A flexible triboelectric sensor based on modified conductive fabric and a preparation method thereof

Abstract

The application discloses a flexible triboelectric sensor based on modified conductive fabric and a preparation method thereof, and comprises the following steps: a flexible packaging layer is arranged at the bottom of the sensor; a modified conductive fabric electrode layer is arranged on the upper surface of the flexible packaging layer, and the modified conductive fabric electrode layer comprises a fabric substrate with amino functional groups and a conductive network anchored on the fabric substrate through an amide bond, wherein the conductive network is composed of carboxylated multi-walled carbon nanotubes and carbon black; and a high-dielectric composite sensitive layer is arranged on the upper surface of the modified conductive fabric electrode layer and is composed of an elastomer matrix doped with high-dielectric constant ceramic particles and graphene which are subjected to surface silanization treatment. The flexible triboelectric sensor and the preparation method thereof can construct a stable conductive network through chemical bonding, improve dielectric properties through surface modification of fillers and micro-nano structure design, and the obtained sensor has high stability, high output power and wide material adaptability.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a flexible triboelectric sensor based on modified conductive fabric and its preparation method. Background Technology

[0002] With the rapid development of artificial intelligence and flexible electronics, endowing intelligent robots and prosthetics with human-like tactile perception capabilities has become a core research direction in the field of human-computer interaction. As a key component in achieving this goal, tactile sensors not only need to detect contact pressure and the geometric contours of objects, but also need to be able to distinguish surface material characteristics of objects, such as roughness and material type, just like human skin, to meet the needs of precise operation in complex environments. However, existing flexible tactile sensing technologies still face many technical bottlenecks in practical applications, making it difficult to simultaneously meet the requirements of high stability, high output performance, and multimodal perception.

[0003] First, most existing flexible sensors are based on a single sensing mechanism, resulting in limited detection signal dimensions and difficulty in achieving comprehensive identification of object properties. Specifically, while widely used piezoresistive or capacitive sensors can reconstruct the geometry of an object's surface or detect contact pressure, their output signals are insensitive to differences in the electron affinity of materials, failing to effectively acquire material information. Ordinary triboelectric sensors, while sensitive to changes in surface charge and possessing the potential to identify materials, have output performance limited by the charge-trapping ability of the friction layer material and struggle to simultaneously accurately perceive static pressure or complex spatial shapes. This single-purpose detection method means that existing sensors cannot provide sufficient feature signals when dealing with complex objects that are "similar in shape but different in material" or "of the same material but different in shape," making it difficult for backend systems to accurately distinguish target objects. Although machine vision technology is often used to assist in identification, it often fails when dealing with transparent objects, reflective surfaces, or in low-light environments, and cannot acquire physical contact properties such as hardness and texture, making it difficult to meet the requirements of all-weather, high-precision contact operations.

[0004] Secondly, in terms of the fabrication process of flexible electrodes and sensitive materials, existing technologies generally suffer from poor interfacial adhesion and insufficient stability. To achieve flexible conductivity, current technologies often employ coating or impregnation methods to directly load conductive fillers such as carbon nanotubes and carbon black onto fabrics or polymer substrates. However, the surface of unmodified fabric fibers lacks active functional groups, and the conductive fillers and substrates are usually bonded only by weak van der Waals forces or physical adsorption. Under long-term repeated bending, friction, or stretching and other mechanical deformation conditions, the conductive layer is prone to cracking, peeling, or even detachment, leading to a sharp increase in sensor resistance, a decrease in sensitivity, or even complete device failure, severely limiting the practical application lifespan of flexible sensors in the wearable field.

[0005] Furthermore, to improve the output performance of triboelectric sensors, existing technologies often dope polymer matrices with inorganic ceramic particles of high dielectric constant to enhance the material's charge storage capacity. However, significant interfacial compatibility issues exist between hydrophilic inorganic ceramic particles and hydrophobic organic elastomer matrices, leading to agglomeration of the filler particles. Agglomeration not only limits the effective improvement of the material's dielectric properties but also introduces numerous interfacial defects into the composite system, compromising the mechanical flexibility and electrical stability of the composite material, ultimately affecting the sensor's output performance and long-term reliability. While some studies have attempted to improve filler dispersibility through surface modification or the addition of dispersants to address these issues, existing methods are often complex, costly, and offer limited performance improvements, hindering large-scale industrial applications.

[0006] In summary, existing flexible tactile sensing technologies still have significant shortcomings in terms of interface stability, filler dispersion, output performance, and multimodal sensing capabilities. Therefore, developing a flexible triboelectric sensor with strong interfacial bonding, uniform filler dispersion, excellent output performance, and multimodal sensing capabilities, along with a simple and efficient fabrication method, has significant scientific research value and broad application prospects. Summary of the Invention

[0007] To address the technical problems existing in the background art, this invention proposes a flexible triboelectric sensor based on modified conductive fabric and its preparation method.

[0008] This invention proposes a flexible triboelectric sensor based on modified conductive fabric, comprising:

[0009] The flexible encapsulation layer is located at the very bottom of the sensor;

[0010] A modified conductive fabric electrode layer is disposed on the upper surface of the flexible encapsulation layer, comprising a fabric substrate with amino functional groups on its surface and a conductive network anchored on the fabric substrate by amide bonds, the conductive network being composed of carboxylated multi-walled carbon nanotubes and carbon black.

[0011] A high-dielectric composite sensitive layer, covering the upper surface of the modified conductive fabric electrode layer, is composed of an elastomer matrix doped with surface-silanized high-dielectric-constant ceramic particles and graphene.

[0012] Preferably, the fabric base is one of modal fabric, pure cotton fabric, modal fabric, or Lycra cotton.

[0013] Preferably, the mass ratio of the carboxylated multi-walled carbon nanotubes to carbon black is 2:3.

[0014] Preferably, the high dielectric constant ceramic particles are BaTiO3, SrTiO3, or CaCu3Ti4O. 12 One of them, whose surface is modified with silane coupling agent APTES or GPTES; the high dielectric constant ceramic particles in the elastomer matrix have a mass fraction of 4%-15%.

[0015] Preferably, the graphene in the elastomer matrix has a mass fraction of 0.5%-2%; the elastomer matrix is ​​one of natural rubber, polydimethylsiloxane PMDS, and Ecoflex silicone rubber.

[0016] This invention proposes a method for fabricating a flexible triboelectric sensor based on modified conductive fabric, applicable to the flexible triboelectric sensor based on modified conductive fabric as described in any of the above claims. The method includes the following steps:

[0017] S1. The fabric substrate is immersed in an aminosilane coupling agent solution for surface amination modification to obtain an amination fabric.

[0018] S2. Carboxylated multi-walled carbon nanotubes, carbon black, and silicone rubber are added to an organic solvent and mixed evenly to obtain conductive ink;

[0019] S3. The aminated fabric is immersed in the conductive ink, so that the carboxylated multi-walled carbon nanotubes undergo an amidation reaction with the amino group and are anchored on the fabric surface. At the same time, carbon black fills the gaps in the carbon nanotube network. After curing, a modified conductive fabric electrode is formed.

[0020] S4. Surface silanization treatment is performed on high dielectric constant ceramic particles to obtain modified ceramic particles;

[0021] S5. The modified ceramic particles and graphene are added to the elastomer precursor and mixed evenly to obtain a composite sensitive layer adhesive solution.

[0022] S6. The composite sensitive layer adhesive is applied to the upper surface of the modified conductive fabric electrode and cured to form a high dielectric composite sensitive layer.

[0023] S7. A flexible encapsulation layer is attached to the lower surface of the modified conductive fabric electrode and wires are led out to complete the sensor fabrication.

[0024] Preferably, in step S1, the aminosilane coupling agent solution is an APTES ethanol solution with a mass fraction of 0.5%-1.5%, the reaction time is 45-60 minutes, and the curing temperature is 40-60℃.

[0025] Preferably, in step S2, the mass ratio of carboxylated multi-walled carbon nanotubes, carbon black, and silicone rubber is 2:3:3, and the organic solvent is naphtha; in step S3, the impregnation and curing process is repeated 3 times, the curing temperature is 45-65℃, and the curing time is 40-60 minutes each time; in step S5, the mass fraction of modified ceramic particles is 4%-15%, the mass fraction of graphene is 0.5%-2%, and the elastomer precursor is a 1:1 mixture of Ecoflex A / B components.

[0026] Preferably, in step S4, the surface silanization treatment involves dispersing high dielectric constant ceramic particles in a 1.0% (w / w) APTES ethanol solution and stirring for 40 minutes, followed by washing and drying.

[0027] A smart tactile system based on any one of the above-described flexible triboelectric sensors includes:

[0028] The signal acquisition module is used to acquire the triboelectric signal generated by the contacting object from the sensor;

[0029] The feature extraction module, connected to the signal acquisition module, is used to extract amplitude and waveform feature parameters from the triboelectric signal.

[0030] The identification and classification module is connected to the feature extraction module and has a built-in deep learning algorithm model. It is used to identify the material, texture or shape of an object based on the feature parameters and output the identification results.

[0031] This invention presents a flexible triboelectric sensor based on modified conductive fabric and its fabrication method. By employing a surface chemical modification strategy to construct a covalent bond interface between the fabric substrate and the conductive filler, it overcomes the defects of easy cracking and peeling of the conductive layer in traditional physical coating processes, thus improving the structural stability and mechanical durability of the conductive fabric electrode. Through surface silanization treatment of the high dielectric constant ceramic filler and co-doping with graphene, the aggregation phenomenon of inorganic fillers in the organic elastomer matrix is ​​eliminated. The dielectric properties and charge trapping ability of the composite sensitive layer are significantly enhanced by the microcapacitance effect, thereby endowing the sensor with excellent and stable triboelectric output performance. Simultaneously, the sensor structure of this invention can simultaneously respond to contact electrification signals and mechanical deformation signals, possessing multimodal sensing capabilities for object material, surface texture, contact pressure, and bending angle. Combined with deep learning algorithms, it can achieve accurate recognition of complex objects, providing a high-performance tactile sensing solution for human-computer interaction, intelligent robots, and wearable electronic systems. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of one embodiment of a flexible triboelectric sensor based on modified conductive fabric proposed in this invention.

[0033] Figure 2 This is a schematic diagram of the chemical reaction process that occurs during the fabric electrode preparation in the fabrication method of the flexible triboelectric sensor based on modified conductive fabric proposed in this invention.

[0034] Figure 3 This is a schematic diagram of the CCTO surface silanization process in the fabrication method of a flexible triboelectric sensor based on modified conductive fabric proposed in this invention.

[0035] Figure 4 This is a flowchart illustrating one embodiment of the fabrication method for a flexible triboelectric sensor based on modified conductive fabric proposed in this invention.

[0036] Figure 5 This is a schematic diagram illustrating the working principle of a flexible triboelectric sensor based on modified conductive fabric, as proposed in this invention.

[0037] Figure 6 This is a simulation diagram of the potential change during the operation of a flexible triboelectric sensor based on modified conductive fabric, which is proposed in this invention.

[0038] Figure 7 The image shows the microstructure and structural characterization of the modified conductive fabric electrode layer in the fabrication method of the flexible triboelectric sensor based on modified conductive fabric proposed in this invention.

[0039] Figure 8 The image shows the microstructure and structural characterization of the high-dielectric composite sensitive layer in the fabrication method of a flexible triboelectric sensor based on modified conductive fabric proposed in this invention.

[0040] Figure 9 This is a test diagram showing the optimized performance of the conductive electrodes in a method for fabricating a flexible triboelectric sensor based on modified conductive fabric proposed in this invention.

[0041] Figure 10 This is a test diagram showing the effect of the high dielectric composite sensitive layer composition on the sensor output performance of a flexible triboelectric sensor based on modified conductive fabric, which is proposed in this invention.

[0042] Figure 11 The image shows the basic electrical output performance and mechanical stability test results of a flexible triboelectric sensor based on a modified conductive fabric, according to the fabrication method of the present invention.

[0043] Figure 12 This diagram illustrates the environmental adaptability and basic applications of a flexible triboelectric sensor based on modified conductive fabric, as proposed in this invention. Detailed Implementation

[0044] Reference Figure 1 The present invention proposes a flexible triboelectric sensor based on modified conductive fabric, comprising:

[0045] The flexible encapsulation layer is located at the very bottom of the sensor;

[0046] A modified conductive fabric electrode layer is disposed on the upper surface of a flexible encapsulation layer, comprising a fabric substrate with amino functional groups on its surface and a conductive network anchored to the fabric substrate by amide bonds. The conductive network is composed of carboxylated multi-walled carbon nanotubes and carbon black.

[0047] A high-dielectric composite sensitive layer, covering the upper surface of the modified conductive fabric electrode layer, is composed of an elastomer matrix doped with surface-silanized high-dielectric-constant ceramic particles and graphene.

[0048] In this invention, amino functional groups are introduced onto the surface of a fabric substrate, and a covalent anchoring interface is constructed by their amidation reaction with carboxylated multi-walled carbon nanotubes. Simultaneously, carbon black fills the gaps in the carbon nanotube network to form a point-to-line interwoven conductive pathway, significantly enhancing the bonding strength and deformation resistance between the conductive layer and the flexible substrate. Furthermore, APTES is used to treat CaCu3Ti4O4... 12 Surface silanization modification improves its dispersion and interfacial compatibility in the hydrophobic Ecoflex matrix. Furthermore, it synergistically incorporates graphene sheets to construct discrete microcapacitor units within the insulating matrix, enabling the composite sensing layer to maintain high flexibility while achieving a synergistic improvement in dielectric constant and charge trapping capability. The three-layer structure works in concert to achieve a resistance change rate of less than 5% after 12,000 bending cycles, an open-circuit voltage of 145 V, and a power density of 940.8 mW / m². 2 This solves the technical problems of existing flexible triboelectric sensors, such as the easy detachment of conductive electrodes, the agglomeration of filler in the sensitive layer leading to limited dielectric properties, and poor output stability.

[0049] In this embodiment, the fabric base is one of modal fabric, pure cotton fabric, modal fabric, or Lycra cotton.

[0050] High dielectric constant ceramic particles are BaTiO3, SrTiO3, and CaCu3Ti4O 12 One of them has its surface modified with silane coupling agents APTES or GPTES; the mass fraction of high dielectric constant ceramic particles in the elastomer matrix is ​​4%-15%.

[0051] The mass fraction of graphene in the elastomer matrix is ​​0.5%-2%; the elastomer matrix is ​​one of natural rubber, polydimethylsiloxane PMDS, and Ecoflex silicone rubber.

[0052] Specifically, such as Figure 1As shown, the sensor's overall structure adopts a single-electrode design, consisting of a flexible encapsulation layer, a modified conductive fabric electrode layer, and a high-dielectric composite sensitive layer from bottom to top. The flexible encapsulation layer can be made of medical-grade PU tape to isolate environmental moisture. The modified conductive fabric electrode layer uses amino-rich modal fabric as a framework, with a mixed conductive network of carboxylated multi-walled carbon nanotubes (c-MWCNTs) and carbon black (CB) chemically bonded and physically reinforced by silicone rubber (SR), serving as a charge collection electrode. The high-dielectric composite sensitive layer is attached to the fabric electrode and consists of an organic elastomer (such as Ecoflex) doped with surface-doped copper-calcium titanate (APTES-CCTO) particles and graphene (GR), serving as a functional layer for triboelectric charging and charge trapping.

[0053] Reference Figures 1-12 This invention proposes a method for fabricating a flexible triboelectric sensor based on modified conductive fabric, applicable to any of the aforementioned flexible triboelectric sensors based on modified conductive fabric. The method includes the following steps:

[0054] S1. The fabric substrate is immersed in an aminosilane coupling agent solution for surface amination modification to obtain an amination fabric.

[0055] In this embodiment, the aminosilane coupling agent solution in step S1 is an APTES ethanol solution with a mass fraction of 0.5%-1.5%, the reaction time is 45-60 minutes, and the curing temperature is 40-60℃.

[0056] Specifically, by controlling the APTES concentration to 1.0 wt%, excessive self-polymerization and crosslinking due to too high a concentration or incomplete modification due to too low a concentration was avoided; a 60-minute reaction time ensured sufficient diffusion of hydrolyzed silanol and its condensation with the hydroxyl groups on the cellulose surface; and gentle curing at 50 °C promoted the formation of the Si–O–Si network without damaging the cellulose crystal structure; XPS measurements showed that the surface –NH2 areal density of the fabric reached 4.2 × 10⁻⁶ under these conditions. 15 cm -2 Compared to a 0.5% concentration, this is 2.8 times higher, and the final electrode conductivity stability is 3 times higher.

[0057] Specifically, Figure 2As shown, APTES is first hydrolyzed and condensed, then reacted with hydroxyl groups (-OH) on the fiber surface to introduce abundant active amino (-NH2) sites, thus obtaining a modified fabric (NH2-Fabric). The amino groups on the modified fabric are then amidated by carboxyl multi-walled carbon nanotubes (c-MWCNTs), covalently locking the c-MWCNTs onto the fiber surface. This chemical bonding enhances the adhesion between the c-MWCNTs and the substrate interface, effectively reducing the peeling of the filler from the fabric substrate and improving the stability of the conductive network. Next, zero-dimensional carbon black (CB) particles are used as auxiliary conductive fillers, filling the voids in the micro / nano network constructed by c-MWCNTs. This synergistic effect of 0D CB and 1D c-MWCNTs constructs a more efficient and dense conductive pathway, ensuring the electrode maintains long-term electrical stability under repeated use.

[0058] It's important to note that triboelectric charging (TENG) is essentially the process where charge transfer occurs at the interface when two different materials come into contact and then separate, ultimately leading to the accumulation of static charge on the material surfaces. The dielectric constant ε measures a material's ability to store charge. Under the same contact conditions, materials with higher dielectric constants are better able to retain the surface charge generated by friction, thus reducing charge loss and degradation. Therefore, adjusting the dielectric constant of the material to regulate the surface charge density is an effective way to improve the triboelectric output performance of TENG.

[0059] In designing the high-dielectric composite sensing layer, a composite modification strategy combining high-dielectric ceramic fillers with conductive fillers was adopted, selecting CaCu3Ti4O4 as the filler, which has a high dielectric constant. 12 CCTO powder was used as the main reinforcing filler. To address the interfacial compatibility issue between the hydrophilic inorganic ceramic and the hydrophobic organic elastomer, the CCTO powder was surface-silanized using APTES, as described in the following process. Figure 3 As shown, this modification method introduces an organic molecular layer onto the particle surface, effectively mitigating the agglomeration of CCTO fillers. Building upon this, a small amount of graphene (GR) is introduced as a dopant to further enhance the material's polarization capability. According to percolation theory, the conductive GR sheets dispersed in the insulating Ecoflex matrix act as microelectrodes, isolated from each other by thin polymer layers, thus forming a massive number of "microcapacitors" within the composite material. This microcapacitance effect, synergistic with the high-dielectric CCTO, significantly improves the overall dielectric constant and charge trapping capability of the composite sensitive layer, laying the physical foundation for realizing a high-performance triboelectric tactile sensor.

[0060] S2. Carboxylated multi-walled carbon nanotubes, carbon black, and silicone rubber are added to an organic solvent and mixed evenly to obtain conductive ink.

[0061] In step S2, the mass ratio of carboxylated multi-walled carbon nanotubes, carbon black, and silicone rubber is 2:3:3, and the organic solvent is naphtha; in step S3, the impregnation and curing process is repeated 3 times, the curing temperature is 45-65℃, and the curing time is 40-60 minutes each time; in step S5, the mass fraction of modified ceramic particles is 4%-15%, the mass fraction of graphene is 0.5%-2%, and the elastomer precursor is a 1:1 mixture of Ecoflex A / B components.

[0062] In this embodiment, the mass ratio of carboxylated multi-walled carbon nanotubes, carbon black, and silicone rubber in step S2 is 2:3:3, and naphtha is the organic solvent. By setting this mass ratio, the silicone rubber can fully encapsulate the conductive filler and provide sufficient adhesion. Naphtha, as an organic solvent with a moderate boiling point (60–100 °C), good solubility, and easy volatility, is beneficial for rapid film formation after impregnation. Under this ratio, the viscosity of the conductive ink is 850 mPa·s, which is suitable for the capillary absorption characteristics of fabrics. The resulting electrode peel strength reaches 12.6 N / cm (90° peel test), which is 4.1 times higher than the 1:1:1 ratio, and the resistance drift is <4% after 500 finger presses.

[0063] S3. The aminated fabric is immersed in conductive ink, so that the carboxylated multi-walled carbon nanotubes undergo an amidation reaction with the amino groups and are anchored on the fabric surface. At the same time, carbon black fills the gaps in the carbon nanotube network. After curing, a modified conductive fabric electrode is formed.

[0064] S4. Surface silanization treatment is performed on high dielectric constant ceramic particles to obtain modified ceramic particles.

[0065] In this embodiment, the surface silanization treatment in step S4 involves dispersing high dielectric constant ceramic particles in a 1.0% (w / w) APTES ethanol solution and stirring for 40 minutes, followed by washing and drying.

[0066] S5. Add the modified ceramic particles and graphene to the elastomer precursor and mix them evenly to obtain the composite sensitive layer adhesive.

[0067] S6. Apply the composite sensitive layer adhesive to the upper surface of the modified conductive fabric electrode, and form a high dielectric composite sensitive layer after curing.

[0068] S7. Attach a flexible encapsulation layer to the lower surface of the modified conductive fabric electrode and lead out wires to complete the sensor fabrication.

[0069] Example 1:

[0070] In this embodiment, modal fiber is selected as the fabric substrate; the mass ratio of carboxylated multi-walled carbon nanotubes to carbon black is 2:3; and the high dielectric constant ceramic particles are CaCu3Ti4O. 12Its surface is modified with the silane coupling agent APTES; CaCu3Ti4O 12 The mass fraction of graphene in the elastomer matrix is ​​8%; the mass fraction of graphene in the elastomer matrix is ​​1.5%.

[0071] It should be noted that by selecting modal fiber as the fabric base, its high crystallinity and abundant surface hydroxyl (–OH) density provide sufficient reaction sites for the APTES hydrolysis-condensation reaction, promoting the formation of a uniform and dense amino (–NH2) layer; this structure results in an amino areal density of 4.2 × 10⁻⁶. 15 cm -2 It is about 2.8 times higher than ordinary cotton fabric, thereby improving the grafting density of carboxylated multi-walled carbon nanotubes and the continuity of the conductive network; the inherent low modulus and high elongation at break of modal fiber also endow the device with excellent fit and wearing comfort, thus ensuring the efficiency of chemical modification while supporting the signal stability of the sensor under dynamic bending conditions.

[0072] In this embodiment, the mass ratio of carboxylated multi-walled carbon nanotubes to carbon black is 2:3. By limiting this mass ratio, 1D carboxylated multi-walled carbon nanotubes serve as a long-range electron transport framework, while 0D carbon black acts as a node bridging and void filler, forming a geometrically complementary point-line synergistic conductive network within the fabric pores. At this ratio, the carbon black fully wets the surface of the carbon nanotubes and reduces the interfacial contact resistance, preventing excessive carbon nanotubes from causing entanglement and agglomeration or excessive carbon black from causing high-resistance interparticle contact.

[0073] Specifically, CaCu3Ti4O 12 The mass fraction in the elastomer matrix is ​​8%. This is achieved by using APTES-CaCu3Ti4O... 12 The doping concentration is limited to 8 wt% to ensure that the filler density is sufficient to excite strong interfacial polarization and microcapacitance effect, while avoiding micro-agglomeration caused by local oversaturation.

[0074] Specifically, the mass fraction of graphene in the elastomer matrix is ​​1.5%. By controlling the graphene doping amount to 1.5 wt%, keeping it below the percolation threshold, the graphene sheets in Ecoflex / APTES-CaCu3Ti4O are ensured to be within the range of percolation threshold. 12 The layers are isolated and dispersed within the matrix, with each layer forming an independent microcapacitor unit together with the surrounding dielectric; this structure makes the equivalent dielectric constant ε eff Significant improvements were achieved, with an open-circuit voltage of 145 V (32% higher than the group without graphene), a short-circuit current of 10.5 μA (41% higher), and a power density of 940.8 mW / m². When the graphene content increased to 2.0 wt%, the open-circuit voltage dropped sharply by 18% due to the formation of leakage channels caused by local percolation, verifying that this parameter is the critical point for maximizing the microcapacitance effect without sacrificing insulation.

[0075] Specifically, the elastomer matrix is ​​Ecoflex silicone rubber. By selecting Ecoflex two-component addition-cure silicone rubber as the elastomer matrix, its ultra-high elasticity (Shore A hardness of approximately 0.5 and elongation at break >900%) effectively buffers mechanical impacts and maintains the structural integrity of the sensitive layer under large deformations. Its non-polar surface has a similar surface energy to the APTES modified layer, reducing interfacial tension and promoting uniform filler coating. The curing shrinkage rate is <0.1%, avoiding debonding stress between the sensitive layer and the electrode.

[0076] In this embodiment, the sensor fabrication process is as follows: Figure 4 As shown, the impregnation and curing process in step S3 was repeated three times, with a curing temperature of 50℃ and a curing time of 40 minutes each time. Through three cycles of impregnation and curing, carboxylated multi-walled carbon nanotubes were grafted layer by layer, and carbon black gradually filled the gaps to form a three-dimensional interpenetrating conductive network. The 50℃ / 40 min condition ensured that the amidation reaction was sufficient (FTIR confirmed that the –CO–NH– peak intensity reached saturation) and that the silicone rubber was completely cross-linked, avoiding high-temperature damage to the fibers. This process achieved a conductivity of 0.20 S / m, which is 12 times higher than that of the first cycle and only 2.3% higher than that of the fourth cycle, but the increased thickness led to a 15% decrease in flexibility, and the response time was stabilized at 27.5 ms. In step S5, the mass fraction of modified ceramic particles was 8%, the mass fraction of graphene was 1.5%, and the elastomer precursor was a 1:1 mixture of Ecoflex A / B components.

[0077] Specifically, Figure 5 The working principle of the fabric-based triboelectric sensor FCG-TENG was demonstrated. Figure 6As shown, finite element simulations were performed using COMSOL Multiphysics to demonstrate the evolution of the potential distribution of the device in four stages: contact, separation, complete separation, and proximity. This involved the coupling of contact electrification and electrostatic induction, clearly illustrating the energy conversion process of the FCG-TENG. The sensor operates in single-electrode mode, with the system initially electrically neutral. In this specific triboelectric pairing, the high-dielectric composite sensing layer (CGE composite) acts as the negative triboelectric material, while the Kapton film acts as the positive triboelectric material. Due to the high electron affinity of the CGE composite, electrons transfer from the Kapton surface to the CGE composite surface when the two materials come into contact under external force. Based on the law of charge conservation, a certain amount of positive charge accumulates on the Kapton surface, while an equal amount of negative charge accumulates on the CGE composite surface. Subsequently, when the CGE composite layer separates from the Kapton, their established electrostatic equilibrium is disrupted. The negative charge on the CGE surface can no longer be effectively shielded by the positive charge of the Kapton. In this situation, the CGE surface uses its own electric field to induce a positive charge on the conductive fabric electrode. Simultaneously, free electrons on the fabric electrode flow into the ground through the external circuit to balance the potential difference, generating a transient current. When the two are completely separated, the induced positive charge on the electrode reaches its maximum value, and the system is in electrostatic equilibrium. Conversely, when the Kapton approaches the CGE composite again, the Kapton's positive electric field begins to re-shield the negative charge of the CGE, causing the binding force of the induced positive charge on the electrode to weaken. Free electrons then flow back from the ground to the conductive fabric electrode, forming a reverse current. This continues until the two are in complete contact, the induced charge on the electrode is completely released, and the system completes one power generation cycle. In this periodic contact-separation motion, electrostatic induction drives electrons to flow back and forth between the conductive fabric and the ground, thereby outputting an alternating current signal in the external circuit.

[0078] like Figure 7 The microstructure and structural characterization of the modified conductive fabric electrode layer are shown in the figure. Figure 7 a and Figure 7 In the diagram, b represents the SEM image and EDS element distribution map of the unmodified fabric at different magnifications. Figure 7 c and Figure 7 In the diagram, d represents the SEM images and EDS elemental distribution of NH2-Fabric at different magnifications. Figure 7 e and Figure 7 In the figure, f represents the SEM image and EDS elemental distribution map of the modified conductive fabric electrode (sample) impregnated with CB / c-MWCNTs / SR composite filler. Figure 7In the figure, g represents the FTIR spectra of the unmodified fabric, NH2-Fabric, conductive filler, and the finally obtained modified conductive fabric electrode (sample). Figure 7 h in Figure 7 The magnified spectrum of the region within the red dashed box in g is shown. The shaded area indicates the characteristic peaks of the NH and amide bond bending vibrations belonging to amino groups and the -CO-NH- group. Figure 7 The XRD crystal structure diagrams of the above samples are shown in Figure i.

[0079] Figure 7 Figure c shows the surface morphology of NH2-Fabric obtained after APTES hydrolysis modification. Compared with the unmodified fabric, the morphology has changed slightly. Although the overall fiber structure remains intact, the surface roughness has increased slightly. This roughened surface helps to enhance the interfacial adhesion between the fabric fibers and the conductive filler, while providing more anchoring points for the conductive filler to be loaded on the fabric.

[0080] Figure 7 As shown in image 'e', ​​the fiber surface is completely coated with a dense and uniform composite coating, transforming the original smooth surface into a rough one. This is evident in the high-magnification SEM image. Figure 7 In the ii section of the diagram, it can be clearly observed that 1D tubular c-MWCNTs and 0D granular CBs are intertwined and tightly packed together. This unique bridging structure verifies the design of the cooperative conductive network described above.

[0081] Figure 7 g and Figure 7 FTIR spectral analysis of h in the NH2-Fabric showed that, compared to the original fabric, NH2-Fabric exhibited higher concentrations in the 1550-1650 cm⁻¹ range. -1 A clear characteristic signal of amino groups (-NH2) was observed in the region, directly confirming that APTES had been successfully grafted onto the fiber surface. Further observation of the final prepared modified conductive fabric electrode (sample) revealed that it exhibited characteristics within the 1500-1600 cm⁻¹ region. -1 The region absorption peak is broader and significantly stronger, corresponding to the superposition effect of the amide I and amide II bands of the amide bond (-CO-NH-). This demonstrates that a robust covalent bond interface is formed between c-MWCNTs and NH2-Fabric through an amidation reaction, providing excellent structural stability for the conductive network.

[0082] Figure 7 The XRD pattern of i in the sample shows that, despite the multiple chemical modifications and composite coatings during the preparation process, the diffraction peaks of the final modified conductive fabric electrode (sample) are still highly consistent with those of the original fabric. This indicates that the preparation process can completely preserve the intrinsic crystal structure of the flexible substrate, thereby ensuring that the fabric electrode and the unmodified fabric have the same excellent mechanical properties.

[0083] Figure 8 The microstructure and structure of the high dielectric composite sensitive layer are characterized. Figure 8 In the image, 'a' represents the SEM image of the CCTO / Ecoflex composite film. Figure 8 In the image, b represents the SEM image of the APTES-CCTO / Ecoflex composite film at different magnifications. Figure 8 c and Figure 8 In the figure, d represents the SEM image and EDS elemental distribution map of the APTES-CCTO / GR / Ecoflex composite film. Figure 8 In the figure, 'e' represents a comparison of the FTIR spectra of Ecoflex, APTES-CCTO, Graphene, and the high-dielectric composite sensitive layer (sample). Figure 8 In the figure, f represents the XRD crystal structure of each of the above samples.

[0084] like Figure 8 As shown in a, the cross-section of the unmodified CCTO / Ecoflex composite film exhibits obvious phase separation characteristics, and the hydrophilic inorganic ceramic particles undergo severe aggregation in the hydrophobic organic matrix.

[0085] like Figure 8 As shown in b, the dispersion uniformity of inorganic fillers in the polymer matrix is ​​significantly improved after APTES silanization treatment.

[0086] like Figure 8 As shown in c, layered graphene and particulate APTES-CCTO filler are interwoven and tightly stacked to form a typical 0D-2D hybrid network structure. This special structure helps to form a large number of microcapacitor units inside the insulating matrix, thereby improving the overall dielectric polarization response capability of the material.

[0087] like Figure 8 As shown in e, FTIR spectral analysis shows that APTES-CCTO powder exhibits performance in the low wavenumber region (< 1000 cm⁻¹). -1 The sample exhibits a broad and strong absorption band, attributed to the characteristic vibrations of the metal-oxygen bond in the ceramic lattice. After incorporating the modified filler into the matrix, the infrared spectrum of the final high-dielectric composite sensitive layer (sample) is mainly dominated by the characteristic signal of the Ecoflex matrix. The FTIR curve of the high-dielectric composite sensitive layer (sample) is in high agreement with that of the Ecoflex matrix, with no obvious peak shift or new impurity characteristic peaks. This high degree of spectral consistency indicates that the filler was introduced into the system through physical doping, and the multiphase mixing process did not destroy the chemical framework structure of Ecoflex, thus ensuring the mechanical stability of the device.

[0088] like Figure 8As shown in f, the XRD pattern shows that the high-dielectric composite sensitive layer (sample) fully inherits the body-centered cubic perovskite structure characteristic diffraction peaks of APTES-CCTO, including 2 θ = 34.3° (220) crystal plane, 2 θ = 49.3° (400) crystal plane and 2 θ The (422) crystal plane at 61.4° maintains the same peak position as APTES-CCTO, indicating that the crystal structure of CCTO remained unchanged after recombination. Meanwhile, at 2... θ A broadened amorphous diffuse peak at 11.94° clearly superimposed, belonging to the Ecoflex matrix, confirms that the amorphous structure of the elastomer matrix is ​​preserved. It is noteworthy that, although pure graphene exhibits a similar structure at 2°... θ A sharp (002) crystal plane characteristic diffraction peak exists at 26.4°, but the intensity of this peak is relatively weak in the composite film. This is mainly attributed to the low doping amount of graphene and the coating effect of Ecoflex polymer, which partially masks the diffraction signal. Comprehensive analysis shows that the crystal structure of the functional fillers (CCTO, graphene) remains intact during the preparation process, and a stable physical-chemical coupling is formed between the components, without significant chemical reactions or crystal transformations.

[0089] It should be noted that the conductivity of the electrodes is a key factor determining the internal resistance and charge transfer efficiency of the sensor. First, the conductivity variations of different fabric substrates under the same impregnation conditions were compared. Unmodified fabric and modified fabric NH2-Fabric, each with dimensions of 2.5 cm (L) × 1.5 cm (W) × 1 mm (D), were immersed in a CB / c-MWCNTs / SR composite conductive dispersion. After multiple impregnations and drying, the resistance (R) was measured. The conductivity (σ) of the samples under different impregnation cycles was calculated using the formula σ = L / (R × S), where the cross-sectional area S is defined as S = W × D. For ease of recording, the samples were labeled CM. X @UF and CM X @NF, where “CM” represents a mixed conductive filler of 0D CB and 1D c-MWCNTs, “X” represents the mass ratio of the two, “UF” represents unmodified fabric, and “NF” represents modified fabric NH2-Fabric.

[0090] like Figure 9 As shown, Figure 9 a and Figure 9 In the figure, b represents the conductivity change curves of unmodified and modified fabrics impregnated with different carbon black to carbon nanotube mass ratios as the number of impregnations increases. Figure 9The illustration in b is a photograph of the prepared flexible conductive fabric placed on a green leaf, demonstrating its lightweight and flexibility. Figure 9 In the figure, 'c' represents the effect of modified fabric electrodes prepared with different filler ratios and impregnation times on the output performance of FCG-TENG. Figure 9 The value of 'a' indicates that the conductivity of the unmodified fabric still increases very slowly, and the saturation conductivity remains at a low level of < 0.03 S / m, which is far from meeting the requirements for high-performance electrodes. Figure 9 The value of b indicates that NH2-Fabric exhibits a significant increase in conductivity, with the conductivity of the modified fabric showing a steep upward trend as the number of impregnation cycles increases, rapidly exceeding the percolation threshold and stabilizing at 0.18–0.22 S / m. This result strongly demonstrates the necessity of surface chemical modification in constructing low-impedance, high-stability conductive networks. Figure 9 The 'c' in the figure represents the effect of different CB / c-MWCNT mass ratios and impregnation cycle numbers on the output characteristics of FCG-TENG. The number of impregnation cycles directly determines the loading and distribution density of conductive filler on the fiber surface. In the low impregnation cycle stage (1-2 times), although a certain amount of conductive filler adheres to the fabric surface, a continuous conductive path has not yet been formed, resulting in high electrode internal resistance and hindering the effective transfer of induced charges. When the number of impregnation cycles increases to 3, the output performance shows a significant jump and reaches its peak. This is because after the filler loading exceeds the percolation threshold, the carbon black particles effectively fill the gaps formed by the overlapping of carbon nanotubes, and the two conductive particles form a tight physical contact, successfully constructing a three-dimensional interconnected dense conductive network. After entering the excessive impregnation stage (>3 times), the sensor performance does not continue to improve; the fabric conductive network has become saturated, and the excess filler has a negligible gain on conductivity.

[0091] CM 2:3 The ratio of 0D CB particles consistently outperforms other groups, an advantage stemming from the unique geometrical complementarity between 0D CB particles and 1D c-MWCNTs. The high aspect ratio 1D c-MWCNTs form the core framework of the conductive network, providing channels for long-range, rapid electron transport; the small-sized 0D CB particles act as "connecting bridges" and gap fillers, embedding themselves in the gaps formed by the overlapping c-MWCNTs, optimizing network continuity. If the c-MWCNT content is too high, entanglement and aggregation can easily occur, leading to increased porosity and disrupting the integrity of the conductive pathway; if the CB content is too high, the lack of a long-range conductive framework forces electrons to frequently cross particle interfaces, causing a sharp increase in contact resistance. In contrast, CM... 2:3 Under the current ratio, the two can achieve synergistic effect. CB effectively fills the blind area of ​​the c-MWCNTs skeleton, increases the node density of the conductive path, and constructs a perfect synergistic network of "point-line" interweaving.

[0092] It should be noted that the surface charge density of the friction layer is related to the dielectric constant of the material (ε). r Closely related to this, excellent dielectric constant and charge trapping ability can significantly enhance the internal polarization effect of the device, thereby improving output power. Introducing CCTO ceramic filler with high dielectric constant is an effective strategy to improve the triboelectric properties of the Ecoflex matrix.

[0093] Specifically, the high dielectric constant ceramic particles are CaCu3Ti4O 12 Its surface is modified with the silane coupling agent APTES. This is achieved by using APTES to modify the surface of CaCu3Ti4O. 12 Surface silanization is performed, causing the silanol groups generated by hydrolysis to undergo a condensation reaction with the metal hydroxyl groups on the particle surface, forming Si-OM (M = Ca / Cu / Ti) covalent bonds. The exposed amino groups then form hydrogen bonds and dipole interactions with the Ecoflex molecular chains, thereby significantly reducing the interfacial tension between the filler and the matrix. This synergistic effect greatly improves the uniformity of filler dispersion in the elastomer.

[0094] like Figure 10 As shown, Figure 10 In the figure, a, b, and c are the output performance curves of the device after doping with different mass fractions of CCTO. As the CCTO doping amount gradually increases, the open-circuit voltage (VOC) and short-circuit current (I) of the device increase. SC and short-circuit charge (Q) SC The performance enhancement effect showed a trend of first increasing and then decreasing, reaching its optimal peak at a doping concentration of 8 wt%. This performance enhancement effect is due to the introduction of CCTO into the composite material system, which can significantly strengthen the internal dielectric polarization, increase the dielectric constant of the matrix, and thus effectively improve the surface charge induction density at the triboelectric interface, optimizing the device output performance. When the doping concentration of unmodified CCTO exceeds 8 wt%, the device output performance begins to decline. This is mainly because inorganic CCTO particles are prone to agglomeration in the organic matrix, resulting in an increase in interface defects inside the composite film. This not only damages the structural integrity of the dielectric layer but also exacerbates charge dissipation losses, ultimately leading to a decrease in device output performance.

[0095] To overcome the problem of poor interfacial compatibility, APTES-modified CCTO powder was introduced. Figure 10In the samples d, e, and f, at the same optimal doping amount (8 wt%), the open-circuit voltage of the APTES-CCTO sample increased to 110 V, an increase of approximately 12% compared to the unmodified sample. APTES acts as a "molecular bridge" between the inorganic and organic interfaces, effectively suppressing the agglomeration of inorganic fillers and improving their dispersion uniformity in the matrix, thereby significantly reducing interfacial voids. Secondly, the tight interfacial bonding enhances the interfacial polarization effect, and the polar groups introduced by APTES provide additional charge trapping sites, effectively reducing charge loss during polarization. When the loading of APTES-CCTO further increases beyond 8 wt%, local agglomeration inevitably occurs due to filler oversaturation, increasing leakage current channels and causing the induced charge to be unable to be maintained. On the other hand, the high concentration of rigid ceramic particles significantly increases the Young's modulus of the composite film, reduces the flexibility and conformability of the material, and thus reduces the effective micro-contact area during friction, weakening the contact charging efficiency.

[0096] Building on this, in order to further enhance the sensor’s output capability, highly conductive two-dimensional graphene (GR) was introduced into the optimal 8wt% APTES-CCTO / Ecoflex system to construct a micro-nano collaborative “microcapacitor” network. Figure 10 The values ​​of g, h, and i in the figure reveal the nonlinear regulation of graphene content on the output performance of FCG-TENG. When the GR content increases from 0 to 1.5 wt%, the device performance experiences a second leap. OC and I SC The maximum values ​​reached were 145 V and 10.5 μA, respectively. This phenomenon can be explained by the microcapacitor theory: the conductive graphene sheets dispersed in the insulating matrix can act as microelectrodes, and the APTES-CCTO / Ecoflex composite system between the sheets acts as a microdielectric layer. Together, they constitute a large number of discrete microcapacitor units. As the graphene concentration increases, the number of microcapacitors inside the matrix also increases, which can effectively improve the equivalent dielectric constant ε of the composite material. eff Furthermore, the GR content can enhance the system's charge trapping ability through interfacial polarization, thereby increasing the surface charge density at the triboelectric interface and ultimately optimizing the sensor's output performance. However, when the GR content further increases to 2.0 wt% or higher, the output performance decreases. When the GR content increases to 2.0 wt%, especially 2.5 wt%, the dielectric loss increases, the material crosses the percolation threshold, and the originally isolated graphene sheets begin to overlap, forming a continuous conductive path inside the composite film. The static charge generated by friction no longer accumulates on the surface but is rapidly dissipated through internal leakage current.

[0097] Figure 11This refers to the basic electrical output performance and mechanical stability of the FCG-TENG. Figure 11 a- Figure 11 In the figure, c represents the effect of different contact pressures (10-35 kPa) on the output performance of FCG-TENG at a fixed frequency. Figure 11 d- Figure 11 In the figure, f represents the effect of different operating frequencies (0.5-4.0 Hz) on the output performance of FCG-TENG under a fixed pressure of 30 kPa. Figure 11 In this context, 'h' represents the sensor's response time characteristic test. Figure 11 In the figure, g represents the long-term cyclic stability test of FCG-TENG over 4000 seconds. The illustration shows magnified waveform details at the initial, middle, and final stages (100 s, 2000 s, and 3900 s), demonstrating excellent durability.

[0098] Figure 11 a- Figure 11 Figure c illustrates the variations in open-circuit voltage, short-circuit current, and transferred charge of the FCG-TENG under a fixed 3Hz frequency test condition, depending on the external impact pressure (10-35 kPa). The results show that all electrical output signals exhibit a significant positive correlation with the applied pressure. When the pressure increases from 10 kPa to 35 kPa, V... OC The pressure dependence, increasing approximately linearly from 70V to 160V, is primarily attributed to the change in effective contact area. Due to the micron-scale roughness on the surface of the sensitive layer, only partial point contact occurs at low pressures. As the pressure increases, the flexible Ecoflex substrate undergoes elastic deformation, resulting in a tighter microscopic contact between the friction layer and the Kapton film, significantly increasing the effective contact area and thus inducing more triboelectric charge.

[0099] Operating frequency is another key factor affecting the dynamic performance of a sensor. Figure 11 d- Figure 11 The value f in the figure records the output characteristics of FCG-TENG in the frequency range of 0.5 Hz to 4.0 Hz. It is worth noting that the sensor's V... OC and Q SC It remained relatively stable at different frequencies, without exhibiting significant fluctuations. This experimental phenomenon is highly consistent with the fundamental theoretical model of triboelectric nanogenerators, where the open-circuit voltage and transferred charge essentially depend on the effective charge density σ of the triboelectric surface. eff The maximum separation distance (x) and the maximum separation distance (x) are both parameters that do not change with frequency in the fixed-stroke test mode. In stark contrast, I... SCThe frequency increases as the frequency increases because short-circuit current is defined as the rate of change of charge over time. Higher operating frequencies mean shorter contact-separation cycles and faster transfer rates of induced charge between electrodes, resulting in an increase in the amplitude of instantaneous current. This significant frequency dependence gives FCG-TENG the potential to monitor dynamic mechanical stimulation.

[0100] Mechanical durability is a core indicator for evaluating the long-term operational capability of flexible wearable sensors. To assess the sensor's durability and reliability, the FCG-TENG underwent a cumulative 12,000 continuous contact-separation cycle test under conditions of 30 kPa / 3 Hz. The relevant test results are as follows: Figure 11 As shown in g in the figure. Throughout the entire test cycle, the output voltage remained stable, with no significant attenuation or fluctuation observed. For real-time monitoring applications, the sensor's response speed is crucial. Figure 11 The 'h' in the figure illustrates the response waveform of FCG-TENG to transient mechanical shock. By analyzing the rising edge of the signal, the response time of FCG-TENG was measured to be only 27.5 ms. This millisecond-level fast response capability is due to the highly conductive fabric electrodes and the efficient charge transport of the modified sensitive layer, ensuring that the sensor can quickly capture instantaneous changes in human movement or external vibration.

[0101] Figure 12 This section focuses on optimizing the output performance, environmental stability, and application demonstration of the FCG-TENG. Figure 12 In the figure, 'a' represents the comparison of the output voltage when FCG-TENG is in contact with materials of different electron affinity potentials. Figure 12 b- Figure 12 In this context, 'c' represents the environmental adaptability test of FCG-TENG. Figure 12 In the figure, d represents the charging curve of FCG-TENG for capacitors of different capacitance values; Figure 12 The 'e' in the diagram is used to evaluate the output power and drive the rectifier circuit schematic of electronic devices. Figure 12 In this context, f represents the curves showing the changes in output power density, output voltage, and current as a function of load resistance. Figure 12 The 'g' in the figure represents a demonstration of the self-powered application of FCG-TENG: Figure 12 In the text, the i in g acts as a wearable power source to collect energy from finger taps; Figure 12 The g in the ii drive commercial electronic timer; Figure 12 The iii lights in h form an LED array that spells "AHU".

[0102] To comprehensively evaluate the versatility of FCG-TENG in real-world scenarios, its output performance when in contact with common everyday materials was first tested. For example... Figure 12As shown in Figure a, when FCG-TENG comes into contact with materials of different electron affinities, including polymers (PTFE, PET, Kapton), natural fibers (Cotton), and metals (Copper), it can generate stable pulsed electrical signals. This broad material compatibility can effectively utilize various contact interfaces that are ubiquitous in the environment to achieve efficient energy harvesting.

[0103] Considering that wearable electronic devices typically need to adapt to complex and changing real-world working environments, especially scenarios involving fluctuations in body temperature, high summer temperatures, or heat generation from the electronic device itself, the thermal and humidity stability of FCG-TENG were systematically evaluated. For example... Figure 12 As shown in b, the device output voltage remains highly stable over a wide temperature range of 25 °C to 75 °C, which directly demonstrates the material's excellent thermal resistance.

[0104] like Figure 12 As shown in Figure c, the device's moisture resistance was tested. The sensor was placed in environments with different relative humidity levels (35%-85% RH) and left to stand for 48 hours before electrical tests. The results showed that the FCG-TENG exhibited extremely high stability within the 35% to 75% RH range. When the humidity further increased to 85% RH, although the output voltage showed a slight decrease, the device retained approximately 95% of its initial performance without structural failure. This is mainly because the encapsulation layer introduced at the bottom of the fabric electrode creates a dense hydrophobic barrier, effectively blocking the penetration of most environmental water molecules into the electrode interface and suppressing leakage current channels, thus ensuring the device's reliability in all-weather environments.

[0105] Figure 12 Figure d shows the charging curves of FCG-TENG for capacitors of different capacities (2.2-10.0 μF). The 2.2 μF capacitor can be charged to above 2 V in only about 15 seconds, demonstrating excellent instantaneous charging capability.

[0106] Figure 12 As shown in e, a rectifier circuit is constructed to verify the device's ability to drive electronic loads and store energy in practice.

[0107] like Figure 12 As shown in f, in order to quantify the power output level of the device, the variation of power density, voltage, and current with external load is studied, based on the power density formula Pd = I 2 R / A, where R is the load resistance and A is the effective friction area. When the external load resistance increases to 50 MΩ, the instantaneous peak power density reaches 940.8 mW / m². 2 Its performance surpasses that of most recently reported sensors.

[0108] like Figure 12 As shown in g, a 6×6 cm sample was prepared. 2 The sensor, activated by a human hand striking it, successfully powered a commercial electronic timer and simultaneously illuminated 52 series-connected green LEDs. This result directly demonstrates the practical application capabilities of FCG-TENG in driving wearable electronic products.

[0109] The present invention proposes an intelligent tactile system based on any of the above-mentioned flexible triboelectric sensors, comprising:

[0110] The signal acquisition module is used to acquire the triboelectric signal generated by the contacting object from the sensor;

[0111] The feature extraction module, connected to the signal acquisition module, is used to extract amplitude and waveform feature parameters from the triboelectric signal.

[0112] The recognition and classification module is connected to the feature extraction module and has a built-in deep learning algorithm model. It is used to identify the material, texture or shape of an object based on feature parameters and output the recognition results.

[0113] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A flexible triboelectric sensor based on modified conductive fabric, characterized in that, include: The flexible encapsulation layer is located at the bottom of the sensor; A modified conductive fabric electrode layer is disposed on the upper surface of the flexible encapsulation layer, comprising a fabric substrate with amino functional groups on its surface and a conductive network anchored on the fabric substrate by amide bonds, the conductive network being composed of carboxylated multi-walled carbon nanotubes and carbon black. A high-dielectric composite sensitive layer, covering the upper surface of the modified conductive fabric electrode layer, is composed of an elastomer matrix doped with surface-silanized high-dielectric-constant ceramic particles and graphene. The fabric base is one of modal fabric, pure cotton fabric, modal fabric, and Lycra cotton; The mass ratio of the carboxylated multi-walled carbon nanotubes to carbon black is 2:

3.

2. The flexible triboelectric sensor based on modified conductive fabric according to claim 1, characterized in that, The high dielectric constant ceramic particles are BaTiO3, SrTiO3, and CaCu3Ti4O3. 12 One of them, whose surface is modified with silane coupling agent APTES or GPTES; the high dielectric constant ceramic particles in the elastomer matrix have a mass fraction of 4%-15%.

3. The flexible triboelectric sensor based on modified conductive fabric according to claim 1, characterized in that, The graphene in the elastomer matrix has a mass fraction of 0.5%-2%; the elastomer matrix is ​​one of natural rubber, polydimethylsiloxane PMDS, and Ecoflex silicone rubber.

4. A method for fabricating a flexible triboelectric sensor based on modified conductive fabric, applied to the flexible triboelectric sensor based on modified conductive fabric as described in any one of claims 1-3, characterized in that, The method includes the following steps: S1. The fabric substrate is immersed in an aminosilane coupling agent solution for surface amination modification to obtain an amination fabric. S2. Carboxylated multi-walled carbon nanotubes, carbon black, and silicone rubber are added to an organic solvent and mixed evenly to obtain conductive ink; S3. The aminated fabric is immersed in the conductive ink, so that the carboxylated multi-walled carbon nanotubes undergo an amidation reaction with the amino group and are anchored on the fabric surface. At the same time, carbon black fills the gaps in the carbon nanotube network. After curing, a modified conductive fabric electrode is formed. S4. Surface silanization treatment is performed on high dielectric constant ceramic particles to obtain modified ceramic particles; S5. The modified ceramic particles and graphene are added to the elastomer precursor and mixed evenly to obtain a composite sensitive layer adhesive solution. S6. The composite sensitive layer adhesive is applied to the upper surface of the modified conductive fabric electrode and cured to form a high dielectric composite sensitive layer. S7. A flexible encapsulation layer is attached to the lower surface of the modified conductive fabric electrode and wires are led out to complete the sensor fabrication. In step S1, the aminosilane coupling agent solution is an APTES ethanol solution with a mass fraction of 0.5%-1.5%, the reaction time is 45-60 minutes, and the curing temperature is 40-60℃.

5. The method for preparing a flexible triboelectric sensor based on modified conductive fabric according to claim 4, characterized in that, In step S2, the mass ratio of carboxylated multi-walled carbon nanotubes, carbon black, and silicone rubber is 2:3:3, and the organic solvent is naphtha; in step S3, the impregnation and curing process is repeated 3 times, the curing temperature is 45-65℃, and the curing time is 40-60 minutes each time; in step S5, the mass fraction of modified ceramic particles is 4%-15%, the mass fraction of graphene is 0.5%-2%, and the elastomer precursor is a 1:1 mixture of Ecoflex A / B components.

6. The method for preparing a flexible triboelectric sensor based on modified conductive fabric according to claim 4, characterized in that, In step S4, the surface silanization treatment involves dispersing high dielectric constant ceramic particles in a 1.0% (w / w) APTES ethanol solution and stirring for 40 minutes, followed by washing and drying.

7. A smart tactile system based on the flexible triboelectric sensor according to any one of claims 1 to 3, characterized in that, include: The signal acquisition module is used to acquire the triboelectric signal generated by the contacting object from the sensor; The feature extraction module, connected to the signal acquisition module, is used to extract amplitude and waveform feature parameters from the triboelectric signal. The identification and classification module is connected to the feature extraction module and has a built-in deep learning algorithm model. It is used to identify the material, texture or shape of an object based on the feature parameters and output the identification results.

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