Multilayer coupled triboelectric nanogenerator proximity sense sensor and non-contact following system

Abstract

The present application relates to a multilayer coupling friction nanogenerator proximity sensor and a non-contact following system, the sensor comprising, from bottom to top, a charge collection layer, a charge blocking layer, a charge capture layer and a charge generation layer arranged in sequence; wherein the surface of the charge generation layer has a threaded microstructure; the charge collection layer contains carbon black in an Ecoflex matrix; the charge blocking layer contains calcium copper titanate CCTO in an Ecoflex matrix; the charge capture layer contains MXene in an Ecoflex matrix; and the charge generation layer contains cobalt-nanoporous carbon Co-NPC in an Ecoflex matrix. The present application introduces functional materials such as Co-NPC, MXene and CCTO in different functional layers, realizes the synergistic regulation of the charge generation, capture, blocking and collection processes, and enables the device to obtain a higher output voltage and good response sensitivity under the condition of a smaller effective area; a regular spiral microstructure is also constructed to further improve the sensing performance; in addition, the non-contact following system of the present application can realize one-dimensional and two-dimensional motion following.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology, specifically relating to a multilayer coupled triboelectric nanogenerator proximity sensor and a non-contact following system. Background Technology

[0002] With the rapid development of humanoid robots and artificial intelligence (AI), acquiring rich and diverse external physical information has become extremely important for improving the level of intelligent applications in human-computer interaction. Meanwhile, due to the massive number of sensors to be used in the future, the large size, heavy weight, and short lifespan of traditional batteries pose a problem in terms of energy supply for these sensors. Energy harvesting is a promising alternative to revolutionize sensor technology. Among various energy harvesting methods, such as piezoelectricity, pyroelectricity, photoelectricity, and triboelectricity, triboelectric nanogenerators (TENGs) have attracted widespread attention for effectively harvesting mechanical energy from the environment through the coupling effect of contact electrification and electrostatic induction. In the low-frequency range, TENGs, as a supplement to electromagnetic generators, have advantages such as diverse material selection, cost-effectiveness, and high low-frequency energy conversion efficiency. TENGs can not only serve as energy sources but also capture response electrical signals generated by contact and non-contact motion between objects and them, enabling self-powered sensing operations. Significant progress has been made in the development of contact-type TENG materials using various triboelectric materials. For example, Chai et al. combined ferroelectric composite materials with conductive layers to develop a high-output TENG by improving the dielectric constant, charge trapping effect, and ferroelectric polarization intensity; Wang et al. reported using glass fiber fabric as a friction material and inorganic ferroelectric thin film as a dielectric layer. However, the contact operation of TENGs heavily depends on continuous contact and separation processes, leading to device wear, performance degradation, and shortened lifespan.

[0003] Another approach utilizes TENG sensors operating in non-contact mode. Within a certain distance, the movement of a charged object generates a response electrical signal through electrostatic induction in free space, offering a favorable solution to mitigate the harmful effects of repeated friction. However, research on non-contact TENG sensors is still in its early stages, as the output power is proportional to the square of the charge density, and increasing the triboelectric charge density remains a challenge.

[0004] The output performance of current non-contact TENG sensors is limited by the dynamic balance between charge generation and stability between key components. For example, Zhou et al. used a polydimethylsiloxane (PDMS) dielectric layer to generate charge and a biogel electrode layer to collect charge, achieving an output voltage of 5 mV at a separation distance of 1 cm; Anaya et al. used aluminum foil (7 × 3.6 cm) to achieve the same result. 2A pre-charged negative PDMS film was added to the topology for charge generation, thereby achieving an output voltage of 1.3 V at 1 cm; Chou et al. used bismuth selenide Bi2Se3 / silicone rubber nanocomposite to fabricate a topological insulator (size 5×5 cm). 2 Charge generation was achieved using a graphite-like fabric for charge trapping, resulting in a high output voltage of 94 V at 1 cm. While progress has been made, current work focuses solely on the generation and trapping of triboelectric charges, thus limiting the reported maximum output voltage to tens of volts at 1 cm. Therefore, further dynamic balancing of charge handling aspects (such as charge blocking and collection) beyond charge generation and trapping is crucial for improving non-contact sensing performance.

[0005] Regarding the manufacturing methods for non-contact TENG sensors, there are already methods such as casting, assembly coating, and electrospinning. Casting methods result in long mold development cycles, cumbersome processes, and material waste, making it difficult to produce finely designed sensors. Assembly methods are crude and cumbersome. Coating and electrospinning methods are difficult to fabricate structured devices. In contrast, ink-to-ink technology shows great promise due to its additive manufacturing concept with controllable precision, enabling the construction of multiple functional components in non-contact TENG sensors. Designing and optimizing ink formulations through the combination of functional fillers and polymer matrices is crucial; these formulations should possess good printability, such as appropriate viscosity, sufficient adhesion, rapid diffusion, and different properties suitable for various charge handling roles. Regarding polymer materials, Ecoflex, with its high electronegativity, flexibility, tensile strength, and biocompatibility, is widely chosen for developing high-performance non-contact TENG sensors. However, its inherent low viscosity and rapid curing characteristics pose challenges for its application in printable slurries. Existing technologies have attempted to address this issue. For example, Yuan et al. prepared an ink by adding silver flake filler, Ecoflex, and a crosslinking agent to a methyl isobutyl ketone solvent and printed it onto a PDMS substrate. After solvent evaporation, a silver / Ecoflex thin-film sensor was obtained. The rapid curing problem of Ecoflex was solved by adding a low-volatility solvent. Similarly, Zhang et al. prepared a 30-nanometer silica / Ecoflex composite ink and realized a sensor with an integrated multi-component structure using a 3D ink printer. This pioneering work verified the feasibility of manufacturing devices by directly printing functional electronic inks based on Ecoflex. However, the types of inks prepared were limited, and the printed device structure was simple, which could not meet the requirements for developing high-performance non-contact TENG sensors with complex functional layers. Summary of the Invention

[0006] Based on the aforementioned shortcomings and deficiencies in the prior art, one of the objectives of this invention is to at least solve one or more of the aforementioned problems in the prior art. In other words, one of the objectives of this invention is to provide a multilayer coupled triboelectric nanogenerator proximity sensor and non-contact following system that meets one or more of the aforementioned requirements.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A multilayer coupled triboelectric nanogenerator proximity sensor includes a charge collection layer, a charge blocking layer, a charge trapping layer and a charge generation layer stacked sequentially from bottom to top; wherein the surface of the charge generation layer has a threaded microstructure. The charge collection layer is an Ecoflex matrix containing carbon black; The charge blocking layer is an Ecoflex matrix containing calcium copper titanate (CCTO). The charge trapping layer is an Ecoflex matrix containing MXene; The charge generation layer is a cobalt-nanoporous carbon (Co-NPC) matrix in the Ecoflex matrix.

[0008] As a preferred embodiment, the number of turns in the threaded microstructure is 30 to 45.

[0009] As a preferred option, the proportion of carbon black in the Ecoflex matrix is ​​2 to 4 wt% for the charge collection layer.

[0010] As a preferred option, the proportion of CCTO in the Ecoflex matrix is ​​20–40 wt% for the charge blocking layer.

[0011] As a preferred option, for the charge trapping layer, the proportion of MXene in the Ecoflex matrix is ​​5 to 7 wt%.

[0012] As a preferred option, the proportion of Co-NPC in the Ecoflex matrix is ​​1 to 3 wt% for the charge generation layer.

[0013] As a preferred embodiment, the thickness ratio of the charge collection layer, charge blocking layer, charge trapping layer and charge generation layer is 1:(1~1.5):(4.5~5.5):(2.5~3.5), and the total thickness is 1~2 mm.

[0014] As a preferred embodiment, the fabrication method of the multilayer coupled triboelectric nanogenerator proximity sensor includes the following steps: (1) Ecoflex / carbon black paste is printed onto the printing substrate by direct ink writing, and a charge collection layer is obtained after curing; (2) Ecoflex / CCTO paste is printed onto the charge collection layer by direct ink writing, and a charge blocking layer is obtained after curing; (3) Ecoflex / MXene paste is printed onto the charge blocking layer by ink direct writing, and a charge trapping layer is obtained after curing; (4) The Ecoflex / Co-NPC paste is printed onto the charge trapping layer by direct ink writing, and the charge generation layer is obtained after curing.

[0015] As a preferred embodiment, the curing temperature is 50–70°C and the curing time is at least 6 hours.

[0016] The present invention also provides a non-contact following system, including a movable platform and a multilayer coupled triboelectric nanogenerator proximity sensor as described in any of the preceding embodiments, mounted on the movable platform; In one-dimensional motion tracking mode, the proximity sensor maintains a fixed distance from the target object during motion tracking. Alternatively, in two-dimensional motion following mode, a proximity sensor array can be used to achieve motion following between the movable platform and the target object while maintaining a fixed distance.

[0017] Compared with the prior art, the beneficial effects of this invention are: (1) This invention effectively suppresses charge leakage and self-discharge phenomena from the material and structural levels by introducing a high-dielectric charge blocking layer between the charge trapping layer and the charge collection layer and combining it with the synergistic design of the charge trapping layer, thereby improving the charge retention capability and output stability. At the same time, by introducing functional materials such as Co-NPC, MXene and CCTO into different functional layers, the synergistic control of charge generation, trapping, blocking and collection processes is realized, so that the device can obtain a high output voltage and good response sensitivity under the condition of a small effective area. (2) By constructing a regular spiral microstructure on the top layer of the sensor device, the present invention significantly enhances the local electric field distribution and non-contact electrostatic induction intensity, thereby further improving the sensing performance; (3) The sensor device of the present invention is made of flexible elastomer materials such as Ecoflex. The overall structure is lightweight, flexible and stretchable, which is convenient for integration with flexible electronic systems, wearable devices and robot surfaces. At the same time, individual device units can be flexibly assembled into sensor arrays to realize real-time identification and tracking of one-dimensional and two-dimensional motion trajectories of target objects. It has broad engineering application prospects in non-contact motion perception, human-computer interaction, robot environmental perception and indoor activity monitoring. Attached Figure Description

[0018] Figure 1The design, fabrication, and mechanism of the multilayer coupled triboelectric nanogenerator proximity sensor according to embodiments of the present invention are as follows: (a) Schematic diagram of layer-by-layer fabrication using Ecoflex-based ink slurries of different compositions via ink direct writing technology; (b) Schematic diagram of surface structure and function of each layer; (c) Microscopic photograph of the top view of the spiral surface microstructure; (d) Microscopic photograph of the corresponding cross-section; (e) Schematic diagram of almost no charge transfer between PTFE and pure Ecoflex; (f) Schematic diagram of band shift after the introduction of the Co-NPC / Ecoflex charge generation layer; (g) Schematic diagram of further band shift caused by the MXene / Ecoflex charge trapping layer; (h) Schematic diagram of the rapid band change caused by the CCTO / Ecoflex charge blocking layer; (i–l) Flexible display of the 3×3 array lightweight sensing patch: (i) photograph of the actual object; (j) photograph of the twisted object; (k) photograph of the stretched object; (l) photograph of the folded object. Figure 2 Morphology and composition characterization of key functional layers in embodiments of the present invention: SEM images and XRD analysis diagrams of (a) carbon black / Ecoflex, (b) CCTO / Ecoflex, (c) MXene / Ecoflex and (d) Co-NPC / Ecoflex; Figure 3 The embodiments of this invention optimize the microstructure of triboelectric surfaces through simulation and experimentation: (a) Simulation and optical micrographs of the COMSOL potential distribution of square ring and spiral structures; (b) Measured comparison of the output voltage of non-contact TENGs with different surface microstructures (size ≈ 2.5 cm × 2.5 cm, distance ≈ 1 cm); (c) Schematic diagram of the synergistic sensing region of edge field effect and electrostatic induction in the spiral structure; (d) Changes in the spacing between spiral walls when the number of spiral turns within a fixed area; (e) Measured results of the output voltage of a self-powered non-contact TENG varying with the number of spiral turns; (f) COMSOL simulation results of potential distribution of spiral structure at different distances, (g) Comparison of output voltage of non-contact TENG with different layer combinations (carbon black / Ecoflex; Co-NPC / Ecoflex-carbon black / Ecoflex; Co-NPC / Ecoflex-MXene / Ecoflex-carbon black / Ecoflex; Co-NPC / Ecoflex-MXene / Ecoflex-CCTO / Ecoflex-carbon black / Ecoflex; and Co-NPC / Ecoflex-MXene / Ecoflex-CCTO / Ecoflex-carbon black / Ecoflex with microstructure); Figure 4The following is a comprehensive sensing performance evaluation of the multilayer coupled triboelectric nanogenerator proximity sensor according to an embodiment of the present invention: (a) Schematic diagram of the corona discharge system for unipolar charge injection, (b) Comparison of the surface potential enhancement effects of contact electrification and corona discharge, (c) Potential decay curve over time, (d) Output voltage variation at different distances, (e) Transfer charge variation at different distances, (f) Current variation at different distances, (g) Output voltage under different humidity conditions, (h) Voltage and current variations under different loads, (i) Peak power under different loads, (j) Current amplification management circuit, (k) Large-area TENG illuminating array LEDs, (l) Output voltage measured for different sensing materials; Figure 5 The following is a demonstration of robot motion following based on a multilayer coupled triboelectric nanogenerator proximity sensor array according to an embodiment of the present invention: (a) working principle of one-dimensional non-contact motion recognition, (b) photograph of one-dimensional motion following experimental device, (c) output voltage and velocity signal graphs collected in real time during one-dimensional motion following, (d) working principle of two-dimensional non-contact motion recognition, (e) photograph of two-dimensional motion following experimental device, (f) schematic diagram of different Greek letter-shaped motion trajectories used for testing, (g) 6-channel voltage signals collected synchronously in real time during different Greek letter-shaped motion processes, (h) electrostatic signal response measured for π-shaped motion trajectory, (i) flowchart of motion trajectory classification machine learning algorithm based on convolutional neural network, and (j) confusion matrix diagram of verification results. Detailed Implementation

[0019] The following provides a detailed description of the multilayer coupled triboelectric nanogenerator proximity sensor and non-contact following system of the present invention.

[0020] The multilayer coupled triboelectric nanogenerator proximity sensor of the present invention consists of four core functional layers, which are as follows from bottom to top: The bottom layer is a carbon black / Ecoflex charge collection layer. Carbon black particles are uniformly dispersed in the Ecoflex matrix to form a continuous and low internal resistance conductive path with excellent conductivity, which can quickly and efficiently transfer the captured charge. The middle lower layer is a CCTO / Ecoflex charge blocking layer. Calcium copper titanate (CCTO) has a high dielectric constant and a stable crystal structure, which can effectively suppress charge self-discharge and significantly improve the long-term stability and durability of the sensor. The upper middle layer is an MXene / Ecoflex charge trapping layer. MXene, as a two-dimensional layered material, is rich in -O and -F functional groups, which not only enhances the electronegativity of Ecoflex, but also forms a microcapacitor structure to efficiently adsorb and stably store charges. The top layer is a Co-NPC / Ecoflex charge generation layer. Cobalt-nanoporous carbon Co-NPC has a high specific surface area and an optimized spiral microstructure with 30 to 45 turns, preferably 45 turns, which greatly improves the charge generation efficiency and electrostatic induction effect, and its performance is better than that of traditional square structures. The four functional layers of this invention are integrally formed using ink direct writing technology, and the whole structure is highly flexible and can withstand mechanical deformations such as bending, stretching, and twisting. The structure is compact and highly coordinated.

[0021] The aforementioned cobalt-nanoporous carbon (Co-NPC) material was prepared using zeolite imidazole framework materials as precursors via a one-step thermal carbonization process. By controlling the carbonization conditions, a balance was achieved between the degree of graphitization, conductivity, and structural stability. The cobalt-based nanoporous carbon (Co-NPC) material was further composited with a flexible polymer matrix to form a charge-generating functional layer, enhancing triboelectric charging capability and charge accumulation. Simultaneously, high-dielectric-constant functional fillers were introduced into the flexible polymer matrix to form a high-dielectric composite material layer, enhancing the system's polarization capability and improving charge storage and blocking effects. The functional composite materials were constructed layer by layer in a predetermined sequence and cured to ultimately form a multilayer integrated flexible device structure with synergistic effects of charge generation, capture, blocking, and collection.

[0022] The functional material ratio optimization and device geometry design of this invention significantly improve the output performance of a non-contact triboelectric nanogenerator proximity sensor by optimizing the functional material ratio and device geometry. Specifically, in the charge generation layer, the optimal doping ratio of cobalt-based nanoporous carbon (Co-NPC) material in the Ecoflex matrix is ​​1–3 wt%, preferably 2 wt%, ensuring dielectric enhancement while preventing charge leakage. In the charge blocking layer, the high dielectric constant filler CCTO is doped in the Ecoflex matrix at a ratio of 20–40 wt%, with an optimal doping ratio of 30 wt%, effectively enhancing polarization and suppressing charge self-discharge. In the charge trapping layer, MXene is doped in the Ecoflex matrix at a ratio of 5–7 wt%, with an optimal doping ratio of 6 wt%. In the charge collection layer, carbon black is doped in the Ecoflex matrix at a ratio of 2–4 wt%, and these doping ratios can be determined according to actual application requirements.

[0023] The sensor device of this invention adopts a four-layer functional structure with a total thickness of 1-2 mm. The thickness ratio of the charge collection layer, charge blocking layer, charge trapping layer, and charge generation layer is 1:(1-1.5):(4.5-5.5):(2.5-3.5). The specific thickness and the thickness of each layer can be determined according to actual application requirements. The output voltage of the device gradually increases with the stacking of functional layers, and the output voltage is further improved after the introduction of the spiral microstructure, indicating that the optimization of functional material ratio and geometric structure design have a significant synergistic enhancement effect on charge generation, storage, and stable output. Note that the output voltage measured by an oscilloscope will be lower than that measured by an electrometer, and a comparison needs to be made based on the same measurement method.

[0024] The top surface structure design of this invention: The top surface structure of the device is a regular spiral microstructure constructed on a Co-NPC / Ecoflex composite material. By comparing the output performance of planar structures, square periodic structures, and spiral structures, it was found that, under the same material composition and testing conditions, the spiral microstructure can introduce more continuous edges within a limited area, thereby significantly enhancing the edge electric field concentration effect and improving the spatial electric field distribution characteristics. In non-contact operating mode, this structure is more conducive to electrostatic induction coupling, enabling more efficient redistribution of induced charges on and inside the device surface. Experimental results show that when an external object moves at a distance of about 1 cm, the output voltage of the device using the spiral microstructure can reach about 24V, which is significantly higher than the output levels corresponding to the planar and square structures. Simultaneously, electric field simulation results show that the spiral microstructure generates a higher local electric field intensity in its edge region, further verifying the advantages of this structure in enhancing non-contact electrostatic induction intensity and output performance.

[0025] The performance and application of the TENG proximity sensor of this invention: The aforementioned multilayer coupled triboelectric nanogenerator proximity sensor can output stable and high-amplitude electrical signals within a centimeter-level distance. When the target object is moving at a distance of approximately 1 cm, the output voltage can reach approximately 24V (measured by an oscilloscope), demonstrating excellent non-contact response capability. Relying on the synergistic regulation of charge behavior by multilayer functional materials and the enhancement effect of the helical microstructure on the local electric field, the device exhibits high sensitivity and stability to the movement of the target object. To verify its applicability in practical scenarios, this invention investigated the application of the aforementioned TENG proximity sensor in single motion sensing, including non-contact detection of human hand movements, walking processes, and ball movements. Furthermore, by integrating multiple TENG proximity sensors into a sensing array, real-time recognition and reconstruction of two-dimensional motion trajectories were further realized, and successfully applied to scenarios such as robot motion following and complex trajectory recognition. Research shows that non-contact sensors based on the triboelectric effect can not only achieve stable self-powered motion sensing but also have the potential to expand into more complex spatial perception and intelligent interaction systems.

[0026] The sensor of this invention is adjustable and customizable in size and shape: the sensor is constructed based on a flexible Ecoflex composite material system, and its size and shape can be designed and adjusted according to actual application requirements; and without damaging the overall structure of the device and the non-contact sensing performance, the sensor can be cut and rearranged to be suitable for non-contact motion sensing of different areas and different application scenarios.

[0027] This invention first uses a 3D ink direct-write machine to print layer by layer, doping highly conductive carbon black, high dielectric constant calcium copper titanate (CCTO), high electronegativity MXene, and high specific surface area Co-NPC into Ecoflex, respectively, and mixing them with isopropanol solvent to obtain four different printable ink slurries. From bottom to top, this invention prepares a non-contact triboelectric nanogenerator proximity sensor consisting of a carbon black / Ecoflex charge collection layer, a CCTO / Ecoflex electron blocking layer, an MXene / Ecoflex charge trapping layer, and a Co-NPC / Ecoflex charge generation layer with a surface helical structure. This integrated printing method increases the effective contact area between the charge collection layer and the charge blocking layer.

[0028] The following specific embodiments further explain and illustrate the multilayer coupled triboelectric nanogenerator proximity sensor and non-contact following system of the present invention.

[0029] The method for fabricating a multilayer coupled triboelectric nanogenerator proximity sensor according to an embodiment of the present invention includes the following steps: (1) Preparation of CO-NPC functional materials: 3.3 g of cobalt nitrate hexahydrate was dissolved in 45 mL of methanol, and 3.7 g of 2-methylimidazolium (MIM) was dissolved in 90 mL of methanol. The two solutions were then rapidly mixed and magnetically stirred for 2 h. The mixed solution was sealed and aged at room temperature for 24 h. After aging, about one-third of the supernatant was gently poured off, and the resulting purple precipitate was collected by centrifugation and washed three times with methanol. Then, the sample was filtered and washed with deionized water using a circulating water multifunctional vacuum pump. The washed sample was dried in a vacuum furnace at 60 °C for 24 h to obtain ZIF-67 powder. Subsequently, the obtained ZIF-67 powder was subjected to high-temperature carbonization treatment under a nitrogen atmosphere at 5 °C·min. -1 The heating rate was increased from room temperature to 800℃ to obtain higher output performance. After holding at 800℃ for 5 hours, it was naturally cooled to room temperature to finally obtain Co-NPC powder for use. (2) Preparation of MXene material: 10 mL of 9 M hydrochloric acid solution was added to a PTFE reactor, followed by 0.8 g of lithium fluoride (LiF). The mixture was stirred at 30 °C and 300 r / min for 5 min. Subsequently, 0.5 g of Ti3AlC2 powder was slowly added, and the mixture was stirred continuously at 47 °C for 24 h to etch the Al layer in the MAX phase and realize Ti3C2T x After the peeling and reaction were completed, the resulting solution was evenly distributed into 4 centrifuge tubes and diluted with deionized water to 35 mL. To remove excess acid from the mixed solution, the centrifuge was centrifuged 8 times at 10000 r / min for 5 min each time. After centrifugation, the supernatant was discarded, deionized water was added and shaken well, and then the solution was placed back into the centrifuge. The washing process was repeated until the pH value was close to 6. After the last centrifugation, the supernatant was discarded, a small amount of deionized water was added, and the solution was shaken well to obtain a dark green MXene precursor solution. This solution was placed in an ultrasonic cleaner and ultrasonically sonicated for 15 minutes to disperse the MXene evenly. Then, the sample was evenly distributed into two centrifuge tubes and centrifuged at 3000 r / min for 20 min. After centrifugation, the solution was placed into a sample bottle to obtain an MXene aqueous solution. The solution was then pre-frozen in a freeze dryer for 5 h and then vacuum dried to obtain solid layered MXene. (3) Preparation of CCTO material: 0.94 g calcium nitrate tetrahydrate, 2.39 g copper acetate monohydrate and 5.44 mL tetrabutyl titanate were added to a beaker containing 28.8 mL 2-methoxyethanol and magnetically stirred at 60 °C for 30 min to obtain a homogeneous solution. Then 0.96 mL acetic acid was added dropwise as a stabilizer to form a transparent emerald green gel. The gel was dried at 120 °C to obtain the CCTO precursor. The precursor was then transferred to a crucible and sintered at 1050 °C for 2 h under a nitrogen atmosphere to finally obtain brown CCTO powder. (4) Preparation of Ecoflex-based printable ink: 10g Ecoflex A and 0.75g finely ground carbon black were weighed and added to a 25mL plastic beaker, and 10mL isopropanol was added as a solvent; then, the mixture was dispersed at 12000r / min for 5min using a high-speed homogenizer; then 10g Ecoflex B was added and dispersed at 5000r / min for 3min; the mixed slurry was placed in a 60℃ forced-air drying oven to evaporate part of the solvent, and Ecoflex / carbon black slurry with suitable viscosity for direct writing printing was obtained; in addition, CCTO / Ecoflex, MXene / Ecoflex and Co-NPC / Ecoflex inks were all prepared by the same method, and their functional filler mass fractions were 30wt%, 6wt% and 2wt%, respectively; (5) Device preparation: 10g Ecoflex A and 10g Ecoflex B were thoroughly mixed and placed in a vacuum drying oven for 3 min to remove air bubbles. The mixture was then poured onto a PET film and coated with a doctor blade to form a film with a thickness of about 500μm. After curing, a pure Ecoflex substrate was obtained. The substrate was cut into 5cm×5cm pieces and fixed on the heating platform of the V-ONE direct writing printer. Ecoflex / carbon black paste was loaded into a dispensing syringe, capped, and centrifuged at 5000r / min for 5 min to remove residual air bubbles. The substrate was then installed in the V-ONE direct writing printer to prepare a charge collection layer with a size of 2.5cm×2.5cm. After printing, the device was placed in a 60℃ forced-air drying oven for 8 h to cure. The same method was then used to print CCTO / Ecoflex layer, MXene / Ecoflex layer and Co-NPC / Ecoflex layer on it. Finally, the wires were connected and fixed to the charge collection layer using Ecoflex / carbon black paste and cured in a 60℃ forced-air drying oven for 8 h.

[0030] The following provides a detailed description of the design, fabrication, and mechanism of the non-contact triboelectric nanogenerator proximity sensor according to an embodiment of the present invention: Ink direct writing (DIW) technology is gaining popularity due to its high controllability, ease of operation, and high efficiency. Figure 1 (a) Demonstrates the process of fabricating an integrated self-powered non-contact TENG sensor using four different functional composite ink slurries: the first layer is a carbon black / Ecoflex / isopropanol ink used to print the charge collection layer, i.e., the flexible electrode; isopropanol first dissolves Ecoflex, then does it with carbon black, allowing the highly conductive carbon black to be uniformly and densely embedded in Ecoflex, forming a polymer composite film with a complete conductive path; due to the presence of isopropanol, the ink does not solidify before printing, and after printing, the isopropanol is heated to evaporate, resulting in a solidified conductive elastic film with a sheet resistance of 32.6 kΩ, while the impedance of the TENG itself is typically tens to hundreds of megohms, 200-300 times higher than that of the conductive film, therefore, after series voltage division... The conductive film resistance has almost no effect on the output voltage; the second layer is a high dielectric constant CCTO / Ecoflex / isopropanol ink, which can serve as a polarization and charge blocking layer to suppress the self-discharge effect of the charge trapping layer and achieve long-term, high-performance non-contact operation; the third layer, MXene / Ecoflex / isopropanol ink, is used to trap charges: the two-dimensional structure of MXene is easy to form microcapacitor arrays, and its surface oxygen-containing functional groups and abundant -F groups can significantly improve the electronegativity of Ecoflex; the fourth layer, Co-NPC / Ecoflex / isopropanol ink, is responsible for charge generation: Co-NPC has a high specific surface area, providing more electronic active sites and effective contact area; Figure 1(b) The device structure and the function of each layer are shown in the diagram, from top to bottom: Co-NPC / Ecoflex, an elastic charge generation layer with a spiral structure, MXene / Ecoflex, an elastic charge trapping layer, CCTO / Ecoflex, an elastic charge blocking layer, and carbon black / Ecoflex, an elastic charge collection layer. Figure 1 (c) is a top view photomicrograph of a 2.5cm × 2.5cm spiral microstructure; Figure 1 (d) The cross-sectional view shows a four-layer integrated structure with a total thickness of 1 mm. The thickness ratio of the charge collection layer, charge blocking layer, charge trapping layer, and charge generation layer is 1:1:5:3. The charge transfer behavior between polytetrafluoroethylene (PTFE, positively charged) and the surfaces of different layered materials and the corresponding band changes are as follows: Figure 1 As shown in (e)–(h), there are significant differences in charge transfer behavior between PTFE and various Ecoflex-based surfaces (including pure Ecoflex, Co-NPC / Ecoflex with microstructure, Co-NPC-Ecoflex / MXene-Ecoflex with microstructure, and Co-NPC-Ecoflex / MXene-Ecoflex / CCTO-Ecoflex with microstructure). This is mainly due to the band shift caused by the dielectric properties of different functional materials (Co-NPC, MXene) and CCTO. First, such as Figure 1 As shown in (e), the Fermi level of PTFE is very close to that of Ecoflex, with only a small number of electrons transferring from PTFE to Ecoflex, resulting in a weak potential on the surface. Secondly, the Co-NPC / Ecoflex nanocomposite incorporates the high specific surface area functional material Co-NPC, and a helical microstructure is constructed on its surface using direct ink writing technology, significantly improving the surface charge density of the device. Therefore, the Fermi level of the Co-NPC / Ecoflex nanocomposite with the helical microstructure shifts downward, while more charge transfers from PTFE to the Co-NPC / Ecoflex nanocomposite, such as... Figure 1 As shown in (f); furthermore, the introduction of the electronegative material MXene into Ecoflex allows for the trapping of more charges in the system, thereby promoting a more significant band transfer between PTFE and the Co-NPC / MXene / Ecoflex nanocomposite; simultaneously, due to the increased charge quantity, the charge transfer from PTFE to the Co-NPC / MXene / Ecoflex nanocomposite is further enhanced, as shown in (f). Figure 1As shown in (g); moreover, the polarization effect of the entire system reaches its maximum after the introduction of the dielectric material CCTO into Ecoflex, enabling a large amount of charge to be transferred and effectively trapped in the Co-NPC / MXene / CCTO / Ecoflex composite system, such as Figure 1 As shown in (h). Furthermore, as... Figure 1 As shown in (i)–(l), the prepared sensor patch has the characteristics of being lightweight, flexible and stretchable, indicating that the prepared functional paste can be successfully printed on the Ecoflex substrate and form an integrated structured device. The first layer of the device is a polymer nanocomposite material composed of carbon black / Ecoflex, which is used as a stretchable electrode. The carbon black material (Ketjenblack EC600JD) has a smaller particle size, higher specific surface area and specific volume, and a more disordered graphene layer structure. This high-structure carbon black is composed of smaller aggregates and exhibits a highly branched morphology, thus having a lower conductive percolation threshold, which is beneficial to improving the electrical conductivity of the composite material.

[0031] like Figure 2 As shown in (a)-(d), the magnified SEM images reveal the aggregates and pore structure of carbon black, with typical pore sizes of approximately 10-20 nm distributed among the carbon black aggregates; the average particle size of the carbon black is approximately 38 nm; subsequently, X-ray diffraction (XRD) was used to analyze the phase composition of carbon black in the carbon black / Ecoflex samples; as shown... Figure 2 As shown in (ii) of (a), the absence of clearly distinguishable diffraction peaks indicates that carbon black exhibits poor crystallization characteristics, further confirming the disorder of its internal graphene layer structure. Figure 2 (a) shows that (iii) the carbon black particles can be uniformly dispersed and embedded in the Ecoflex matrix without obvious agglomeration. This uniform dispersion is beneficial to improving the mechanical properties and electrical conductivity stability of the polymer nanocomposite. Figure 2 (a) (vi) shows the Raman spectrum of the carbon black / Ecoflex composite material, where the broad peak position is similar to that of pure carbon black, indicating that carbon black has been successfully dispersed in the Ecoflex matrix. Notably, the peak position shows a slight left shift, indicating that the Ecoflex polymer chain is doped into the carbon black structure, causing lattice expansion and increasing the interlayer spacing (d-spacing). The uniform doping of carbon black in the Ecoflex matrix gives the composite material excellent conductivity, indicating that the stretchable conductive electrode has been successfully prepared.

[0032] To address the self-discharge problem in the device, a second layer with high dielectric properties, namely a charge barrier layer, was fabricated between the charge trapping layer and the charge collecting layer; for example... Figure 2As shown in (b) of (i), the prepared CCTO nanoparticles are non-spherical with a clear crystal structure and an average particle size of approximately 200 nm; Figure 2 As shown in (ii) of (b), the XRD diffraction peaks of the CCTO material are highly consistent with the standard results in the PDF card, and its characteristic crystal planes are located at (220), (422) and (620), respectively, indicating that the prepared material has a good crystal structure; like Figure 2 As shown in (iii) of (b), after copper perovskite (CuCaTiO4, CCTO) is doped into Ecoflex elastomer, SEM images show that the surface of the composite material exhibits a large number of irregular protrusions, wrinkles, and depressions interwoven, forming a non-spherical three-dimensional morphology with clear crystal faces; from the perspective of particle structure, CCTO basically maintains its original morphological characteristics during the composite process; as shown in (iii) of (b), after copper perovskite (CuCaTiO4, CCTO) is doped into Ecoflex elastomer, SEM images show that the surface of the composite material exhibits a large number of irregular protrusions, wrinkles, and depressions interwoven, forming a non-spherical three-dimensional morphology with clear crystal faces; from the perspective of particle structure, CCTO basically maintains its original morphological characteristics during the composite process; Figure 2 As shown in (b) and (iv), diffraction peaks corresponding to the characteristic crystal planes of CCTO, such as (220), (422), and (620), appeared in the XRD spectrum of the CCTO / Ecoflex nanocomposite, indicating that CCTO has been successfully doped into the Ecoflex matrix.

[0033] The third layer, composed of MXene / Ecoflex composite material, serves as a charge storage and trapping layer. High-resolution X-ray photoelectron spectroscopy (XPS) was used to characterize the chemical states of MXene, Ecoflex, and the MXene / Ecoflex nanocomposite. Full-spectrum scanning of MXene revealed the presence of F and O elements in addition to the main elements C and Ti, indicating possible functionalization modification of the MXene surface during etching and exfoliation. The XPS full spectrum of MXene / Ecoflex detected Si, C, Ti, O, and F elements, indicating that MXene is uniformly distributed within the Ecoflex matrix and forms chemical bonds, including C–Ti, C–Ti–O, C–C, C–OH, and C–F bonds. Raman spectra of MXene, Ecoflex, and MXene / Ecoflex composites show that MXene has a characteristic peak (approximately 295 cm⁻¹). -1 and 386cm -1 The presence of these components within the Ecoflex matrix indicates that MXene and Ecoflex have achieved effective bonding; for example... Figure 2As shown in (c) of (i), the single-layer two-dimensional MXene material obtained under the support of an alumina AAO template has a size in the nanoscale range; the XRD pattern of MXene shows strong diffraction peaks at 6.5°, 28.4°, and 61°, corresponding to the (002), (104), and (220) crystal planes, respectively, indicating a large interlayer spacing and successful synthesis of MXene; at the same time, the flat baseline indicates that the material has good crystallinity and high purity, such as Figure 2 (c) is shown in (ii); like Figure 2 As shown in (iii) of (c), the SEM image (scale bar is 1 μm) of the MXene / Ecoflex composite material shows that its surface is generally uniform and relatively flat. Figure 2 In (c) of (iv), the XRD patterns of the MXene / Ecoflex composite material and pure Ecoflex were compared. New diffraction peaks were observed at 2θ = 6.5°, 28° and 32°, corresponding to the (002), (104) and (111) crystal planes of MXene, indicating that MXene still maintains a layered crystal structure in the polymer matrix. The broad diffuse peaks in the range of 2θ = 10°–30° are the amorphous characteristic peaks of pure Ecoflex. No impurity peaks were observed in the spectrum, and the characteristic peaks of MXene did not shift significantly, indicating that MXene and Ecoflex are mainly composited by physical mixing and no new phase is generated.

[0034] The fourth layer, composed of a Co-NPC / Ecoflex composite material, is used for charge generation; such as Figure 2 As shown in (d) of (i), the surface morphology of Co-NPC was analyzed using field emission scanning electron microscopy. Surface roughness is an important parameter affecting TENG performance. With the increase of average surface roughness, the effective frictional contact area between materials increases, thereby generating more charge and improving output performance. The average particle size of Co-NPC nanoparticles is approximately 500 nm. Figure 2 (d) of (ii) and Figure 2 As shown in (d) and (iv), the XRD patterns of Co-NPC and Co-NPC / Ecoflex nanocomposite films are presented respectively. Compared with pure Ecoflex, the (111) and (200) diffraction peaks of Co-NPC were successfully observed in the XRD pattern of the Co-NPC / Ecoflex nanocomposite film, indicating that Co-NPC has been well doped into the Ecoflex matrix. The above results were also verified by field emission scanning electron microscopy (FEM) images. Figure 2 (d) of (iii) was further verified, wherein Co-NPC particles were uniformly distributed within the Ecoflex matrix.

[0035] Figure 3 As a concentrated presentation of the core optimization experiments in this study, focusing on the core objective of "improving the charge density and dynamic balance of non-contact TENGs," a complete logical chain of "structure type screening - precise parameter control - synergistic enhancement of layer number - distance adaptability verification" was employed. Combined with COMSOL simulations and quantitative experiments, the study systematically revealed the regulatory mechanism of surface microstructure and functional layer number on sensing performance. A unified variable was controlled throughout the experiment: the effective sensor area was 6.25 cm². 2 (2.5cm×2.5cm), test frequency 3Hz, non-contact object is positively charged PTFE film, to ensure the reliability and comparability of all comparative data.

[0036] In terms of surface microstructure type optimization Figure 3 (a) and 3(b) verified through both simulation and experiment that the spiral structure has significant advantages over the square ring structure. COMSOL electrostatic field simulation showed that the potential distribution of the spiral structure is more uniform (voltage range -50 to 50V), and there is no electric field concentration at the corners of the square ring. This is because the "toroidal topology" of the spiral can maximize the storage of electromagnetic energy and reduce energy loss. Experimental data showed that at a size of 2.5 cm × 2.5 cm, the peak-to-peak output voltage of the spiral structure at a distance of 1 cm reached 4.8 V, which is 3 times that of the square ring structure (1.6 V). Its core mechanism is the synergistic effect of the "edge field effect + electrostatic induction" of the spiral structure, which effectively expands the effective area of ​​charge induction. For parameter optimization of the spiral structure, Figure 3 (d) and 3(e) quantitatively investigated the relationship between the number of spiral turns, wall spacing, and output voltage. When the sensor area was fixed, the wall spacing decreased rapidly with increasing spiral turns when the number of spiral turns n was less than 25 (linear fitting R²=0.94), and decreased slowly when the number of spiral turns n was greater than 25 (R²=0.97). This change was completely synchronized with the "rapid rise followed by saturation" trend of the output voltage. When the number of spiral turns n increased to 45, the output voltage reached a maximum value of 4.8V. At this time, the wall spacing was 220μm, which balanced the effective sensing area and fabrication feasibility. However, if the number of spiral turns n exceeded 45, the spiral walls would stick together due to the limitation of the printing needle diameter, and the performance would decrease. Therefore, 45 spiral turns n was determined to be the optimal parameter. Figure 3 (f) By simulating the potential distribution under different friction pair spacings (0.2–0.8 mm), it was found that the larger the spacing, the more significant the potential difference, increasing from 8 V at 0.2 mm to 27 V at 0.8 mm. This characteristic provides theoretical support for the subsequent ultra-long-range detection at 5.5 m. The principle is that as the spacing increases, charge leakage decreases, the electric field gradient increases, and thus enhances the potential difference-driven electron flow; Figure 3The functional layer comparison experiment (g) reveals the importance of the synergistic effect of the entire "charge generation-capture-blocking-collection" chain: a single layer of carbon black / Ecoflex only outputs 5 V, which increases to 9 V after adding a Co-NPC / Ecoflex charge generation layer, reaches 15 V after adding an MXene / Ecoflex charge capture layer, and increases to 21 V after adding a CCTO / Ecoflex charge blocking layer. Finally, the output voltage reaches 24 V after combining with a spiral microstructure. Moreover, the four-layer structure has the best charge retention performance, with only 30% decay of surface potential within 50 hours, which confirms the key role of CCTO in suppressing self-discharge. In summary, through multi-dimensional and quantitative research, the optimal structural parameters and functional configuration of the non-contact TENG were clarified: a spiral surface microstructure (45 turns) + four functional layers (Co-NPC / Ecoflex-MXene / Ecoflex-CCTO / Ecoflex-carbon black / Ecoflex), ultimately achieving a high output of 24 V at a distance of 1 cm. This not only verifies the scientific nature of the structural design and material ratio, but also lays the core performance foundation for subsequent one-dimensional / two-dimensional motion following applications.

[0037] Based on the self-powered non-contact TENG with optimal material selection and structural design, its non-contact sensing performance was comprehensively evaluated. To further improve the surface charge density, corona discharge treatment was introduced. Figure 4 (a) Schematic diagram of corona discharge injection principle: A tungsten steel needle is placed 1 cm from the sensor surface. An -8 kV DC high voltage is applied to ionize the air, generating positive and negative ions. Under the action of electric field E, positive ions migrate towards the tungsten steel needle (negative electrode), while negative ions move in the opposite direction and accumulate at the sensor (grounding terminal), thus achieving efficient injection of negative charge. If a positive voltage is applied, positive charge is injected into the sensor surface. Figure 4 (b) The surface potential after contact charging and corona discharge was compared: Corona discharge made the surface potential of the non-contact TENG reach 2.7 kV, which is 27 times that of contact charging (0.1 kV), indicating that a large number of negative charges were injected into the surface, significantly increasing the surface charge density and thus greatly enhancing the electrical output performance of the device. To ensure the long-term durability of self-powered non-contact triboelectric nanogenerators (TENGs), it is desirable that the accumulated surface charge be maintained over a prolonged period. Typically, multilayered charge dynamic equilibrium non-contact triboelectric nanogenerators with excellent charge storage performance and minimal charge dissipation are crucial. Therefore, the stability of self-powered non-contact TENGs was tested. Figure 4 (c) shows that the initial surface potential of the device was 2.7 kV, which dropped to 1.89 kV after 28 h, with a potential loss of only 30%, confirming its excellent charge retention capability. Due to the significant differences in electronegativity between different materials, the voltage values ​​generated also differ, such as... Figure 4As shown in Figure 1. For example, the triboelectric effect between PTFE and the sensing layer is the strongest, generating a voltage as high as 24 V. Therefore, PTFE film was uniformly selected as the standard test object in subsequent experiments. Among them, the maximum detection distance of the non-contact TENG can reach 5.5 m.

[0038] During the research, the self-powered non-contact TENG used the principle of electrostatic induction to sense the distance to external objects. The key output performance is shown in Figures 4(d), 4(e), and 4(f): At 1 Hz, when the distance increases from 1 mm to 25 cm, the output voltage drops from 25 V to 1.4 mV, the corresponding transferred charge drops from 8 nC to 0.2 nC, and the current drops from 180 nA to 0.9 nA. This is attributed to the reduction of electrostatic induction between the device and the object being measured.

[0039] For practical applications, environmental parameters such as humidity can affect device performance. When the relative humidity increases from 30% to 80%, the peak-to-peak voltage, transferred charge, and current all decrease, from 24 V to 7.5 V, 7 nC to 1.5 nC, and 140 nA to 28 nA, respectively. This is because the increased moisture in the air provides additional conduction paths for surface charges. Within the comfortable RH range of 40-60%, the output signal decreases only slightly with increasing humidity; even in the extreme high humidity environment of 80% RH, the device can still generate a recognizable signal, and only humidity calibration is needed to meet the requirements for accurate sensing.

[0040] The output performance of a self-powered non-contact TENG is directly related to the load: the load voltage increases linearly with the load resistance, while the load current is inversely proportional. Figure 4 (h) Provides the current and voltage variations in the range of 1 Ω–200 MΩ, with a maximum output power density of 2.5 µW cm⁻¹. -2 (Load 60 MΩ, 3 Hz) Figure 4 (i) When using a power management circuit in ultra-high output mode (rectifier bridge + 4.7 µF input capacitor + diode + 400 V gas discharge tube), the energy output capability can be significantly improved: the electrical energy generated by the TENG is first stored in the capacitor, and when the gas discharge tube reaches the threshold, the capacitor simultaneously and instantaneously releases energy, increasing the peak current from µA to A (Figure 4(j)). With a device area of ​​15 cm²... -2 At that time, the system can generate a pulse current of up to 1 A and light up 500 LEDs, such as Figure 4 As shown in k.

[0041] A single self-powered non-contact TENG can detect the distance between a target and a sensor. More importantly, the non-contact following system of this invention can follow moving objects approaching or moving away at different speeds at a fixed distance, which is of great significance for human-computer interaction on mobile platforms (such as slides, timing belts, robots, etc.). In one-dimensional motion following mode, Figure 5 (a) indicates that at a fixed distance, when a positively charged object moves backward, the sensor output signal increases and generates a negative velocity command, causing the sensor's slide to move backward accordingly; when the object stops, the signal returns to its initial value and stops as well; the process is reversed when the object moves away. Thus, non-contact dynamic following between the object and the slide can be achieved solely by the change in the sensor's dynamic output voltage. Figure 5 (b) is a one-dimensional follower experimental setup: the sensor is fixed to the synchronous belt slide, and the positively charged PTFE membrane is installed on the other side of the synchronous belt (fixed to the red bracket). The upper right corner shows an enlarged view of the PTFE membrane. Figure 5 (c) The voltage signal and corresponding velocity signal were recorded during the one-dimensional motion following process: the voltage fluctuation caused by the start and stop of the object is also reflected in the velocity curve (small peaks in the signal), indicating that the sensor is extremely sensitive to distance changes, and the voltage and velocity signals show an inverse trend, which can be widely used in one-dimensional motion following scenarios.

[0042] Compared to one-dimensional motion tracking, two-dimensional motion tracking has a wider range of applications, and its working principle is as follows: Figure 5 As shown in (d): The target is initially located at position B2. It moves in a two-dimensional plane at a vertical distance of 15 mm from the sensor array plane (i.e., it leaves B2 and moves closer to the surrounding sensors). Each sensor will generate a corresponding dynamic voltage response signal in sequence. By classifying the motion of different sensor signal change sequences, the two-dimensional motion tracking of the self-powered non-contact TENG array can be realized. Figure 5 (e) shows a photograph of the two-dimensional experimental setup, with a side view of the object under test and the array in the upper right corner.

[0043] As a further application, the aforementioned TENG proximity sensor array is used as a smart non-contact input terminal to identify motion trajectories in the shape of different Greek letters. Figure 5 (f) illustrates the test trajectories of six common Greek letters “π, θ, Σ, Δ, α, β”, and establishes the correspondence between each trajectory and the signal excitation sequence; Figure 5 (g) shows the six-channel real-time voltage signals corresponding to the six letter trajectories, and establishes the correspondence between each trajectory and the signal excitation sequence. It is evident that the channel order is completely consistent with expectations. Figure 5 Taking the π-shaped trajectory of (h) as an example: Phase I: The target moves from B2 to B3. The B2 signal gradually increases, the B3 signal gradually decreases, and C2 and C3 remain almost unchanged. Phase II: The target reaches B3. The B2 signal returns to its initial value, the B3 signal drops to its lowest value, and C2 and C3 remain unchanged. Phase III: The target moves along a curved path close to B2 (from near B2 to C2). The B2 signal first decreases and then increases, the B3 signal first increases and then returns to its initial value, the C2 signal gradually drops to its lowest value, and C3 remains almost unchanged. Phase IV: The target moves along the curve through B2 and then turns towards C3 to complete a π-shape. The B2 signal again first decreases and then increases, the B3 signal returns to its initial value and then fluctuates slightly, the C2 signal first increases and then returns to its initial value, and the C3 signal finally drops to its lowest value.

[0044] To achieve convenient human-computer interaction, a machine learning algorithm based on a one-dimensional convolutional neural network (CNN) was designed to train and classify Greek letter trajectory data. Figure 5 (i) The network structure is given: two layers of Conv1d + ReLU + BN stacked + fully connected layer. Sixty sets of data were collected for each letter trajectory, and the training / validation sets were divided in a 4:1 ratio. After data preprocessing, CNN classification was used, and the resulting confusion matrix showed a recognition accuracy of 97.9%. Figure 5 As shown in (j), the model has strong generalization ability, is not prone to overfitting, and can be easily embedded in modern electronic devices, significantly expanding the application scenarios of the self-powered non-contact TENG proximity sensor array terminal. The results show that the intelligent input terminal, based on the coupling effect of contact electrification and electrostatic induction, has achieved accurate recognition of different trajectories of moving objects, providing a new and efficient way for non-contact human-computer interaction.

[0045] Given that there are numerous embodiments of the present invention, and the raw materials and quantities involved can be selected within a limited range according to actual needs, and that the experimental data for each embodiment are extensive and numerous, it is not suitable to list and describe them one by one here. However, the content to be verified and the final conclusions obtained in each embodiment are similar. Therefore, the verification content of each embodiment will not be described one by one here.

[0046] The above description is merely a detailed explanation of preferred embodiments and principles of the present invention. For those skilled in the art, there may be changes in specific implementation methods based on the ideas provided by the present invention, and these changes should also be considered within the scope of protection of the present invention.

Claims

1. A multilayer coupled triboelectric nanogenerator proximity sensor, characterized in that, It includes a charge collection layer, a charge blocking layer, a charge trapping layer and a charge generation layer stacked sequentially from bottom to top; wherein the surface of the charge generation layer has a threaded microstructure. The charge collection layer is an Ecoflex matrix containing carbon black; The charge blocking layer is an Ecoflex matrix containing calcium copper titanate (CCTO). The charge trapping layer is an Ecoflex matrix containing MXene; The charge generation layer is a cobalt-nanoporous carbon (Co-NPC) matrix in the Ecoflex matrix.

2. The multilayer coupled triboelectric nanogenerator proximity sensor according to claim 1, characterized in that, The number of turns in the threaded microstructure is 30 to 45.

3. The multilayer coupled triboelectric nanogenerator proximity sensor according to claim 1, characterized in that, For the charge collection layer, the proportion of carbon black in the Ecoflex matrix is ​​2–4 wt%.

4. The multilayer coupled triboelectric nanogenerator proximity sensor according to claim 1, characterized in that, For the charge blocking layer, the proportion of CCTO in the Ecoflex matrix is ​​20–40 wt%.

5. The multilayer coupled triboelectric nanogenerator proximity sensor according to claim 1, characterized in that, For the charge trapping layer, MXene accounts for 5–7 wt% of the Ecoflex matrix.

6. The multilayer coupled triboelectric nanogenerator proximity sensor according to claim 1, characterized in that, For the charge generation layer, the proportion of Co-NPC in the Ecoflex matrix is ​​1–3 wt%.

7. The multilayer coupled triboelectric nanogenerator proximity sensor according to claim 1, characterized in that, The thickness ratio of the charge collection layer, charge blocking layer, charge trapping layer and charge generation layer is 1:(1~1.5):(4.5~5.5):(2.5~3.5), and the total thickness is 1~2 mm.

8. The multilayer coupled triboelectric nanogenerator proximity sensor according to any one of claims 1-7, characterized in that, Its preparation method includes the following steps: (1) Ecoflex / carbon black paste is printed onto the printing substrate by direct ink writing, and a charge collection layer is obtained after curing; (2) Ecoflex / CCTO paste is printed onto the charge collection layer by direct ink writing, and a charge blocking layer is obtained after curing; (3) Ecoflex / MXene paste is printed onto the charge blocking layer by ink direct writing, and a charge trapping layer is obtained after curing; (4) The Ecoflex / Co-NPC paste is printed onto the charge trapping layer by direct ink writing, and the charge generation layer is obtained after curing.

9. The multilayer coupled triboelectric nanogenerator proximity sensor according to claim 8, characterized in that, The curing temperature is 50–70°C, and the curing time is at least 6 hours.

10. A non-contact following system, characterized in that, Includes a movable platform and a multilayer coupled triboelectric nanogenerator proximity sensor as described in any one of claims 1-9 mounted on the movable platform; In one-dimensional motion tracking mode, the proximity sensor maintains a fixed distance from the target object during motion tracking. Alternatively, in two-dimensional motion following mode, a proximity sensor array can be used to achieve motion following between the movable platform and the target object while maintaining a fixed distance.

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