A method for preparing a pressure sensor based on ion-electron cooperative transmission assembly

Abstract

The application relates to the technical field of sensor preparation, in particular to a pressure sensor preparation method based on ion-electron cooperative transmission assembly, which comprises the following steps: obtaining a composite film and conductive hydrogel; performing plasma treatment on the composite film, wherein the composite film comprises carbon nanotubes and thermoplastic polyurethane; covering a bridging layer on the surface of the conductive hydrogel; and assembling the conductive hydrogel and the composite film through hot-press crosslinking to generate a pressure sensor. The conductive hydrogel of the application is distorted in the ion migration path when subjected to pressure, the resistance change rate is improved, thereby improving the sensitivity of the pressure sensor. The ion migration rate is more rapid than the pure electronic conduction response, and the pressure sensor also maintains super-linear response in the pressure range. In addition, the contact point density of the composite film increases under pressure, which conforms to the ion-electric cooperative amplification mechanism, and the bridging layer can realize efficient conversion of electric charges.

Description

Technical Field

[0001] This application relates to the field of sensor fabrication technology, and in particular to a method for fabricating a pressure sensor based on ion-electron co-transport assembly. Background Technology

[0002] Touch is one of the core perceptual modalities for humans and animals to perceive the external environment, acquire key information (such as object shape, texture, hardness, temperature, sliding tendency, and force), and interact safely and precisely with the physical world. The research background of tactile sensors is rooted in human desire to endow machines with advanced tactile perception capabilities and achieve more natural and safer human-computer interaction.

[0003] In recent years, significant advancements have been made in microelectronics, new materials (such as flexible / stretchable materials, piezoelectric / piezoresistive / capacitive sensitive materials), and micro / nano fabrication processes, providing more possibilities for the design of high-performance tactile sensors. However, the stable, reliable, and large-area integrated simulation of the multifunctional and distributed sensing characteristics of biological skin, especially in terms of high resolution, wide range, low power consumption, strong robustness, and real-time signal processing and recognition, still presents formidable technical challenges. From a biomimetic perspective, human skin converts mechanical stimuli into electrochemical signals through ion channels (such as mechanoreceptors), a process that relies on changes in ion gradients and electronic signal transmission at neural synapses. However, traditional tactile sensors (such as piezoresistive and capacitive sensors) rely on only a single electronic conduction mechanism, which limits their adaptability, safety, and autonomy in complex, dynamic, and unstructured environments. Furthermore, their sensitivity is generally low, failing to efficiently simulate the ion-electron co-transmission characteristics of living organisms. Summary of the Invention

[0004] The main objective of this application is to propose a method for fabricating a pressure sensor based on ion-electron co-transmission assembly, aiming to solve the above-mentioned problems.

[0005] To achieve the above objectives, this application proposes a method for fabricating a pressure sensor based on ion-electron co-transport assembly, the method comprising the following steps: Obtaining composite films and conductive hydrogels; The composite film is subjected to plasma treatment, and the composite film comprises carbon nanotubes and thermoplastic polyurethane. A bridging layer is applied to the surface of the conductive hydrogel. A pressure sensor is generated by assembling a conductive hydrogel with a composite film through hot-press crosslinking.

[0006] In some embodiments, obtaining the composite film and the conductive hydrogel includes: 2-Acrylamide-2-methylpropanesulfonic acid is mixed and dissolved in ethylene glycol solution to generate a base solution; After dehydration, titanium carbide two-dimensional nanomaterials were dispersed in a solvent and then stirred and sonicated to obtain a dispersion. The dispersion, zinc salt ion crosslinking agent, acrylic acid and photoinitiator are added to the base liquid, mixed evenly and degassed to obtain the precursor prepolymer liquid; The precursor prepolymer liquid is added into a pretreated polydimethylsiloxane mold, and a crosslinking and curing reaction is carried out under the protection of ultraviolet light and inert gas to generate a conductive hydrogel.

[0007] In some embodiments, after the cross-linking and curing reaction under ultraviolet light and inert gas protection to generate a conductive hydrogel, the process further includes: The conductive hydrogel was purified by immersing it in a buffer solution, and the buffer solution was replaced at intervals until the conductivity of the conductive hydrogel met the threshold.

[0008] In some embodiments, obtaining the composite film and the conductive hydrogel further includes: The carbon nanotubes were functionalized by mixed acid oxidation, and then generated by centrifugal washing and vacuum freeze-drying. The thermoplastic polyurethane is dissolved in an organic solvent, pretreated by swelling, and then a silane coupling agent is added and subjected to ultrasonic treatment to generate a functional thermoplastic polyurethane base liquid. The functionalized carbon nanotubes are added to the functional thermoplastic polyurethane base liquid, along with a dispersant and a rheology modifier, and a composite slurry is formed through a multi-step dispersion process. The composite slurry is coated onto the substrate using a slot coating process and then dried by gradient heating to form a wet gel film. The composite film is obtained by hot-pressing the wet gel film using a hot press.

[0009] In some embodiments, after hot pressing the wet gel membrane with a hot press to obtain the composite film, the composite film is further subjected to a qualification test, which includes sheet resistance test, tensile test elongation at break, non-agglomeration area test, and network connectivity test.

[0010] In some embodiments, the assembly of the conductive hydrogel and the composite film to form a pressure sensor via thermo-press crosslinking includes: The conductive hydrogel is used as an ion-conducting core layer by hot-press crosslinking and is directly laminated with the composite film to generate a pressure sensor.

[0011] In some embodiments, the assembly of the conductive hydrogel and the composite film to form the pressure sensor via hot-press crosslinking further includes: The conductive hydrogel is sandwiched between the composite films as an ion-conducting core layer through hot-press crosslinking.

[0012] In some embodiments, the mixed acid oxidation method uses a mixture of concentrated nitric acid and concentrated sulfuric acid.

[0013] In some embodiments, the dispersion is an MXene dispersion.

[0014] In some embodiments, the conductive hydrogel includes hydrogen bonds formed by linking the sulfonic acid groups of the 2-acrylamide-2-methylpropanesulfonic acid to the end groups of the MXenes dispersion.

[0015] The embodiments of this application include at least the following beneficial effects: This application provides a method for fabricating a pressure sensor based on ion-electron co-transmission assembly. The conductive hydrogel of this application exhibits ion migration path distortion and resistance change rate increase under pressure, thereby improving the sensitivity of the pressure sensor. The ion migration rate is faster than that of pure electronic conduction response, and it maintains superlinear response within the pressure range. In addition, the contact point density of the composite film increases under pressure, which conforms to the ion-electron co-amplification mechanism, and efficient charge conversion can be achieved in the bridging layer. Attached Figure Description

[0016] Figure 1 A flowchart illustrating the fabrication method of a pressure sensor based on ion-electron co-transport assembly provided in this application embodiment; Figure 2 A schematic diagram of a pressure sensor provided in an embodiment of this application; Figure 3 A flowchart illustrating the method for preparing the composite thin film provided in the embodiments of this application; Figure 4 A schematic diagram of the composite thin film for a pressure sensor provided in an embodiment of this application; Figure 5 This is a flowchart of the conductive hydrogel preparation method provided in the embodiments of this application; Figure 6 A schematic diagram of the conductive hydrogel of the pressure sensor provided in the embodiments of this application; Figure 7 A schematic diagram showing the resistance change of the electronic layer impedance of the pressure sensor provided in this application embodiment under different pressures; Figure 8 A schematic diagram of fatigue resistance testing of a pressure sensor provided in an embodiment of this application; Figure 9 This is a schematic diagram of the training and testing results of the pressure sensor provided in this application for handwriting recognition. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0018] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

[0019] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0021] In related technologies, ion-electronic tactile sensors utilize mobile ions (such as hydrogels and ionic liquids) in flexible materials to sense external stimuli. Ions can produce significant capacitance / resistance changes under minute pressures, replacing the electronic conduction of traditional electronic sensors. They can simultaneously detect physical quantities such as pressure, shear force, temperature, and humidity, achieving signal decoupling through differences in ion migration behavior. However, problems such as humidity changes causing hydrogel expansion / contraction, ion concentration drift leading to signal distortion, hydrogel dehydration and cracking, and potential leakage and system contamination by ionic liquids still restrict the fabrication and use of ion-electronic sensors.

[0022] In view of this, this application provides a method for fabricating a pressure sensor based on ion-electron co-transmission assembly.

[0023] Example 1 refer to Figures 1-2As shown, the sensor in this application includes a conductive hydrogel and a composite film. Specifically, the preparation method includes: S101: Obtaining composite films and conductive hydrogels S102: The composite film is subjected to plasma treatment, wherein the composite film comprises carbon nanotubes and thermoplastic polyurethane; S103: Cover the surface of the conductive hydrogel with a bridging layer; S104: A pressure sensor is generated by assembling a conductive hydrogel and a composite film through hot-press cross-linking.

[0024] Specifically, in step S101, the composite film includes carbon nanotubes and thermoplastic polyurethane, wherein the composite film serves as the electronic layer of the pressure sensor.

[0025] The conductive hydrogel in steps S101-S104 exhibits distorted ion migration paths and increased resistance change rate under pressure, thereby enhancing the sensitivity of the pressure sensor. The ion migration rate is faster than that of pure electronic conduction, and it maintains a superlinear response within the pressure range. Furthermore, the composite film exhibits increased contact point density under pressure, conforming to the ionization-co-amplification mechanism, and enabling efficient charge conversion in the bridging layer.

[0026] refer to Figures 3-4 As shown, further, the preparation of the composite film in step S101 includes: S201: The carbon nanotubes are functionalized by mixed acid oxidation, and then functionalized carbon nanotubes are generated by centrifugal washing and vacuum freeze-drying. S202: The thermoplastic polyurethane is dissolved in an organic solvent, pretreated by swelling, and then a silane coupling agent is added and ultrasonically treated to generate a functional thermoplastic polyurethane base liquid. S203: The functionalized carbon nanotubes are added to the functionalized thermoplastic polyurethane base liquid, and a dispersant and rheology modifier are added. After multi-step dispersion treatment, a composite slurry is formed. S204: The composite slurry is coated onto the substrate using a slot coating process and then dried by gradient heating to form a wet gel film; S205: The wet gel film is hot-pressed using a hot press to obtain the composite film.

[0027] Specifically, in step S201, the mixed acid oxidation method uses a mixture of concentrated nitric acid and concentrated sulfuric acid, with a volume ratio of 1:3. The mixture is refluxed at 60°C for 8 hours. The residual acid is removed by centrifugation (12000 rpm, 15 min), and then freeze-dried under vacuum (-50°C, 10 Pa) for storage. Specifically, in step S202, the organic solvent is DMF, namely N,N-dimethylformamide, with a concentration of 15wt%. It is pretreated by swelling under magnetic stirring at 60°C for 4 hours. Then, 0.3% silane coupling agent KH550 is added, and ultrasonic treatment is performed for 30 minutes (40kHz, 300W). Specifically, step S203 involves a multi-step dispersion process, which includes three steps: pre-dispersion, fine dispersion, and stabilization to achieve high-concentration dispersion. Subsequently, 0.5% BYK-2150 dispersant and 0.2% hydroxyethyl cellulose are added in stages, and the storage modulus G' = 500-800 Pa (1 Hz) is controlled using a rotational rheometer. Specifically, in step S204, a laser thickness gauge is used to detect the thickness of the wet film on the substrate at a speed of 0.5-1.2 m / min, where the substrate temperature is 80±2℃. The thickness can be monitored using an infrared thermal imager, and the film thickness tolerance is detected using a β-ray thickness gauge to control it within a range of ±5 μm. Gradient temperature drying was used: 80℃ (2min) → 100℃ (3min) → 120℃ (5min) to form a wet gel film. The solvent residue was detected by gas chromatography-mass spectrometry (GC-MS), and the residue of N-methylpyrrolidone (NMP) was <500ppm. Specifically, in step S205, a hot press (temperature 150℃, pressure 5MPa, time 5min) is used to enhance the interlayer bonding force, and the surface roughness is detected by atomic force microscopy (AFM) to make the surface roughness Ra≤200nm; Specifically, after hot pressing the wet gel film in step S205 to obtain the composite film, the composite film is further subjected to a qualification test, which includes sheet resistance test, tensile test elongation at break, non-agglomeration area test, and network connectivity test.

[0028] Specifically, the sheet resistance was tested using the four-probe method, ensuring it was ≤100Ω / sq (when the carbon nanotube content was 1.5%); the elongation at break was ≥400% in tensile testing; and the uniformity of carbon nanotube distribution was observed using scanning electron microscopy (no agglomerated areas >5μm). refer to Figures 5-6 As shown, the preparation of the conductive hydrogel in step S101 further includes: S301: 2-Acrylamide-2-methylpropanesulfonic acid is mixed and dissolved with ethylene glycol solution to generate a base solution; S302: Titanium carbide two-dimensional nanomaterials are dehydrated, dispersed in a solvent, and then stirred and ultrasonically treated to obtain a dispersion. S303: Add the dispersion, zinc salt ion crosslinking agent, acrylic acid and photoinitiator to the base liquid, mix evenly and degas to obtain the precursor prepolymer liquid; S304: The precursor prepolymer liquid is added into the pretreated polydimethylsiloxane mold, and a cross-linking and curing reaction is carried out under the protection of ultraviolet light and inert gas to generate a conductive hydrogel.

[0029] Specifically, in step S301, 1.000g of 2-acrylamide-2-methylpropanesulfonic acid (AMPS, with a purity ≥98%) is weighed using an analytical balance (accuracy 0.1mg) and placed in a dry 5mL glass beaker; 2.000g of ethylene glycol (EG, with a purity ≥99.5%) is measured and dissolved using a constant temperature magnetic stirrer (25±0.5℃, 300rpm) for 30 minutes until the solution is colorless and transparent, thus completing the preparation of the AMPS-ethylene glycol base solution; Specifically, in step S302, MXene is dispersed. The target concentration is 0.5%, but 16.1 mg of titanium carbide two-dimensional nanomaterial (Ti3C2Tx.MXene, with a monolayer ratio >95%, prepared by centrifugal exfoliation) needs to be added. The nanomaterial is placed in a vacuum drying oven at 60°C for 4 hours to dehydrate. The dehydrated titanium carbide two-dimensional nanomaterial is then dispersed in a solvent, first magnetically stirred (200 rpm, 5 min), and then sonicated with a probe (20 kHz, 50% amplitude, ice bath). Finally, 10 μL of the dispersion is dropped onto a silicon wafer, and the MXene layer thickness is measured to be ≤3 nm using an atomic force microscope (AFM) to verify the dispersion. Specifically, in step S303, the dispersion, zinc salt ion crosslinking agent, acrylic acid, and photoinitiator are added to the base liquid, mixed evenly, and degassed to obtain the precursor prepolymer liquid, which specifically includes: After adding the dispersion to the base solution, add 0.200g Zn(NO3)·6H2O as an ionic crosslinking agent (AR grade). Reduce the stirring speed to 150rpm to avoid bubbles. The solution turns into a pale blue opalescent color. Place the glass beaker in a 4°C ice bath, slowly add 1.000g of acrylic acid (containing 100ppm MEHQ polymerization inhibitor), stir for 20 minutes, and control the temperature to <15°C; 0.020 g of 1173 photoinitiator (dissolved in 0.5 mL of anhydrous ethanol) was added under light-protected conditions, and the mixture was ultrasonically degassed (40 kHz, 5 min) to carry out the reaction and obtain the precursor prepolymer solution. Specifically, in step S304, an ultraviolet curing process is carried out using an ultraviolet wavelength of 365±5nm and a light intensity of 10±0.5mW / cm², with nitrogen as the inert gas.

[0030] Furthermore, after a cross-linking and curing reaction is carried out under the protection of ultraviolet light and an inert gas to generate a conductive hydrogel, the process also includes: The conductive hydrogel was purified by immersing it in a buffer solution, and the buffer solution was replaced at intervals until the conductivity of the conductive hydrogel met the threshold.

[0031] Specifically, replace it every 6 hours until the conductivity is <5μS / cm (approximately 48 hours); test the compression modulus (strain rate 1mm / min) using a universal testing machine.

[0032] Specifically, in step S103, the conductive hydrogel and the composite film are assembled to form a pressure sensor through hot-press cross-linking, which specifically includes: First, the interface is functionalized by treating the composite film with O2 plasma to increase the surface -OH / -COOH groups. Then, a bridging layer (PEDOT) is coated on the surface of the MPAA conductive hydrogel, which is a conductive hydrogel doped with AMPS in MXenes dispersion, to enhance the electron-ion coupling efficiency. Cross-linking was performed by hot pressing at 80℃ and 0.3MPa for 120s, during which dehydration of the hydrogel was prevented. Assembly method 1: MPAA hydrogel, as an ion-conductive core layer (thickness 0.5-1mm), was sandwiched between two CNT / TPU films (thickness 100μm) to form an electron-ion heterogeneous interface. Assembly method 2: MPAA hydrogel, as an ion-conductive core layer (thickness 0.5-1mm), was directly assembled with a CNT / TPU film (thickness 100μm) to form a bilayer structure to form an electron-ion heterogeneous interface.

[0033] Example 2 In this embodiment, based on the preparation method of the conductive hydrogel described in Example 1, the target concentration of the MXene dispersion is systematically adjusted from 0.5% to 1%, requiring the weighing of approximately 32.2 mg of 2-acrylamide-2-methylpropanesulfonic acid (monolayer ratio >95%), and the magnetic stirring time is increased to achieve dispersion. The enhanced structural stability is achieved by forming strong hydrogen bonds between the AMPS sulfonic acid groups (-SO3H) and the terminal oxygen on the surface of the increased-concentration MXenes, thereby further enhancing the ion-electron synergistic effect.

[0034] 1. Preparation method of electronic layer based on CNT / TPU thin film Considering that the prepared electronic layer film needs to be well assembled with the conductive hydrogel prepared in Example 1, carbon nanotubes (CNTs) are doped into thermoplastic polyurethane (TPU) to prepare the film. Breakthrough improvements in mechanical properties and piezoresistive effect can be achieved through nanoscale synergistic effects. To further enhance these synergistic effects, this example uses CNT / TPU (3% content) electronic thin films, prepared as follows: (1) The CNTs were functionalized by mixed acid oxidation (concentrated nitric acid: concentrated sulfuric acid = 1:3 volume ratio). The reflux treatment time at 60℃ was extended to 9 hours to improve the dispersion stability. The residual acid was removed by centrifugation (14000rpm, 15min) and deionized water was washed up to 5 times to ensure the pH value was neutral. The CNTs were then freeze-dried in vacuum (-50℃, 10Pa) and stored for later use. (2) Dissolve TPU particles in DMF (concentration 15wt%) and perform swelling pretreatment by magnetic stirring at 60℃ for 4 hours; then add 0.5% silane coupling agent KH550 to enhance the interfacial compatibility between CNT and TPU, and sonicate (40kHz, 350W) for 40 minutes. (3) Add 3% CNT to the TPU solution in three batches with a 10-minute interval between each batch. Use a high-speed shear emulsifier (6000 rpm) for initial dispersion. Use a two-way planetary mixer (30 rpm revolution, 800 rpm rotation) to process under a vacuum of 0.08 MPa for 45 minutes. Then add 0.8% BYK-2150 dispersant and 0.3% hydroxyethyl cellulose in steps. Use a rotational rheometer to control the storage modulus G' in the range of 900-1200 Pa (1 Hz) to ensure that the slurry has both coatability and stability. (4) Slit coating is performed. A laser thickness gauge is used at a speed of 0.4-0.8 m / min, and the substrate temperature is 80±2℃ (monitored by an infrared thermal imager). The film thickness tolerance is detected by a β-ray thickness gauge and controlled within the range of ±3μm. Gradient temperature drying is used: 80℃ (3min) → 100℃ (4min) → 120℃ (8min). Solvent residue detection: GC-MS determination of NMP residue <300ppm; Stage 1: 2MPa / 60s (preliminary bonding), Stage 2: 6MPa / 120s (forced flow), Stage 3: 2MPa / 60s (stress release); A hot press is used (temperature 155℃, pressure 5MPa, time 8min) to enhance interlayer bonding and promote the penetration and entanglement of CNTs in TPU, thus completing the hot press composite. (5) The sheet resistance of the four-probe method is ≤50Ω / sq; the elongation at break of the tensile test is ≥350%; the SEM observation requires that there is no agglomerated area >3μm and the CNT network connectivity is greater than 85%.

[0035] 2. Assembly of a pressure sensor using ion-electron co-transmission assembly First, the interface functionalization process is carried out by treating the CNT / TPU film with O2 plasma (power 120W, time 45 seconds) to increase the surface -OH / -COOH groups. The surface of the MPAA hydrogel was coated with PEDOT, a bridging layer, to enhance the electron-ion coupling efficiency; cross-linking was carried out by hot pressing at 80°C and 0.3MPa for 120 seconds to prevent hydrogel dehydration. Assembly Method 1: MPAA hydrogel is used as an ion-conducting core layer (thickness 0.5-1mm) sandwiched between two CNT / TPU films (thickness 100μm), forming an electron-ion heterogeneous interface. Assembly Method 2: MPAA hydrogel, as the ion-conductive core layer (thickness 0.5-1mm), is directly assembled with CNT / TPU film (thickness 100μm) to form a bilayer structure, creating an electron-ion heterogeneous interface.

[0036] Example 3 Furthermore, in this embodiment, the amount of 2-acrylamide-2-methylpropanesulfonic acid is adjusted according to the concentration of the MXene dispersion, for example: Based on the preparation method of the conductive hydrogel described in Example 1, the target concentration of MXene was systematically adjusted from 0.5% to 2%. This required weighing approximately 64.4 mg of titanium carbide two-dimensional nanomaterials (Ti3C2Tx.MXene, with a monolayer ratio >95%, prepared by centrifugal exfoliation) and increasing the magnetic stirring time to disperse them. The increased concentration of MXenes was further enhanced by the formation of strong hydrogen bonds between the AMPS sulfonic acid groups (-SO3H) and the terminal oxygen on the surface, thereby improving structural stability and further enhancing the ion-electron synergistic effect.

[0037] Considering the optimal assembly method between the hydrogel ion layer and the CNT / TPU film electronic layer prepared with different concentrations of ionization synergistic effect in the piezoresistive sensor, this example uses the 3% CNT / TPU electronic film prepared in Example 2 as the electronic layer.

[0038] First, the interface is functionalized by treating the CNT / TPU film with O2 plasma (120W power, 45 seconds) to increase the surface -OH / -COOH groups; then, PEDOT is coated on the surface of the MPAA hydrogel to enhance the electron-ion coupling efficiency; finally, hot-press crosslinking is performed at 80℃ and 0.3MPa for 120 seconds to prevent hydrogel dehydration. Assembly Method 1: MPAA hydrogel, as the ion-conducting core layer (thickness 0.5-1mm), is sandwiched between two CNT / TPU films (thickness 100μm), forming an electron-ion heterogeneous interface; Assembly Method 2: MPAA hydrogel, as the ion-conducting core layer (thickness 0.5-1mm), is directly assembled with the composite film (CNT / TPU film, thickness 100μm), forming a bilayer structure, thus creating an electron-ion heterogeneous interface.

[0039] In some other embodiments, the amount of 2-acrylamide-2-methylpropanesulfonic acid is adjusted according to the concentration of the MXene dispersion.

[0040] refer to Figure 7 As shown, the breakthrough improvement in sensitivity of the present invention is reflected in the distortion of the ion migration path and the increase in the resistance change rate when the MXene-doped MPAA hydrogel (4% concentration) ion layer is subjected to pressure; the contact point density of the 3% CNT / TPU electron layer response film increases under pressure, which also increases the resistance change, thus conforming to the ionization-co-amplification mechanism.

[0041] refer to Figure 8 As shown, this invention achieves significant improvements in both temperature stability and fatigue resistance, exhibiting a faster ion migration rate than pure electronic conduction and maintaining a superlinear response within the pressure range. Therefore, this electron-ion co-transport architecture utilizes a triple-gain mechanism: MXene constructs a fast ion channel to enhance dynamic response; a CNT network provides a stable electronic framework; and a heterogeneous interface PEDOT bridging layer enables efficient charge conversion, ultimately overcoming existing technological bottlenecks in key indicators such as sensitivity, environmental adaptability, and lifetime.

[0042] refer to Figure 9 As shown, the recognition accuracy reached 96.67% through deep learning model verification, proving the beneficial effect of the embodiments prepared by this method and providing a new generation of sensing solutions for fields such as artificial intelligence, precision medicine, and industry.

[0043] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0044] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0045] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0046] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0047] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0048] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0049] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0050] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0051] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for fabricating a pressure sensor based on ion-electron co-transport assembly, characterized in that, The method includes the following steps: Obtaining composite films and conductive hydrogels; The composite film is subjected to plasma treatment, and the composite film comprises carbon nanotubes and thermoplastic polyurethane. A bridging layer is applied to the surface of the conductive hydrogel. A pressure sensor is generated by assembling a conductive hydrogel with a composite film through hot-press crosslinking.

2. The method for fabricating a pressure sensor based on ion-electron co-transport assembly according to claim 1, characterized in that, The process of obtaining the composite film and the conductive hydrogel includes: 2-Acrylamide-2-methylpropanesulfonic acid is mixed and dissolved in ethylene glycol solution to generate a base solution; After dehydration, titanium carbide two-dimensional nanomaterials were dispersed in a solvent and then stirred and sonicated to obtain a dispersion. The dispersion, zinc salt ion crosslinking agent, acrylic acid and photoinitiator are added to the base liquid, mixed evenly and degassed to obtain the precursor prepolymer liquid; The precursor prepolymer liquid is added into a pretreated polydimethylsiloxane mold, and a crosslinking and curing reaction is carried out under the protection of ultraviolet light and inert gas to generate a conductive hydrogel.

3. The method for fabricating a pressure sensor based on ion-electron co-transport assembly according to claim 2, characterized in that, After the cross-linking and curing reaction is carried out under the protection of ultraviolet light and inert gas to generate a conductive hydrogel, the process includes: The conductive hydrogel was purified by immersing it in a buffer solution, and the buffer solution was replaced at intervals until the conductivity of the conductive hydrogel met the threshold.

4. The method for fabricating a pressure sensor based on ion-electron co-transport assembly according to claim 2, characterized in that, The process of obtaining the composite film and the conductive hydrogel further includes: The carbon nanotubes were functionalized by mixed acid oxidation, and then generated by centrifugal washing and vacuum freeze-drying. The thermoplastic polyurethane is dissolved in an organic solvent, pretreated by swelling, and then a silane coupling agent is added and subjected to ultrasonic treatment to generate a functional thermoplastic polyurethane base liquid. The functionalized carbon nanotubes are added to the functional thermoplastic polyurethane base liquid, along with a dispersant and a rheology modifier, and a composite slurry is formed through a multi-step dispersion process. The composite slurry is coated onto the substrate using a slot coating process and then dried by gradient heating to form a wet gel film. The composite film is obtained by hot-pressing the wet gel film using a hot press.

5. The method for fabricating a pressure sensor based on ion-electron co-transport assembly according to claim 4, characterized in that, After hot-pressing the wet gel membrane with a hot press to obtain the composite film, the method further includes conducting qualification tests on the composite film. The qualification tests include sheet resistance test, tensile test elongation at break, non-agglomerated area test, and network connectivity test.

6. The method for fabricating a pressure sensor based on ion-electron co-transport assembly according to claim 1, characterized in that, The process of assembling a conductive hydrogel and a composite film to generate a pressure sensor via hot-press crosslinking includes: The conductive hydrogel is used as an ion-conducting core layer by hot-press crosslinking and is directly laminated with the composite film to generate a pressure sensor.

7. The method for fabricating a pressure sensor based on ion-electron co-transport assembly according to claim 6, characterized in that, The method of assembling a pressure sensor by hot-press crosslinking of a conductive hydrogel and a composite film further includes: The conductive hydrogel is sandwiched between the composite films as an ion-conducting core layer through hot-press crosslinking.

8. The method for fabricating a pressure sensor based on ion-electron co-transport assembly according to claim 4, characterized in that, The mixed acid oxidation method uses a mixture of concentrated nitric acid and concentrated sulfuric acid.

9. The method for fabricating a pressure sensor based on ion-electron co-transport assembly according to claim 2, characterized in that, The dispersion is an MXene dispersion.

10. The method for fabricating a pressure sensor based on ion-electron co-transport assembly according to claim 9, characterized in that, The conductive hydrogel includes hydrogen bonds, which are formed by linking the sulfonic acid groups of the 2-acrylamide-2-methylpropanesulfonic acid to the end groups of the MXenes dispersion.

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