Preparation method of high-sensitivity nanofiber composite burl core yarn strain sensor

Abstract

The application provides a preparation method of a high-sensitivity nanofiber composite bamboo-joint core-spun yarn strain sensor and belongs to the field of wearable flexible sensors. The method comprises the following steps: S1, polyurethane is dissolved in a solvent to prepare a spinning solution, nanofiber / drawing filament composite yarn is prepared through an electric auxiliary core spinning technology, and a stretching device is used to impart deformation to the drawing filament; S2, the composite yarn in the above deformation state is placed in a conductive nanoparticle / polymer dilute solution for immersion; S3, the immersed composite yarn is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation; and S4, the stretching device is removed, and the composite yarn is subjected to heat treatment to obtain a nanofiber composite bamboo-joint core-spun yarn sensor. The sensor has a radial core-shell structure and an axial concave-convex structure, is high in sensitivity, has a stress detection limit as low as 0.01 N, and simultaneously has excellent mechanical properties.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of wearable flexible sensors, and particularly relates to a preparation method of a high-sensitivity nanofiber composite bunched core yarn strain sensor. BACKGROUND

[0002] Yarn-based strain sensors have good flexibility, are easy to weave, and can be stretched and deformed, and thus have good application potential in human-computer interaction and intelligent wearable fields. The conjugate electrospinning process has the technical advantages of simple operation and wide raw material sources, and the obtained nanofiber yarn has the characteristics of small fiber diameter (300-1000 nm) and easy deformation under external force, and thus has unique advantages in the preparation of yarn-based strain sensors. For example, a carbon / graphene flexible strain sensor in patent CN201710451744.9 has the characteristics of brittleness and high conductivity, which may cause the sensor to be easily broken under stress, and the resistance change may not be sensitive; a multi-element nanocarbon fiber yarn strain sensor in patent CN202210296896.7 may have a performance decline after repeated use, such as a performance unchanged after more than 30 times of washing, which may affect the reliability of long-term use; a conductive spiral yarn self-powered sensor with a surface interval structure in patent CN202110795748.5 utilizes triboelectricity, and there may be a contact problem between the triboelectric layer and the conductive electrode, which affects the stability and durability of the sensor. The principle of the currently published nanofiber yarn sensor is that the slippage of nanofibers causes a change in the resistance of the yarn, but after twisting, the nanofibers are closely arranged and cannot sense small external forces, and the response time is long; at the same time, these nanofiber yarn sensors have low mechanical strength and poor sensing performance stability under repeated external force action, which limits their practical application in human activity monitoring, motion behavior tracking, medical health recovery, and user five-sense recognition fields.

[0003] Therefore, it is necessary to provide a preparation method of a high-sensitivity nanofiber composite bunched core yarn strain sensor to overcome the defects of low sensing sensitivity, long response time, inability to sense small external forces, and poor sensing performance stability under repeated external force action of the current yarn-based strain sensor. SUMMARY

[0004] The purpose of the present application is to overcome the defects of low sensing sensitivity, long response time, inability to sense small external forces, and poor sensing performance stability under repeated external force action of the current yarn-based strain sensor, and to provide a preparation method of a high-sensitivity nanofiber composite bunched core yarn strain sensor, wherein the preparation method is as follows:

[0005] The first step is to dissolve polyurethane in a good solvent to prepare a spinning solution, and to prepare a nanofiber / drawing filament composite yarn by an electric auxiliary core spinning technology, and to add an additional stress to the drawing filament to impart deformation;

[0006] The second step is to immerse the nanofiber / drawing filament composite yarn in the above deformed state in a conductive nanoparticle / polymer dilute solution;

[0007] The third step is to immerse the composite yarn after the above immersion in water, and to construct a nanoparticle / polymer conductive layer on the surface of the composite yarn by non-solvent induced phase separation;

[0008] The fourth step is to remove the additional stress, and to heat treat the composite yarn to remove the non-solvent water, to obtain a concave-convex nanofiber composite core-spun yarn sensor.

[0009] As a preferred technical solution:

[0010] The preparation method of a high-sensitivity nanofiber composite core-spun yarn strain sensor as described above, wherein the electric auxiliary core spinning technology in the first step is a synergistic combination of a conjugate electrospinning process and a core-spun yarn forming process, two injectors encapsulating spinning solutions are respectively connected with high-voltage positive and negative electrodes, nanofibers are collected by drawing filaments under a certain strain, and the nanofibers are coated on the drawing filaments to obtain a nanofiber composite yarn.

[0011] The preparation method of a high-sensitivity nanofiber composite core-spun yarn strain sensor as described above, wherein the polymer in the spinning solution of the electric auxiliary core spinning technology in the first step is polyurethane, and the solvent is one or a combination of N-N dimethylformamide, dimethyl sulfoxide, N-N dimethylacetamide, and acetone, and the mass fraction of the polymer in the spinning solution is 3-30%.

[0012] The preparation method of a high-sensitivity nanofiber composite core-spun yarn strain sensor as described above, wherein the polymer in the spinning solution of the electric auxiliary core spinning technology in the first step is polyurethane, and the solvent is one or a combination of N-N dimethylformamide, dimethyl sulfoxide, N-N dimethylacetamide, and acetone, and the mass fraction of the polymer in the spinning solution is 3-30%.

[0013] The preparation method of a high-sensitivity nanofiber composite core-spun yarn strain sensor as described above, wherein the positive and negative high-voltage voltages in the conjugate electrospinning process of the electric auxiliary core spinning technology are ±3-±30 kV, the spinning angles of the two injectors are 10-80°, the perfusion speed is 0.5-5 mL / h, the receiving distance is 5-30 cm, the spinning environment temperature is 10-40℃, and the environment humidity is 40%-90% RH.

[0014] The preparation method of the high-sensitivity nanofiber composite slub core yarn strain sensor as described above, in the second step of the impregnation process, the polymer is one or a combination of polyvinyl butyral, polyamide and polyvinylpyrrolidone, the conductive nanoparticles are one or a combination of silver nanoparticles, copper nanoparticles and carbon black nanoparticles, the solvent is one or a combination of ethanol, N-methyl pyrrolidone and tert-butyl alcohol, the mass fraction of the polymer in the prepared impregnation solution is 1-5%, the mass fraction of the conductive nanoparticles is 1-30%, and the impregnation time is 10-60 s.

[0015] The preparation method of the high-sensitivity nanofiber composite slub core yarn strain sensor as described above, in the third step of the impregnation process, water is selected as a non-solvent to induce polymer phase separation, and a stable nanoparticle / polymer conductive layer is constructed on the surface of the nanofiber composite yarn, the impregnation time is 10-60 s, and the soaking temperature is 20-30 DEG C.

[0016] The preparation method of the high-sensitivity nanofiber composite slub core yarn strain sensor as described above, in the fourth step of the heat treatment process, the heat treatment temperature is 70-160 DEG C, the treatment time is 5-30 min, and the nanofiber composite slub core yarn is obtained.

[0017] The preparation method of the high-sensitivity nanofiber composite slub core yarn strain sensor as described above, the nanofiber composite slub core yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, and when an external force acts, the nanofiber conductive layer produces a high-sensitivity straightening-deformation change, and the composite yarn sensor exhibits excellent negative resistance response characteristics.

[0018] The preparation method of the high-sensitivity nanofiber composite slub core yarn strain sensor as described above, the nanofiber composite slub core yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R2=99.8%), and a stress detection limit as low as 0.01 N, and the slub core yarn has excellent mechanical properties (tensile breaking strength≥100 MPa, elongation at break≥200%), and can be combined into a fabric through a weaving process to realize real-time detection of human motion state and physical health condition.

[0019] The beneficial effects of the present application are:

[0020] (1) The nanofiber composite bamboo core-spun yarn strain sensor of the present invention adopts the electric-assisted core spinning technology (combining the conjugated electrospinning process and the core-spun yarn forming process) to prepare the nanofiber / filament composite yarn, and adopts the stretching device to maintain a certain deformation of the involved filaments in the yarn-making process; and uses the non-solvent induced phase separation technology to construct the nanoparticle / polymer conductive layer under the stretching state. After completion, the external force of the stretching device is removed, and the involved filaments return to their original length, so that the final yarn has a radial core-shell structure and an axial concave-convex structure.

[0021] (2) The nanofiber composite bamboo core-spun yarn strain sensor in the present invention has an axial concave-convex structure, that is, the nanofiber conductive layer forms a regular arch structure in the axial direction of the filament. When an external force is applied, the nanofiber conductive layer produces a highly sensitive stretching-deformation change, which improves the sensing sensitivity of the strain sensor and quickly senses the external tiny external force.

[0022] (3) The nanofiber composite bamboo core-spun yarn strain sensor in the present invention has a radial core-shell structure, the inner layer is a polyurethane traction filament, and the outer layer is a nanofiber composite conductive layer. The traction filament of the inner layer ensures that the yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%) and has stable sensing performance under multiple cycles of external force.

[0023] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0025] Figure 1 Schematic diagram of the preparation process of a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic structural diagram of a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor in an embodiment of the present invention; wherein: 1 is a polyurethane pulling filament, 2 is a nanofiber layer, and 3 is a nanoparticle / polymer conductive layer. DETAILED DESCRIPTION

[0027] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, 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 fall equally within the scope limited by the appended claims of the application.

[0028] Example 1

[0029] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, comprising the following steps:

[0030] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 18% using NN dimethylformamide as solvent. In the conjugated electrospinning, the positive and negative high voltages are 10kV, the spinning angles of the two syringes are 30°, the spinning solution infusion speed is 1mL / h, the receiving distance is 10cm, the spinning environment temperature is 20℃, and the ambient humidity is 50%RH; the pulling filament uses 80dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament 80% deformation, and the polyurethane pulling filament moves at a rate of 0.2m / min.

[0031] Step 2: Prepare a conductive nanoparticle / polymer impregnation modification solution: Select polyvinyl butyral polymer, use ethanol as solvent to prepare a 1% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 10%; place the above-mentioned nanofiber / filament composite yarn in the 80% deformation state in the conductive nanoparticle / polymer dilute solution and immerse it for 20 seconds.

[0032] Step 3: Immerse the above-mentioned impregnated composite yarn in water, and construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 20°C and the immersion time is 20s.

[0033] Step 4: Remove the external stress of the stretching device and heat-treat the composite yarn to remove the non-solvent water. The heat treatment temperature is 90°C and the treatment time is 10 minutes to obtain the nanofiber composite bamboo core-spun yarn.

[0034] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0035] Example 2

[0036] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, comprising the following steps:

[0037] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use dimethyl sulfoxide as solvent to prepare polyurethane solution with mass fraction of 20%, in conjugate electrospinning, positive and negative high voltage is ±15kV, two injector spinning angle is 25°, spinning solution infusion speed is 1.5mL / h, receiving distance is 15cm, spinning environment temperature is 25℃, and environment humidity is 60%RH; the traction filament selects 100dtex polyurethane filament, and the polyurethane traction filament is additionally given 90% deformation by the additional stretching device, and the moving speed of the polyurethane traction filament is 0.5m / min.

[0038] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare solution with mass fraction of 2%, and select copper nanoparticles, and the mass fraction of conductive nanoparticles is 15%; the nanofiber / filament composite yarn in the above 90% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 30s.

[0039] Third step: the composite yarn after impregnation is impregnated in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, and the temperature of water is controlled to be 25℃, and the impregnation time is 30s.

[0040] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 100℃, and the treatment time is 20min, and the nanofiber composite core-spun slub yarn is obtained.

[0041] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0042] Example 3

[0043] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, the specific steps are:

[0044] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 22%, in conjugate electrospinning, positive and negative high voltage is ±20kV, two injector spinning angle is 35°, spinning solution infusion speed is 3mL / h, receiving distance is 20cm, spinning environment temperature is 30℃, and environment humidity is 70%RH; the traction filament selects 150dtex polyurethane filament, and the polyurethane traction filament is given 100% deformation by an additional stretching device, and the moving speed of the polyurethane traction filament is 3m / min.

[0045] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinylpyrrolidone polymer, use tert-butyl alcohol as solvent to prepare solution with mass fraction of 3%, and select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 25%; the nanofiber / filament composite yarn in the above 100% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 40s.

[0046] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so that the conductivity of the composite yarn is improved, the temperature of water is controlled to be 15℃, and the immersion time is 40s.

[0047] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 150℃, and the treatment time is 30min, and the nanofiber composite core-spun yarn with bamboo joints is obtained.

[0048] The prepared core-spun yarn with bamboo joints has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the core-spun yarn with bamboo joints has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0049] Example 4

[0050] A preparation method of a high-sensitivity nanofiber composite core-spun yarn strain sensor, and the specific steps are as follows:

[0051] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 25% by taking acetone as solvent, in conjugate electrospinning, positive and negative high voltage is ±5kV, two injector spinning angle is 60°, spinning solution infusion speed is 4mL / h, receiving distance is 25cm, spinning environment temperature is 16℃, environment humidity is 55%RH; select 200dtex polyurethane filament as traction filament, additional stretching device adds 110% deformation to polyurethane traction filament, polyurethane traction filament moving speed is 1.5m / min.

[0052] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, prepare solution with mass fraction of 4% by taking nitrogen methyl pyrrolidone as solvent, select copper nanoparticles, mass fraction of conductive nanoparticles is 5%; place nanofiber / filament composite yarn in 110% deformation state in conductive nanoparticle / polymer dilute solution for impregnation for 55s.

[0053] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, control the temperature of water to be 22℃, and the immersion time is 40s.

[0054] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, heat treatment temperature is 110℃, and treatment time is 15min, to obtain nanofiber composite slub core spun yarn.

[0055] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0056] Example 5

[0057] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0058] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use dimethyl sulfoxide as solvent to prepare polyurethane solution with mass fraction of 10%, in conjugate electrospinning, positive and negative high voltage is ±5kV, two injector spinning angle is 45°, spinning solution infusion speed is 4mL / h, receiving distance is 6cm, spinning environment temperature is 16℃, environment humidity is 55%RH; choose 160dtex polyurethane filament as traction filament, additional stretching device adds 120% deformation to polyurethane traction filament, polyurethane traction filament moving speed is 0.4m / min.

[0059] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyamide polymer, use ethanol as solvent to prepare solution with mass fraction of 3.5%, choose copper nanoparticles, mass fraction of conductive nanoparticles is 21%; place the nanofiber / filament composite yarn in 120% deformation state in conductive nanoparticle / polymer dilute solution for impregnation for 22s.

[0060] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, the temperature of water is controlled to be 15℃, and the immersion time is 34s.

[0061] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 75℃, and the treatment time is 16min, to obtain nanofiber composite core-spun slub yarn.

[0062] The prepared slub core-spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0063] Example 6

[0064] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, the specific steps are:

[0065] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 26%, in conjugate electrospinning, positive and negative high voltage is ±8kV, two injector spinning angle is 65°, spinning solution infusion speed is 2.3mL / h, receiving distance is 26cm, spinning environment temperature is 17℃, and environment humidity is 56%RH; the traction filament selects 250dtex polyurethane filament, and the polyurethane traction filament is additionally given 130% deformation by the additional stretching device, and the moving speed of the polyurethane traction filament is 0.5m / min.

[0066] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinylpyrrolidone polymer, use tert-butyl alcohol as solvent to prepare solution with mass fraction of 2.1%, and select silver nanoparticles, and the mass fraction of conductive nanoparticles is 12%; the nanofiber / filament composite yarn in the above 130% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 13s.

[0067] Third step: the composite yarn after impregnation is impregnated in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 26℃, and the impregnation time is 60s.

[0068] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 85℃, and the treatment time is 26min, and the nanofiber composite slub core spun yarn is obtained.

[0069] The prepared slub core spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0070] Example 7

[0071] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, and the specific steps are as follows:

[0072] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 18% (3-30%) by using acetone as solvent, in conjugate electrospinning, positive and negative high voltage is ±16kV, two injector spinning angle is 22°, spinning solution infusion speed is 3.5mL / h, receiving distance is 14cm, spinning environment temperature is 35℃, and environment humidity is 60%RH; the polyurethane traction filament is selected to be 105dtex, the polyurethane traction filament is added with 140% deformation by using additional stretching device, and the moving speed of the polyurethane traction filament is 0.6m / mi.

[0073] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: polyamide polymer is selected, and solution with mass fraction of 4% is prepared by using nitrogen methyl pyrrolidone as solvent, silver nanoparticles are selected, and the mass fraction of conductive nanoparticles is 8%; the nanofiber / filament composite yarn in the state of 140% deformation is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 55s.

[0074] Third step: the composite yarn after impregnation is impregnated in water, and the nanofiber / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so that the conductivity of the composite yarn is improved, the temperature of water is controlled to be 23℃, and the impregnation time is 28s.

[0075] Fourth step: remove the additional stress of the stretching device, and perform heat treatment on the composite yarn to remove the non-solvent water, the heat treatment temperature is 140℃, the treatment time is 16min, and the nanofiber composite core-spun slub yarn is obtained.

[0076] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and physical health condition.

[0077] Example 8

[0078] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0079] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use dimethyl sulfoxide as solvent to prepare polyurethane solution with mass fraction of 16%, in conjugate electrospinning, positive and negative high voltage is ±16kV, two injector spinning angle is 75°, spinning solution infusion speed is 3mL / h, receiving distance is 26cm, spinning environment temperature is 18℃, environment humidity is 55%RH; choose 270dtex polyurethane filament as traction filament, additional stretching device gives polyurethane traction filament with 150% deformation, polyurethane traction filament moving speed is 3.3m / min.

[0080] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyvinylpyrrolidone polymer, use ethanol as solvent to prepare solution with mass fraction of 4.5%, choose carbon black nanoparticles, mass fraction of conductive nanoparticles is 16%; place the above nanofiber / filament composite yarn in 150% deformation state in conductive nanoparticle / polymer dilute solution for impregnation of 56s.

[0081] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through nonsolvent induced phase separation to improve the conductivity of the composite yarn, control the temperature of water to be 27℃, and the immersion time is 38s.

[0082] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove the nonsolvent water, heat treatment temperature is 150℃, and treatment time is 23min, to obtain nanofiber composite slub core spun yarn.

[0083] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0084] Example 9

[0085] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0086] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, adopt N-N dimethylformamide as solvent to prepare polyurethane solution with mass fraction of 24%, in conjugate electrospinning, positive and negative high voltage is ±26kV, two injector spinning angle is 75°, spinning solution infusion speed is 1.2mL / h, receiving distance is 25cm, spinning environment temperature is 36℃, environment humidity is 46%RH; traction filament selects 160dtex polyurethane filament, additional stretching device is added to polyurethane traction filament to form 160% deformation, and the moving speed of polyurethane traction filament is 4.8m / min.

[0087] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, adopt N-methyl pyrrolidone as solvent to prepare solution with mass fraction of 3.2%, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 10%(1-30%); the nanofiber / filament composite yarn in 160% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 48s.

[0088] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, the temperature of water is controlled to be 22℃, and the immersion time is 58s.

[0089] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 160℃, and the treatment time is 80min, and the nanofiber composite slub core spun yarn is obtained.

[0090] The prepared slub core spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity(S≥25), excellent linear sensing characteristics(correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, and the slub core spun yarn has excellent mechanical properties(tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0091] Example 10

[0092] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, and the specific steps are as follows:

[0093] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 30% by taking acetone as solvent, in conjugate electrospinning, positive and negative high voltage is ±18kV, two injector spinning angle is 16°, spinning solution infusion speed is 4mL / h, receiving distance is 8cm, spinning environment temperature is 34℃, and environment humidity is 88%RH; traction filament selects 270dtex polyurethane filament, additional stretching device adds 170% deformation to polyurethane traction filament, and moving speed of polyurethane traction filament is 0.6m / min.

[0094] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinylpyrrolidone polymer, prepare solution with mass fraction of 4.5% by taking tert-butyl alcohol as solvent, select silver nanoparticles, and mass fraction of conductive nanoparticles is 16%; the nanofiber / filament composite yarn in 170% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 60s.

[0095] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 23℃, and the immersion time is 12s.

[0096] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 78℃, and the treatment time is 8min, so as to obtain nanofiber composite slub core-spun yarn.

[0097] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and meanwhile, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and body health condition.

[0098] Example 11

[0099] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0100] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylformamide as solvent to prepare polyurethane solution with mass fraction of 26%, in conjugate electrospinning, positive and negative high voltage is ±4kV, two injector spinning angle is 70°, spinning solution infusion speed is 3.9mL / h, receiving distance is 30cm, spinning environment temperature is 10℃, environment humidity is 44%RH; choose 220dtex polyurethane filament as traction filament, additional stretching device adds 180% deformation to polyurethane traction filament, polyurethane traction filament moving speed is 3.6m / min.

[0101] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyvinyl butyral polymer, use t-butyl alcohol as solvent to prepare solution with mass fraction of 2%, choose silver nanoparticles, mass fraction of conductive nanoparticles is 17%; place the above nanofiber / filament composite yarn in 180% deformation state in conductive nanoparticle / polymer dilute solution for impregnation of 55s.

[0102] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, the temperature of water is controlled to be 26℃, and the immersion time is 20s.

[0103] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, heat treatment temperature is 155℃, and treatment time is 9min, to obtain nanofiber composite slub core spun yarn.

[0104] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0105] Example 12

[0106] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0107] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use dimethyl sulfoxide as solvent to prepare polyurethane solution with mass fraction of 6%, in conjugate electrospinning, positive and negative high voltage is ±24kV, two injector spinning angle is 56°, spinning solution infusion speed is 3.2mL / h, receiving distance is 17cm, spinning environment temperature is 37℃, and environment humidity is 80%RH; traction filament selects 140dtex polyurethane filament, additional stretching device adds 190% deformation to polyurethane traction filament, and the moving speed of polyurethane traction filament is 4.4m / min.

[0108] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinylpyrrolidone polymer, use nitrogen methyl pyrrolidone as solvent to prepare solution with mass fraction of 3.8%, and select silver nanoparticles, and the mass fraction of conductive nanoparticles is 16%; the nanofiber / filament composite yarn in the above 190% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 27s.

[0109] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 20℃, and the immersion time is 17s.

[0110] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 78℃, and the treatment time is 9min, and the nanofiber composite core-spun slub yarn is obtained.

[0111] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0112] Example 13

[0113] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0114] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 21%, in conjugate electrospinning, positive and negative high voltage is ±26kV, two injector spinning angle is 15°, spinning solution infusion speed is 0.8mL / h, receiving distance is 9cm, spinning environment temperature is 25℃, and environment humidity is 46%RH; the traction filament selects 55dtex polyurethane filament, the additional stretching device is attached to the polyurethane traction filament with 200% deformation, and the moving speed of the polyurethane traction filament is 2.5m / mi.

[0115] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinylpyrrolidone polymer, use nitrogen methyl pyrrolidone as solvent to prepare solution with mass fraction of 2.5%, and select silver nanoparticles, and the mass fraction of conductive nanoparticles is 13%; the nanofiber / filament composite yarn in the above 200% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 22s.

[0116] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 26℃, and the immersion time is 58s.

[0117] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 155℃, and the treatment time is 5min, and the nanofiber composite core-spun slub yarn is obtained.

[0118] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0119] Embodiment 14

[0120] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0121] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylformamide as solvent to prepare polyurethane solution with mass fraction of 5%, in conjugate electrospinning, positive and negative high voltage is ±6kV, two injector spinning angle is 14°, spinning solution infusion speed is 1.5mL / h, receiving distance is 15cm, spinning environment temperature is 38℃, and environment humidity is 60%RH; the traction filament selects 60dtex polyurethane filament, and the polyurethane traction filament is given 60% deformation by the additional stretching device, and the moving speed of the polyurethane traction filament is 0.6m / min.

[0122] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use ethanol as solvent to prepare solution with mass fraction of 4%, and select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 26%; the nanofiber / filament composite yarn in the 60% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 46s.

[0123] Third step: the composite yarn after impregnation is impregnated in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so that the conductivity of the composite yarn is improved, the temperature of water is controlled to be 35℃, and the impregnation time is 45s.

[0124] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 76℃, and the treatment time is 27min, and the nanofiber composite core-spun slub yarn is obtained.

[0125] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0126] Example 15

[0127] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0128] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, dimethyl sulfoxide is used as solvent to prepare polyurethane solution with mass fraction of 18%, in conjugate electrospinning, positive and negative high voltage is ±3kV, two injector spinning angle is 26°, spinning solution infusion speed is 3.8mL / h, receiving distance is 11cm, spinning environment temperature is 16℃, and environment humidity is 45%RH; the polyurethane traction filament is selected as 58dtex, the polyurethane traction filament is added with 65% deformation by the additional stretching device, and the moving speed of the polyurethane traction filament is 0.8m / min.

[0129] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: polyvinylpyrrolidone polymer is selected, and t-butyl alcohol is used as solvent to prepare solution with mass fraction of 3%, silver nanoparticles are selected, and the mass fraction of conductive nanoparticles is 14%; the nanofiber / filament composite yarn in the above 65% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 25s.

[0130] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 28℃, and the immersion time is 14s.

[0131] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 85℃, and the treatment time is 11min, so as to obtain nanofiber composite core-spun slub yarn.

[0132] The prepared slub core-spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and meanwhile, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and physical health condition.

[0133] Example 16

[0134] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0135] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 25% by taking acetone as solvent, in conjugate electrospinning, positive and negative high voltage is ±5kV, two injector spinning angle is 78°, spinning solution infusion speed is 3.3mL / h, receiving distance is 23cm, spinning environment temperature is 36℃, and environment humidity is 44%RH; the traction filament selects 74dtex polyurethane filament, the additional stretching device is attached to the polyurethane traction filament with 70% deformation, and the moving speed of the polyurethane traction filament is 2.3m / min.

[0136] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, prepare solution with mass fraction of 2.4% by taking nitrogen methyl pyrrolidone as solvent, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 5%; the nanofiber / filament composite yarn in the above 70% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 35s.

[0137] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 21℃, and the immersion time is 17s.

[0138] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 80℃, and the treatment time is 7min, so as to obtain nanofiber composite core-spun slub yarn.

[0139] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and physical health condition.

[0140] Example 17

[0141] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0142] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 5%, in conjugate electrospinning, positive and negative high voltage is ±11kV, two injector spinning angle is 13°, spinning solution infusion speed is 1.1mL / h, receiving distance is 6cm, spinning environment temperature is 16℃, and environment humidity is 25%RH; the traction filament selects 70dtex polyurethane filament, the additional stretching device is added to the polyurethane traction filament with 75% deformation, and the moving speed of the polyurethane traction filament is 0.3m / min.

[0143] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use ethanol as solvent to prepare solution with mass fraction of 1.5%, and select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 5%; the nanofiber / filament composite yarn in the above 75% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 45s.

[0144] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so that the conductivity of the composite yarn is improved, the temperature of water is controlled to be 20℃, and the immersion time is 15s.

[0145] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 145℃, and the treatment time is 13min, and the nanofiber composite core-spun yarn with bamboo joints is obtained.

[0146] The prepared bamboo joint core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite bamboo joint core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the bamboo joint core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0147] Example 18

[0148] A preparation method of a high-sensitivity nanofiber composite bamboo joint core-spun yarn strain sensor, and the specific steps are as follows:

[0149] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 20% by using solvent, in conjugate electrospinning, positive and negative high voltage is ±12kV, two injector spinning angle is 60°, spinning solution infusion speed is 0.8mL / h, receiving distance is 24cm, spinning environment temperature is 19℃, and environment humidity is 43%RH;select 90dtex polyurethane filament as traction filament, additional stretching device is attached to polyurethane traction filament with 85% deformation, and the moving speed of polyurethane traction filament is 5m / min.

[0150] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, prepare solution with mass fraction of 3% by using nitrogen methyl pyrrolidone as solvent, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 16%;place the nanofiber / filament composite yarn in 85% deformation state in the conductive nanoparticle / polymer dilute solution for impregnation for 24s.

[0151] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn, the temperature of water is controlled to be 27℃, and the immersion time is 30s.

[0152] Fourth step: remove the additional stress of the stretching device, and perform heat treatment on the composite yarn to remove non-solvent water, the heat treatment temperature is 95℃, and the treatment time is 7min, and the nanofiber composite core-spun slub yarn is obtained.

[0153] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and body health condition.

[0154] Example 19

[0155] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0156] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 23%, in conjugate electrospinning, positive and negative high voltage is ±5kV, two injector spinning angle is 76°, spinning solution infusion speed is 1.5mL / h, receiving distance is 15cm (5-30cm), spinning environment temperature is 36℃, environment humidity is 55%RH; choose 225dtex polyurethane filament as traction filament, additional stretching device is attached to polyurethane traction filament to give 90% deformation, polyurethane traction filament moving speed is 0.9m / min.

[0157] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyamide polymer, use tert-butyl alcohol as solvent to prepare solution with mass fraction of 5%, choose silver nanoparticles, mass fraction of conductive nanoparticles is 16%; place the nanofiber / filament composite yarn in 90% deformation state in conductive nanoparticle / polymer dilute solution for impregnation for 38s.

[0158] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, the temperature of water is controlled to be 22℃, and the immersion time is 26s.

[0159] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 75℃, and the treatment time is 23min, to obtain nanofiber composite slub core spun yarn.

[0160] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0161] Example 20

[0162] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0163] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 4%, in conjugate electrospinning, positive and negative high voltage is ±6kV, two injector spinning angle is 11°, spinning solution infusion speed is 3.9mL / h, receiving distance is 14cm, spinning environment temperature is 22℃, and environment humidity is 53%RH; the traction filament selects 150dtex polyurethane filament, the additional stretching device is attached to the polyurethane traction filament with 95% deformation, and the moving speed of the polyurethane traction filament is 0.8m / min.

[0164] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use N-methyl pyrrolidone as solvent to prepare solution with mass fraction of 2%, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 14%; the nanofiber / filament composite yarn in the above 95% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 45s.

[0165] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, the temperature of water is controlled to be 21℃, and the immersion time is 16s.

[0166] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 135℃, and the treatment time is 6min, and the nanofiber composite slub core spun yarn is obtained.

[0167] The prepared slub core spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, and the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0168] Example 21

[0169] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, and the specific steps are as follows:

[0170] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylformamide as solvent to prepare polyurethane solution with mass fraction of 5%, in conjugate electrospinning, positive and negative high voltage is ±4kV, two injector spinning angle is 16°, spinning solution infusion speed is 1.6mL / h, receiving distance is 25cm, spinning environment temperature is 15℃, environment humidity is 58%RH; choose 300dtex polyurethane filament as traction filament, additional stretching device adds 115% deformation to polyurethane traction filament, and the moving speed of polyurethane traction filament is 2.6m / min.

[0171] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: use polyvinylpyrrolidone polymer, use nitrogen methyl pyrrolidone as solvent to prepare solution with mass fraction of 1.6%, and use silver nanoparticles, the mass fraction of conductive nanoparticles is 7%; put the nanofiber / filament composite yarn in 115% deformation state into the conductive nanoparticle / polymer dilute solution for impregnation for 48s.

[0172] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, improve the conductivity of the composite yarn, the temperature of water is controlled to be 27℃, and the immersion time is 17s.

[0173] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 146℃, and the treatment time is 14min, to obtain nanofiber composite slub core spun yarn.

[0174] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, and the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0175] Example 22

[0176] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0177] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylformamide as solvent to prepare polyurethane solution with mass fraction of 8%, in conjugate electrospinning, positive and negative high voltage is ±16kV, two injector spinning angle is 45°, spinning solution infusion speed is 3.7mL / h, receiving distance is 28cm, spinning environment temperature is 33℃, and environment humidity is 78%RH; the traction filament selects 55dtex polyurethane filament, the additional stretching device is attached to the polyurethane traction filament with 125% deformation, and the moving speed of the polyurethane traction filament is 4m / min.

[0178] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use tert-butyl alcohol as solvent to prepare solution with mass fraction of 3.7%, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 18%; the nanofiber / filament composite yarn in the above 125% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 47s.

[0179] Third step: the above impregnated composite yarn is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, the temperature of water is controlled to be 22℃, and the immersion time is 20s.

[0180] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 77℃, and the treatment time is 28min, and the nanofiber composite slub core spun yarn is obtained.

[0181] The prepared slub core spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, and meanwhile, the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and physical health condition.

[0182] Example 23

[0183] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, and the specific steps are as follows:

[0184] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylformamide as solvent to prepare polyurethane solution with mass fraction of 5%, in conjugate electrospinning, positive and negative high voltage is ±17kV, two injector spinning angle is 35°, spinning solution infusion speed is 5mL / h, receiving distance is 14cm, spinning environment temperature is 38℃, environment humidity is 67%RH; choose 265dtex polyurethane filament as traction filament, additional stretching device adds 135% deformation to polyurethane traction filament, moving speed of polyurethane traction filament is 3.8m / min.

[0185] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: use polyvinylpyrrolidone polymer, use ethanol as solvent to prepare solution with mass fraction of 2.6%, choose silver nanoparticles, mass fraction of conductive nanoparticles is 30%; place nanofiber / filament composite yarn in 135% deformation state in conductive nanoparticle / polymer dilute solution for impregnation of 56s.

[0186] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through nonsolvent induced phase separation, improve the conductivity of the composite yarn, the temperature of water is controlled to be 21℃, the immersion time is 46s.

[0187] Fourth step: remove the additional stress of the stretching device, heat treat the composite yarn to remove nonsolvent water, heat treatment temperature is 79℃, treatment time is 9min, obtain nanofiber composite slub core spun yarn.

[0188] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has stress detection limit as low as 0.01N, at the same time, the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, realizes real-time detection of human motion state and physical health condition.

[0189] Example 24

[0190] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0191] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 9% using acetone as the solvent. In the conjugated electrospinning, the positive and negative high voltages are ±7kV, the spinning angles of the two syringes are 33°, the spinning solution infusion speed is 4.3mL / h, the receiving distance is 14cm, the spinning environment temperature is 37°C, and the ambient humidity is 44%RH; the pulling filament is 74dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 145% deformation, and the polyurethane pulling filament moves at a rate of 0.8m / min.

[0192] Step 2: Prepare a conductive nanoparticle / polymer impregnation modification solution: Select polyvinyl butyral polymer, use tert-butyl alcohol as solvent to prepare a 2.3% mass fraction solution, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 26%; place the above-mentioned nanofiber / filament composite yarn in the 145% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 36 seconds.

[0193] Step 3: Immerse the above-mentioned impregnated composite yarn in water, and construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 29°C and the immersion time is 47s.

[0194] Step 4: Remove the external stress of the stretching device and heat-treat the composite yarn to remove the non-solvent water. The heat treatment temperature is 155°C and the treatment time is 26 minutes to obtain the nanofiber composite bamboo core-spun yarn.

[0195] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0196] Example 25

[0197] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, comprising the following steps:

[0198] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 28%, in conjugate electrospinning, positive and negative high voltage is ±27kV, two injector spinning angle is 56°, spinning solution infusion speed is 4mL / h, receiving distance is 22cm, spinning environment temperature is 24℃, environment humidity is 60%RH; choose 78dtex polyurethane filament as traction filament, additional stretching device gives polyurethane traction filament with 155% deformation, polyurethane traction filament moving speed is 0.4m / min.

[0199] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyvinyl butyral polymer, use nitrogen methyl pyrrolidone as solvent to prepare solution with mass fraction of 3.7%, choose copper nanoparticles, mass fraction of conductive nanoparticles is 9%; put above-mentioned nanofiber / filament composite yarn in 155% deformation state in conductive nanoparticle / polymer dilute solution for impregnation for 11s.

[0200] Third step: immerse above-mentioned impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on surface of composite yarn through non-solvent induced phase separation to improve conductivity of composite yarn, temperature of water is controlled to be 23℃, impregnation time is 41s.

[0201] Fourth step: remove additional stress of stretching device, heat treat composite yarn to remove non-solvent water, heat treatment temperature is 89℃, treatment time is 18min, obtain nanofiber composite slub core spun yarn.

[0202] Prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has stress detection limit as low as 0.01N, at the same time, slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, realizes real-time detection on human motion state and physical health condition.

[0203] Example 26

[0204] A preparation method of high-sensitivity nanofiber composite slub core spun yarn strain sensor, specific steps are as follows:

[0205] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use dimethyl sulfoxide as solvent to prepare polyurethane solution with mass fraction of 3%, in conjugated electrospinning, positive and negative high voltage is ±22kV, two injector spinning angle is 52°, spinning solution infusion speed is 4mL / h, receiving distance is 24cm, spinning environment temperature is 16℃, environment humidity is 60%RH; choose 295dtex polyurethane filament as traction filament, additional stretching device gives polyurethane traction filament with 165% deformation, polyurethane traction filament moving speed is 3.6m / min.

[0206] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyvinyl butyral polymer, use nitrogen methyl pyrrolidone as solvent to prepare solution with mass fraction of 1%, choose silver nanoparticles, mass fraction of conductive nanoparticles is 5%; place the above nanofiber / filament composite yarn in 165% deformation state in conductive nanoparticle / polymer dilute solution for impregnation of 41s.

[0207] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, control the temperature of water to be 27℃, and the immersion time is 24s.

[0208] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, heat treatment temperature is 147℃, and treatment time is 27min, to obtain nanofiber composite slub core spun yarn.

[0209] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, while the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), and can be combined into fabric through weaving process to realize real-time detection of human motion state and physical health condition.

[0210] Example 27

[0211] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0212] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 16% by taking acetone as solvent, in conjugate electrospinning, positive and negative high voltage is ±27kV, two injector spinning angle is 39°, spinning solution infusion speed is 4.4mL / h, receiving distance is 19cm, spinning environment temperature is 15℃, and environment humidity is 66%RH; the traction filament selects 63dtex polyurethane filament, the additional stretching device is attached to the polyurethane traction filament with 175% deformation, and the moving speed of the polyurethane traction filament is 0.5m / min.

[0213] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, prepare solution with mass fraction of 4% by taking ethanol as solvent, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 22%; the nanofiber / filament composite yarn in the above 175% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 44s.

[0214] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 26℃, and the immersion time is 17s.

[0215] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 105℃, and the treatment time is 24min, so as to obtain nanofiber composite slub core spun yarn.

[0216] The prepared slub core spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and meanwhile, the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and body health condition.

[0217] Embodiment 28

[0218] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, and the specific steps are as follows:

[0219] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use dimethyl sulfoxide as solvent to prepare polyurethane solution with mass fraction of 27%, in conjugate electrospinning, positive and negative high voltage is ±6kV, two injector spinning angle is 55, spinning solution infusion speed is 3.2mL / h, receiving distance is 16cm, spinning environment temperature is 33℃, and environment humidity is 66%RH; traction filament selects 119dtex polyurethane filament, additional stretching device adds 185% deformation to polyurethane traction filament, and moving speed of polyurethane traction filament is 4.4m / min.

[0220] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use t-butyl alcohol as solvent to prepare solution with mass fraction of 4.5%, and select carbon black nanoparticles, mass fraction of conductive nanoparticles is 11%; the nanofiber / filament composite yarn in 185% deformation state is placed in conductive nanoparticle / polymer dilute solution for impregnation for 18s.

[0221] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 23℃, and the immersion time is 54s.

[0222] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 156℃, and the treatment time is 20min, so as to obtain nanofiber composite slub core-spun yarn.

[0223] The prepared slub core-spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and body health condition.

[0224] Example 29

[0225] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0226] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 15%, in conjugate electrospinning, positive and negative high voltage is ±15kV, two injector spinning angle is 75°, spinning solution infusion speed is 4.2mL / h, receiving distance is 25cm, spinning environment temperature is 36℃, and environment humidity is 48%RH; the traction filament selects 190dtex polyurethane filament, and the polyurethane traction filament is given 195% deformation by the additional stretching device, and the moving speed of the polyurethane traction filament is 3m / min.

[0227] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: use polyvinylpyrrolidone polymer, use nitrogen methyl pyrrolidone as solvent to prepare solution with mass fraction of 2%, and use silver nanoparticles, and the mass fraction of conductive nanoparticles is 25%; the nanofiber / filament composite yarn in the above 195% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 55s.

[0228] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 20℃ (20-30℃), and the immersion time is 29s.

[0229] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 142℃, and the treatment time is 16min, and the nanofiber composite core-spun slub yarn is obtained.

[0230] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, and the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0231] Example 30

[0232] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, the specific steps are:

[0233] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylformamide as solvent to prepare polyurethane solution with mass fraction of 8%, in conjugate electrospinning, positive and negative high voltage is ±12kV, two injector spinning angle is 36°, spinning solution infusion speed is 1.2mL / h, receiving distance is 17cm, spinning environment temperature is 29℃, and environment humidity is 53%RH; the 85dtex polyurethane filament is selected as the traction filament, the polyurethane traction filament is given 58% deformation by the additional stretching device, and the moving speed of the polyurethane traction filament is 0.8m / min.

[0234] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use tert-butyl alcohol as solvent to prepare solution with mass fraction of 1.8%, and select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 12%; the nanofiber / filament composite yarn in the 58% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 26s.

[0235] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so that the conductivity of the composite yarn is improved, the temperature of water is controlled to be 24℃, and the immersion time is 30s.

[0236] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 80℃, and the treatment time is 5min, and the nanofiber composite core-spun yarn with bamboo joints is obtained.

[0237] The prepared core-spun yarn with bamboo joints has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and meanwhile, the core-spun yarn with bamboo joints has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and body health condition.

[0238] Embodiment 31

[0239] A preparation method of a high-sensitivity nanofiber composite core-spun yarn strain sensor, and the specific steps are as follows:

[0240] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 25% by using acetone as solvent, in conjugate electrospinning, positive and negative high voltage is ±24kV, two injector spinning angle is 40°, spinning solution infusion speed is 3mL / h, receiving distance is 26cm, spinning environment temperature is 17℃, environment humidity is 60%RH; choose 90dtex polyurethane filament as traction filament, additional stretching device adds 69% deformation to polyurethane traction filament, polyurethane traction filament moving speed is 5m / min.

[0241] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyvinyl butyral polymer, prepare solution with mass fraction of 3.9% by using nitrogen methyl pyrrolidone as solvent, choose copper nanoparticles, mass fraction of conductive nanoparticles is 10%(1-30%); place nanofiber / filament composite yarn in 69% deformation state in conductive nanoparticle / polymer dilute solution for impregnation for 16s.

[0242] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, control the temperature of water to be 21℃, and the immersion time is 40s.

[0243] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, heat treatment temperature is 88℃, and treatment time is 27min, to obtain nanofiber composite slub core spun yarn.

[0244] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity(S≥25), excellent linear sensing characteristics(correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, while the slub core spun yarn has excellent mechanical properties(tensile breaking strength≥100MPa, elongation at break≥200%), and can be combined into fabric through weaving process to realize real-time detection of human motion state and physical health condition.

[0245] Example 32

[0246] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0247] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 28%, in conjugate electrospinning, positive and negative high voltage is ±14kV, two injector spinning angle is 33°, spinning solution infusion speed is 3.6mL / h, receiving distance is 12cm, spinning environment temperature is 34℃, and environment humidity is 68%RH; the 98dtex polyurethane filament is selected as the traction filament, the polyurethane traction filament is given 72% deformation by the additional stretching device, and the moving speed of the polyurethane traction filament is 4.5m / min.

[0248] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use ethanol as solvent to prepare solution with mass fraction of 2.5%, and select silver nanoparticles, and the mass fraction of conductive nanoparticles is 13%; the nanofiber / filament composite yarn in the 72% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 56s.

[0249] Third step: the composite yarn after impregnation is impregnated in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so that the conductivity of the composite yarn is improved, the temperature of water is controlled to be 26℃, and the impregnation time is 10s.

[0250] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 88℃, and the treatment time is 28min, and the nanofiber composite core-spun slub yarn is obtained.

[0251] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and meanwhile, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and body health condition.

[0252] Embodiment 33

[0253] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0254] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylformamide as solvent to prepare polyurethane solution with mass fraction of 6%, in conjugate electrospinning, positive and negative high voltage is ±18kV, two injector spinning angle is 32°, spinning solution infusion speed is 3.4mL / h, receiving distance is 21cm, spinning environment temperature is 16℃, and environment humidity is 58%RH; the traction filament selects 60dtex polyurethane filament, and the polyurethane traction filament is additionally given 86% deformation by the additional stretching device, and the moving speed of the polyurethane traction filament is 1.4m / min.

[0255] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use ethanol as solvent to prepare solution with mass fraction of 1.8%, and select silver nanoparticles, and the mass fraction of conductive nanoparticles is 21%; the nanofiber / filament composite yarn in the above 86% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 43s.

[0256] Third step: the composite yarn after impregnation is impregnated in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so that the conductivity of the composite yarn is improved, the temperature of water is controlled to be 24℃, and the impregnation time is 46s.

[0257] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 149℃, and the treatment time is 27min, and the nanofiber composite core-spun slub yarn is obtained.

[0258] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and physical health condition.

[0259] Embodiment 34

[0260] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, the specific steps are:

[0261] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 8% by using acetone as solvent, in conjugate electrospinning, positive and negative high voltage is ±27kV, two injector spinning angle is 75°, spinning solution infusion speed is 3.2mL / h, receiving distance is 24cm, spinning environment temperature is 33℃, and environment humidity is 73%RH; the polyurethane filaments are selected as 198dtex(50-300dtex) polyurethane filaments, the polyurethane filaments are added with 96% deformation by using additional stretching device, and the moving speed of polyurethane filaments is 0.6m / min.

[0262] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, prepare solution with mass fraction of 2.6% by using nitrogen methyl pyrrolidone as solvent, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 16%; the nanofiber / filament composite yarn in 96% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 44s.

[0263] Third step: the composite yarn after impregnation is impregnated in water, and the nanofiber / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so that the conductivity of the composite yarn is improved, the temperature of water is controlled to be 20℃(20-30℃), and the impregnation time is 40s.

[0264] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 76℃, the treatment time is 26min, and the nanofiber composite core-spun slub yarn is obtained.

[0265] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity(S≥25), excellent linear sensing characteristics(correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and meanwhile, the slub core-spun yarn has excellent mechanical properties(tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and body health condition.

[0266] Embodiment 35

[0267] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0268] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use dimethyl sulfoxide as solvent to prepare polyurethane solution with mass fraction of 25%, in conjugated electrospinning, positive and negative high voltage is ±3kV, two injector spinning angle is 77°, spinning solution infusion speed is 2mL / h, receiving distance is 20cm, spinning environment temperature is 21℃, and environment humidity is 60%RH; the traction filament selects 200dtex polyurethane filament, and the polyurethane traction filament is additionally given 106% deformation by an additional stretching device, and the moving speed of the polyurethane traction filament is 4m / min.

[0269] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use ethanol as solvent to prepare solution with mass fraction of 3%, and select silver nanoparticles, and the mass fraction of conductive nanoparticles is 23%; the nanofiber / filament composite yarn in the above 106% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 56s.

[0270] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 22℃, and the immersion time is 36s.

[0271] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 150℃, and the treatment time is 6min, so as to obtain nanofiber composite core-spun slub yarn.

[0272] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, and meanwhile, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and body health condition.

[0273] Embodiment 36

[0274] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0275] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use dimethyl sulfoxide as solvent to prepare polyurethane solution with mass fraction of 6%, in conjugate electrospinning, positive and negative high voltage is ±4kV, two injector spinning angle is 11°, spinning solution infusion speed is 3.7mL / h, receiving distance is 23cm, spinning environment temperature is 36℃, environment humidity is 89%RH; choose 67dtex polyurethane filament as traction filament, additional stretching device adds 118% deformation to polyurethane traction filament, and the moving speed of polyurethane traction filament is 0.9m / min.

[0276] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyvinyl butyral polymer, use tert-butyl alcohol as solvent to prepare solution with mass fraction of 2.8%, choose silver nanoparticles, mass fraction of conductive nanoparticles is 26%; put the nanofiber / filament composite yarn in 118% deformation state into conductive nanoparticle / polymer dilute solution for impregnation for 29s.

[0277] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, the temperature of water is controlled to be 26℃, and the immersion time is 54s.

[0278] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 142℃, and the treatment time is 8min, to obtain nanofiber composite slub core spun yarn.

[0279] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, while the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), and can be combined into fabric through weaving process to realize real-time detection of human motion state and physical health condition.

[0280] Example 37

[0281] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0282] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 22%, in conjugate electrospinning, positive and negative high voltage is ±16kV, two injector spinning angle is 62°, spinning solution infusion speed is 4.7mL / h, receiving distance is 18cm, spinning environment temperature is 36℃, and environment humidity is 77%RH; the traction filament selects 230dtex polyurethane filament, and the polyurethane traction filament is additionally given 127% deformation by the additional stretching device, and the moving speed of the polyurethane traction filament is 2.2m / min.

[0283] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: use polyvinyl butyral polymer, use ethanol as solvent to prepare solution with mass fraction of 2%, and use copper nanoparticles, and the mass fraction of conductive nanoparticles is 13%; the nanofiber / filament composite yarn in the above 127% deformation state is placed in the conductive nanoparticle / polymer dilute solution and impregnated for 40s.

[0284] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 20℃ (20-30℃), and the immersion time is 32s.

[0285] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 136℃, and the treatment time is 26min, and the nanofiber composite core-spun slub yarn is obtained.

[0286] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and meanwhile, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and body health condition.

[0287] Embodiment 38

[0288] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and the specific steps are as follows:

[0289] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 34% by taking acetone as solvent, in conjugate electrospinning, positive and negative high voltage is ±5kV, two injector spinning angle is 68°, spinning solution infusion speed is 3.9mL / h, receiving distance is 17cm, spinning environment temperature is 17℃, and environment humidity is 90%RH; the traction filament selects 56dtex polyurethane filament, and the polyurethane traction filament is additionally given 132% deformation by the additional stretching device, and the moving speed of the polyurethane traction filament is 4.1m / min.

[0290] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, prepare solution with mass fraction of 3.3% by taking nitrogen methyl pyrrolidone as solvent, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 29%; the nanofiber / filament composite yarn in the above 132% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 45s.

[0291] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so as to improve the conductivity of the composite yarn, the temperature of water is controlled to be 22℃, and the immersion time is 15s.

[0292] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 135℃, and the treatment time is 13min, and the nanofiber composite slub core spun yarn is obtained.

[0293] The prepared slub core spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and meanwhile, the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and body health condition.

[0294] Example 39

[0295] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, and the specific steps are as follows:

[0296] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use dimethyl sulfoxide as solvent to prepare polyurethane solution with mass fraction of 23%, in conjugate electrospinning, positive and negative high voltage is ±11kV, two injector spinning angle is 36°, spinning solution infusion speed is 2.9mL / h, receiving distance is 26cm, spinning environment temperature is 34℃, environment humidity is 80%RH; choose 60dtex polyurethane filament as traction filament, additional stretching device adds 147% deformation to polyurethane traction filament, polyurethane traction filament moving speed is 0.6m / min.

[0297] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyvinylpyrrolidone polymer, use ethanol as solvent to prepare solution with mass fraction of 5%, choose silver nanoparticles, mass fraction of conductive nanoparticles is 17%; place the nanofiber / filament composite yarn in 147% deformation state in conductive nanoparticle / polymer dilute solution for impregnation of 51s.

[0298] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, the temperature of water is controlled to be 25℃, and the immersion time is 50s.

[0299] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 120℃, and the treatment time is 20min, to obtain nanofiber composite slub core spun yarn.

[0300] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0301] Example 40

[0302] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0303] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 14% using NN dimethylformamide as solvent. In the conjugated electrospinning, the positive and negative high voltages are ±7kV, the spinning angles of the two syringes are 28°, the spinning solution infusion speed is 3.8mL / h, the receiving distance is 9cm, the spinning environment temperature is 39℃, and the ambient humidity is 60%RH; the pulling filament is 280dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 159% deformation, and the polyurethane pulling filament moves at a rate of 5m / min.

[0304] Step 2: Prepare a conductive nanoparticle / polymer impregnation modification solution: Select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 4% solution by mass, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 6%; place the above-mentioned nanofiber / filament composite yarn in the 159% deformation state in the conductive nanoparticle / polymer dilute solution and immerse it for 13 seconds.

[0305] Step 3: Immerse the above-mentioned impregnated composite yarn in water, and construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 27°C and the immersion time is 46 seconds.

[0306] Step 4: Remove the external stress of the stretching device and heat-treat the composite yarn to remove the non-solvent water. The heat treatment temperature is 86°C and the treatment time is 9 minutes to obtain the nanofiber composite bamboo core-spun yarn.

[0307] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0308] Example 41

[0309] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, comprising the following steps:

[0310] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylformamide as solvent to prepare polyurethane solution with mass fraction of 28%, in conjugate electrospinning, positive and negative high voltage is ±8kV, two injector spinning angle is 47°, spinning solution infusion speed is 3mL / h, receiving distance is 11cm, spinning environment temperature is 30℃, environment humidity is 64%RH; choose 220dtex polyurethane filament as traction filament, additional stretching device adds 168% deformation to polyurethane traction filament, polyurethane traction filament moving speed is 3.2m / min.

[0311] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare solution with mass fraction of 3%, choose carbon black nanoparticle, mass fraction of conductive nanoparticle is 26%; place above-mentioned nanofiber / filament composite yarn in 168% deformation state in conductive nanoparticle / polymer dilute solution for impregnation of 36s.

[0312] Third step: immerse above-mentioned impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on surface of composite yarn through non-solvent induced phase separation, improve conductivity of composite yarn, temperature of water is controlled to be 20℃ (20~30℃), impregnation time is 31s.

[0313] Fourth step: remove additional stress of stretching device, heat treat composite yarn to remove non-solvent water, heat treatment temperature is 121℃, treatment time is 23min, obtain nanofiber composite slub core spun yarn.

[0314] Prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has stress detection limit as low as 0.01N, at the same time, slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be compounded into fabric through weaving process, realizes real-time detection on human motion state and physical health condition.

[0315] Embodiment 42

[0316] A preparation method of high-sensitivity nanofiber composite slub core spun yarn strain sensor, specific steps are as follows:

[0317] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 17% by using acetone as solvent, in conjugate electrospinning, positive and negative high voltage is ±19kV, two injector spinning angle is 77°, spinning solution infusion speed is 2mL / h, receiving distance is 3cm, spinning environment temperature is 28℃, environment humidity is 78%RH; select 260dtex polyurethane filament as traction filament, additional stretching device adds 173% deformation to polyurethane traction filament, moving speed of polyurethane traction filament is 0.5m / min.

[0318] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, prepare solution with mass fraction of 2.9% by using tert-butyl alcohol as solvent, select carbon black nanoparticles, mass fraction of conductive nanoparticles is 26%; place nanofiber / filament composite yarn in 173% deformation state in conductive nanoparticle / polymer dilute solution for impregnation for 37s.

[0319] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, improve the conductivity of the composite yarn, the temperature of water is controlled at 20℃ (20-30℃), and the immersion time is 13s.

[0320] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 93℃, and the treatment time is 7min, to obtain nanofiber composite slub core spun yarn.

[0321] The prepared slub core spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, and the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection of human motion state and physical health condition.

[0322] Example 43

[0323] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are as follows:

[0324] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylformamide as solvent to prepare polyurethane solution with mass fraction of 14%, in conjugate electrospinning, positive and negative high voltage is ±21kV, two injector spinning angle is 16°, spinning solution infusion speed is 0.6mL / h, receiving distance is 14cm, spinning environment temperature is 27℃, environment humidity is 88%RH; choose 296dtex polyurethane filament as traction filament, additional stretching device adds 182% deformation to polyurethane traction filament, and the moving speed of polyurethane traction filament is 0.7m / min.

[0325] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: choose polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare solution with mass fraction of 3%, choose carbon black nanoparticles, mass fraction of conductive nanoparticles is 22%; place the nanofiber / filament composite yarn in 182% deformation state in conductive nanoparticle / polymer dilute solution for impregnation of 50s.

[0326] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn, the temperature of water is controlled at 23℃, and the immersion time is 29s.

[0327] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 147℃, and the treatment time is 8min, to obtain nanofiber composite slub core spun yarn.

[0328] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), and a stress detection limit as low as 0.01N, while the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), and can be combined into fabric through weaving process to realize real-time detection of human motion state and physical health condition.

[0329] Example 44

[0330] A preparation method of a high-sensitivity nanofiber composite slub core spun yarn strain sensor, the specific steps are:

[0331] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, prepare polyurethane solution with mass fraction of 12% by taking acetone as solvent, in conjugate electrospinning, positive and negative high voltage is ±16kV, two injector spinning angle is 42°, spinning solution infusion speed is 2.6mL / h, receiving distance is 25cm, spinning environment temperature is 33℃, and environment humidity is 66%RH; the polyurethane long filament is selected for traction, and the polyurethane traction long filament is given 194% deformation by the additional stretching device, and the moving speed of the polyurethane traction long filament is 4.1m / min.

[0332] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: polyvinyl butyral polymer is selected, and a solution with mass fraction of 4% is prepared by taking tert-butyl alcohol as solvent, silver nanoparticles are selected, and the mass fraction of conductive nanoparticles is 10%(1-30)%; the nanofiber / filament composite yarn in the 194% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 32s.

[0333] Third step: the composite yarn after impregnation is immersed in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation, so that the conductivity of the composite yarn is improved, the temperature of water is controlled to be 25℃, and the immersion time is 47s.

[0334] Fourth step: remove the additional stress of the stretching device, and perform heat treatment on the composite yarn to remove the non-solvent water, the heat treatment temperature is 160℃, the treatment time is 23min, and the nanofiber composite core-spun slub yarn is obtained.

[0335] The prepared slub core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure, the nanofiber composite slub core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core-spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and physical health condition.

[0336] Embodiment 45

[0337] A preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, the specific steps are:

[0338] First step: adopt electric auxiliary core spinning technology to prepare nanofiber / filament composite yarn, use N-N dimethylacetamide as solvent to prepare polyurethane solution with mass fraction of 16%, in conjugate electrospinning, positive and negative high voltage is ±6kV, two injector spinning angle is 72°, spinning solution infusion speed is 2.8mL / h, receiving distance is 7cm, spinning environment temperature is 34℃, and environment humidity is 82%RH; the traction filament selects 298dtex polyurethane filament, the additional stretching device adds 54% deformation to the polyurethane traction filament, and the moving speed of the polyurethane traction filament is 0.7m / min.

[0339] Second step: prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use ethanol as solvent to prepare solution with mass fraction of 2%, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 5%; the nanofiber / filament composite yarn in the above 54% deformation state is placed in the conductive nanoparticle / polymer dilute solution for impregnation for 57s.

[0340] Third step: immerse the above impregnated composite yarn in water, construct nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, improve the conductivity of the composite yarn, and the temperature of water is controlled to be 26℃, and the immersion time is 30s.

[0341] Fourth step: remove the additional stress of the stretching device, and heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 98℃, and the treatment time is 17min, and the nanofiber composite slub core spun yarn is obtained.

[0342] The prepared slub core spun yarn strain sensor has radial core-shell structure and axial concave-convex structure, the nanofiber composite slub core spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R 2 =99.8%), has a stress detection limit as low as 0.01N, and at the same time, the slub core spun yarn has excellent mechanical properties (tensile breaking strength≥100MPa, elongation at break≥200%), can be combined into fabric through weaving process, and realizes real-time detection on human motion state and physical health condition.

Claims

1. A preparation method of a high-sensitivity nanofiber composite bunched core yarn strain sensor, characterized by, The preparation method is: The first step is to dissolve polyurethane in a good solvent to prepare a spinning solution, and to prepare a nanofiber / drawing filament composite yarn through an electric auxiliary core spinning technology, and to add an external stress to the drawing filament through a stretching device to impart deformation to the drawing filament; The second step is to immerse the nanofiber / drawing filament composite yarn in a deformed state in a conductive nanoparticle / polymer dilute solution; The third step is to immerse the composite yarn after immersion in water, and to construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through a non-solvent induced phase separation; The fourth step is to remove the external stress of the stretching device, and to heat treat the composite yarn to remove the non-solvent water, to obtain a concave-convex nanofiber composite core-in-sheath yarn sensor; In the first step, the nanofiber / drawing filament composite yarn is prepared by an electric auxiliary core spinning technology, wherein the electric auxiliary core spinning technology is a conjugate electrospinning process and a core-in-sheath yarn forming process, two injectors encapsulating spinning solutions are respectively connected with high-voltage positive and negative electrodes, and the nanofiber is collected by drawing the filament under strain, and the nanofiber is coated on the drawing filament to obtain the nanofiber / drawing filament composite yarn; In the first step, the drawing filament of the electric auxiliary core spinning technology is a polyurethane filament with a specification of 50-300 dtex; the deformation rate of the polyurethane filament is 50-200%, and the moving speed of the drawing filament is 0.1-5 m / min; In the second step, the polymer in the conductive nanoparticle / polymer dilute solution is selected from one or a combination of polyvinyl butyral, polyamide, and polyvinyl pyrrolidone; and the conductive nanoparticles are selected from one or a combination of silver nanoparticles, copper nanoparticles, and carbon black nanoparticles; In the fourth step, the heat treatment temperature is 70-160℃, and the treatment time is 5-30 min; The high-sensitivity nanofiber composite core-in-sheath yarn strain sensor prepared by the preparation method has a radial core-shell structure and an axial concave-convex structure.

2. The preparation method of a high-sensitivity nanofiber composite bunched core yarn strain sensor according to claim 1, characterized in that, In the first step, the good solvent in the spinning solution of the electric auxiliary core spinning technology is selected from one or a combination of N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide, and acetone, and the mass fraction of the polymer in the prepared spinning solution is 3-30%.

3. The preparation method of a high-sensitivity nanofiber composite bunched core yarn strain sensor according to claim 1, characterized in that, In the conjugate electrospinning process of the electric auxiliary core spinning technology, the positive and negative high-voltage voltages are ±3-±30 kV, the spinning angles of the two injectors are 10-80°, the perfusion speed is 0.5-5 mL / h, the receiving distance is 5-30 cm, the spinning environment temperature is 10-40℃, and the environment humidity is 40%-90% RH.

4. The preparation method of a high-sensitivity nanofiber composite bunched core yarn strain sensor according to claim 1, characterized in that, In the second step, the solvent of the conductive nanoparticle / polymer dilute solution is selected from one or a combination of ethanol, nitrogen methyl pyrrolidone, and tert-butyl alcohol.

5. The method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to claim 1, characterized in that: In the second step, the mass fraction of the polymer in the prepared immersion solution is 1-5%, and the mass fraction of the conductive nanoparticles is 1-30%.

6. The preparation method of a high-sensitivity nanofiber composite bunched core yarn strain sensor according to claim 5, characterized in that, The immersion time of the second step is 10-60 s.

7. The method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to claim 1, characterized in that: The third step of the immersion process selects water as a non-solvent to induce polymer phase separation, to build a stable nanoparticle / polymer conductive layer on the surface of the nanofiber composite yarn, and the immersion time is 10-60s and the immersion temperature is 20-30 DEG C.

8. A high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor obtained by the preparation method according to any one of claims 1 to 7, characterized in that: The high-sensitivity nanofiber composite slub core yarn strain sensor has a radial core-shell structure and an axial concave-convex structure.

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