Stretchable pressure-sensing fabric resistant to tensile interference and method of making, using same

Abstract

The application belongs to the technical field of intelligent pressure sensing, and relates to a stretchable pressure sensing fabric with stretch interference resistance and a preparation method and application thereof. The preparation method comprises the following steps: covering a friction electricity generation outer layer on the outer side of a conductive inner core to prepare a friction nanometer power generation yarn; weaving the friction nanometer power generation yarn into a three-bond knot to construct a friction nanometer power generation network; and attaching the friction nanometer power generation network to a fabric to obtain the pressure sensing fabric. The application is based on the friction nanometer power generation yarn, constructs a friction nanometer power generation network through a specific weaving method, and further optimizes the grid density, so as to construct the stretchable pressure sensing fabric with stretch interference resistance. The pressure sensing fabric has little interference to the pressure sensing result under large tensile deformation, and has great application potential in the preparation of smart wearable textiles with motion and stretch interference resistance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of intelligent pressure sensing, and relates to a stretchable pressure sensing fabric resistant to tensile interference and a preparation method and application thereof. BACKGROUND

[0002] A flexible pressure sensor is an intelligent device that converts pressure action into an electrical signal to realize real-time monitoring of pressure. In recent years, with the rapid development of artificial intelligence, the Internet of Things, and wearable electronics, flexible pressure sensors have shown broad application prospects in human-computer interaction, medical health, electronic skin, and perceptual reconstruction, and have attracted much attention. Flexible fabric-based pressure sensors, also known as pressure sensing fabrics, have a unique textile structure. Compared with traditional thin-film and block-shaped pressure sensors, they exhibit good flexibility, deformability, biocompatibility, and wearing comfort.

[0003] A flexible triboelectric nanogenerator is a device that utilizes the principle of coupling between triboelectricity and electrostatic induction. It generates triboelectric charges through the contact of two flexible polymer materials with different electronegativities, and generates an alternating current signal in an external circuit during the contact and separation of the two materials, thereby realizing the conversion of mechanical energy into electrical energy. The triboelectric nanogenerator (TENG) based on the phenomenon of triboelectricity has unique advantages and application potential in self-powered pressure sensing.

[0004] Li Hui et al. reported in "Preparation of Flexible Fully Knitted Triboelectric Nanogenerator Fabric" (Textile Research Journal, 2018) that polyamide fibers and polyester sewing threads were wound around the surface of silver-plated metal filaments by conical knitting to form two composite conductive fiber ropes with a skin-core structure. The polyamide fibers and polyester sewing threads in the skin layer serve as the friction layer, and the silver-plated metal filaments in the core layer serve as the electrode layer. The two composite conductive fiber ropes are woven into a flexible self-powered fabric as a triboelectric nanogenerator.

[0005] Chinese invention patent CN115118176A discloses a stretch-insensitive triboelectric nanogenerator (TGN). The TGN has a sandwich structure consisting of, from top to bottom, a friction layer, an electrode, and an encapsulation layer. A mixed solution of liquid organic small molecule monomers, a crosslinker, and a photoinitiator is infiltrated into polymer films of the friction and encapsulation layers. The film is then irradiated with ultraviolet light, forming a crosslinked interpenetrating network in the exposed areas, thereby increasing the mechanical strength of the localized regions of the film. When the TGN is subjected to transverse stress and strain, a significant difference in strain occurs between the high-modulus region and the unmodified portion. Applying a fixed amount of pressure to the high-modulus region under varying stretching conditions can produce a stable triboelectric output. This invention only discloses the TGN, but does not further investigate weaving the TGN into a power-generating fabric to study its resistance to stretch interference. Furthermore, the invention's complex preparation process and the use of organic reagents contradict the concept of environmental friendliness.

[0006] Today's pressure sensing fabrics have achieved great development, but they still face many scientific problems that need to be solved urgently. Among them, how to develop and prepare pressure sensing fabrics with good resistance to tensile interference, achieve pressure / tension decoupling, and avoid the influence of tensile deformation on pressure sensing signals in actual application scenarios is one of the major issues currently facing us. Summary of the Invention

[0007] Terms and Claims of the Present Invention:

[0008] 1. The articles "a", "an" and "the" include plural referents unless expressly limited to one or more referents in other ways.

[0009] 2. Numerical ranges: Unless expressly stated otherwise, all ranges or ratios disclosed herein are to be understood to include any and all subranges or subratios contained therein. For example, a range or ratio stated as 1 to 30 is to be considered inclusive of any and all subranges or subratios, integers, decimals, or subranges or subratios comprised therein, including the minimum value of 1 and the maximum value of 30.

[0010] 3. In the present invention, the friction nano-power generation network has the same meaning as N-TENG, and the pressure sensing fabric has the same meaning as T-TENG.

[0011] To address the technical problem of existing pressure sensing fabrics interfering with pressure sensing signals due to tensile deformation in practical applications, the present invention aims to provide a stretchable pressure sensing fabric that is resistant to tensile interference, as well as its preparation method and application. This pressure sensing fabric exhibits high tensile resilience and excellent resistance to tensile interference.

[0012] In order to achieve the above object, the present invention adopts the following technical solutions:

[0013] The present application provides a method for preparing a stretchable pressure sensing fabric, comprising the following steps:

[0014] S1, wrapping a friction power generation outer layer outside a conductive inner core to prepare a friction nanometer power generation yarn;

[0015] S2, braiding the friction nanometer power generation yarn of step S1 into a three-bond knot to construct a friction nanometer power generation network;

[0016] S3, attaching the friction nanometer power generation network of step S2 to a fabric to obtain the pressure sensing fabric.

[0017] Preferably, the conductive inner core of step S1 is a silver-plated nylon yarn.

[0018] Preferably, the friction power generation outer layer of step S1 is a polyester filament.

[0019] Further preferably, the polyester of step S1 is polyethylene terephthalate.

[0020] Preferably, the friction nanometer power generation yarn of step S1 has a skin-core structure.

[0021] Preferably, the friction nanometer power generation yarn of step S1 is prepared by a braiding process.

[0022] Preferably, the friction nanometer power generation yarn of step S1 is prepared by a high-speed braiding machine.

[0023] Preferably, the friction nanometer power generation yarn of step S1 is prepared by adjusting the gear ratio of the high-speed braiding machine to 0.2-0.5.

[0024] Further preferably, the gear ratio of the high-speed braiding machine is 0.3.

[0025] Preferably, the mesh density of the friction nanometer power generation network of step S2 is 4-7 PPI.

[0026] Further preferably, the mesh density of the friction nanometer power generation network of step S2 is 4.25-5.95 PPI.

[0027] Preferably, the fabric of step S3 is an elastic fabric, and the elastic recovery rate of the elastic fabric is 150%-230%.

[0028] Further preferably, the elastic fabric is a composite fabric of polyamide fiber and polyurethane fiber.

[0029] The present application also provides a pressure sensing fabric prepared by the above preparation method.

[0030] The application also provides the pressure sensing fabric for use in the preparation of products for medical rehabilitation and sports monitoring.

[0031] The application also provides an intelligent wearable textile comprising the pressure sensing fabric.

[0032] The pressure sensing fabric of the application has good anti-stretching interference capability when sensing pressure, and can be used in the fields of sports monitoring and the preparation of products for medical rehabilitation. The pressure sensing fabric of the application can be used to prepare products for medical rehabilitation, which can be worn on the human body to monitor the pressure on bedridden patients under different actions, and to give early warning for the case of keeping the same pressure for a long time, thereby preventing the occurrence of bedsores.

[0033] In addition, the pressure sensing fabric of the application can accurately monitor the pressure on the human body during sports, thereby meeting the self-powered sensing demand of intelligent fire-fighting clothes.

[0034] Compared with the prior art, the application has the following beneficial effects:

[0035] 1. The application is based on friction nanometer power generation yarn, and network weaving technology is innovatively selected to construct a fabric structure of three treasure knots, and the grid density is further adjusted to construct a friction nanometer power generation network.

[0036] 2. The N-TENG is attached to the elastic fabric to prepare a stretchable pressure sensing fabric with good anti-stretching interference capability. The pressure sensing fabric has high stretch rebound capability, and the pressure sensing result is almost not disturbed under large tensile deformation conditions, which has great application potential in the field of intelligent wearable textiles resistant to motion interference.

[0037] 3. The pressure sensing fabric of the application has good washing resistance, and still has stable electrical output performance after 20 times of washing.

[0038] 4. The pressure sensing fabric of the application has high power density and excellent cycle working stability (10000s). BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is a preparation flow chart of the friction nanometer power generation network of the application;

[0040] Figure 2 It is an SEM image of the three treasure knots of the friction nanometer power generation network of the application;

[0041] Figure 3 It is an SEM image of the double connection of Comparative Example 1 of the application;

[0042] Figure 4 SEM image of the cross-knot of Comparative Example 2 of the present application;

[0043] Figure 5 The electrical output performance of the frictional nanogenerator network of Example 1 of the present application at different frequencies under 60N pressure;

[0044] Figure 6 The electrical output performance of Comparative Example 1, Comparative Example 2 and Example 1 of the present application at 2Hz under 60N pressure;

[0045] Figure 7 The current and power density as a function of load resistance of Example 1 of the present application;

[0046] Figure 8 The grid density of the frictional nanogenerator network in Example 1-3 and Comparative Example 3-4 of the present application, wherein 2.55PPI, 3.40PPI, 4.25PPI, 5.10PPI, 5.95PPI are the grid density of the frictional nanogenerator network in Comparative Example 3, Comparative Example 4, Example 3, Example 2 and Example 1, respectively;

[0047] Figure 9 The pressure sensing fabric prepared in Example 1 of the present application;

[0048] Figure 10 The corresponding relationship between the grid density of the frictional nanogenerator network in Example 1-3 and Comparative Example 3-4 of the present application and the stretchable deformation ability and pressure sensing performance of T-TENG, wherein the left graph is the corresponding relationship between the grid density and the deformation ability of T-TENG, and the right graph is the corresponding relationship between the grid density and the pressure sensing performance of T-TENG;

[0049] Figure 11 The electrical output performance of the pressure sensing fabric of Example 1 of the present application under 60N pressure at different tensile strains (0, 20%, 40%, 60%, 80%, 100%);

[0050] Figure 12 The electrical output performance of the pressure sensing fabric of Comparative Example 1 and Comparative Example 2 of the present application under 60N pressure at different tensile strains;

[0051] Figure 13 The electrical output performance of the knitted fabric of Comparative Example 6-7 of the present application under 60N pressure at different tensile strains, wherein the tensile strains of the plain knitted fabric are 0, 20%, 40% and 60%, respectively, and the tensile strains of the rib knitted fabric are 0, 20%, 40%, 60%, 80%, 100% and 120%, respectively;

[0052] Figure 14The voltage diagram for the stability test of the embodiment 1 of the present application is detected;

[0053] Figure 15 The voltage diagram for the wash resistance performance test of the embodiment 1 of the present application is detected;

[0054] Figure 16 The pressure on the bedridden patient under different actions is monitored and early warning diagram of the embodiment 1 of the present application is monitored;

[0055] Figure 17 The breathing, pulse and palm pressure of the human body in motion are monitored diagram of the embodiment 1 of the present application. DETAILED DESCRIPTION

[0056] The present application will be further described in detail below in combination with examples and comparative examples, but the embodiments of the present application are not limited thereto.

[0057] Example 1

[0058] A stretchable pressure sensing fabric, a preparation method thereof, comprising the following steps:

[0059] S1, using silver-plated nylon yarn as the conductive inner core, using a high-speed braiding machine, through high-speed braiding process (the gear ratio of the high-speed braiding machine is 0.3), the silver-plated nylon yarn is wound on the center shaft of the high-speed braiding machine, and the polyethylene terephthalate filament is fixed on the 8 spools of the interlacing structure of the braiding machine. After starting the braiding machine, with the rotation of the interlacing structure, half of the outside yarn rotates clockwise and half of the outside yarn rotates counterclockwise, so as to form a dense friction power generation outer layer around the silver-plated nylon yarn, and build a friction nanometer power generation yarn with a skin-core structure;

[0060] Among them, the specification of silver-plated nylon yarn is 20D, and the specification of polyester filament is 150D;

[0061] S2, the friction nanometer power generation yarn of step S1 is braided into a three-bond knot to build a friction nanometer power generation network, wherein the grid density of the friction nanometer power generation network is 5.95PPI;

[0062] S3, the friction nanometer power generation network of step S2 is attached to the composite fabric of polyamide fiber and polyurethane fiber, and the pressure sensing fabric is obtained;

[0063] The preparation flow chart of the friction nanometer power generation network of step S2 is shown in Figure 1 ;

[0064] The SEM diagram of the three-bond knot of step S2 is shown in Figure 2 .

[0065] Example 2

[0066] A stretchable pressure sensing fabric, a preparation method thereof, comprising the following steps:

[0067] S1, using silver-plated nylon yarn as the conductive inner core, using a high-speed braiding machine, through high-speed braiding process (the gear ratio of the high-speed braiding machine is 0.3), the silver-plated nylon yarn is wound on the middle line shaft of the high-speed braiding machine, and the polyethylene terephthalate filament is fixed on the 8 spools of the interlacing structure of the braiding machine as the outer yarn. After starting the braiding machine, with the rotation of the interlacing structure, half of the outer yarn rotates clockwise and the other half rotates counterclockwise, so as to form a dense friction power generation outer layer around the silver-plated nylon yarn, and build a friction nanometer power generation yarn with a skin-core structure;

[0068] Among them, the specification of silver-plated nylon yarn is 20D, and the specification of polyester filament is 150D;

[0069] S2, the friction nanometer power generation yarn of step S1 is braided into a three treasure knot to build a friction nanometer power generation network, wherein the grid density of the friction nanometer power generation network is 5.10PPI;

[0070] S3, the friction nanometer power generation network of step S2 is attached to the composite fabric of polyamide fiber and polyurethane fiber, and the pressure sensing fabric is obtained;

[0071] The preparation flow chart of the friction nanometer power generation network of step S2 is shown in Figure 1 .

[0072] Example 3

[0073] A stretchable pressure sensing fabric, a preparation method thereof, comprising the following steps:

[0074] S1, using silver-plated nylon yarn as the conductive inner core, using a high-speed braiding machine, through high-speed braiding process (the gear ratio of the high-speed braiding machine is 0.3), the silver-plated nylon yarn is wound on the middle line shaft of the high-speed braiding machine, and the polyethylene terephthalate filament is fixed on the 8 spools of the interlacing structure of the braiding machine as the outer yarn. After starting the braiding machine, with the rotation of the interlacing structure, half of the outer yarn rotates clockwise and the other half rotates counterclockwise, so as to form a dense friction power generation outer layer around the silver-plated nylon yarn, and build a friction nanometer power generation yarn with a skin-core structure;

[0075] Among them, the specification of silver-plated nylon yarn is 20D, and the specification of polyester filament is 150D;

[0076] S2, the friction nanometer power generation yarn of step S1 is braided into a three treasure knot to build a friction nanometer power generation network, wherein the grid density of the friction nanometer power generation network is 5.10PPI;

[0077] S3, attaching the friction nanogenerator network described in step S2 on the composite fabric of polyamide fiber and polyurethane fiber, to obtain the pressure sensing fabric;

[0078] The preparation flow chart of the friction nanogenerator network described in step S2 is shown in Figure 1

[0079] Comparative Example 1

[0080] The difference between this comparative example and Example 1 is that the "braided into a three-bond knot" described in step S2 is replaced by "braided into a double knot", and the SEM image of the double knot is shown in Figure 3

[0081] Comparative Example 2

[0082] The difference between this comparative example and Example 1 is that the "braided into a three-bond knot" described in step S2 is replaced by "braided into a cross knot", and the SEM image of the cross knot is shown in Figure 4

[0083] Comparative Example 3

[0084] The difference between this comparative example and Example 1 is that the grid density of the friction nanogenerator network described in step S2 is replaced by 2.55 PPI.

[0085] Comparative Example 4

[0086] The difference between this comparative example and Example 1 is that the grid density of the friction nanogenerator network described in step S2 is replaced by 3.40 PPI.

[0087] Comparative Example 5

[0088] The difference between this comparative example and Example 1 is that the grid density of the friction nanogenerator network described in step S2 is replaced by 8 PPI.

[0089] Comparative Example 6

[0090] A stretchable pressure sensing fabric, and a preparation method thereof, comprising the following steps:

[0091] S1, using silver-plated nylon yarn as a conductive inner core, using a high-speed braiding machine, and through a high-speed braiding process (the gear ratio of the high-speed braiding machine is 0.3), the silver-plated nylon yarn is wound on the center shaft of the high-speed braiding machine, and polyethylene terephthalate filaments are used as outer yarns and fixed on the 8 spools of the interlacing structure of the braiding machine. After starting the braiding machine, with the rotation of the interlacing structure, half of the outer yarns rotate clockwise and half rotate counterclockwise, so as to form a dense friction power generation outer layer around the silver-plated nylon yarn, and to construct a friction nanogenerator yarn with a skin-core structure;

[0092] ​​​The specification of the silver-plated nylon yarn is 20D, and the specification of the polyester filament is 150D.

[0093] S2, the friction nanometer power yarn knitted in step S1 obtains a plain knitted fabric with tensile deformation ability, that is, the pressure sensing fabric.

[0094] Comparative Example 7

[0095] A stretchable pressure sensing fabric, a preparation method thereof, comprising the following steps:

[0096] S1, using silver-plated nylon yarn as the conductive inner core, using a high-speed knitting machine, and through high-speed knitting process (the gear ratio of the high-speed knitting machine is 0.3), the silver-plated nylon yarn is wound on the center shaft of the high-speed knitting machine, and the polyethylene terephthalate filament is fixed on the 8 spools of the interlacing structure of the knitting machine. After starting the knitting machine, with the rotation of the interlacing structure, half of the outer yarn rotates clockwise and half of the outer yarn rotates counterclockwise, so as to form a dense friction power outer layer around the silver-plated nylon yarn, and build a friction nanometer power yarn with a skin-core structure;

[0097] The specification of the silver-plated nylon yarn is 20D, and the specification of the polyester filament is 150D.

[0098] S2, the friction nanometer power yarn knitted in step S1 obtains a plain knitted fabric with tensile deformation ability, that is, the pressure sensing fabric.

[0099] Effect performance test

[0100] Test Example 1, relationship between grid density and pressure sensing performance, stretchable deformation ability and tensile interference resistance

[0101] 1.1 Pressure sensing performance

[0102] Pressure sensing performance detection method: the sample is fixed on the clamp of the linear motor, the sample electrode is connected to the positive electrode of the Keithley electrometer, the periodic movement of the linear motor realizes the contact and separation of the sample and the acrylic plate (pressure 60N, frequency 2Hz), and the LabView software is used to realize real-time data acquisition of the open circuit voltage (Voc) and short circuit current (Isc) generated in the test process.

[0103] The electrical output performance results of the friction nanometer power network N-TENG prepared in Example 1 are shown in Figure 5 The electrical output performance results of the pressure sensing fabric of Example 1 at 2Hz and 60N are shown in Figure 6 The electrical output performance of the pressure sensing fabric of Example 1-3 and Comparative Example 3-5 is shown in Table 1.

[0104] Table 1

[0105] Serial No. Voc (V) Isc (pA) Example 1 40.1 0.13 Example 2 37.1 0.126 Example 3 25.1 0.07 Comparative Example 3 12.3 0.025 Comparative Example 4 18.2 0.05 Comparative Example 5 50.3 0.25

[0106] The current and power density of the pressure sensing fabric of Example 1 as a function of the load resistance are shown in Figure 7 The maximum power density of the pressure sensing fabrics of Example 1 and Comparative Examples 3-5 at a load resistance of 1 GΩ is shown in Table 2 below.

[0107] Table 2

[0108] Serial No. Power density (mW / m 2 ) Example 1 2.5 Comparative Example 3 0.01 Comparative Example 4 0.05 Comparative Example 5 5

[0109] The results of Table 1 and Table 2 show that the open circuit voltage Voc of the N-TENG of Example 1 is 40.1 V, the short circuit current Isc is 0.13 μΑ, and the pressure sensing fabric of Example 1 has a maximum power density of 2.5 mW·m -2 Compared with the pressure sensing fabrics of Comparative Examples 3-4 prepared using a conventional grid density, the pressure sensing fabrics of Examples 1-3 have significantly improved electrical output performance under external pressure, showing excellent pressure sensing signals.

[0110] 1.2 Stretchable deformation ability

[0111] Figure 8 The grid density of the frictional nanogenerators in Examples 1-3 and Comparative Examples 3-4 of the present application is shown in the following table.

[0112] Deformation ability test method: The frictional nanogenerator was attached to a composite fabric of polyamide fibers and polyurethane fibers to prepare a pressure sensing fabric (as shown in Figure 9 The pressure sensing fabric was stretched to the maximum deformation, the length before and after deformation was measured using a vernier caliper, and the deformation rate was calculated.

[0113] Figure 10 The corresponding relationship between the grid density of the frictional nanogenerator and the stretchable deformation ability and pressure sensing performance of the T-TENG in Examples 1-3 and Comparative Examples 3-4 of the present application is shown in the following table.

[0114] The stretchable deformation ability of the pressure sensing fabrics of Examples 1-3 and Comparative Examples 3-5 is shown in Table 3.

[0115] Table 3

[0116] Serial No. Strain Rate (%) Example 1 105 Example 2 148 Example 3 234 Comparative Example 3 494 Comparative Example 4 308 Comparative Example 5 60

[0117] From Figure 10From the results of Table 3, it can be seen that when other parameters are unchanged, only the grid density is changed: when the grid density is 2.55 PPI, the strain rate is close to 500%; when the grid density is 3.40 PPI, the strain rate is about 300%; when the grid density is 4.25-5.95 PPI, the strain rate is reduced to 105%-234%; and when the grid density of Comparative Example 5 is 8 PPI, the strain rate can only reach 60%. Under the same conditions, the specific grid density used in Examples 1-3 shows a more suitable stretchable deformation ability.

[0118] 1.3 Anti-stretch interference ability

[0119] Anti-stretch interference ability test method: the pressure sensing fabric is stretched to 20%, 40%, 60%, 80% and 100% deformation rate and fixed on the clamp of the linear motor, the electrode of the sample is connected to the positive electrode of the Keithley electrometer, the sample is contacted and separated with natural rubber by periodic movement of the linear motor (fixed pressure 60N, frequency 2Hz), and LabView software is used to collect real-time data of open circuit voltage (Voc) and short circuit current (Isc) during the test.

[0120] The electrical output performance of the pressure sensing fabrics of Examples 1-3 and Comparative Examples 3-5 under the same pressure at different tensile strains is shown in Tables 4 and 5.

[0121] Table 4

[0122]

[0123]

[0124] Table 5

[0125]

[0126] The results of Tables 4 and 5 show that the pressure sensing fabrics of Examples 1-3 have a tensile strain of more than 100%, and under the condition of increasing strain, the amount of change in the electrical signal under the same pressure is less than 11.5%, showing good anti-stretch interference. Among them, the amount of change in the electrical signal of the pressure sensing fabric of Example 1 under the same pressure is not more than 7% (as shown in Table 4), and the anti-stretch interference performance is the best. The grid density of Comparative Examples 3-4 changes the grid density of the friction nanogenerator network, and under the condition of increasing strain, the friction power generation performance is poor, and the anti-stretch interference ability is poor. Figure 11

[0127] Therefore, under the same conditions, using a specific grid density of the friction nanogenerator network, the pressure sensing fabric obtained has excellent anti-stretch interference ability when sensing pressure. ​

[0128] 1.4 Conclusion

[0129] The above results show that, under the same conditions, only changing the grid density of the friction nanometer power network, the pressure sensing performance of Comparative Example 3-4 is poor; the stretchable deformation ability of Comparative Example 5 is poor, which is difficult to meet the application requirements of smart wear.

[0130] Test Example 2, Relationship between knotting mode and pressure sensing performance, stretchable deformation ability and tensile interference resistance

[0131] 2.1 Pressure sensing performance

[0132] The pressure sensing performance detection method is the same as that of Test Example 1.

[0133] The electrical output performance results of the pressure sensing fabric of Example 1 and Comparative Examples 1-2 at 2 Hz and 60 N are shown in Table 5. Figure 6 The electrical output performance of the pressure sensing fabric of Example 1 and Comparative Examples 1-2 is shown in Table 6.

[0134] Table 6

[0135] Serial No. Voc (V) Isc (pA) Example 1 40.1 0.13 Comparative Example 1 18.2 0.12 Comparative Example 2 26.1 0.13

[0136] The maximum power density of the pressure sensing fabric of Example 1 and Comparative Examples 1-2 under a load resistance of 1 GΩ is shown in Table 7.

[0137] Table 7

[0138] Serial No. Power density (mW / m 2 ) Example 1 2.5 Comparative Example 1 0.1 Comparative Example 2 1.5

[0139] The results of Table 6 and Table 7 show that, compared with Comparative Examples 1-2 using conventional knotting modes such as cross knot or double knot, the pressure sensing fabric prepared by using the knotting mode of three treasure knot of Example 1 exhibits good electrical output performance under external pressure, and the pressure sensing signal is excellent.

[0140] 2.2 Stretchable deformation ability

[0141] The deformation ability test method is the same as that of Test Example 1.

[0142] The stretchable deformation ability results of the pressure sensing fabric of Example 1 and Comparative Examples 1-2 are shown in Table 8.

[0143] Table 8

[0144] Serial No. Strain Rate (%) Example 1 105 Comparative Example 1 60 Comparative Example 2 80

[0145] From the results of Table 8, when other parameters are unchanged, only the knotting mode of the pressure sensing fabric is changed: the strain rate of Comparative Example 1 can only reach 60%; the strain rate of Comparative Example 2 can only reach 80%. Under the same conditions, the specific three-bow knotting mode of Example 1 shows more than 100% stretchable deformation ability, which can meet the application requirements of the pressure sensing fabric in smart wear.

[0146] 2.3 Anti-stretch interference ability

[0147] The anti-stretch interference ability test method is the same as that of Test Example 1.

[0148] The electrical output performance of the pressure sensing fabrics of Example 1 and Comparative Examples 1-2 under different tensile strains and the same pressure is shown in Tables 9, 10 and Figure 11-12 .

[0149] Table 9

[0150]

[0151] Table 10

[0152]

[0153] The results of Tables 9, 10 and Figure 11-12 show that the pressure sensing fabric of Example 1 has more than 100% tensile strain, and under the same pressure, the change in electrical signal is less than 7% as the strain increases, showing excellent anti-stretch interference performance. Comparative Examples 1-2 only change the knotting mode of the friction nanogenerator network, and under the same pressure, the change in electrical signal is 50% and 92.3% respectively as the strain increases, and the anti-stretch interference ability is poor.

[0154] Therefore, under the same conditions, the friction nanogenerator network prepared by using a specific knotting mode has excellent anti-stretch interference ability when the pressure sensing fabric obtained by further application senses pressure.

[0155] 2.4 Conclusion

[0156] The above results show that under the same conditions, only changing the knotting mode of the friction nanogenerator network, the pressure sensing performance, stretchable deformation ability and anti-stretch interference ability of Comparative Examples 1-2 are poor, and it is difficult to avoid the influence of stretchable deformation on the pressure sensing signal in actual application scenarios.

[0157] Test Example 3, Relationship between weaving mode and pressure sensing performance, stretchable deformation ability and anti-stretch interference ability

[0158] 3.1 Pressure sensing performance

[0159] The pressure sensing performance detection method is the same as that of Test Example 1.

[0160] The electrical output performance of the pressure sensing fabric of Example 1 and Comparative Examples 6-7 is shown in Table 11.

[0161] Table 11

[0162] Serial No. Voc (V) Isc (pA) Example 1 40.1 0.13 Comparative Example 6 125.1 0.05 Comparative Example 7 150.2 0.08

[0163] The maximum power density of the pressure sensing fabric of Example 1 and Comparative Examples 6-7 under a load resistance of 1 GΩ is shown in the following Table 12.

[0164] Table 12

[0165] Serial No. Power density (mW / m 2 ) Example 1 2.5 Comparative Example 6 2.5 Comparative Example 7 5

[0166] The results of Table 11 and Table 12 show that the plain knit fabric or the rib knit fabric obtained by knitting the friction nanogenerator yarn of Comparative Examples 6-7 has a higher power density due to the higher density of the friction nanogenerator yarn caused by the knitting process.

[0167] 3.2 Stretchable deformation ability

[0168] The deformation ability test method is the same as that of Test Example 1.

[0169] The stretchable deformation ability results of the pressure sensing fabric of Example 1 and Comparative Examples 6-7 are shown in Table 13.

[0170] Table 13

[0171] Serial No. Strain Rate (%) Example 1 105 Comparative Example 6 60 Comparative Example 7 120

[0172] As can be seen from the results of Table 13, Comparative Example 6 obtains a plain knit fabric by knitting the friction nanogenerator yarn, and the strain rate thereof can only reach 60%. Under the same conditions, Example 1 exhibits a stretchable deformation ability of more than 100%, which can meet the application requirements of the pressure sensing fabric in smart wearables.

[0173] 3.3 Anti-stretching interference ability

[0174] The anti-stretching interference ability test method is the same as that of Test Example 1.

[0175] The electrical output performance of the pressure sensing fabric of Example 1 and Comparative Examples 6-7 under different stretching strains and under the same pressure is shown in Table 14 and Table 15. The electrical output performance of the pressure sensing fabric of Comparative Examples 6-7 under different stretching strains and under the same pressure is shown in Figure 13 .

[0176] Table 14

[0177]

[0178] Table 15

[0179]

[0180] Table 14, Table 15 and Figure 13 The results of Table 15 show that the stretchable pressure sensing fabric of Example 1 endows the stretch strain of more than 100%, and the amount of change of the electrical signal under the same pressure is less than 7% in the case of strain increase, which shows excellent anti-stretch interference performance. The plain knit fabric or rib knit fabric with stretch deformation ability knitted by the friction nanometer power generation yarn of Comparative Examples 6-7 has the amount of change of the electrical signal of 280% and 166.3% respectively under the same pressure in the case of strain increase, and has poor anti-stretch interference ability.

[0181] Therefore, under the same other conditions, the stretchable pressure sensing fabric of Example 1 has excellent anti-stretch interference ability when sensing pressure.

[0182] 3.4 Conclusion

[0183] The above results show that the stretchable deformation ability of the pressure sensing fabric knitted by the friction nanometer power generation yarn of Comparative Example 6 is poor; the anti-stretch interference ability of Comparative Examples 6-7 is poor, and it is difficult to avoid the influence of stretch deformation on the pressure sensing signal in the actual application scenario.

[0184] Test Example 4, stability and washing resistance performance detection

[0185] Stability performance detection method: set a long-period cycle test experiment, and continuously beat the stretchable pressure sensing fabric under the impact of 1Hz frequency and 60N pressure for 10000s, and test the electrical output performance of the pressure sensing fabric during beating.

[0186] The stability test detection diagram of the stretchable pressure sensing fabric of Example 1 continuously beaten for 10000s is shown in Figure 14 , wherein the left graph of local magnification is the detailed voltage change graph of the first 10 cycles, and the right graph of local magnification is the detailed voltage change graph of the last 10 cycles. The stability test results of the stretchable pressure sensing fabric of Example 1 and Comparative Examples 1-7 continuously beaten for 10000s are shown in Table 16.

[0187] Table 16

[0188]

[0189]

[0190] Washability testing method: A beaker containing laundry detergent and tap water was placed on a magnetic stirrer with a magnet to simulate a household drum washing machine. The pressure-sensing fabric was placed in the beaker. The spin speed was set at 500 rpm, and each wash cycle lasted 20 minutes. The fabric was then dried in a 60°C oven for 30 minutes. The fabric was subjected to a 2 Hz frequency and 60 N pressure shock, and the electrical output performance of the fabric was measured after each wash cycle. The test was repeated 20 times.

[0191] The voltage diagram for detecting the washability of the stretchable pressure sensing fabric of Example 1 is shown in FIG. Figure 15 ; The water resistance performance detection voltage of the stretchable pressure sensing fabrics of Example 1 and Comparative Examples 1-7 is shown in Table 17.

[0192] Table 17

[0193] Serial No. Voc (V) after 0 washes Voc (V) after 20 washes Example 1 40.1 43.2 Example 2 37.1 40.2 Example 3 25.1 27.4 Comparative Example 1 18.2 15.1 Comparative Example 2 26.1 20.3 Comparative Example 3 12.3 15.2 Comparative Example 4 18.2 20.2 Comparative Example 5 50.3 57.7 Comparative Example 6 125.1 120.3 Comparative Example 7 150.2 140.8

[0194] The stretchable pressure sensing fabric of the embodiment of the present invention exhibits excellent cycle stability (10000s) (e.g. Figure 14 As shown) and water washability (as Figure 15 The comparative example uses a cross knot, a double knot, different mesh densities, and different weaving methods, which results in poor stability and washability of the material.

[0195] Application Examples

[0196] The stretchable pressure sensing fabric of the present invention is used in the field of sports monitoring and in the preparation of products for medical rehabilitation by utilizing its ability to resist stretching interference during pressure sensing.

[0197] The stretchable pressure sensing fabric of Example 1 is worn on the human body, and self-powered pressure sensing for bedridden patients is achieved by monitoring the changes in electrical signals transmitted by the stretchable pressure sensing fabric when the bedridden patient makes different movements.

[0198] The present invention can monitor the pressure on bedridden patients under different movements and can issue early warning if the same pressure is maintained for a long time (such as Figure 16 to prevent the occurrence of bedsores.

[0199] The stretchable pressure sensing fabric of Example 1 is worn on the human body, and can accurately monitor the physiological signs of the human body such as breathing and pulse during exercise, as well as the pressure of the basketball on the palm (e.g. Figure 17 As shown in Figure 2), the self-powered sensing requirements of smart fire suits are met.

[0200] Finally, it should be noted that the above is only to illustrate the technical solutions of the present application, and is not a limitation on the scope of protection of the present application, and simple modifications or equivalent replacements of the technical solutions of the present application by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A method for preparing a stretchable pressure sensing fabric, characterized in that: The following steps are involved: S1, coating the outer layer of triboelectricity generation on the outside of the conductive inner core to prepare triboelectric nanogenerator yarn; S2, weaving the triboelectric nanogenerator yarn described in step S1 into a three-treasure knot to construct a triboelectric nanogenerator network; S3, attaching the triboelectric nano-power generation network described in step S2 to the fabric to obtain the pressure sensing fabric; The mesh density of the triboelectric nanopower generation network described in step S2 is 4-7 PPI.

2. The preparation method according to claim 1, characterized in that The conductive inner core described in step S1 is silver-plated nylon yarn, and the friction-generated outer layer is polyester filament.

3. The preparation method according to claim 1, characterized in that The friction nanogenerator yarn described in step S1 is prepared through a weaving process.

4. The preparation method according to claim 1, characterized in that The mesh density of the triboelectric nanopower generation network described in step S2 is 4.25-5.95 PPI.

5. The preparation method according to claim 1, characterized in that The fabric described in step S3 is a stretch fabric, and the elastic recovery rate of the stretch fabric is 150%-230%.

6. The preparation method according to claim 5, characterized in that The stretch fabric is a composite fabric of polyamide fiber and polyurethane fiber.

7. The pressure sensing fabric prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the pressure sensing fabric according to claim 7 in the preparation of products for medical rehabilitation and sports monitoring.

9. A smart wearable textile, characterized in that: The pressure sensing fabric according to claim 7 is included.

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