Double-network ionizing pressure sensor with modified fiber sensing layer and preparation method of double-network ionizing pressure sensor

Abstract

The invention belongs to the technical field of flexible sensing, and discloses a dual-network ionizing pressure sensor with a modified fiber sensing layer and a preparation method thereof, and the dual-network ionizing pressure sensor comprises a flexible packaging layer, an electrode layer and a flexible ionizing sensing functional layer. The flexible ionization sensing functional layer is composed of non-woven fabric fibers and a polyvinyl alcohol / alkaline glycosaminoglycan / phosphoric acid ion gel layer, wherein the surfaces of the non-woven fabric fibers are modified by polydopamine / alkaline matter, and the non-woven fabric fibers are provided with a 3D network, and the polyvinyl alcohol / alkaline glycosaminoglycan / phosphoric acid ion gel layer wraps the surfaces of the fibers. A pressure signal can be efficiently converted into a capacitance signal by utilizing a dual-network active layer constructed by non-woven fabric fibers and polyvinyl alcohol / alkaline glycosaminoglycan / phosphoric acid and a unique dual-electric-layer sensing effect of the dual-network active layer. The flexible ionizing pressure sensor has excellent sensing performance.

Description

Technical Field

[0001] This invention belongs to the field of flexible sensor technology, specifically relating to a dual-network ionized pressure sensor based on a modified fiber sensing layer and its fabrication method. Background Technology

[0002] In modern intelligent systems such as smart healthcare and human-computer interaction, pressure sensing technology is a core support, and its performance directly determines the system's effectiveness. Compared to traditional rigid pressure sensors, flexible pressure sensors possess superior environmental adaptability and conformability, maintaining stable high-precision sensing even under complex and harsh working conditions, making them an indispensable core component of these intelligent systems. With the advancement of the intelligent industry, market demand for these sensors is surging, and performance requirements are becoming increasingly stringent, making technological upgrades imperative. Flexible pressure sensors are classified into four main categories based on different electromechanical conversion theories: piezoresistive, capacitive, piezoelectric, and triboelectric. Among them, flexible capacitive pressure sensors, due to their combination of flexibility and signal response advantages, have become a research hotspot, with broad application prospects in wearable devices, precision integration of intelligent devices, and other fields.

[0003] Chinese patent document CN 120628369 A discloses an array-type flexible capacitive pressure sensor with stable operation, good signal transmission, and high flexibility, as well as its fabrication process. This array-type flexible capacitive pressure sensor includes indium tin oxide / polyethylene terephthalate (ITO / PET) upper and lower electrodes obtained by magnetron sputtering, a polydimethylsiloxane / multi-walled carbon nanotube (PDMS / MWCNTs) dielectric layer, a sponge wrapping layer, and a gel encapsulation layer. This sensor achieves a relative capacitance change >17 within a range of 0-150 kPa. Similarly, existing flexible capacitive pressure sensors mostly employ traditional parallel plate structures, which have inherent drawbacks: the capacitance per square centimeter is only on the order of picofarads (pF), resulting in low sensitivity and a narrow sensing range. Current complex working conditions demand higher accuracy and stability in pressure detection, and these shortcomings have become a core bottleneck for the large-scale application of high-end intelligent equipment, hindering industrial upgrading.

[0004] To address the aforementioned problems, and considering the ion-capacitive pressure sensing mechanism in a double-layer sensing system, this invention proposes a flexible ionized pressure sensor and its fabrication method. Summary of the Invention

[0005] To address the aforementioned deficiencies in the existing technology, one objective of this invention is to provide a method for preparing a dual-network ionized pressure sensor based on a modified fiber sensing layer. The method involves using a modified solution to physically polymerize dopamine (DA) into polydopamine (PDA), which then self-assembles on the surface of a three-dimensional network of nonwoven fibers (NWFs). This introduces more hydrophilic groups, achieving uniform loading of polyvinyl alcohol / chitosan / phosphate (PVA / CS / H3PO4) ion gel, thereby constructing a fiber / gel dual-layer network sensing layer and realizing high sensitivity and a wide sensing range for the pressure sensor.

[0006] The second objective of this invention is to provide a dual-network ionized pressure sensor based on a modified fiber sensing layer. By constructing a modified fiber network / ion gel dual-network sensing functional layer, high-sensitivity pressure sensing over a wide range can be achieved while ensuring the sensor's excellent flexibility.

[0007] The third objective of this invention is to provide a practical model and technical support for a flexible ionized pressure sensor, which verifies the feasibility and practicality of the pressure sensor in backpack posture correction scenarios, clarifies the demand-oriented R&D direction for the scenario-based design of subsequent high-performance sensors, and provides a practical and feasible compatibility design idea for the collaborative integration of multiple sensing modules in wearable electronics.

[0008] The present invention is achieved through the following technical solution.

[0009] One aspect of the present invention provides a method for fabricating a dual-network ionized pressure sensor with a modified fiber sensing layer, comprising the following steps: (a) Cleaning the flexible fiber substrate material; (b) Under vacuum conditions, alkaline amino polysaccharides and dilute acetic acid are mixed at a mass ratio of 1:(20~25) and stirred at a certain speed to prepare an alkaline amino polysaccharide aqueous solution. (c) Dopamine, soluble alkaline compound and deionized water were mixed at a mass ratio of 25:(1~2):1000, and the pH value was controlled to obtain a dopamine (DA) modified solution. (d) The cleaned flexible fiber substrate material is immersed in dopamine (DA) modification solution to modify the nonwoven fiber and self-assemble the hydrophilic groups of polydopamine. After drying, the self-assembled nonwoven fiber is obtained. (e) Under vacuum conditions, polyvinyl alcohol, alkaline amino polysaccharide, phosphoric acid and deionized water are mixed and stirred in stages according to a mass ratio of 10:(6~14):(1~1.5):100 to obtain polyvinyl alcohol / alkaline amino polysaccharide / phosphate ionic liquid. (f) Under vacuum conditions, the self-assembled nonwoven fibers are immersed in polyvinyl alcohol / alkaline amino polysaccharide / phosphate ion liquid and dried to obtain a flexible ionized pressure sensing layer. (g) Cut the flexible encapsulation layer and the copper foil electrode layer, and encapsulate them in a three-dimensional stacking order of polyimide flexible encapsulation layer-copper foil electrode layer-flexible ionized pressure sensing layer-copper foil electrode layer-polyimide flexible encapsulation layer to obtain a dual-network ionized pressure sensor with modified fiber sensing layer.

[0010] According to an exemplary embodiment of the present invention, the alkaline aminopolysaccharide includes chitin (CTS), chitosan oligosaccharide (COS), or chitosan (CS).

[0011] According to an exemplary embodiment of the present invention, the soluble alkaline compound is KOH or NaOH.

[0012] According to an exemplary embodiment of the present invention, the phosphoric acid is phosphoric acid or phytic acid.

[0013] According to an exemplary embodiment of the present invention, the polyvinyl alcohol is polyvinyl alcohol 1788, polyvinyl alcohol 2499, or polyvinyl alcohol 1799. According to an exemplary embodiment of the present invention, the vacuum condition is 1×10⁻⁶. - ³ ~10 -5 Pa.

[0014] According to an exemplary embodiment of the present invention, in step (b), the temperature is 50~60°C and the rotation speed is 100~150 r·min. -1 Stir for 5-8 hours.

[0015] According to an exemplary embodiment of the present invention, in step (c), the pH value is controlled to be 8~8.4; According to an exemplary embodiment of the present invention, in step (d), the self-assembly time is 7~8h; and the drying is carried out continuously at 60~90℃ for 6~10h.

[0016] According to an exemplary embodiment of the present invention, in step (e), the segmented mixing and stirring includes adding polyvinyl alcohol powder to deionized water and mixing at 60~90°C and 200~500 r·min. -1 Stir until completely dissolved, then cool to room temperature; add alkaline aminopolysaccharide aqueous solution and phosphoric acid, and incubate at room temperature, 100–400 rpm. -1 Stir until it becomes thick.

[0017] According to an exemplary embodiment of the present invention, in step (f), the ionogel-loaded modified nonwoven fibers are subjected to drying at 40-65°C for 3-5 hours.

[0018] In another aspect, the present invention provides a dual-network ionized pressure sensor with a modified fiber sensing layer prepared by the method described above.

[0019] In another aspect, the present invention provides an application of the dual-network ionized pressure sensor with the modified fiber sensing layer described above in a backpack posture correction scenario.

[0020] The present invention, by adopting the above technical solution, has the following beneficial effects: 1. The polyvinyl alcohol / chitosan / phosphoric acid (PVA / CS / H3PO4) ternary ion gel system used in this invention accurately anchors the performance requirements of ionization pressure sensors in core dimensions such as sensitivity, stability and durability, and realizes multi-dimensional synergistic optimization of material composition and structural design.

[0021] 2. All components of this gel system can form stable covalent and hydrogen bonds with polydopamine (PDA) molecules, which promotes the uniform and firm loading of the ion gel onto the surface of the nonwoven fiber (NWFs) substrate. This fundamentally solves the technical problems of uneven loading and easy detachment under external force in traditional gel coatings. While giving the sensor high pressure response sensitivity, it ensures the structural stability of the interface between the sensitive layer and the substrate, laying a solid structural foundation for the long-term continuous operation of the sensor.

[0022] 3. The molecular chains of alkaline aminopolysaccharides (chitosan (CTS), chitosan oligosaccharides (COS), or chitosan (CS)) and polyvinyl alcohol (PVA) are intertwined and cross-linked on the surface of nonwoven fibers (NWFs), forming a dense, shell-like protective layer. This effectively blocks external environmental factors such as humidity and oxygen from eroding and damaging the sensitive layer, significantly extending the sensor's service life while ensuring the long-term stability of its core sensing performance, such as pressure response linearity and signal output repeatability. Furthermore, the dynamic covalent and hydrogen bond network within the polyvinyl alcohol / alkaline aminopolysaccharide / phosphate (PVA / CS, (CTS), (COS) / H3PO4) ionogel maintains a stable three-dimensional cross-linked structure, preventing fluctuations in ion transport efficiency caused by gel network relaxation and collapse during long-term cyclic pressure testing. This ensures that the consistency and accuracy of the force-to-electric signal conversion remain constant throughout multiple cyclic pressure tests.

[0023] 4. This flexible ionized pressure sensor exhibits excellent sensing performance: it displays a maximum sensing value of 15.58 kPa across a wide detection range of 0-1 MPa. -1 High sensitivity, high linearity ≥0.996 (R0). 2 ) and a minimum detection limit of 0.8 Pa.

[0024] Through the synergistic design of the material system, this invention comprehensively improves the structural reliability, service life and performance stability of the voltage-isolated pressure sensor while ensuring excellent sensing performance, and has outstanding practical value and industrialization potential. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a structural diagram of a dual-network ionized pressure sensor based on a modified fiber sensing layer. Figure 2 The images show the scanning electron microscope (SEM) microstructures of the ionosensitive layer at different stages of the process: (a) is the SEM image of the nonwoven fibers (NWFs) in step 1, (b) is the SEM image of the nonwoven fibers (NWFs) modified with polydopamine (PDA) in step 4, and (c) is the SEM image of the nonwoven fibers (NWFs) with the ionogel layer attached in step 6. Figure 3 A line graph showing the force-electrostatic change sensitivity of a dual-network ionized pressure sensor based on a modified fiber sensing layer. Figure 4 This is a test diagram showing the minimum detection limit of a dual-network ionized pressure sensor based on a modified fiber sensing layer. Figure 5 Stability testing of pressure load / unload cycle count for a dual-network ionized pressure sensor based on a modified fiber sensing layer under different frequency characteristic modes; Figure 6 A schematic diagram of a dual-network ionized pressure sensor based on a modified fiber sensing layer used in backpack posture correction applications; Figure 7 Capacitive signal capture images of a dual-network ionized pressure sensor based on a modified fiber sensing layer for backpack posture correction applications: standing still and walking at a constant speed. Figure 8 Capacitive signal capture during the gradual increase of backpack pressure load for a dual-network ionized pressure sensor based on a modified fiber sensing layer. Figures 9(a)-(c) show the real-time detection of joint motion status using a dual-network ionized pressure sensor based on a modified fiber sensing layer.

[0026] In the figure, 1. Polyimide (PI) flexible encapsulation layer, 2. Copper foil electrode layer, 3. Flexible ionization sensing layer, 4. Vernier caliper, 5. Dual-network ionization pressure sensor based on modified fiber sensing layer, 6. Small iron sheet that can provide 0.8 Pa pressure, 7. Backpack. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0028] like Figure 1The diagram shows a schematic of a dual-network ionized pressure sensor 5 based on a modified fiber sensing layer. The dual-network ionized pressure sensor comprises, from top to bottom, a polyimide (PI) flexible encapsulation layer 1, a copper foil electrode layer 2, and a flexible ionized sensing layer 3. The flexible encapsulation layer is a polyimide (PI) film; the electrode layer is commercial copper foil; and the flexible ionized sensing functional layer consists of two parts: nonwoven fibers (NWFs) with a 3D network modified with polydopamine / potassium hydroxide (PDA / KOH) on the surface, and a polyvinyl alcohol / chitosan / phosphate (PVA / CS / H3PO4) ionogel layer wrapped around the fiber surface.

[0029] The sensor features a simple structure and fabrication process, small size, and lightweight design. The sensor's three-dimensional dimensions were measured using a vernier caliper 4; its length and width are 10 mm, and its thickness is only 400 µm.

[0030] This invention provides a method for fabricating a dual-network ionized pressure sensor based on a modified fiber sensing layer, comprising the following steps: Step 1, Clean the flexible fiber substrate material: Commercial nonwoven fiber (NWF) flexible substrates are repeatedly cleaned with ethanol until there is no excess dust on the surface, and then dried at room temperature for later use.

[0031] The purpose of this step is twofold: first, to prevent dust carried by the nonwoven fibers (NWFs) themselves from affecting the ion gel loading process and reducing the uniformity and stability of the polyvinyl alcohol / alkaline aminopolysaccharide / phosphate ion gel loading; and second, to prevent large dust particles from clogging the pores in the nonwoven fibers (NWFs), ultimately preventing the polyvinyl alcohol / alkaline aminopolysaccharide / phosphate ion liquid from completely filling the nonwoven fibers (NWFs) and reducing the loading efficiency.

[0032] Step 2, prepare an alkaline aminopolysaccharide aqueous solution: Prepare a dilute acetic acid solution using deionized water and glacial acetic acid solution at a concentration of 1-2%; mix alkaline aminopolysaccharides (chitosan (CTS), chitosan oligosaccharides (COS), or chitosan (CS)) and dilute acetic acid at a mass ratio of 1:(20-25) using a magnetic stirrer at 50℃-60℃ and 100-150 r·min. -1 Stir the mixture in a beaker at a certain speed for 5-8 hours to reduce the probability of the alkaline aminopolysaccharide polymerizing into a gel state during dissolution. The temperature and stirring speed settings must be maintained until the alkaline aminopolysaccharide particles are completely dissolved, resulting in a pale yellow, transparent alkaline aminopolysaccharide aqueous solution. Otherwise, alkaline aminopolysaccharide particles may adhere to the beaker wall or agglomerate, affecting the concentration of the prepared alkaline aminopolysaccharide aqueous solution.

[0033] In 1×10 - ³ ~10 -5 Under vacuum conditions of Pa, it is used to remove air bubbles generated during stirring.

[0034] Step 3, Preparation of dopamine (DA) modified solution: Place dopamine (DA), soluble alkaline compounds (KOH, NaOH), and deionized water in a beaker at a mass ratio of 25:(1~2):1000. Control the pH to 8~8.4. Stir the solution at a constant speed with a glass stirrer until the overall solution is a light brown transparent modified liquid. Store in a cool place for later use. Dopamine (DA), KOH, or NaOH are all rapidly soluble in water, therefore, there is no need to use a magnetic stirrer or additional heating during the dissolution process.

[0035] It is important to note that the prepared modified solution needs to be used quickly and cannot be stored for extended periods. Otherwise, dopamine (DA) will begin to polymerize over time. Furthermore, the dopamine (DA) modified solution must be prepared in strict accordance with the given relative ratios: a specific amount of dopamine (DA) and KOH or NaOH are needed to create a slightly alkaline reaction environment. Maintaining a pH of 8-8.4 is crucial for the physical aggregation of dopamine (DA) into polydopamine (PDA) which deposits on the surface of nonwoven fibers (NWFs). Step 4, Nonwoven Fiber (NWFs) Modification and Self-Assembly of Polydopamine (PDA) Hydrophilic Groups: After the nonwoven fibers (NWFs) prepared in step 1 are completely soaked in the modification liquid prepared in step 3, they are sealed and placed in a cool place for continuous modification for 7-8 hours to ensure that polydopamine (PDA) has sufficient time to self-assemble on the surface of the nonwoven fibers (NWFs) and to further ensure the uniform loading of polydopamine (PDA) on the fiber surface.

[0036] The modified dopamine (DA) solution changed from an initial light brown transparent liquid to a dark brown turbid liquid. This was because the initially dispersed dopamine (DA) successfully polymerized into polydopamine (PDA). After modification, the modified nonwoven fibers (NWFs) were removed and dried in a constant temperature oven at 60-90℃ for 6-10 hours for later use.

[0037] Polydopamine (PDA) in the dopamine (DA) modified solution will self-assemble on the surface of nonwoven fibers (NWFs). Since PDA itself carries a large number of hydrophilic groups, this self-assembly method on the surface of nonwoven fibers (NWFs) can introduce more hydrophilic groups into the fiber surface, thereby forming stable covalent bonds and hydrogen bonds with all components of the polyvinyl alcohol / alkaline aminopolysaccharide / phosphate gel system, which can then be used to stably and uniformly load the polyvinyl alcohol / alkaline aminopolysaccharide / phosphate gel.

[0038] The modified nonwoven fibers (NWFs) changed from their initial white color to a light brown physical morphology.

[0039] Step 5, prepare polyvinyl alcohol / alkaline aminopolysaccharide / phosphate ionic liquid: According to the mass ratio of polyvinyl alcohol (PVA) (PVA 1788, 2499, 1799), basic amino polysaccharide, phosphoric acid (phosphoric acid (H3PO4) or phytic acid) and deionized water of 10:(6~14):(1~1.5):100, a quantitative amount of polyvinyl alcohol (PVA) powder was added to deionized water and stirred using a magnetic stirrer (60~90℃, 200~500 r • min). -1 Stir until the polyvinyl alcohol (PVA) particles are completely dissolved, forming a transparent, slightly viscous liquid. After cooling to room temperature, add the alkaline aminopolysaccharide (chitosan (CTS), chitosan oligosaccharide (COS), or chitosan (CS)) aqueous solution prepared in step 2 and a quantitative amount of phosphoric acid (H3PO4) or phytic acid according to the specified ratio, and continue stirring (room temperature, 100~400 r • min). -1 (Continue processing until a transparent, precipitate-free, light yellow, viscous liquid is obtained, which is then polyvinyl alcohol / alkaline amino polysaccharide / phosphate ion liquid.)

[0040] The temperature and stirring speed must be strictly controlled during these two dissolution stages; otherwise, a large number of bubbles and undissolved transparent flocculent matter will be generated.

[0041] It should be noted that the addition of phosphoric acid (H3PO4) or phytic acid must be done when the gel mixture has cooled to room temperature; otherwise, phosphoric acid (H3PO4) or phytic acid may decompose at high temperatures, ultimately affecting the sensing performance of the flexible ionized pressure sensor.

[0042] In 1×10 - ³~ 10 -5 Under vacuum conditions of Pa, it is used to remove air bubbles generated during stirring.

[0043] Polyvinyl alcohol (PVA) provides a flexible polymer substrate for the ion gel, phosphoric acid (H3PO4) or phytic acid serves as an ion filler, separating hydrogen ions and phosphate groups to provide sensing properties, and basic amino polysaccharides (chitosan (CTS), chitosan oligosaccharide (COS) or chitosan (CS)) serve as crosslinking agents to make the overall structure of the gel more stable.

[0044] Step 6, Fabrication of a flexible ionized pressure sensing layer: In 1×10 - ³ ~10 -5Under vacuum conditions of Pa, the modified nonwoven fibers (NWFs) from step 4 are completely immersed in the ionic liquid prepared in step 5 for 2-3 hours. Vacuum treatment is performed to ensure the ionic liquid completely fills the interior of the nonwoven fiber (NWFs) network, allowing the polyvinyl alcohol / alkaline aminopolysaccharide / phosphate ion gel to be fully loaded on the surface of the modified nonwoven fibers (NWFs).

[0045] Then, the nonwoven fibers (NWFs) loaded with polyvinyl alcohol / alkaline amino polysaccharide / phosphate ionic liquid are taken out and placed in an oven to be dried continuously at 40~65℃ for 3~5 hours, and then the flexible ionized pressure sensing layer is obtained.

[0046] Step 7, Flexible Ionized Pressure Sensing Encapsulation: A flexible polyimide (PI) encapsulation layer and a copper foil electrode layer were cut using a nanolaser, with a geometric dimension of 10 mm × 10 mm. Following a three-dimensional stacking sequence of "flexible polyimide (PI) encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - flexible polyimide (PI) encapsulation layer," and utilizing the adhesive encapsulation of the flexible polyimide (PI) encapsulation layer itself, a dual-network ionized pressure sensor based on a modified fiber sensing layer was successfully fabricated.

[0047] The present invention will be further illustrated below with specific embodiments and comparative examples. However, it should be understood that these embodiments are for illustrative purposes only and should not be construed as limiting the invention in any way. All raw materials involved in the present invention are commercially available.

[0048] Example 1 The fabrication method of a dual-network ionized pressure sensor with a modified fiber sensing layer includes the following steps: (1) Commercial nonwoven fibers (NWFs) are repeatedly washed with ethanol and dried at room temperature for later use.

[0049] (2) Using 1% dilute acetic acid solution as solvent, the mass ratio of chitosan (CS) to dilute acetic acid is 1:20, at 55℃ and 100 r min - ¹Stir for 6 hours until completely dissolved, 10 -5 Pa vacuum degassing.

[0050] (3) Dopamine (DA): KOH: Deionized water = 25:1:1000 (mass ratio), pH = 8.2, stir until light brown and transparent, and prepare and use immediately in a cool place.

[0051] (4) Non-woven fibers (NWFs) are completely impregnated with the modification liquid, sealed and modified in a cool place for 7.2 hours, and dried at 60°C for 10 hours under constant temperature and humidity. The surface self-assembles polydopamine (PDA) and introduces hydrophilic groups, and the substrate is light brown.

[0052] (5) Polyvinyl alcohol 1788 (PVA): CS: Phosphoric acid (H3PO4): Deionized water = 10:10:1:100 (mass ratio); Polyvinyl alcohol (PVA) at 60℃ and 300 r min - ¹ Stir to dissolve, cool, then add chitosan (CS) aqueous solution and phosphoric acid (H3PO4), and incubate at room temperature for 150°C. min - ¹ Stir until it becomes a light yellow, viscous consistency, 10 -5 Pa vacuum degassing.

[0053] (6) Modified nonwoven fibers (NWFs) at 10 -5 The flexible ionized pressure sensing layer is obtained by immersing the layer in an ionic liquid under vacuum for 2 hours and drying it at 60°C for 4 hours.

[0054] (7) Laser cut a 10 mm × 10 mm polyimide PI encapsulation layer and copper foil electrode, stack them in the order of "polyimide PI flexible encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - polyimide PI flexible encapsulation layer", and use PI adhesive encapsulation to obtain an ionized pressure sensor.

[0055] Example 2 The fabrication method of a dual-network ionized pressure sensor with a modified fiber sensing layer includes the following steps: (1) Commercial nonwoven fibers (NWFs) are repeatedly washed with ethanol and dried at room temperature for later use.

[0056] (2) Using 1.2% dilute acetic acid solution as solvent, the mass ratio of chitosan (CS) to dilute acetic acid is 1:20, at 56℃ and 100 r min - ¹Stir for 6 hours until completely dissolved, 10 - ³ Pa vacuum degassing.

[0057] (3) Dopamine (DA): KOH: Deionized water = 25:1:1000 (mass ratio), pH = 8.3, stir until light brown and transparent, and prepare and use immediately in a cool place.

[0058] (4) Non-woven fibers (NWFs) are completely impregnated with the modification liquid, sealed and modified in a cool place for 8 hours, and dried at 60°C for 6 hours under constant temperature and humidity. The surface self-assembles polydopamine (PDA) and introduces hydrophilic groups, and the substrate is light brown.

[0059] (5) Polyvinyl alcohol 1799 (PVA): CS: Phosphoric acid (H3PO4): Deionized water = 10:6:1.2:100 (mass ratio); Polyvinyl alcohol (PVA) at 65℃ and 200 r min - ¹ Stir to dissolve, cool, then add chitosan (CS) aqueous solution and phosphoric acid (H3PO4), and incubate at room temperature for 120°C. min - ¹ Stir until it becomes a light yellow, viscous consistency, 10 - ³ Pa vacuum degassing.

[0060] (6) Modified nonwoven fibers (NWFs) at 10 - A flexible ionized pressure sensing layer was obtained by immersing the layer in an ionic liquid under a vacuum of 3 Pa for 2.5 h and drying it at 60 °C for 4 h.

[0061] (7) Laser cut a 10 mm × 10 mm polyimide PI encapsulation layer and copper foil electrode, stack them in the order of "polyimide PI flexible encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - polyimide PI flexible encapsulation layer", and use PI adhesive encapsulation to obtain an ionized pressure sensor.

[0062] Example 3 The fabrication method of a dual-network ionized pressure sensor with a modified fiber sensing layer includes the following steps: (1) Commercial nonwoven fibers (NWFs) are repeatedly washed with ethanol and dried at room temperature for later use.

[0063] (2) Using 1.4% dilute acetic acid solution as solvent, the mass ratio of chitosan (CTS) to dilute acetic acid is 1:22, at 60℃ and 120 r min - ¹Stir for 7 hours until completely dissolved, 10 -4 Pa vacuum degassing.

[0064] (3) Dopamine (DA): NaOH: Deionized water = 25:1.2:1000 (mass ratio), pH = 8.1, stir until light brown and transparent, and prepare and use immediately in a cool place.

[0065] (4) Non-woven fibers (NWFs) are completely impregnated with the modification liquid, sealed and modified in a cool place for 7.6 hours, and dried at 70°C for 8 hours under constant temperature and humidity. The surface self-assembles polydopamine (PDA) and introduces hydrophilic groups, and the substrate is light brown.

[0066] (5) Polyvinyl alcohol 2499 (PVA): CTS: Phytic acid: Deionized water = 10:8:1.3:100 (mass ratio); Polyvinyl alcohol (PVA) at 70℃ and 350 r min - ¹ Stir to dissolve, cool, then add chitosan (CTS) aqueous solution and phytic acid, at room temperature 110°C. min - ¹ Stir until it becomes a light yellow, viscous consistency, 10 -4 Pa vacuum degassing.

[0067] (6) Modified nonwoven fibers (NWFs) at 10 -4 The flexible ionized pressure sensing layer is obtained by immersing the layer in an ionic liquid under vacuum for 3 hours and drying it at 45°C for 5 hours.

[0068] (7) Laser cut a 10 mm × 10 mm polyimide PI encapsulation layer and copper foil electrode, stack them in the order of "polyimide PI flexible encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - polyimide PI flexible encapsulation layer", and use PI adhesive encapsulation to obtain an ionized pressure sensor.

[0069] Example 4 The fabrication method of a dual-network ionized pressure sensor with a modified fiber sensing layer includes the following steps: (1) Commercial nonwoven fibers (NWFs) are repeatedly washed with ethanol and dried at room temperature for later use.

[0070] (2) Using 1.5% dilute acetic acid solution as solvent, the mass ratio of chitosan oligosaccharide (COS) to dilute acetic acid is 1:23, at 50℃ and 140 r min - ¹Stir for 5 hours until completely dissolved, 10 - ³ Pa vacuum degassing.

[0071] (3) Dopamine (DA): NaOH: Deionized water = 25:1.3:1000 (mass ratio), pH = 8.2, stir until light brown and transparent, and prepare and use immediately in a cool place.

[0072] (4) Non-woven fibers (NWFs) are completely impregnated with the modification liquid, sealed and modified in a cool place for 8 hours, and dried at 75°C for 7 hours. The surface self-assembles polydopamine (PDA) and introduces hydrophilic groups, and the substrate is light brown.

[0073] (5) Polyvinyl alcohol 1788 (PVA): COS: Phosphoric acid (H3PO4): Deionized water = 10:7:1.5:100 (mass ratio); Polyvinyl alcohol (PVA) was heated at 75℃ and 280 r min - ¹ Stir to dissolve, cool, then add chitosan oligosaccharide (COS) aqueous solution and phosphoric acid (H3PO4), incubate at room temperature for 300°C. min -¹ Stir until it becomes a light yellow, viscous consistency, 10 - ³ Pa vacuum degassing.

[0074] (6) Modified nonwoven fibers (NWFs) at 10 - A flexible ionized pressure sensing layer was obtained by immersing the layer in an ionic liquid under a vacuum of 3 Pa for 2 hours and drying it at 50°C for 4.5 hours.

[0075] (7) Laser cut a 10 mm × 10 mm polyimide PI encapsulation layer and copper foil electrode, stack them in the order of "polyimide PI flexible encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - polyimide PI flexible encapsulation layer", and use PI adhesive encapsulation to obtain an ionized pressure sensor.

[0076] Example 5 The fabrication method of a dual-network ionized pressure sensor with a modified fiber sensing layer includes the following steps: (1) Commercial nonwoven fibers (NWFs) are repeatedly washed with ethanol and dried at room temperature for later use.

[0077] (2) Using 1.8% dilute acetic acid solution as solvent, the mass ratio of chitosan (CS) to dilute acetic acid is 1:24, at 57℃ and 150 r min - ¹Stir for 6 hours until completely dissolved, 10 -4 Pa vacuum degassing.

[0078] (3) Dopamine (DA): KOH: Deionized water = 25:1.4:1000 (mass ratio), pH = 8.3, stir until light brown and transparent, and prepare and use immediately in a cool place.

[0079] (4) Non-woven fibers (NWFs) are completely impregnated with the modification liquid, sealed and modified in a cool place for 7.7h, and dried at 80℃ for 6.5h under constant temperature and humidity. The surface self-assembles polydopamine (PDA) and introduces hydrophilic groups, and the substrate is light brown.

[0080] (5) Polyvinyl alcohol 2499 (PVA): CS: Phytic acid: Deionized water = 10:12:1.4:100 (mass ratio); Polyvinyl alcohol (PVA) at 80℃ and 500 r min - ¹ Stir to dissolve, cool, then add chitosan (CS) aqueous solution and phytic acid, incubate at room temperature (350°C). min - ¹ Stir until it becomes a light yellow, viscous consistency, 10 -4 Pa vacuum degassing.

[0081] (6) Modified nonwoven fibers (NWFs) at 10 -4The flexible ionized pressure sensing layer is obtained by immersing the layer in an ionic liquid under vacuum for 2.8 hours and drying it at 40°C for 5 hours.

[0082] (7) Laser cut a 10 mm × 10 mm polyimide PI encapsulation layer and copper foil electrode, stack them in the order of "polyimide PI flexible encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - polyimide PI flexible encapsulation layer", and use PI adhesive encapsulation to obtain an ionized pressure sensor.

[0083] Example 6 The fabrication method of a dual-network ionized pressure sensor with a modified fiber sensing layer includes the following steps: (1) Commercial nonwoven fibers (NWFs) are repeatedly washed with ethanol and dried at room temperature for later use.

[0084] (2) Using 1.3% dilute acetic acid solution as solvent, the mass ratio of chitosan oligosaccharide (COS) to dilute acetic acid is 1:25, at 51℃ and 110 r min - ¹Stir for 8 hours until completely dissolved, 10 - ³ Pa vacuum degassing.

[0085] (3) Dopamine (DA): NaOH: Deionized water = 25:1.5:1000 (mass ratio), pH = 8.4, stir until light brown and transparent, and prepare and use immediately in a cool place.

[0086] (4) Non-woven fibers (NWFs) are completely impregnated with the modification liquid, sealed and modified in a cool place for 7.7h, and dried at 85℃ for 7.5h under constant temperature and humidity. The surface self-assembles polydopamine (PDA) and introduces hydrophilic groups, and the substrate is light brown.

[0087] (5) Polyvinyl alcohol 1799 (PVA): COS: Phosphoric acid (H3PO4): Deionized water = 10:9:1.1:100 (mass ratio); Polyvinyl alcohol (PVA) at 70℃ and 400 r min - ¹ Stir to dissolve, cool, then add chitosan oligosaccharide (COS) aqueous solution and phosphoric acid (H3PO4), incubate at room temperature for 180°C. min - ¹ Stir until it becomes a light yellow, viscous consistency, 10 - ³ Pa vacuum degassing.

[0088] (6) Modified nonwoven fibers (NWFs) at 10 - A flexible ionized pressure sensing layer was obtained by immersing the layer in an ionic liquid under a vacuum of 3 Pa for 2.7 h and drying it at 65 °C for 3 h.

[0089] (7) Laser cut a 10 mm × 10 mm polyimide PI encapsulation layer and copper foil electrode, stack them in the order of "polyimide PI flexible encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - polyimide PI flexible encapsulation layer", and use PI adhesive encapsulation to obtain an ionized pressure sensor.

[0090] Example 7 The fabrication method of a dual-network ionized pressure sensor with a modified fiber sensing layer includes the following steps: (1) Commercial nonwoven fibers (NWFs) are repeatedly washed with ethanol and dried at room temperature for later use.

[0091] (2) Using 1.1% dilute acetic acid solution as solvent, the mass ratio of chitosan (CTS) to dilute acetic acid is 1:21, at 55℃ and 130 r min - ¹Stir for 7 hours until completely dissolved, 10 - ³ Pa vacuum degassing.

[0092] (3) Dopamine (DA): KOH: Deionized water = 25:1:1000 (mass ratio), pH = 8.2, stir until light brown and transparent, and prepare and use immediately in a cool place.

[0093] (4) Non-woven fibers (NWFs) are completely impregnated with the modification liquid, sealed and modified in a cool place for 8 hours, and dried at 90℃ for 6 hours under constant temperature and humidity. The surface self-assembles polydopamine (PDA) and introduces hydrophilic groups, and the substrate is light brown.

[0094] (5) Polyvinyl alcohol 1799 (PVA): CTS: Phosphoric acid (H3PO4): Deionized water = 10:14:1.2:100 (mass ratio); Polyvinyl alcohol (PVA) at 90℃ and 450 r min - ¹ Stir to dissolve, cool, then add chitosan (CTS) aqueous solution and phosphoric acid (H3PO4), incubate at room temperature (220°C). min - ¹ Stir until it becomes a light yellow, viscous consistency, 10 - ³ Pa vacuum degassing.

[0095] (6) Modified nonwoven fibers (NWFs) at 10 - A flexible ionized pressure sensing layer was obtained by immersing the layer in an ionic liquid under a vacuum of 3 Pa for 2.4 h and drying it at 55 °C for 3.5 h.

[0096] (7) Laser cut a 10 mm × 10 mm polyimide PI encapsulation layer and copper foil electrode, stack them in the order of "polyimide PI flexible encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - polyimide PI flexible encapsulation layer", and use PI adhesive encapsulation to obtain an ionized pressure sensor.

[0097] Example 8 The fabrication method of a dual-network ionized pressure sensor with a modified fiber sensing layer includes the following steps: (1) Commercial nonwoven fibers (NWFs) are repeatedly washed with ethanol and dried at room temperature for later use.

[0098] (2) Using 2% dilute acetic acid solution as solvent, the mass ratio of chitosan (CTS) to dilute acetic acid is 1:22, at 50℃ and 120 r min - ¹Stir for 5 hours until completely dissolved, 10 -5 Pa vacuum degassing.

[0099] (3) Dopamine (DA): NaOH: Deionized water = 25:1.1:1000 (mass ratio), pH = 8.3, stir until light brown and transparent, and prepare and use immediately in a cool place.

[0100] (4) Non-woven fibers (NWFs) are completely impregnated with the modification liquid, sealed and modified in a cool place for 7 hours, and dried at 65°C for 10 hours under constant temperature and humidity. The surface self-assembles polydopamine (PDA) and introduces hydrophilic groups, and the substrate is light brown.

[0101] (5) Polyvinyl alcohol 1788 (PVA): CTS: Phytic acid: Deionized water = 10:11:1:100 (mass ratio); Polyvinyl alcohol (PVA) at 85℃ and 300 r min - ¹ Stir to dissolve, cool, then add chitosan (CTS) aqueous solution and phytic acid, incubate at room temperature (400°C). min - ¹ Stir until it becomes a light yellow, viscous consistency, 10 -5 Pa vacuum degassing.

[0102] (6) Modified nonwoven fibers (NWFs) at 10 -5 The flexible ionized pressure sensing layer was obtained by immersing the layer in an ionic liquid under vacuum for 2.6 hours and drying it at 60°C for 4 hours.

[0103] (7) Laser cut a 10 mm × 10 mm polyimide PI encapsulation layer and copper foil electrode, stack them in the order of "polyimide PI flexible encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - polyimide PI flexible encapsulation layer", and use PI adhesive encapsulation to obtain an ionized pressure sensor.

[0104] Comparative Example 1 A method for fabricating a dual-network ionized pressure sensor with a nonwoven fiber sensing layer (without dopamine modification) includes the following steps: (1) Commercial nonwoven fibers (NWFs) are repeatedly washed with ethanol and dried at room temperature for later use.

[0105] (2) Using 2% dilute acetic acid solution as solvent, the mass ratio of chitosan (CS) to dilute acetic acid is 1:20, at 55℃ and 100 r min - ¹Stir for 6 hours until completely dissolved, 10 - ³ Pa vacuum degassing.

[0106] (3) Polyvinyl alcohol (PVA): CS: Phosphoric acid (H3PO4): Deionized water = 10:10:1:100 (mass ratio); Polyvinyl alcohol (PVA) at 60℃ and 300 r min - ¹ Stir to dissolve, cool, then add chitosan (CS) aqueous solution and phosphoric acid (H3PO4), and incubate at room temperature for 150°C. min - ¹ Stir until it becomes a light yellow, viscous consistency, 10 - ³ Pa vacuum degassing.

[0107] (4) Nonwoven fibers (NWFs) at 10 - A flexible ionized pressure sensing layer was obtained by immersing the layer in an ionic liquid under a vacuum of 3 Pa for 3 hours and drying it at 60°C for 4 hours.

[0108] (5) Laser cut a 10 mm × 10 mm PI encapsulation layer and copper foil electrode, stack them in the order of “polyimide (PI) flexible encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - polyimide (PI) flexible encapsulation layer”, and use PI adhesive encapsulation to obtain an ionized pressure sensor.

[0109] Comparative Example 2 A method for preparing a dual-network ionized pressure sensor with a modified fiber sensing layer (without alkaline amino polysaccharides in the gel layer) includes the following steps: (1) Commercial nonwoven fibers (NWFs) are repeatedly washed with ethanol and dried at room temperature for later use to avoid dust affecting the uniformity and stability of ion gel loading and to prevent pore blockage.

[0110] (3) Dopamine (DA): KOH: Deionized water = 25:1:1000 (mass ratio), pH = 8.2, stir until light brown and transparent, and prepare and use immediately in a cool place.

[0111] (4) Non-woven fibers (NWFs) are completely impregnated with the modification liquid, sealed and modified in a cool place for 3 hours, and dried at 60°C for 6 hours under constant temperature and humidity. The surface self-assembles polydopamine (PDA) and introduces hydrophilic groups, and the substrate is light brown.

[0112] (5) Polyvinyl alcohol (PVA): Phosphoric acid (H3PO4): Deionized water = 10:1:100 (mass ratio); Polyvinyl alcohol (PVA) at 60℃ and 300 r min - ¹ Stir to dissolve, cool, then add phosphoric acid (H3PO4), and incubate at room temperature for 150°C. min - ¹ Stir until it becomes a light yellow, viscous consistency, 10 - ³ Pa vacuum degassing.

[0113] (6) Modified nonwoven fibers (NWFs) at 10 - A flexible ionized pressure sensing layer was obtained by immersing the layer in an ionic liquid under a vacuum of 3 Pa for 2.5 h and drying it at 60 °C for 4 h.

[0114] (7) Laser cut a 10 mm × 10 mm PI encapsulation layer and copper foil electrode, stack them in the order of "polyimide PI flexible encapsulation layer - copper foil electrode layer - flexible ionized pressure sensing layer - copper foil electrode layer - polyimide PI flexible encapsulation layer", and use PI adhesive encapsulation to obtain an ionized pressure sensor.

[0115] Sensitivity, sensing range, and cyclic pressure loading / unloading stability under 12000 seconds were tested on the dual-network ionized pressure sensors with modified fiber sensing layers obtained in Examples 1-8 and the flexible ionized pressure sensors obtained in Comparative Examples 1-2. The test results are shown in Table 1. Table 1

[0116] As can be seen from the results in Table 1, the dual-network ionized pressure sensors based on modified fiber sensing layers proposed in Examples 1-8 of this invention have the dual advantages of wide-range detection and high-sensitivity response, with a sensitivity of not less than 15 kPa. -1The sensor exhibits a sensing range of no less than 975 kPa and a stability error of less than 5%. Furthermore, leveraging the inherent flexibility and lightweight structure of the nonwoven fiber (NWFs) network, this sensor demonstrates excellent flexibility and deformation adaptability, allowing it to stably conform to human skin or flexible substrate surfaces. This lays a solid foundation for its practical applications in wearable health monitoring, smart electronic skin, and other fields, and possesses broad industrialization prospects. In contrast, the flexible ionized pressure sensor obtained in Comparative Examples 1-2 exhibits relatively low sensitivity and a limited effective sensing range, demonstrating performance fatigue under repeated pressure cycle tests.

[0117] like Figure 2 The image shows a comparison of the scanning electron microscope (SEM) microstructures of the ionization sensing layer at different stages of the manufacturing process. Figure 2 (a) is a scanning electron microscope image of the nonwoven fibers (NWFs) from step 1, in which the three-dimensional network of the nonwoven fibers (NWFs) without any treatment can be observed; Figure 2 (b) is a scanning electron microscope image of the nonwoven fibers (NWFs) modified with polydopamine (PDA) in step 4. Figure 2 In (b), it can be observed that a large number of polydopamine (PDA) hydrophilic active sites are attached to the surface of the nonwoven fibers (NWFs) modified with polydopamine (PDA); Figure 2 (c) is a scanning electron microscope image of the nonwoven fibers (NWFs) with the ion gel layer attached in step 6. It can be observed from the image that a layer of polyvinyl alcohol / chitosan / phosphate (PVA / CS / H3PO4) gel layer is attached to the surface of the nonwoven fibers (NWFs), which verifies the effectiveness and feasibility of the preparation process of the dual-network ionized pressure sensor based on the modified fiber sensing layer of the present invention.

[0118] In addition, such as Figure 3 The figure shows a line graph illustrating the force-electrostatic change sensitivity of a dual-network ionized pressure sensor based on a modified fiber sensing layer. The overall process can be divided into three stages: S1, S2, and S3. It can be observed that this ionized pressure sensor exhibits excellent performance: sensitivity ≥6.27 kPa within the 0-1 MPa range. - ¹, and with a linearity (R²) ≥ 0.996, the sensing performance exhibited is far superior to that of traditional bipolar capacitive pressure sensors.

[0119] In addition, such as Figure 4 The figure shown is a test diagram of the minimum detection limit of a dual-network ionized pressure sensor based on a modified fiber sensing layer. This sensor is able to detect a small iron piece 6 placed on its surface, providing a pressure of 0.8 Pa, demonstrating its great potential in micro-pressure detection applications.

[0120] In addition, such as Figure 5The image shows the stability test of a dual-network ionized pressure sensor based on a modified fiber sensing layer under different frequency characteristic modes for pressure load / unload cycle counts. We set up two pressure load / unload modes: Mode 1: Single-stage, slow; Mode 2: Multi-stage, fast; This is used to simulate the stability of the electrical signal output of a flexible ionized pressure sensor under different complex scenarios. The figure shows that even after nearly 12,000 seconds of multimodal, rapid cyclic pressure testing, the sensor of this invention maintains an electrical signal output close to that at the beginning of the small test, without significant signal drift, thus ensuring the signal acquisition stability of the sensor.

[0121] In addition, such as Figure 6 The diagram illustrates a dual-network ionized pressure sensor based on a modified fiber sensing layer used for backpack posture correction. To verify the application potential of this sensor in the field of smart wearables, a backpack posture correction scenario was designed. The sensor is integrated into the two shoulder straps of the backpack 7. Through the signal output from the sensors at the shoulders, the backpacker's posture can be assessed in real time, enabling timely correction of uneven shoulders and hunchback, preventing the continued deterioration of poor posture.

[0122] In addition, such as Figure 7 As shown, this is an example of a dual-network ionized pressure sensor based on a modified fiber sensing layer used for backpack posture correction applications: capturing capacitive signals during standing still and walking at a constant speed. From the obtained capacitive signals, it can be observed that the sensor of this invention has a stable electrical signal output when the backpacker is standing still; when the backpacker is walking at a constant speed, the sensor of this invention can maintain a stable output and also detect the backpacker's walking status in real time.

[0123] In addition, such as Figure 8 As shown, a dual-network ionized pressure sensor based on a modified fiber sensing layer is used for backpack posture correction applications: capturing capacitive signals during the gradual increase of backpack pressure load. This verifies the high resolution of the sensor for different backpack load conditions.

[0124] Additionally, as shown in Figures 9(a)-(c), a dual-network ionized pressure sensor based on a modified fiber sensing layer is used for real-time detection of joint movement status. The sensor of this invention is integrated at the wrist joint, elbow joint, and biceps brachii muscle. Due to the high sensitivity, wide measurement range, and excellent fit of the sensor of this invention, it can promptly capture the wearer's limb movement status, providing real-time exercise training guidance.

[0125] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A method for fabricating a dual-network ionized pressure sensor with a modified fiber sensing layer, characterized in that, Includes the following steps: (a) Cleaning the flexible fiber substrate material; (b) Under vacuum conditions, alkaline amino polysaccharides and dilute acetic acid are mixed at a mass ratio of 1:(20~25) and stirred at a certain speed to prepare an alkaline amino polysaccharide aqueous solution. (c) Dopamine, soluble alkaline compound and deionized water are mixed at a mass ratio of 25:(1~2):1000, and the pH value is controlled to obtain dopamine modified solution; (d) The cleaned flexible fiber substrate material is immersed in dopamine modification solution to modify the nonwoven fiber and self-assemble the hydrophilic groups of polydopamine. After drying, the self-assembled nonwoven fiber is obtained. (e) Under vacuum conditions, polyvinyl alcohol, alkaline amino polysaccharide, phosphoric acid and deionized water are mixed and stirred in stages according to a mass ratio of 10:(6~14):(1~1.5):100 to obtain polyvinyl alcohol / alkaline amino polysaccharide / phosphate ionic liquid. (f) Under vacuum conditions, the self-assembled nonwoven fibers are immersed in polyvinyl alcohol / alkaline amino polysaccharide / phosphate ion liquid and dried to obtain a flexible ionized pressure sensing layer. (g) Cutting the flexible encapsulation layer and the copper foil electrode layer, This yields a dual-network ionized pressure sensor with a modified fiber sensing layer.

2. The method for preparing a dual-network ionized pressure sensor with a modified fiber sensing layer according to claim 1, characterized in that, The alkaline aminopolysaccharide includes chitin (CTS), chitosan oligosaccharide (COS), or chitosan (CS).

3. The method for preparing a dual-network ionized pressure sensor with a modified fiber sensing layer according to claim 1, characterized in that, The soluble alkaline compound is KOH or NaOH; The phosphoric acid content is phosphoric acid or phytic acid; The polyvinyl alcohol is polyvinyl alcohol 1788, polyvinyl alcohol 2499 or polyvinyl alcohol 1799.

4. The method for preparing a dual-network ionized pressure sensor with a modified fiber sensing layer according to claim 1, characterized in that, Vacuum conditions are 1×10 - ³ ~10 -5 Pa.

5. The method for preparing a dual-network ionized pressure sensor with a modified fiber sensing layer according to claim 1, characterized in that, In step (b), the temperature is 50~60℃ and the rotation speed is 100~150 r·min. -1 Stir for 5-8 hours.

6. The method for preparing a dual-network ionized pressure sensor with a modified fiber sensing layer according to claim 1, characterized in that, In step (c), the pH value is controlled to be 8~8.4; In step (d), the self-assembly time is 7~8h; and the drying is carried out continuously at 60~90℃ for 6~10h.

7. The method for preparing a dual-network ionized pressure sensor with a modified fiber sensing layer according to claim 1, characterized in that, In step (e), the staged mixing and stirring includes adding polyvinyl alcohol powder to deionized water and mixing at 60-90°C and 200-500 r·min. -1 Stir until completely dissolved, then cool to room temperature; add alkaline aminopolysaccharide aqueous solution and phosphoric acid, and incubate at room temperature, 100–400 rpm. -1 Stir until it becomes thick.

8. The method for preparing a dual-network ionized pressure sensor with a modified fiber sensing layer according to claim 1, characterized in that, In step (f), the ionomer gel modifies the nonwoven fibers for 2-3 hours and then dries them at 40-65°C for 3-5 hours.

9. A dual-network ionized pressure sensor with a modified fiber sensing layer prepared by the method described in any one of claims 1-8.

10. An application of a dual-network ionized pressure sensor with a modified fiber sensing layer as described in claim 9 in a backpack posture correction scenario.

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