A flexible strain sensing component, its preparation and use on smart compression hosiery

Abstract

The present application relates to a kind of flexible strain sensing components and its preparation and application on intelligent pressure socks, first polypropylene microsphere dispersion liquid is mixed with single layer MXene dispersion liquid and is self-assembled, then polyurethane particles are added to the solution assembled and stirred to form spinning solution, then the filament of wet spinning is carried out to the spinning solution, finally polypropylene wrinkle layer is formed on the filament surface, and the flexible strain sensing component is prepared;The strain sensing range of flexible strain sensing component is 0~300%, and the sensitivity range is 0~150000;Application is: flexible strain sensing component and flexible wire are assembled to obtain the intelligent pressure socks for monitoring leg swelling change.The preparation method of flexible strain sensing component uses wet spinning method, and preparation is simple;Flexible strain sensing component greatly improves the sensing range and sensitivity of sensor;The intelligent pressure socks for monitoring leg swelling change assembled has good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flexible sensors, and relates to a flexible strain sensing component and preparation and application thereof to intelligent compression stockings. BACKGROUND

[0002] The flexible strain sensor refers to a working process of converting some deformation physical signals of the sensor itself into electrical signals.

[0003] Generally, the flexible strain sensor is prepared by using interface polymerization, in-situ polymerization, reduction oxidation, self-assembly and dip coating methods, and the base material thereof is usually yarn or part of fabric, and the preparation process is complex.

[0004] The construction of the intelligent compression stocking is mostly used to monitor the change of the pressure of the compression stocking on the leg of a patient in real time, and the measurement of the leg swelling of the patient also needs to be completed by going to a hospital for health detection or by self-measurement, and the measurement is very cumbersome and complex. The reason for this result is that the initial strain range of the intelligent compression stocking worn by people is 70% to 100%, but the strain of some patients with serious leg swelling exceeds 200% when wearing the compression stocking, which completely exceeds the sensing range of the existing flexible strain sensor.

[0005] On the other hand, the leg swelling of some patients with slight varicose veins is irregular and small-amplitude change, instead of large-amplitude change, and therefore the sensitivity of the required strain sensor needs to be very high.

[0006] Therefore, it is of great significance to research a flexible strain sensing component and preparation and application thereof to intelligent compression stockings to solve the problem that the flexible strain sensing component in the prior art cannot increase the sensing range while increasing the sensitivity. SUMMARY

[0007] The application aims to solve the problems in the prior art and provide a flexible strain sensing component and preparation and application thereof to intelligent compression stockings.

[0008] To achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows:

[0009] A preparation method of a flexible strain sensing component, wherein first, polypyrrole (PPy) microsphere dispersion liquid and single-layer MXene dispersion liquid are mixed for self-assembly, then polyurethane particles are added to the assembled solution and stirred to form a spinning solution, then wet spinning is performed on the spinning solution to obtain filaments, and finally a polypyrrole (PPy) wrinkle layer is formed on the surface of the filaments to obtain the flexible strain sensing component.

[0010] As a preferred technical scheme:

[0011] The preparation method of the flexible strain sensing component as described above specifically comprises the following steps:

[0012] (1) Preparation of single-layer MXene dispersion liquid: LiF and Ti3AlC2 are added to a hydrochloric acid (HCl) solution for stirring, and then centrifuged for several times until the lower layer of the precipitate is expanded. Dimethyl sulfoxide (DMSO) is added to the lower layer of the expanded precipitate and centrifuged for several times, and the single-layer MXene dispersion liquid is collected;

[0013] (2) Preparation of polypyrrole microsphere dispersion liquid: polypyrrole microspheres are dispersed in DMSO to obtain a polypyrrole microsphere dispersion liquid;

[0014] (3) The polypyrrole microsphere dispersion liquid obtained in step (2) is mixed with the single-layer MXene dispersion liquid obtained in step (1) for self-assembly, and polyurethane particles are added to the assembled solution for stirring to form a spinning solution;

[0015] (4) Wet spinning is performed on the spinning solution obtained in step (3) to obtain a filament, and the filament is dried and then subjected to pre-drawing treatment;

[0016] (5) The pre-drawn filament in step (4) is soaked in a mixed solution of ferric chloride hexahydrate (FeCl3·6H2O) and sodium sulfosalicylate (the solvent of the mixed solution is water, and the total concentration of the mixed solution is 19.2wt%), and is subjected to cold storage. Then, a mixture of pyrrole and cyclohexane is poured into the cold storage mixed solution, and is frozen for 6-10min, and then is subjected to cold storage for 24-36h. The freezing is for the purpose of forming an interface, and then the polypyrrole is polymerized in the cold storage environment;

[0017] (6) The pre-drawing of the filament is removed, the filament is ultrasonically cleaned with ultrapure water, and is dried to obtain the flexible strain sensing component.

[0018] In the preparation method of the flexible strain sensing component as described above, the mass ratio of LiF to Ti3AlC2 in step (1) is 1.6:1, the concentration of the hydrochloric acid solution is 9mol / L, the mass-volume ratio of LiF to the hydrochloric acid solution is 1.6g:40ml, and the concentration of the single-layer MXene dispersion liquid is 15-25mg / ml.

[0019] In step (2), the concentration of the polypyrrole microsphere dispersion liquid is 3-5mg / ml.

[0020] In step (3), the volume ratio of the polypyrrole microsphere dispersion liquid to the single-layer MXene dispersion liquid is 1:3-5, and the content of the polyurethane in the spinning solution is 50-250mg / ml.

[0021] In the preparation method of the flexible strain sensing component as described above, the pre-drawing range in step (4) is 50-200%.

[0022] The preparation method of the flexible strain sensing component as described above, in step (5), the mass ratio of the ferric chloride hexahydrate and sodium sulfosalicylate is 1:1, and the volume ratio of the pyrrole and cyclohexane is 1:39.

[0023] The application further provides the flexible strain sensing component prepared by the method as described in any one of the above, and the flexible strain sensing component is a double-layer filament structure, the core layer is a polyurethane elastic matrix of self-assembled single-layer MXene and polypyrrole microspheres, and the shell layer is polypyrrole with a wrinkle structure.

[0024] The strain sensing range of the flexible strain sensing component is 0-300% (the highest of the prior art is only about 180%), and the sensitivity range (GF) is 0-150000 (the highest of the prior art is only about 50000).

[0025] The application further provides a preparation method of an intelligent pressure sock for monitoring leg swelling changes, which is assembled from the flexible strain sensing component and a flexible wire.

[0026] The flexible wire is a polyurethane filament with a polypyrrole (PPy) wrinkle layer on the surface.

[0027] As a preferred technical solution:

[0028] The preparation method of the intelligent pressure sock for monitoring leg swelling changes as described above specifically comprises the following steps:

[0029] (1) sewing the flexible strain sensing component into the medical pressure sock, selecting three parts of the upper, middle and lower parts of the medical pressure sock in the transverse direction to sew out three circular rings, using flat sewing or right and wrong sewing, and leaving 0.5-1 cm of the port for sewing;

[0030] (2) connecting the port of the flexible strain sensing component in step (1) and one end of the flexible wire by using conductive silver paste, then sewing the flexible wire into the medical pressure sock along the radial direction of the medical pressure sock, and finally leaving 1-2 cm of the port of the flexible wire;

[0031] (3) fixing the Bluetooth module of the internal power supply and the signal acquisition device on the top of the pressure sock, connecting the port of the flexible wire in step (2) and the positive and negative electrodes of the signal acquisition device, and assembling the intelligent pressure sock for monitoring leg swelling changes.

[0032] The preparation method of the intelligent pressure sock for monitoring leg swelling changes as described above, the preparation of the flexible wire comprises the following steps:

[0033] (1) mixing trihydroxymethyl aminomethane, a hydrochloric acid solution and ultrapure water to adjust the pH to 8.5-8.7 to obtain a mixed solution;

[0034] (2) adding dopamine into the mixed solution of step (1) and ultrasonicating for 5-8 min, then putting polyurethane filaments with linear density of 40-120D and pre-drawing of 200-350% into the solution and soaking for 8-12 h;

[0035] (3) soaking the polyurethane filaments of step (2) in a mixed solution of FeCl3·6H2O and sodium sulfosalicylate (the solvent of the mixed solution is water, and the total concentration of the mixed solution is 19.2 wt%) and refrigerating, then pouring a mixed solution of pyrrole and cyclohexane into the refrigerated mixed solution, freezing for 6-10 min, and then refrigerating for 24-36 h;

[0036] (4) removing the pre-drawing of the polyurethane filaments, ultrasonicating and washing the filaments with ultrapure water, and drying to obtain flexible wires.

[0037] The preparation method of the intelligent pressure sock for monitoring changes in leg swelling as described above, the mass ratio of FeCl3·6H2O and sodium sulfosalicylate in step (3) is 1:1, and the volume ratio of pyrrole and cyclohexane is 1:39.

[0038] Invention principle:

[0039] The flexible strain sensors disclosed in the prior art can generally only test low strain high sensitivity and high strain low sensitivity, because: in some highly stretched states, part of the conductive substance will have irreversible cracks, faults or plastic deformation, resulting in that the sensitivity cannot be larger under high strain.

[0040] The preparation of the flexible strain sensing component of the application adopts wet spinning and the mutual attraction of positive and negative charges to greatly improve the sensitivity and strain sensing range of the flexible strain sensor. Specifically, the application adopts a wet spinning method, and the flexible elastic body of the spinning selects polyurethane (TPU), which provides good physical and mechanical properties and can also appropriately reduce the plastic deformation problem of the conductive material. The self-assembly of single-layer MXene and PPy microspheres is adopted for the conductive material. MXene is a sheet-shaped material with a negative surface, and PPy is a microsphere structure with a positive charge. The mutual attraction of positive and negative charges can reduce the irreversible cracks between the conductive materials as much as possible, and in a highly stretched state, the mutual attraction of positive and negative charges will make it less likely for the conductive materials to have faults. MXene is a sheet-shaped material, and if only MXene is used as the conductive material, there is a possibility that two or more pieces of MXene will be arranged in parallel without contact inside the flexible sensing component. The added PPy positive microspheres utilize the point-surface contact attraction and form a bridge effect, which can attract sheet-shaped MXene together or have microspheres as a conductive sensing bridge, thereby increasing the sensing range of the flexible strain sensor. In addition, the PPy wrinkle surface structure introduced by pre-drawing can also reduce certain faults under high strain, because the wrinkles will be stretched and the wave peaks of the wrinkles will be reduced without faults, but if there is only a single layer of PPy, the PPy will have faults under the same strain. Since this wrinkle layer also uses positive PPy, it not only interfaces polymerizes on the surface of the filament, but also performs positive and negative adsorption with the MXene on the surface of the filament after wet spinning, thereby increasing the bonding force between the wrinkle layer and the filament. Although the filament surface also has PPy after wet spinning, the PPy wrinkle repels it, but the size of PPy is much smaller than that of MXene, and the amount of PPy added in the spinning solution is also much smaller, so the bonding force between the wrinkle layer and the filament is generally improved.

[0041] Advantages:

[0042] (1) The preparation method of the flexible strain sensing component of the application adopts a wet spinning method, which is simple to prepare;

[0043] (2) The flexible strain sensing component of the present application, the spinned flexible elastic body selects polyurethane (TPU), which provides better physical and mechanical properties, the self-assembly of single-layer MXene and PPy adopted by the conductive material, which has excellent electrical properties and sensing properties, MXene is a sheet with negative surface, PPy is a microspherical structure with positive electricity, the adsorption self-assembly of the positive and negative structures can greatly improve the sensing range and sensitivity of the sensor, overcoming the limitation of the previous flexible sensor which can only test low strain high sensitivity and high strain low sensitivity, at the same time, the introduction of PPy with wrinkle structure on the outer layer of the sensing component can further improve the sensing range of the sensing component;

[0044] (3) The preparation method of the intelligent pressure sock for monitoring leg swelling changes of the present application is simple to prepare; wherein the flexible wire is obtained by the method of interfacial polymerization, PPy is polymerized on the PU filament, and a larger degree of wrinkle structure is introduced, which can endow the flexible wire with strain sensitivity and excellent electrical conductivity, ensuring the stability of the electrical transmission of the intelligent pressure sock. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 The structure diagram of the intelligent pressure sock for monitoring leg swelling changes of the present application is shown in the figure;

[0046] Among them, 1 is a medical pressure sock; 2 is a flexible strain sensing component; 3 is a flexible wire; 4 is a Bluetooth module of an internal power supply and signal acquisition device; 5 is a Type-C interface; 6 is a USB interface; 7 is an HDMI interface. DETAILED DESCRIPTION

[0047] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application. In addition, it should be understood that after reading the content taught by the present application, those skilled in the art can make various modifications or modifications to the present application, and these equivalent forms also fall within the scope of the claims attached to the present application.

[0048] The test method adopted by the present application is as follows:

[0049] Strain sensing range and sensitivity range: the flexible strain sensing component is fixed on the stretching device, and the two ends of the flexible strain sensing component are connected to the test resistance of the multimeter at the same time. With the stretching of the stretching device, the resistance also changes constantly. When the resistance suddenly jumps to infinity, the test stops. The strain corresponding to the last moment before the mutation is the "maximum sensing strain", and the whole test strain process is the "strain sensing range". At the same time, according to the formula The sensitivity GF corresponding to the strain at each moment is calculated, that is, the "sensitivity range"; in the formula: GF-sensitivity; R0-initial resistance; ΔR-the difference between the resistance under a certain strain and the initial resistance; ε-strain change; ΔL-the difference between a certain length of stretching and the initial length; L0-initial length.

[0050] The polyurethane filament in the application is Spandex filament.

[0051] Example 1

[0052] A preparation method of a flexible strain sensing component, the specific steps are as follows:

[0053] (1) Preparation of single-layer MXene dispersion liquid: LiF and Ti3AlC2 with a mass ratio of 1.6:1 are added to a hydrochloric acid solution with a concentration of 9 mol / L for stirring, and then centrifuged 5 times until the lower layer of the expanded precipitate is expanded, dimethyl sulfoxide is added to the lower layer of the expanded precipitate and centrifuged 3 times, and a single-layer MXene dispersion liquid with a concentration of 25 mg / ml is collected; wherein the mass-volume ratio of LiF to the hydrochloric acid solution is 1.6 g:40 ml;

[0054] (2) Preparation of polypyrrole microsphere dispersion liquid: polypyrrole microspheres are dispersed in dimethyl sulfoxide to obtain a polypyrrole microsphere dispersion liquid with a concentration of 3 mg / ml;

[0055] (3) The polypyrrole microsphere dispersion liquid obtained in step (2) and the single-layer MXene dispersion liquid obtained in step (1) are mixed in a volume ratio of 1:3 for self-assembly, and then polyurethane particles (BASF-1170A) are added to the assembled solution and stirred to form a spinning solution with a polyurethane content of 50 mg / ml;

[0056] (4) Wet spinning is performed on the spinning solution obtained in step (3) to obtain a filament, and the filament is dried and then treated with a 50% pre-drawing process;

[0057] (5) The pre-drawn filament in step (4) is soaked in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate with a mass ratio of 1:1 (the solvent of the mixed solution is water, and the total concentration of the mixed solution is 19.2wt%), and is refrigerated, then a mixed solution of pyrrole and cyclohexane with a volume ratio of 1:39 is poured into the refrigerated mixed solution, frozen for 6 min, and then refrigerated for 24 h;

[0058] (6) The pre-drawing of the filament is removed, the filament is ultrasonically cleaned with ultrapure water, and dried to obtain a flexible strain sensing component.

[0059] The prepared flexible strain sensing component is a double-layer filament structure, the core layer is a polyurethane elastic matrix of self-assembled single-layer MXene and polypyrrole microspheres, and the shell layer is polypyrrole with a wrinkle structure; the strain sensing range of the flexible strain sensing component is 0-220%, and the sensitivity range is 0-150000.

[0060] Example 2

[0061] A preparation method of a flexible strain sensing component, the specific steps are as follows:

[0062] (1) Preparation of single-layer MXene dispersion liquid: LiF and Ti3AlC2 with a mass ratio of 1.6:1 were added to a hydrochloric acid solution with a concentration of 9 mol / L for stirring, followed by centrifugation for 6 times until the lower layer of the precipitate swelled, dimethyl sulfoxide was added to the lower layer of the swelled precipitate and centrifuged for 4 times, and a single-layer MXene dispersion liquid with a concentration of 22 mg / ml was collected; wherein the mass-volume ratio of LiF to hydrochloric acid solution is 1.6 g:40 ml;

[0063] (2) Preparation of polypyrrole microsphere dispersion liquid: polypyrrole microspheres were dispersed in dimethyl sulfoxide to obtain a polypyrrole microsphere dispersion liquid with a concentration of 3.5 mg / ml;

[0064] (3) The polypyrrole microsphere dispersion liquid obtained in step (2) and the single-layer MXene dispersion liquid obtained in step (1) were mixed in a volume ratio of 1:3.5 for self-assembly, and polyurethane particles (BASF-1185A) were added to the assembled solution and stirred to form a spinning solution with a polyurethane content of 100 mg / ml;

[0065] (4) The spinning solution obtained in step (3) was subjected to wet spinning to obtain a filament, and the filament was dried and subjected to a 100% pre-drawing treatment;

[0066] (5) The pre-drawn filament in step (4) was soaked in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate with a mass ratio of 1:1 (the solvent of the mixed solution is water, and the total concentration of the mixed solution is 19.2 wt%), and was refrigerated, then a mixture of pyrrole and cyclohexane with a volume ratio of 1:39 was poured into the refrigerated mixed solution, frozen for 7 min, and then refrigerated for 28 h;

[0067] (6) The pre-drawing of the filament was removed, the filament was ultrasonically cleaned with ultrapure water, and was dried to obtain a flexible strain sensing component.

[0068] The prepared flexible strain sensing component is a double-layer filament structure, the core layer is a polyurethane elastic matrix of self-assembled single-layer MXene and polypyrrole microspheres, and the shell layer is polypyrrole with a wrinkle structure; the strain sensing range of the flexible strain sensing component is 0-245%, and the sensitivity range is 0-125000.

[0069] Example 3

[0070] A preparation method of a flexible strain sensing component, the specific steps are as follows:

[0071] (1) Preparation of single-layer MXene dispersion liquid: LiF and Ti3AlC2 with a mass ratio of 1.6:1 were added to a hydrochloric acid solution with a concentration of 9 mol / L for stirring, followed by centrifugation for 7 times until the lower layer of the precipitate swelled, dimethyl sulfoxide was added to the lower layer of the swelled precipitate and centrifuged for 5 times, and a single-layer MXene dispersion liquid with a concentration of 18 mg / ml was collected; wherein the mass-volume ratio of LiF to hydrochloric acid solution is 1.6 g:40 ml;

[0072] (2) Preparation of polypyrrole microsphere dispersion liquid: polypyrrole microspheres were dispersed in dimethyl sulfoxide to obtain a polypyrrole microsphere dispersion liquid with a concentration of 4 mg / ml;

[0073] (3) The polypyrrole microsphere dispersion liquid obtained in step (2) and the single-layer MXene dispersion liquid obtained in step (1) were mixed in a volume ratio of 1:4 for self-assembly, and polyurethane particles (BASF-1198A) were added to the assembled solution and stirred to form a spinning solution with a polyurethane content of 150 mg / ml;

[0074] (4) Wet spinning was performed on the spinning solution obtained in step (3) to obtain filaments, and the filaments were dried and then pre-drawn by 125%;

[0075] (5) The pre-drawn filaments in step (4) were soaked in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate with a mass ratio of 1:1 (the solvent of the mixed solution is water, and the total concentration of the mixed solution is 19.2 wt%), and then refrigerated, then a mixture of pyrrole and cyclohexane with a volume ratio of 1:39 was poured into the refrigerated mixed solution, frozen for 8 min, and then refrigerated for 30 h;

[0076] (6) The pre-drawing of the filaments was removed, the filaments were ultrasonically cleaned with ultrapure water, and then dried to obtain a flexible strain sensing component.

[0077] The prepared flexible strain sensing component has a double-layer filament structure, the core layer is a polyurethane elastic matrix of self-assembled single-layer MXene and polypyrrole microspheres, and the shell layer is polypyrrole with a wrinkle structure; the strain sensing range of the flexible strain sensing component is 0-250%, and the sensitivity range is 0-128000.

[0078] Example 4

[0079] A preparation method of a flexible strain sensing component, the specific steps are as follows:

[0080] (1) Preparation of single-layer MXene dispersion liquid: LiF and Ti3AlC2 with a mass ratio of 1.6:1 were added to a hydrochloric acid solution with a concentration of 9 mol / L for stirring, followed by centrifugation for 8 times until the lower layer of the expanded precipitate, dimethyl sulfoxide was added to the lower layer of the expanded precipitate and centrifuged for 6 times, and a single-layer MXene dispersion liquid with a concentration of 15 mg / ml was collected; wherein the mass-volume ratio of LiF to the hydrochloric acid solution was 1.6 g:40 ml;

[0081] (2) Preparation of polypyrrole microsphere dispersion liquid: polypyrrole microspheres were dispersed in dimethyl sulfoxide to obtain a polypyrrole microsphere dispersion liquid with a concentration of 4.5 mg / ml;

[0082] (3) The polypyrrole microsphere dispersion liquid obtained in step (2) and the single-layer MXene dispersion liquid obtained in step (1) were mixed in a volume ratio of 1:4.5 for self-assembly, and polyurethane particles (BASF-1170A) were added to the assembled solution and stirred to form a spinning solution with a polyurethane content of 200 mg / ml;

[0083] (4) The spinning solution obtained in step (3) was subjected to wet spinning to obtain a filament, and the filament was dried and subjected to a pre-drawing treatment of 150%;

[0084] (5) The pre-drawn filament in step (4) was soaked in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate with a mass ratio of 1:1 (the solvent of the mixed solution is water, and the total concentration of the mixed solution is 19.2 wt%), and was refrigerated, then a mixture of pyrrole and cyclohexane with a volume ratio of 1:39 was poured into the refrigerated mixed solution, frozen for 9 min, and then refrigerated for 32 h;

[0085] (6) The pre-drawing of the filament was removed, the filament was ultrasonically cleaned with ultrapure water, and was dried to obtain a flexible strain sensing component.

[0086] The prepared flexible strain sensing component has a double-layer filament structure, the core layer is a polyurethane elastic matrix of self-assembled single-layer MXene and polypyrrole microspheres, and the shell layer is polypyrrole with a wrinkle structure; the strain sensing range of the flexible strain sensing component is 0-275%, and the sensitivity range is 0-117000.

[0087] Example 5

[0088] A preparation method of a flexible strain sensing component, the specific steps are as follows:

[0089] (1) Preparation of single-layer MXene dispersion liquid: LiF and Ti3AlC2 with a mass ratio of 1.6:1 were added to a hydrochloric acid solution with a concentration of 9 mol / L for stirring, followed by centrifugation for 9 times until the lower layer of the precipitate swelled, dimethyl sulfoxide was added to the lower layer of the swelled precipitate and centrifuged for 7 times, and a single-layer MXene dispersion liquid with a concentration of 10 mg / ml was collected; wherein the mass-volume ratio of LiF to the hydrochloric acid solution was 1.6 g:40 ml;

[0090] (2) Preparation of polypyrrole microsphere dispersion liquid: polypyrrole microspheres were dispersed in dimethyl sulfoxide to obtain a polypyrrole microsphere dispersion liquid with a concentration of 5 mg / ml;

[0091] (3) The polypyrrole microsphere dispersion liquid obtained in step (2) and the single-layer MXene dispersion liquid obtained in step (1) were mixed in a volume ratio of 1:5 for self-assembly, and polyurethane particles (BASF-1185A) were added to the assembled solution and stirred to form a spinning solution with a polyurethane content of 250 mg / ml;

[0092] (4) Wet spinning was performed on the spinning solution obtained in step (3) to obtain a filament, and the filament was dried and subjected to a pre-drawing treatment of 200%;

[0093] (5) The pre-drawn filament in step (4) was soaked in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate with a mass ratio of 1:1 (the solvent of the mixed solution is water, and the total concentration of the mixed solution is 19.2 wt%), and was refrigerated, then a mixture of pyrrole and cyclohexane with a volume ratio of 1:39 was poured into the refrigerated mixed solution, frozen for 10 min, and then refrigerated for 36 h;

[0094] (6) The pre-drawing of the filament was removed, the filament was ultrasonically cleaned with ultrapure water, and was dried to obtain a flexible strain sensing component.

[0095] The prepared flexible strain sensing component has a double-layer filament structure, the core layer is a polyurethane elastic matrix of self-assembled single-layer MXene and polypyrrole microspheres, and the shell layer is polypyrrole with a wrinkle structure; the strain sensing range of the flexible strain sensing component is 0-300%, and the sensitivity range is 0-121000.

[0096] Example 6

[0097] A preparation method of an intelligent pressure sock for monitoring leg swelling changes, the specific steps are as follows:

[0098] (1) As shown in Figure 1 , the flexible strain sensing component 2 prepared in Example 1 was sewn into the medical pressure sock 1, and the medical pressure sock 1 was sewn out of three circular rings at the upper, middle and lower parts of the transverse direction; the sewing method was flat sewing, and the port of the sewing was left with 0.5 cm;

[0099] (2) Preparation of flexible lead wire 3:

[0100] (2.1) Adjust the pH of the mixed solution obtained by mixing trihydroxymethyl aminomethane, hydrochloric acid solution and ultrapure water to 8.5;

[0101] (2.2) Add dopamine to the mixed solution of step (2.1) and ultrasonic for 5 min, then put the polyurethane filament with linear density of 40D and pre-drawing of 200% into it and soak for 8h;

[0102] (2.3) Soak the polyurethane filament of step (2.2) in the mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate with a mass ratio of 1:1 (the solvent of the mixed solution is water, and the total concentration of the mixed solution is 19.2wt%), and refrigerate, then pour the mixed solution of pyrrole and cyclohexane with a volume ratio of 1:39 into the refrigerated mixed solution, freeze for 6 min, and then refrigerate for 24h;

[0103] (2.4) Remove the pre-drawing of the polyurethane filament, ultrasonic and clean the filament with ultrapure water, and dry to obtain the flexible lead wire 3;

[0104] The prepared flexible lead wire 3 is a polyurethane filament with a poly-pyrrole wrinkle layer on the surface;

[0105] (3) Connect the port of the flexible strain sensing component 2 in step (1) and one end of the flexible lead wire 3 with conductive silver paste, then sew the flexible lead wire 3 into the medical pressure stocking 1 along the radial direction, and finally leave a 1cm port for the flexible lead wire 3;

[0106] (4) Fix the built-in power supply and Bluetooth module 4 of the signal acquisition device on the top of the medical pressure stocking 1, install Type-C interface 5, USB interface 6 and HDMI 7 interface on the right side of the built-in power supply and Bluetooth module of the signal acquisition device, and connect the port of the flexible lead wire 3 in step (3) with the positive and negative electrodes of the signal acquisition device, to obtain the intelligent pressure stocking for monitoring the change of leg swelling.

[0107] Example 7

[0108] A preparation method of an intelligent pressure stocking for monitoring the change of leg swelling, the specific steps are as follows:

[0109] (1) Sew the flexible strain sensing component prepared in Example 2 into the medical pressure stocking, select the upper, middle and lower parts of the medical pressure stocking transversely to sew out 3 circular rings, the sewing method is flat sewing, and the port of the sewing is left with 0.6cm;

[0110] (2) Preparation of flexible lead wire:

[0111] (2.1) mixed solution was obtained by mixing tris-hydroxymethyl aminomethane, hydrochloric acid solution and ultrapure water to adjust pH to 8.55;

[0112] (2.2) dopamine was added to the mixed solution of step (2.1) and ultrasonic treatment was performed for 6 min, then polyurethane filaments with linear density of 60D and pre-drawing of 250% were put into the mixed solution and soaked for 9 h;

[0113] (2.3) the soaked polyurethane filaments of step (2.2) were further soaked in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate with a mass ratio of 1:1 (the solvent of the mixed solution was water, and the total concentration of the mixed solution was 19.2 wt%), and refrigerated, then a mixed solution of pyrrole and cyclohexane with a volume ratio of 1:39 was poured into the refrigerated mixed solution, frozen for 7 min, and then refrigerated for 28 h;

[0114] (2.4) the pre-drawing of the polyurethane filaments was removed, the filaments were ultrasonically treated and washed with ultrapure water, and dried to obtain flexible wires;

[0115] The prepared flexible wires were polyurethane filaments with poly-pyrrole wrinkle layers on the surface;

[0116] (3) the port of the flexible strain sensing component in step (1) and one end of the flexible wire were connected by using conductive silver paste, then the flexible wire was sewn into the medical pressure stocking along the radial direction of the medical pressure stocking, and finally the flexible wire was left with a port of 1.2 cm;

[0117] (4) the built-in power supply and the Bluetooth module of the signal acquisition device were fixed on the top of the medical pressure stocking, and the port of the flexible wire in step (3) was connected to the positive and negative electrodes of the signal acquisition device, to obtain an intelligent pressure stocking for monitoring the change of leg swelling.

[0118] Example 8

[0119] A preparation method of an intelligent pressure stocking for monitoring the change of leg swelling, the specific steps are as follows:

[0120] (1) the flexible strain sensing component prepared in Example 3 was sewn into the medical pressure stocking, and three circular rings were sewn out of the medical pressure stocking by selecting the upper, middle and lower parts of the medical pressure stocking in the transverse direction, the sewing method was flat sewing, and the port of the sewing was left with 0.7 cm;

[0121] (2) preparation of flexible wire:

[0122] (2.1) mixed solution was obtained by mixing tris-hydroxymethyl aminomethane, hydrochloric acid solution and ultrapure water to adjust pH to 8.6;

[0123] (2.2) Dopamine was added to the mixed solution of step (2.1) and ultrasonic treatment was performed for 7 min, then polyurethane filaments with a linear density of 80D and a pre-drawing of 300% were put into the solution and soaked for 10 h;

[0124] (2.3) The polyurethane filaments soaked in step (2.2) were further soaked in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate with a mass ratio of 1:1 (the solvent of the mixed solution was water, and the total concentration of the mixed solution was 19.2 wt%), and refrigerated, then a mixed solution of pyrrole and cyclohexane with a volume ratio of 1:39 was poured into the refrigerated mixed solution, frozen for 8 min, and then refrigerated for 30 h;

[0125] (2.4) The pre-drawing of the polyurethane filaments was removed, the filaments were ultrasonically treated and washed with ultrapure water, and dried to obtain flexible wires;

[0126] The prepared flexible wires were polyurethane filaments with a poly-pyrrole wrinkle layer on the surface;

[0127] (3) The port of the flexible strain sensing component in step (1) and one end of the flexible wire were connected by using conductive silver paste, then the flexible wire was sewn into the medical pressure stocking along the radial direction of the medical pressure stocking, and finally the flexible wire was left with a port of 1.5 cm;

[0128] (4) The built-in power supply and the Bluetooth module of the signal acquisition device were fixed on the top of the medical pressure stocking, and the port of the flexible wire in step (3) was connected to the positive and negative electrodes of the signal acquisition device, to obtain an intelligent pressure stocking for monitoring the change of leg swelling.

[0129] Example 9

[0130] A preparation method of an intelligent pressure stocking for monitoring the change of leg swelling, the specific steps are as follows:

[0131] (1) The flexible strain sensing component prepared in Example 4 was sewn into the medical pressure stocking, and three circular rings were sewn out of the upper, middle and lower parts of the medical pressure stocking in the transverse direction, and the sewing method was forward and reverse sewing, and the port of the sewing was left with 0.8 cm;

[0132] (2) Preparation of flexible wire:

[0133] (2.1) Tris-hydroxymethyl aminomethane, hydrochloric acid solution and ultrapure water were mixed to adjust the pH to 8.65 to obtain a mixed solution;

[0134] (2.2) Dopamine was added to the mixed solution of step (2.1) and ultrasonic treatment was performed for 8 min, then polyurethane filaments with a linear density of 100D and a pre-drawing of 320% were put into the solution and soaked for 11 h;

[0135] (2.3) The polyurethane filament soaked in step (2.2) is soaked in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate with a mass ratio of 1:1 (the solvent of the mixed solution is water, and the total concentration of the mixed solution is 19.2wt%), and refrigerated, then a mixture of pyrrole and cyclohexane with a volume ratio of 1:39 is poured into the refrigerated mixed solution, frozen for 9min, and then refrigerated for 32h;

[0136] (2.4) The pre-drawing of the polyurethane filament is removed, the filament is ultrasonically cleaned with ultrapure water, and dried to obtain a flexible wire;

[0137] The prepared flexible wire is a polyurethane filament with a poly-pyrrole wrinkle layer on the surface;

[0138] (3) The port of the flexible strain sensing component in step (1) is connected to one end of the flexible wire by using conductive silver paste, then the flexible wire is sewn into the medical compression stocking along the radial direction of the medical compression stocking, and finally the flexible wire has a port of 1.8cm;

[0139] (4) The built-in power supply and the Bluetooth module of the signal acquisition device are fixed on the top of the medical compression stocking, and the port of the flexible wire in step (3) is connected to the positive and negative electrodes of the signal acquisition device, thereby assembling an intelligent compression stocking for monitoring leg swelling changes.

[0140] Example 10

[0141] A preparation method of an intelligent compression stocking for monitoring leg swelling changes, the specific steps are as follows:

[0142] (1) The flexible strain sensing component prepared in Example 5 is sewn into the medical compression stocking, and three circular rings are sewn out of the medical compression stocking by selecting the upper, middle and lower parts of the medical compression stocking in the transverse direction, and the sewing method is forward and reverse sewing, and the port of the sewing has a length of 1cm;

[0143] (2) Preparation of flexible wire:

[0144] (2.1) Tris-hydroxymethyl aminomethane, hydrochloric acid solution and ultrapure water are mixed to adjust the pH to 8.7 to obtain a mixed solution;

[0145] (2.2) Dopamine is added to the mixed solution of step (2.1) and ultrasonicated for 8min, then a polyurethane filament with a linear density of 120D and a pre-drawing of 350% is placed in the solution and soaked for 12h;

[0146] (2.3) The polyurethane filaments soaked in step (2.2) are soaked in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate with a mass ratio of 1:1 (the solvent of the mixed solution is water, and the total concentration of the mixed solution is 19.2wt%), and then refrigerated, and then a mixture of pyrrole and cyclohexane with a volume ratio of 1:39 is poured into the refrigerated mixed solution, frozen for 10 min, and then refrigerated for 36 h;

[0147] (2.4) The pre-drawing of the polyurethane filaments is removed, the filaments are ultrasonically cleaned with ultrapure water, and then dried to obtain flexible wires;

[0148] The prepared flexible wires are polyurethane filaments with a poly-pyrrole wrinkle layer on the surface;

[0149] (3) The port of the flexible strain sensing component in step (1) and one end of the flexible wire are connected by using conductive silver paste, then the flexible wire is sewn into the medical pressure stocking along the radial direction of the medical pressure stocking, and finally the flexible wire is left with a port of 2 cm;

[0150] (4) The built-in power supply and the Bluetooth module of the signal acquisition device are fixed on the top of the medical pressure stocking, and the port of the flexible wire in step (3) is connected to the positive and negative electrodes of the signal acquisition device, thereby obtaining an intelligent pressure stocking for monitoring the swelling changes of the leg.

Claims

1. A method for fabricating a flexible strain sensing component, characterized in that: Specifically, the steps include the following: (1) Preparation of monolayer MXene dispersion: LiF and Ti3AlC2 were added to hydrochloric acid solution and stirred. Then, the mixture was centrifuged several times until the lower precipitate swelled. Dimethyl sulfoxide was added to the swelled lower precipitate and centrifuged several times to collect the monolayer MXene dispersion. (2) Preparation of polypyrrole microsphere dispersion: polypyrrole microspheres were dispersed in dimethyl sulfoxide to obtain polypyrrole microsphere dispersion; (3) First, mix the polypyrrole microsphere dispersion obtained in step (2) with the monolayer MXene dispersion obtained in step (1) for self-assembly, then add polyurethane particles to the assembled solution and stir to form a spinning solution. (4) The spinning solution obtained in step (3) is wet-spun to obtain filaments, and the filaments are dried and then pre-stretched. (5) Immerse the pre-stretched filaments from step (4) in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate and refrigerate them. Then pour a mixture of pyrrole and cyclohexane into the refrigerated mixture, freeze for 6-10 min, and then refrigerate for 24-36 h. (6) Remove the pre-stretching of the filament, sonicate and clean the filament with ultrapure water, and dry it to obtain a flexible strain sensing component.

2. The method for fabricating a flexible strain sensing component according to claim 1, characterized in that, In step (1), the mass ratio of LiF to Ti3AlC2 is 1.6:1, the concentration of hydrochloric acid solution is 9 mol / L, the mass-volume ratio of LiF to hydrochloric acid solution is 1.6 g: 40 ml, and the concentration of monolayer MXene dispersion is 15-25 mg / ml. In step (2), the concentration of the polypyrrole microsphere dispersion is 3–5 mg / ml; In step (3), the volume ratio of polypyrrole microsphere dispersion to monolayer MXene dispersion is 1:3 to 5, and the polyurethane content in the spinning solution is 50 to 250 mg / ml.

3. The method for fabricating a flexible strain sensing component according to claim 1, characterized in that, The pre-stretch range in step (4) is 50% to 200%.

4. The method for fabricating a flexible strain sensing component according to claim 1, characterized in that, In step (5), the mass ratio of ferric chloride hexahydrate to sodium sulfosalicylate is 1:1, and the volume ratio of pyrrole to cyclohexane is 1:

39.

5. A flexible strain sensing component manufactured using the method described in any one of claims 1 to 4, characterized in that: The flexible strain sensing component has a double-layer filament structure. The core layer is a polyurethane elastic matrix consisting of a self-assembled monolayer of MXene and polypyrrole microspheres, and the shell layer is polypyrrole with a pleated structure. The strain sensing range of the flexible strain sensing component is 0–300%, and the sensitivity range is 0–150,000.

6. A method for preparing a smart compression stocking that monitors changes in leg swelling, characterized in that: A smart compression stocking for monitoring leg swelling changes is obtained by assembling the flexible strain sensing component and flexible wire as described in claim 5. The flexible conductor is a polyurethane filament with a polypyrrole corrugated layer on its surface.

7. The method for preparing a smart compression stocking for monitoring leg swelling changes according to claim 6, characterized in that, Specifically, the steps include the following: (1) Sew the flexible strain sensing component into the medical compression stocking. Select the upper, middle and lower parts of the medical compression stocking to sew three rings. The sewing method is flat sewing or double sewing. Leave 0.5 to 1 cm at the sewing end. (2) Connect the port of the flexible strain sensing component in step (1) and one end of the flexible wire with conductive silver paste, then sew the flexible wire into the radial direction of the medical compression stocking, and finally leave a 1-2 cm port on the flexible wire. (3) Fix the Bluetooth module of the built-in power supply and signal acquisition device to the top of the medical compression stocking, and connect the port of the flexible wire in step (2) to the positive and negative poles of the signal acquisition device to assemble the smart compression stocking that monitors changes in leg swelling.

8. A method for preparing a smart compression stocking for monitoring leg swelling changes according to claim 6 or 7, characterized in that, The fabrication of flexible conductors includes the following steps: (1) Mix trihydroxymethylaminomethane, hydrochloric acid solution and ultrapure water to adjust the pH to 8.5-8.7 to obtain a mixed solution; (2) Add dopamine to the mixed solution in step (1) and sonicate for 5 to 8 minutes. Then, put polyurethane filaments with a linear density of 40 to 120D and a pre-stretch of 200 to 350% into the solution and soak for 8 to 12 hours. (3) The polyurethane filaments soaked in step (2) are soaked again in a mixed solution of ferric chloride hexahydrate and sodium sulfosalicylate and refrigerated. Then, a mixture of pyrrole and cyclohexane is poured into the refrigerated mixture, frozen for 6 to 10 minutes, and then refrigerated for 24 to 36 hours. (4) Remove the pre-stretching of the polyurethane filament, sonicate and clean the filament with ultrapure water, and dry it to obtain a flexible wire.

9. A method for preparing a smart compression stocking for monitoring leg swelling changes according to claim 8, characterized in that, In step (3), the mass ratio of ferric chloride hexahydrate to sodium sulfosalicylate is 1:1, and the volume ratio of pyrrole to cyclohexane is 1:39.

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