-coated nylon yarn 5;

[0081] The magnetic sensing fibers and the conductive threads are fixed to the base fabric by sewing.

[0082] When a pressure of 40N is applied to the magnetic sensing fabric used for flexible wearable devices, a current output of up to 470nA can be measured.

[0083] like Figure 7 As shown, the sensing stability test of the magnetic sensing fabric under a cyclic pressure of 40N shows that the signal output of the magnetic sensing fabric remains stable under the cyclic pressure test lasting up to 1000s.

[0084] Figure 8 is the signal of the first 10s of the stability test of the magnetic sensing fabric, Fig. 9 The signal of the last 10 seconds is used to test the stability of the magnetic sensing fabric. Fig. 9 The signal size and Figure 8 It remains consistent, indicating that the magnetic sensing fabric has good stability.

[0085] Example 3

[0086] A magnetic sensing fabric for flexible wearable, such as Figure 5 As shown, it includes a base fabric and magnetic sensing fibers and conductive wires respectively fixed on the base fabric;

[0087] The size of the primary fabric (cotton) is 2.5×2.5cm;

[0088] The magnetic sensing fiber is the polyurethane fiber with magnetoelastic effect of Example 1;

[0089] The magnetic sensing fibers and the conductive wires are located on the front and back sides of the base fabric, and the relative positions of the magnetic sensing fibers and the conductive wires are parallel to each other;

[0090] The conductive wire is an enameled copper wire with a diameter of 1 μm;

[0091] The magnetic sensing fibers and the conductive threads are fixed to the base fabric by sewing.

[0092] When a pressure of 40N is applied to the magnetic sensing fabric used for flexible wearable devices, a current output of up to 600nA can be measured.

[0093] Example 4

[0094] A magnetic sensing fabric for flexible wearable, such as Figure 6 As shown, it is a warp and weft weaving structure, the warp is a magnetic sensing fiber, and the weft is a conductive wire;

[0095] The magnetic sensing fiber is the polyurethane fiber 4 with magnetoelastic effect of Example 1;

[0096] The conductive thread is silver-coated nylon yarn 5;

[0097] When a pressure of 40N is applied to the magnetic sensing fabric used for flexible wearable devices, a current output of up to 400nA can be measured.

[0098] Example 5

[0099] An application of a flexible wearable magnetic sensing fabric, the specific process is as follows:

[0100] The flexible wearable magnetic sensing fabric of Example 2 is sewn along the edge onto an ordinary medical mask to obtain a smart mask for detecting the opening and closing of a human mouth.

[0101] When the smart mask is worn correctly, an electric current signal will be output when the mouth is opened.

[0102] Example 6

[0103] An application of a flexible wearable magnetic sensing fabric, the specific process is as follows:

[0104] The flexible wearable magnetic sensing fabric of Example 2 is sewn onto an ordinary glove along the edge to obtain a smart glove for detecting the bending of fingers.

[0105] After the prepared smart gloves are worn correctly, the fabric is located at the second joint of the index finger. When the finger is bent, an electric current signal is output, and the magnitude of the current increases with the degree of bending of the index finger.

[0106] Example 7

[0107] An application of a flexible wearable magnetic sensing fabric, the specific process is as follows:

[0108] The flexible wearable magnetic sensing fabric of Example 2 is fixed to the front end of a robotic arm to obtain a robotic arm for underwater detection.

[0109] The robotic arm is extended into the water through computer control. When the fabric fixed at the front end of the robotic arm touches an object in the water, an electric current signal is output, thus realizing the detection of underwater objects.

Claims

1. A polyurethane fiber with magnetoelastic effect, characterized in that: It is a core-shell structure, the core layer is polyurethane containing magnetic particles, and the shell layer is polyurethane without magnetic particles; The diameter of the polyurethane fiber having the magnetoelastic effect is 400 to 600 μm.

2. The polyurethane fiber with magnetoelastic effect according to claim 1, characterized in that: The magnetic particles are neodymium iron boron powder modified by tetraethyl silicate and γ-aminopropyltriethoxysilane.

3. The polyurethane fiber with magnetoelastic effect according to claim 2, characterized in that: The particle size of the magnetic particles is 3 to 8 μm.

4. A magnetic sensing fabric for flexible wearable use, characterized in that: It includes a base fabric and magnetic sensing fibers and conductive wires respectively fixed on the base fabric; The magnetic sensor fiber is the polyurethane fiber with magnetoelastic effect as claimed in any one of claims 1 to 3.

5. The flexible wearable magnetic sensing fabric according to claim 4, characterized in that: The magnetic sensing fibers and the conductive wires are located on the same side or on the front and back sides of the base fabric, and the relative positions of the magnetic sensing fibers and the conductive wires are parallel or perpendicular to each other.

6. The flexible wearable magnetic sensing fabric according to claim 4, characterized in that: The magnetic sensing fibers and the conductive threads are fixed to the base fabric by sewing.

7. A magnetic sensing fabric for flexible wearable use, characterized in that: The structure is a warp-weft weaving structure, wherein the warp and weft are independently selected from one or more of magnetic sensing fibers and conductive threads, and the warp and weft are neither conductive threads nor magnetic sensing fibers at the same time; The magnetic sensor fiber is the polyurethane fiber with magnetoelastic effect as claimed in any one of claims 1 to 3.

8. A flexible wearable magnetic sensing fabric according to claim 4 or 7, characterized in that: The conductive wire is a metal coated fiber, a conductive metal wire, a carbon material coated fiber, a conductive polymer coated fiber or a composite material coated fiber.

9. The flexible wearable magnetic sensing fabric according to claim 8, characterized in that: The conductive thread is silver-coated nylon yarn.

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