CN115418860B - Conductive fiber body, preparation method thereof and application thereof in preparation of strain sensor - Google Patents
Conductive fiber body, preparation method thereof and application thereof in preparation of strain sensor Download PDFInfo
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- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
- D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
- D06M15/37—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D06M15/564—Polyureas, polyurethanes or other polymers having ureide or urethane links; Precondensation products forming them
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- A—HUMAN NECESSITIES
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- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
- A61B5/024—Detecting, measuring or recording pulse rate or heart rate
- A61B5/02444—Details of sensor
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
- A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
- A61B5/1118—Determining activity level
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
- A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
- A61B5/1123—Discriminating type of movement, e.g. walking or running
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- D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
- D06M11/73—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with carbon or compounds thereof
- D06M11/74—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with carbon or compounds thereof with carbon or graphite; with carbides; with graphitic acids or their salts
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- D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
- D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
- D06M15/21—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D06M15/327—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of unsaturated alcohols or esters thereof
- D06M15/333—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of unsaturated alcohols or esters thereof of vinyl acetate; Polyvinylalcohol
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
- G01B7/18—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in resistance
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- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
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- A61B2562/0261—Strain gauges
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- D06M2101/00—Chemical constitution of the fibres, threads, yarns, fabrics or fibrous goods made from such materials, to be treated
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Abstract
The application belongs to the field of flexible wearable, and particularly relates to a conductive fiber body, a preparation method thereof and application thereof in preparation of a strain sensor. The conductive fiber body comprises a matrix core material, a microsphere/fiber framework layer and a graphene conductive layer which are sequentially arranged from inside to outside. Use of an electrically conductive fibrous body for the preparation of a strain sensor. The strain sensor prepared by the conductive fiber has extremely high sensitivity, wide strain range, quick response time and good durability, and the high sensitivity under the tiny strain meets the requirements of tiny deformation monitoring, such as the health detection of pulse beating, throat vibration and the like of a human body. Meanwhile, the sensor can be used for severe and large-amplitude motion monitoring, such as joint motion monitoring. The application has simple preparation process and controllable structure, can be integrated into yarns or fabrics through braiding and sewing, and has great application prospect in the flexible wearable sensor.
Description
Technical Field
The application belongs to the field of flexible wearable, and particularly relates to a conductive fiber body, a preparation method thereof and application thereof in preparation of a strain sensor.
Background
In recent years, the application of the flexible strain sensor on intelligent wearable equipment attracts great attention of researchers, and the flexible strain sensor can capture and evaluate human body movement and health conditions in real time, and has great application potential and market value. Traditional semiconductor and metal foil strain plates have limited application in the intelligent wearable field due to the defects of strong rigidity, low sensitivity, narrow sensing range (5%), and the like. However, in the new material, the graphene has the characteristics of light weight, transparency, excellent conductivity, excellent mechanical property and the like, and has extremely important and wide application prospects in the aspect of sensing technology.
The conductive fiber has the characteristics of light weight, softness, braiding and the like, can bear various deformations such as bending, torsion, stretching and the like, endows the fiber-based sensor with the capability of adapting to the wearability of human bodies and skin, and has good reliability when being used for monitoring physiological signals of human bodies. A common preparation method of the fiber-based flexible sensor is to uniformly disperse a conductive material in a melted or dissolved flexible matrix, and the conductive material/flexible matrix homogeneous composite fiber can be prepared by various spinning methods. Another method is to cover or infiltrate the conductive material onto the surface of the fiber to construct a conductive network to prepare the strain sensor. The interface effect of the conductive material and the fiber matrix has an important influence on the performance of the sensor, and the sensitivity of the graphene-based fiber sensor which is generally prepared in the strain range of 0-10% is generally low (GF 0.1-30), so that the improvement of the sensitivity of the graphene-based fiber sensor in the small strain range is a great challenge.
Disclosure of Invention
The application mainly overcomes the defects of the prior art, and provides a conductive fiber body and a preparation method thereof, wherein the number of contact points of a graphene conductive network is increased through structural design, so that the sensitivity is improved. The application prepares the fiber strain sensor with good elasticity, wide strain range and high sensitivity based on the hollow microsphere modified 'chestnut rice stick' -shaped wire fiber body structure and the mechanical flexibility and the electrical conductivity of graphene.
In order to solve the technical problems, the application adopts the following technical scheme:
the conductive fiber body comprises a matrix core material, a microsphere/fiber framework layer and a graphene conductive layer which are sequentially arranged from inside to outside.
Preferably, the matrix core material is made of any one material of polyurethane elastic fiber, polyether ester elastic fiber, polyolefin elastic fiber and elastic polyester fiber, the microsphere/fiber skeleton layer is formed by expanding microspheres and elastic polymers, and the graphene conductive layer is made of graphene oxide.
A method of preparing the above-described conductive fiber body, comprising the steps of:
step S1, preparing an expanded microsphere/elastic polymer finishing liquid: weighing a certain amount of elastic polymer, adding the expanded microspheres, and uniformly dispersing to obtain an expanded microsphere/elastic polymer finishing liquid; wherein, the elastic polymer comprises the following components in percentage by mass: expanded microsphere = 1:3% -10%;
s2, soaking the matrix core material in the expanded microsphere/elastic polymer finishing liquid, and sequentially heating, rinsing and drying to obtain an intermediate;
step S3, dipping the intermediate in graphene finishing liquid, drying, dipping in graphene finishing liquid, drying, circulating for a plurality of times, and performing chemical reduction treatment to obtain a conductive fiber body;
further, in S1, the foaming temperature of the expanded microspheres is 80-120 ℃ and the particle size is 5-10 mu m.
In the step S1, the elastic polymer is any one of aqueous polyurethane, polyvinyl alcohol and polyacrylate aqueous solution.
In S2, the matrix core material is any one of polyurethane elastic fiber, polyether ester elastic fiber, polyolefin elastic fiber and elastic polyester fiber.
Further, in S2, the time condition of soaking is 5-10min, the heating temperature is 80-120 ℃ and the time condition is 10-30min.
Further, in S3, the graphene finishing liquid is graphene oxide aqueous solution, the solid content of the graphene oxide aqueous solution is 5-10mg/mL, the soaking time condition is 5-10min, and the cycle times are 1-5 times.
The application of the conductive fiber body in the preparation of the strain sensor.
The preparation method of the strain sensor comprises the steps of connecting two ends of the conductive fiber body with copper wires by using conductive silver paste, and connecting the cured conductive fiber body with an external power supply to obtain the strain sensor. The technical scheme provided by the application has the beneficial effects that:
(1) The elastic structure of the three-dimensional 'chestnut rice stick' -shaped fiber framework and the continuous corrugated graphene conductive network designed by the application can provide more conductive contact points for stress strain sensing, have larger deformation space and provide a foundation for certain tensile strain;
(2) The skeleton structure designed by the application generates huge microstructure change and conductive network change when the strain occurs, can endow the sensor with extremely high sensitivity and quick response capability even under extremely small strain, and has excellent cycling stability and wide strain range due to the elastic recovery performance of the graphene reinforced microsphere/fiber skeleton;
(3) The strain sensor prepared based on the structure has the function of monitoring the health state and the movement behavior of a human body in real time, can detect the pulse beat, throat vibration and movement states of all joints of the human body, and has great application potential in the aspects of intelligent wearable equipment such as virtual reality, man-machine interaction, health monitoring and the like.
Description of the drawings:
FIG. 1 is an SEM image of polyurethane elastic fiber of example 1 of the present application;
FIG. 2 is an SEM image of an expanded microsphere modified fiber according to example 1 of the present application;
FIG. 3 is an SEM image of a graphene oxide modified microsphere/fiber framework of example 1 of the present application;
FIG. 4 is an SEM image of a reduced graphene oxide modified microsphere/fiber backbone of example 1 of the present application;
FIG. 5 is a graph showing the strain ranges and sensitivity test of the strain sensor of example 1 of the present application in unidirectional stretching;
FIG. 6 is a response time test of the strain sensor of example 1 of the present application at a strain of 0 to 6%;
FIG. 7 is a graph showing 2000 cycle stability tests of the strain sensor of example 1 of the present application at 0-20% strain;
FIG. 8 is a graph showing the detection result of the knee movement of a human body by the strain sensor according to the embodiment 1 of the present application;
FIG. 9 is a graph showing the detection result of the strain sensor according to example 1;
fig. 10 shows the detection result of the strain sensor according to example 1 of the present application on the vibration condition of human pulse.
Specific embodiments:
the application will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present application and are not intended to limit the scope of the present application. Furthermore, it should be understood that various changes and modifications can be made by one skilled in the art after reading the teachings of the present application, and such equivalents are intended to fall within the scope of the application as defined in the appended claims.
The conductive fiber body is of a 'chestnut rice stick' structure, and comprises a matrix core material, a microsphere/fiber framework layer and a graphene conductive layer which are sequentially arranged from inside to outside. Specifically, the application adopts a one-dimensional elastomer as a matrix core material, uses the expansion microsphere to construct a surface microstructure to form a microsphere/fiber skeleton layer, uses a graphene conductive network as a shell to modify a microprotrusion sphere wrapping skeleton and fills gaps among microspheres, thereby preparing the 'rice-stick' -shaped core-spun fiber structure.
According to the application, the chestnut rice rod-shaped conductive fiber body is applied to the preparation of the strain sensor, and when the prepared sensor is subjected to deformation such as stretching, bending, twisting, folding and the like under the action of external force, the deformation of the expansion microsphere, the flattening of the wrinkled graphene and the expansion of microcracks are based, the change of the relative resistance is caused by the change of the conductive network structure, and the deformation of the material is detected and indicated by detecting the change of the relative resistance. In addition, the elastic structure of the three-dimensional 'chestnut rice stick' -shaped fiber framework and the continuous corrugated graphene conductive network can provide more conductive contact points for stress strain sensing, and have a larger deformation space, so that a foundation is provided for tensile strain of the sensor.
The working mechanism of the strain sensor is as follows:
(1) Under the condition of low strain, when external strain is applied, the sensor is stretched by virtue of the inherent excellent elasticity of the matrix and the hollow microspheres, and the closely contacted microspheres are gradually pulled apart to displace, so that the contact resistance is increased;
(2) As the strain is increased, the graphene conductive layers of the outer layers are gradually straightened from a fold shape along the direction parallel to the stress, the graphene conductive network contact points of the outer layers of the adjacent microspheres are reduced, the conductive paths are reduced, and the contact resistance is increased sharply;
(3) At extremely high strains, the sensor further expands, the conductive network develops microcracks, resulting in a further increase in the relative change in resistance. When the strain is released, the expanded sensor can be restored to the original state due to the excellent elastic restoring performance of the framework, the microcracks are gradually closed, the graphene layer is restored to the folded state, and the microspheres are restored to be closely arranged, so that the change of the relative resistance of the sensor is reduced and the initial value is restored. By detecting the relative resistance change, the deformation of the material is detected.
In addition, the application also provides a preparation method of the strain sensor, which mainly comprises the following steps:
step S1, preparing an expanded microsphere/elastic polymer finishing liquid: weighing a certain amount of elastic polymer, adding the expanded microspheres, and uniformly dispersing to obtain an expanded microsphere/elastic polymer finishing liquid; wherein, the elastic polymer comprises the following components in percentage by mass: expanded microsphere = 1:3% -10%; the foaming temperature of the expanded microspheres is 80-120 ℃, the particle size is 5-10 mu m, and the elastic polymer is any one of aqueous polyurethane, polyvinyl alcohol and polyacrylate aqueous solution;
s2, dipping the one-dimensional elastomer in an expanded microsphere/elastic polymer finishing liquid for 5-10min, placing the dipped one-dimensional elastomer in an oven with the temperature of 80-120 ℃ for heating for 10-30min, heating a low-boiling-point core material in the expanded microsphere to generate pressure to cause microsphere volume expansion, constructing an expanded microsphere modified 'chestnut rice stick' -shaped fiber skeleton with a core-shell structure, rinsing with deionized water, and drying in air to obtain an intermediate; wherein the one-dimensional elastomer is any one of polyurethane elastic fiber, polyether ester elastic fiber, polyolefin elastic fiber and elastic polyester fiber, the time condition of impregnation is 5-10min, the temperature condition of heating is 80-120 ℃ and the time condition is 10-30min; the preparation method is not limited to the dosage of the one-dimensional elastomer, and one-dimensional elastomer materials with corresponding lengths can be adopted according to actual needs;
step S3, dipping the intermediate in graphene finishing liquid for 5-10min, drying in a 50 ℃ oven, dipping in graphene finishing liquid for 5-10min, drying in a 50 ℃ oven, circulating for 1-5 times, and performing chemical reduction treatment to obtain a conductive fiber body; the method comprises the steps of realizing a convex spherical microstructure modified by a multi-layer graphene coating by self-assembly bonding effect of graphene and an intermediate to obtain a 'chestnut rice stick' -shaped fiber body; the graphene finishing liquid is graphene oxide aqueous solution, the solid content of the graphene oxide aqueous solution is 5-10mg/mL, and the soaking time is 5-10min; the oxygen-containing functional groups on the surface of the graphene oxide are removed through chemical reduction reaction, the pi-pi conjugated structure is recovered, the strength and the conductivity of a matrix are enhanced, and the chestnut-shaped rod-shaped conductive fiber body with the reduced graphene oxide as a conductive carrier is obtained;
and S4, connecting the two ends of the conductive fiber body with copper wires by using conductive silver paste, and connecting the cured conductive fiber body with an external power supply to obtain the strain sensor.
In the preparation method of the application, the expanded microsphere and the conductive silver paste are both obtained from market purchase, wherein the model of the expanded microsphere is F-48 (Japanese Songben oil pharmaceutical Co., ltd.) and the model of the conductive silver paste is 3812 (Shenzhen Xinwei electronic materials Co., ltd.).
Example 1 ]
A method of manufacturing a strain sensor comprising the steps of:
step S1, preparing an expanded microsphere/elastic polymer finishing liquid: weighing 50g of waterborne polyurethane, adding 2.5g of expansion microspheres, and dispersing by a homogenizer to obtain uniformly dispersed expansion microspheres/polyurethane finishing liquid;
step S2, soaking polyurethane elastic fibers (shown in figure 1) in the expanded microsphere/polyurethane finishing liquid prepared in the step S1 for 10min, heating in an oven at 120 ℃ for 10min, heating and foaming to construct a fiber skeleton (shown in figure 2) modified by the expanded microsphere with a core-shell structure, rinsing with deionized water, and drying in air to obtain an intermediate;
step S3, dipping the intermediate in graphene finishing liquid with solid content of 5mg/mL for 10min, drying in a baking oven at 50 ℃, dipping in the graphene finishing liquid, repeating the steps for 5 times circularly to realize a convex spherical microstructure modified by a multi-layer graphene coating (shown in figure 3), and chemically reducing by ascorbic acid solution to obtain a reduced graphene oxide coating loaded 'rice stick' -shaped conductive fiber body (shown in figure 4);
and S4, coating conductive silver paste on two ends of the rice-bar-shaped conductive fiber body prepared in the step S3 to serve as electrodes, attaching copper wires to the conductive silver paste, and fixing the copper wires with a conductive copper foil adhesive tape to prepare the strain sensor.
The strain sensor prepared by the application is respectively subjected to tensile property test, human body movement detection, human body health monitoring and other tests, and the specific operation is as follows:
(1) Tensile property test: the strain sensor prepared in the embodiment generates strain by controlling a unidirectional tensile sample of a testing machine through a TC-DLJ-PC microcomputer, and is matched with a DM3068 digital multimeter to test the resistance change condition under different tensile strains and the performance stability under cyclic stretching, and the test results are shown in figures 5-7. Wherein stretching the sensor from the initial length to the desired length and then returning to the initial length is a stretch cycle.
As can be seen from fig. 5, the sensor has a wide strain detection range of 0-100%, and the relative resistivity increases with increasing strain. At a strain of 0.5% -20%, the sensitivity factor is 118.24, at a strain of 20% -80%, the sensitivity factor is 331.32, and at a strain of 80% -100%, the sensitivity factor is 904.77. The sensor has a wide strain range, can detect the motion state of a human body, has a relative resistance change rate of 57.75% under 0.5% weak tensile deformation, and provides possibility for detecting weak signal change.
As can be seen from fig. 6, the response time of the sensor is 87.4ms, and this rapid response is not doubtful to help monitor the health index of the human body in real time.
Figure 7 shows performance stability under cyclic stretching, and after 2000 stretch-release cycles, the resistance change of the sensor remains around 2180%, indicating that the sensor strain response has excellent cyclic stability, providing potential for further practical use of the sensor.
(2) Human motion detection: the strain sensor prepared in this example was attached to the knee to monitor and identify knee joint movements such as jogging, sprinting and jumping, with the test results shown in fig. 8. As can be seen from fig. 8, when the knee joint is bent, the resistance of the sensor starts to increase accordingly, excellent repeatable responsiveness to the knee joint movement is achieved, and the peak value and width of the curve are different in different movement states. Similarly, the sensor may identify the human motion state from various response curves.
(3) Human health monitoring: the strain sensor prepared in this example was attached to the neck of a human body to monitor throat vibration, and the test results thereof are shown in fig. 9. As can be seen from fig. 9, when the human body performs swallowing and coughing actions, the sensor will display a corresponding response curve, with different peak values and widths. The sensor is fixed on the wrist to monitor the pulse of the human body, and the test result is shown in fig. 10. As can be seen from fig. 10, the strain sensor prepared in this embodiment can clearly detect the heart rate physiological signal of the human body, and the inset shows the characteristic peak values of the typical human pulse waveform corresponding to the shock wave (P-wave), the tidal wave (T-wave) and the diastolic wave (D-wave). The result shows that the strain sensor prepared by the embodiment can be used for monitoring the human body movements such as pulse beating and throat vibration of the human body, and further can realize real-time monitoring of various health conditions of the human body. Indicating that it has important and diverse potential in wearable electronics, health monitoring and intelligent robotics.
Example 2 ]
A method of manufacturing a strain sensor comprising the steps of:
step S1, preparing an expanded microsphere/elastic polymer finishing liquid: weighing 50g of polyvinyl alcohol, adding 1.5g of expanded microspheres, and dispersing by a homogenizer to obtain uniformly dispersed expanded microspheres/polyvinyl alcohol finishing liquid;
s2, soaking polyurethane elastic fibers in the expanded microsphere/polyvinyl alcohol finishing liquid prepared in the step S1 for 5min, heating in an oven at 120 ℃ for 10min, heating and foaming to construct a fiber skeleton modified by the expanded microsphere with a core-shell structure, rinsing with deionized water, and drying in air to obtain an intermediate;
s3, dipping the intermediate in graphene oxide finishing liquid with solid content of 8mg/mL for 10min, drying in a 50 ℃ oven, dipping in the graphene finishing liquid, repeating the steps for 5 times circularly to realize a convex spherical microstructure modified by the multilayer graphene coating, and chemically reducing by ascorbic acid solution to obtain a chestnut rice rod-shaped conductive fiber body loaded by the reduced graphene oxide coating;
and S4, coating conductive silver paste on two ends of the rice-bar-shaped conductive fiber body prepared in the step S3 to serve as electrodes, attaching copper wires to the conductive silver paste, and fixing the copper wires with a conductive copper foil adhesive tape to prepare the strain sensor.
Example 3 ]
A method of manufacturing a strain sensor comprising the steps of:
step S1, preparing an expanded microsphere/elastic polymer finishing liquid: weighing 50g of waterborne polyurethane, adding 5g of expansion microspheres, and dispersing by a homogenizer to obtain uniformly dispersed expansion microspheres/polyurethane finishing liquid;
s2, soaking the polyolefin elastic fiber in the expanded microsphere/polyurethane finishing liquid prepared in the step S1 for 10min, heating in an oven at 100 ℃ for 10min, heating and foaming to construct a fiber framework modified by the core-shell structure expanded microsphere, rinsing with deionized water, and drying in air for later use to obtain an intermediate;
s3, soaking the intermediate in 10mg/mL graphene oxide finishing liquid for 10min, drying in a 50 ℃ oven, soaking in the graphene finishing liquid, repeating the cycle for 5 times to realize a convex spherical microstructure modified by the multilayer graphene coating, and chemically reducing by ascorbic acid solution to obtain a reduced graphene oxide coating-loaded 'chestnut rice rod' -shaped conductive fiber body;
and S4, coating conductive silver paste on two ends of the rice-bar-shaped conductive fiber body prepared in the step S3 to serve as electrodes, attaching copper wires to the conductive silver paste, and fixing the copper wires with a conductive copper foil adhesive tape to prepare the strain sensor.
Comparative example 1 ]
And S1, soaking polyurethane elastic fibers in 5mg/mL graphene oxide finishing liquid for 10min, drying in a 50 ℃ oven, and then soaking in the graphene finishing liquid, and repeating the steps for 5 times to realize a fiber structure modified by the multilayer graphene coating.
And S2, chemically reducing the fiber structure prepared in the step S1 through ascorbic acid dissolution to obtain the conductive fiber loaded by the reduced graphene oxide coating.
And S3, coating conductive silver paste on two ends of the conductive fiber prepared in the step S2 to serve as electrodes, attaching copper wires to the conductive silver paste, and fixing the copper wires with a conductive copper foil adhesive tape to prepare the strain sensor.
The strain sensor prepared in this example was tested for tensile properties, and it was found that the strain sensor had a wide strain detection range of 0 to 100% and the relative resistance change rate increased with increasing strain. However, at 0-65% strain, the sensitivity factor is 25.43, and at 65% -100% strain, the sensitivity factor is 64.58.
The elastic fiber strain sensor prepared in comparative example 1 has lower sensitivity compared to example 1 because the change in relative resistance is only related to the expansion and closure of microcracks during the strain process, and the structural change and the change in conductive network are not obvious, so that the sensor is insensitive to the stimulus under small strain.
The specific raw materials listed in the present application, as well as the upper and lower limits and interval values of the raw materials and the process parameters, can all realize the present application, and examples are not necessarily presented herein. The embodiments described above and features of the embodiments herein may be combined with each other without conflict.
The foregoing description of the preferred embodiments of the application is not intended to limit the application to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the application are intended to be included within the scope of the application.
Claims (9)
1. The conductive fiber body is characterized by comprising a matrix core material, a microsphere/fiber framework layer and a graphene conductive layer which are sequentially arranged from inside to outside, wherein the matrix core material is made of any one material selected from polyurethane elastic fiber, polyether ester elastic fiber, polyolefin elastic fiber and elastic polyester fiber, the microsphere/fiber framework layer is formed by expanding microspheres and elastic polymers, and the graphene conductive layer is made of graphene oxide.
2. A method of making a conductive fiber body of claim 1, comprising the steps of:
step S1, preparing an expanded microsphere/elastic polymer finishing liquid: weighing a certain amount of elastic polymer, adding the expanded microspheres, and uniformly dispersing to obtain an expanded microsphere/elastic polymer finishing liquid; wherein, the elastic polymer comprises the following components in percentage by mass: expanded microsphere = 1:3% -10%;
s2, soaking the matrix core material in the expanded microsphere/elastic polymer finishing liquid, and sequentially heating, rinsing and drying to obtain an intermediate;
and S3, dipping the intermediate in the graphene finishing liquid, drying, dipping in the graphene finishing liquid, drying, circulating for a plurality of times, and performing chemical reduction treatment to obtain the conductive fiber body.
3. The method of producing a conductive fiber body according to claim 2, wherein in S1, the expanded microspheres have a foaming temperature of 80 to 120 ℃ and a particle size of 5 to 10 μm.
4. The method of producing a conductive fiber body according to claim 2, wherein in S1, the elastic polymer is any one of aqueous polyurethane, polyvinyl alcohol, and an aqueous polyacrylate solution.
5. The method of producing a conductive fiber body according to claim 2, wherein in S2, the matrix core material is any one of polyurethane elastic fiber, polyether ester elastic fiber, polyolefin elastic fiber, and elastic polyester fiber.
6. The method of producing a conductive fiber body according to claim 2, wherein in S2, the time condition for impregnation is 5 to 10 minutes, the temperature condition for heating is 80 to 120 ℃ and the time condition is 10 to 30 minutes.
7. The method for producing a conductive fiber body according to claim 2, wherein in S3, the graphene finishing liquid is an aqueous graphene oxide solution having a solid content of 5 to 10mg/mL, the time condition for impregnation is 5 to 10 minutes, and the cycle number is 1 to 5.
8. Use of the conductive fiber body of claim 1 for the manufacture of a strain sensor.
9. A method for preparing a strain sensor is characterized in that conductive silver paste is used for connecting copper wires at two ends of a conductive fiber body according to claim 1, and the strain sensor is prepared after the conductive fiber body is solidified and then connected with an external power supply.
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| WO2022089510A1 (en) * | 2020-11-02 | 2022-05-05 | 香港理工大学 | Tensile conductive yarn and manufacturing method therefor |
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