Triboelectric nanogenerator with mxene-coated stretchable polyurethane fiber, and preparation method therefor and application thereof
By spraying MXene triboelectric nanogenerators onto stretchable polyurethane fibers with a layered coaxial linear structure, the shortcomings of existing TENG devices in terms of conductivity and stability are overcome, achieving high sensitivity and customizability, making them suitable for motion recognition and energy harvesting in wearable devices.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SHANGHAI SECOND POLYTECHNIC UNIVERSITY
- Filing Date
- 2025-09-22
- Publication Date
- 2026-06-18
AI Technical Summary
Existing triboelectric nanogenerators (TENGs) are mostly planar structures, which are difficult to adapt to irregular human movements. They also have shortcomings in terms of conductivity and stability of triboelectric materials, making it difficult to achieve production and customized integration.
The MXene triboelectric nanogenerator (FM-TENG) is a stretchable polyurethane fiber sprayed with a layered coaxial structure. It uses a weaving technique to wrap silver wire or silver-coated nylon wire around the polyurethane core layer to form a conductive layer, and wraps polyamide fiber around the outer layer to form a triboelectric layer. Combined with the two-dimensional material MXene layer, it improves the electrical output performance.
It achieves high sensitivity and wide detection range in electrical performance, excellent mechanical properties, and can remain stable under complex deformations such as stretching, pressing and twisting. It can also be woven into various textiles for human motion monitoring, with a recognition accuracy of up to 99.02%.
Smart Images
Figure CN2025122836_18062026_PF_FP_ABST
Abstract
Description
A triboelectric nanogenerator made of stretchable polyurethane fiber coated with MXene, its preparation method and its application Technical Field
[0001] This invention relates to the field of flexible electronic device technology, and in particular to a triboelectric nanogenerator made of stretchable polyurethane fiber coated with MXene, its preparation method and its application. Background Technology
[0002] With the rapid development of flexible electronic devices, wearable devices are increasingly widely used in human-computer interaction, medical monitoring, energy harvesting, and other fields. Traditional flexible sensors are usually based on capacitive, piezoresistive, and piezoelectric mechanisms, but these sensors have limitations in terms of sensitivity, detection range, and stability. Triboelectric nanogenerators (TENGs), as an emerging energy harvesting and self-powered sensing technology, have the advantages of simple structure, strong adaptability, and the ability to operate at low frequencies and small amplitudes, thus being considered an ideal choice for next-generation wearable devices. However, most existing TENG devices are planar structures, making it difficult to adapt to irregular human movements. Furthermore, the output performance of nanogenerators is insufficient, and there are challenges in production and customization. Fiber-structured TENGs (F-TENGs) are gradually becoming a research hotspot due to their shape adaptability, weaving properties, and breathability. However, existing F-TENGs have shortcomings in conductivity and the stability of triboelectric materials, and are difficult to produce and customize. Technical issues
[0003] To address the shortcomings of the existing technologies, the present invention aims to provide a stretchable polyurethane fiber-coated MXene triboelectric nanogenerator (FM-TENG) suitable for production, its preparation method, and its applications. The FM-TENG of this invention possesses excellent mechanical properties, stable electrical properties, and high customizability, and can be applied in wearable devices, human motion recognition, energy harvesting, and self-powered sensing. This invention employs a weaving technique to weave silver wires or silver-coated nylon filaments into a conductive layer, surrounding the polyurethane (PU) core layer. This woven structure forms a conductive network that not only provides excellent conductivity but also exhibits stability and reliability, ensuring the electrical performance stability of the FM-TENG under complex deformations such as stretching, compression, and torsion. Technical solutions
[0004] The technical solution of the present invention is described in detail below.
[0005] This invention provides a triboelectric nanogenerator made of stretchable polyurethane fiber coated with MXene. The triboelectric nanogenerator has a layered coaxial structure, comprising, from the inside out, a stretchable layer, a conductive layer, and a triboelectric layer; wherein:
[0006] The stretchable layer is a polyurethane (PU) layer, which is the core component of the triboelectric nanogenerator FM-TENG and is used to provide stretchability.
[0007] The conductive layer is formed by tightly winding silver wire or silver-coated nylon wire onto a stretchable layer;
[0008] The triboelectric layer is a polyamide (PA) layer, which is used to generate the triboelectric effect. It is formed by tightly wrapping polyamide (PA) fibers around the outside of the conductive layer.
[0009] In this invention, a conductive layer is formed on a stretchable layer by a braiding process, and a polyamide (PA) triboelectric layer is formed on the conductive layer by a braiding process.
[0010] In this invention, a two-dimensional material layer is also included outside the triboelectric layer. The two-dimensional material layer is used to improve the electrical output performance and is formed by spraying a two-dimensional material solution onto the triboelectric layer. The two-dimensional material layer is an MXene layer.
[0011] In this invention, the diameter of the triboelectric nanogenerator is 1 ± 0.02 mm.
[0012] In this invention, the triboelectric nanogenerator operates in the range of 5 to 150 kPa and has a sensitivity of 0.0356 VkPa. -1 Up to 0.554VkPa -1 Its elastic recovery rate remains above 95% after at least 500 cycles with an elongation of 0% to 60% and a strain of 0% to 50%.
[0013] This invention also provides a method for preparing the above-mentioned triboelectric nanogenerator, which is prepared through a two-step weaving process; the specific steps are as follows:
[0014] (1) Using polyurethane (PU) fiber as the core component, the polyurethane (PU) fiber is wound around a fixed bobbin and enters the braiding area through a tension device; the silver wire or silver-coated nylon wire wound on the bobbin is tightly wound onto the polyurethane (PU) fiber through the braiding process to form a conductive layer and obtain Ag / PU material.
[0015] (2) By weaving process, polyamide PA fibers wound on the spool are wound onto Ag / PU material to form a triboelectric layer, thus obtaining PA / Ag / PU material with coaxial linear structure.
[0016] This invention also includes step (3): spraying MXene supernatant onto PA / Ag / PU material to obtain a triboelectric nanogenerator with MXene-coated stretchable polyurethane fiber; wherein, the preparation method of MXene supernatant is as follows: after mixing and stirring lithium fluoride and hydrochloric acid, Ti3AlC2 is added to carry out an etching reaction. After the reaction is completed, the resulting solution is centrifuged, the supernatant is discarded, and centrifugation is continued until the pH of the supernatant after centrifugation is 6. Ethanol is added to the centrifuge tube, and ultrasonic centrifugation is performed to obtain MXene supernatant. In a specific embodiment, the concentration of MXene supernatant is 6wt% MXene, which can be obtained by spraying it onto the prepared PA / Ag / PU material once or twice. The amount used does not need to be strictly controlled, and it is used to improve the electrical output performance of the generator.
[0017] Furthermore, the present invention provides an application of the above-mentioned stretchable polyurethane fiber coated with MXene triboelectric nanogenerator in wearable devices.
[0018] Furthermore, this invention provides an application of the aforementioned MXene-coated triboelectric nanogenerator on stretchable polyurethane fibers in monitoring human motion signals. In this application, the MXene-coated triboelectric nanogenerator is integrated into a wearable device using a weaving process to monitor human motion signals in real time. Preferably, the MXene-coated triboelectric nanogenerator is integrated into socks using a weaving process. Based on machine learning algorithms, the signals collected by the FM-TENG are classified to identify five human movements: standing, slow walking, normal walking, running, and jumping. Beneficial effects
[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0020] High sensitivity and wide detection range: The FM-TENG has a sensitivity of 0.554 V / kPa in the pressure range of 5 to 150 kPa.
[0021] Excellent mechanical properties: FM-TENG has an elongation of up to 60%, and after no less than 500 cycles under strain of 0% to 50%, the elastic recovery rate remains above 95%.
[0022] Customizability and scalability: FM-TENG can be woven into various textiles, such as wrist supports and socks, to perfectly fit the human body and enable motion signal monitoring.
[0023] Self-powered and energy harvesting: FM-TENG can convert mechanical energy into electrical energy, providing self-powered capabilities for wearable devices.
[0024] Machine learning-assisted motion recognition: Based on a one-dimensional convolutional neural network 1D-CNN, it can classify the signals collected by FM-TENG and accurately identify five human movements, including standing, walking slowly, walking normally, running and jumping, with a recognition accuracy of up to 99.02%. Attached Figure Description
[0025] Figure 1 is a schematic diagram of the manufacturing process of the present invention.
[0026] Figure 2 is a schematic diagram of the weaving process of the present invention.
[0027] Figure 3 is a schematic diagram of the overall structure of the triboelectric nanogenerator of the present invention.
[0028] Figure 4 is a schematic diagram of the manufacturing process in an embodiment of the present invention.
[0029] Figure 5 shows the electrical output performance in Embodiment 1 of the present invention; (a) open circuit voltage; (b) short circuit current; (c) short circuit charge transfer.
[0030] Figure 6 is a sensing response diagram in Embodiment 1 of the present invention.
[0031] Figure 7 is a schematic diagram of the structure of the smart socks of the present invention.
[0032] Figure 8 is a schematic diagram of the actual test object of the present invention.
[0033] The labels in the image are: 1. Normal knit socks; 2. FM-TENG; 3. Polyurethane (PU) layer; 4. Tube; 5. Silver thread; 6. Knitting area; 7. Polyamide (PA) layer; 8. MXene. Embodiments of the present invention
[0034] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.
[0035] As shown in Figures 1-3, the stretchable polyurethane fiber-coated MXene triboelectric nanogenerator (FM-TENG) 2 of this invention is linear (fibrous) in shape, employing a layered coaxial structure, including a core polyurethane (PU) layer 3, a middle silver conductive layer 4, and an outer polyamide (PA) triboelectric layer 5. The FM-TENG is produced by spraying MXene 8 after a two-step weaving process. The two-step weaving process includes: Step 1: Weaving silver wire (or silver-coated nylon wire) around the polyurethane (PU) layer (fiber); this step forms an Ag / PU core-shell structure. In this process, the PU fiber acts as the core, and through specific weaving machines and processes, the silver wire is tightly wound around the PU fiber, forming a conductive layer. Step 2: Weaving polyamide (PA) fiber around the Ag / PU structure; this step further enhances the structural stability and triboelectric properties of the FM-TENG. The PA fiber, as the outer layer, is tightly wrapped around the Ag / PU structure through weaving technology, forming a complete coaxial structure (PA / Ag / PU).
[0036] Figure 4 shows a schematic diagram of the manufacturing process of the triboelectric nanogenerator with stretchable polyurethane fiber coated with MXene in this embodiment of the invention. Specific embodiments are described below.
[0037] Example 1: Preparation of FM-TENG
[0038] Step 1: Mix 2g of lithium fluoride with 40mL of hydrochloric acid and stir for 30 minutes. Then add 2g of Ti3AlC2 and stir at 35℃ for 24 hours. Centrifuge the above solution (3500 rpm, 10 minutes), discard the supernatant, and continue centrifuging until the pH of the supernatant after centrifugation is 6. Add 40mL of ethanol to the centrifuge tube and perform ultrasonic centrifugation to obtain the supernatant.
[0039] Step Two: Select polyurethane (PU) fiber as the core component, silver wire as the conductive layer, and polyamide (PA) fiber as the triboelectric layer. The PU fiber is wound onto a fixed bobbin and fed into the braiding zone via a tension device. The bobbins in the braiding zone are wound with silver wire to form the first conductive layer (Ag / PU). Then, PA fiber is wound onto the Ag / PU layer to form the second triboelectric layer (PA / Ag / PU). A 6wt% MXene supernatant is sprayed onto the second triboelectric layer (PA / Ag / PU), and the FM-TENG is produced through continuous operation of the braiding machine.
[0040] Step 3: The elastic recovery rate of FM-TENG was tested using a yarn tensile tester. The results showed that after no less than 500 cycles at 50% strain, the elastic recovery rate was 95.12%.
[0041] Step 4: Simulate various operating modes using a linear motion motor, including position control, speed control, force control, and vibration simulation modes, and measure the open-circuit voltage, short-circuit current, and short-circuit charge transfer of the FM-TENG. As shown in Figure 5, the results indicate that the FM-TENG exhibits stable electrical output within the frequency range of 1 to 5 Hz.
[0042] Step 5: Using the FM-TENG as a pressure sensor, test its voltage change under different pressures. As shown in Figure 6, the results show that the FM-TENG operates in the high-sensitivity region below 30 kPa with a sensitivity of 0.537 V kPa⁻¹, and operates in the low-sensitivity region above 30 kPa with a sensitivity of 0.0313 V kPa⁻¹.
[0043] Step 6: Use a digital caliper (PD-301) to measure the diameter of the FM-TENG fiber, which is 0.99 mm.
[0044] Example 2: Preparation of FM-TENG
[0045] Step 1: Same as Step 1 in Example 1.
[0046] Step 2: Same as Step 2 in Example 2.
[0047] Step 3: The elastic recovery rate of FM-TENG was tested using a yarn tensile tester. The results showed that after no less than 500 cycles at 25% strain, the elastic recovery rate remained at 97.05%.
[0048] Step 4: Using a linear motion motor to simulate various operating modes, including position control, speed control, force control, and vibration simulation, the open-circuit voltage, short-circuit current, and short-circuit charge transfer of the FM-TENG were measured. The results show that the FM-TENG exhibits stable electrical output within the frequency range of 1 to 5 Hz.
[0049] Step 5: Using the FM-TENG as a pressure sensor, test its voltage change under different pressures. The results show that the FM-TENG operates in the high-sensitivity region below 30 kPa, with a sensitivity of 0.541 VkPa. -1 It operates in the low-sensitivity region above 30 kPa, with a sensitivity of 0.0327 V kPa. -1 .
[0050] Step 6: Use a digital caliper (PD-301) to measure the diameter of the FM-TENG fiber, which is approximately 1.00 mm and has a high linear sensing response.
[0051] Example 3: Preparation of FM-TENG
[0052] Step 1: Same as Step 1 in Example 1.
[0053] Step 2: Same as Step 2 in Example 2.
[0054] Step 3: The elastic recovery rate of FM-TENG was tested using a yarn stretching tester. The results showed that after no less than 500 cycles without strain, the elastic recovery rate remained at 99.01%.
[0055] Step 4: Using a linear motion motor to simulate various operating modes, including position control, speed control, force control, and vibration simulation, the open-circuit voltage, short-circuit current, and short-circuit charge transfer of the FM-TENG were measured. The results show that the FM-TENG exhibits stable electrical output within the frequency range of 1 to 5 Hz.
[0056] Step 5: Using the FM-TENG as a pressure sensor, test its voltage change under different pressures. The results show that the FM-TENG operates in the high-sensitivity region below 30 kPa, with a sensitivity of 0.554 VkPa. -1 It operates in the low-sensitivity region above 30 kPa, with a sensitivity of 0.0356 V kPa. -1 .
[0057] Step 6: Use a digital caliper (PD-301) to measure the diameter of the FM-TENG fiber, which is approximately 1.02 mm and has a high linear sensing response.
[0058] Example 4: FM-TENG applied to smart socks
[0059] The stretchable polyurethane fiber coated with MXene triboelectric nanogenerator (FM-TENG) of this invention has an overall linear structure; this linear FM-TENG can be integrated into various customized textiles, such as wrist supports and socks, through processes such as weaving. These textiles can perfectly conform to the human body and are used to monitor human motion signals, as shown in Figures 7 and 8.
[0060] In this embodiment of the invention, human motion signals are identified based on smart socks. The socks are woven from FM-TENG fibers using traditional crochet methods, resulting in good elasticity, breathability, and fit. When the human body moves, the FM-TENG device on the socks comes into contact with and separates from the skin or clothing, generating electrical signals. These electrical signals are transmitted to a data acquisition system via wires, where they are recorded and analyzed. The signal data is stored in time-series format, with each time point corresponding to a voltage value. The data also includes motion-related metadata, such as action type and timestamp.
[0061] Data Acquisition: Data originates from human motion signals collected by FM-TENG smart socks worn on the feet. Human motion actions include standing, slow walking, normal walking, running, and jumping. First, voltage output data obtained from the FM-TENG socks is divided into segments based on specific time intervals. Then, signal processing extracts features of different waveforms to obtain voltage output data again, divided into segments based on specific time intervals. Subsequently, signal processing extracts features of different waveforms, including maximum values, minimum values, and peak-to-peak values. Through repeated testing and verification, the features with the most information and strongest discriminative power are selected to form the final feature set. The dataset collected in the form of time-series signals is divided into training and testing sets, with a ratio of 70% and 30%, respectively, for training and optimizing the machine learning algorithm.
[0062] Feature Classification and Motion Recognition: A one-dimensional convolutional neural network (1D-CNN) method is used to effectively classify human motion patterns. Model optimization techniques are employed to improve the performance of the 1D-CNN. These techniques include hyperparameter tuning, systematically adjusting parameters such as the number of layers, the number of neurons per layer, the learning rate, and the batch size to find the optimal configuration. Simultaneously, regularization techniques such as dropout and weight decay are applied to prevent overfitting and improve the model's robustness. Preprocessed feature values are used as input training samples and co-evolved through multiple pooling operations to complete the classification.
[0063] After 200 training epochs, the framework achieves excellent classification accuracy and robustness. Furthermore, t-SNE visualization is used to transform the high-dimensional data from the CNN output into a low-dimensional space, displaying five actions (standing, walking slowly, walking normally, running, and jumping) with 99% confidence, forming five clusters of different colors. A confusion matrix is used to demonstrate the mismatch between the expected and test datasets. Results show that the corrected model achieves an accuracy of 99.02%.
[0064] In summary, this invention utilizes machine learning algorithms based on a one-dimensional convolutional neural network (1D-CNN) to classify signals collected by FM-TENG using training and testing sets. FM-TENG can accurately identify five actions: standing, walking slowly, walking normally, running, and jumping, with a recognition accuracy of up to 99.02%.
Claims
1. A triboelectric nanogenerator made of stretchable polyurethane fiber coated with MXene, characterized in that, This triboelectric nanogenerator exhibits a layered coaxial structure, comprising, from the inside out, a stretchable layer, a conductive layer, a triboelectric layer, and a two-dimensional material layer; wherein: The stretchable layer is a polyurethane (PU) layer, which is the core component of the triboelectric nanogenerator FM-TENG and is used to provide stretchability. The conductive layer is formed by tightly winding silver wire or silver-coated nylon wire onto a stretchable layer; The triboelectric layer is a polyamide (PA) layer, which is used to generate the triboelectric effect. It is formed by tightly wrapping polyamide (PA) fibers around the outside of the conductive layer. Two-dimensional material layers are used to improve electrical output performance and are formed by spraying a two-dimensional material solution onto the triboelectric layer.
2. The triboelectric nanogenerator according to claim 1, characterized in that, A conductive layer is formed on the stretchable layer through a braiding process, and a polyamide (PA) triboelectric layer is formed on the conductive layer through a braiding process.
3. The triboelectric nanogenerator according to claim 1, characterized in that, It also includes a two-dimensional material layer outside the triboelectric layer. The two-dimensional material layer is used to improve the electrical output performance. It is formed by spraying a two-dimensional material solution onto the triboelectric layer. The two-dimensional material layer is an MXene layer.
4. The triboelectric nanogenerator according to claim 1, characterized in that, The diameter of the triboelectric nanogenerator is 1 ± 0.02 mm.
5. The triboelectric nanogenerator according to claim 1, characterized in that, The triboelectric nanogenerator operates in the range of 5 to 150 kPa and has a sensitivity of 0.0356 VkPa. -1 Up to 0.554VkPa -1 Its elastic recovery rate remains above 95% after at least 500 cycles with an elongation of 0% to 60% and a strain of 0% to 50%.
6. A method for preparing a triboelectric nanogenerator according to claim 1, characterized in that, The triboelectric nanogenerator was fabricated using a two-step weaving process and a spraying process; the specific steps are as follows: (1) Using polyurethane (PU) fiber as the core component, the polyurethane (PU) fiber is wound around a fixed bobbin and enters the braiding area through a tension device; the silver wire or silver-coated nylon wire wound on the bobbin is tightly wound onto the polyurethane (PU) fiber through the braiding process to form a conductive layer and obtain Ag / PU material. (2) By weaving process, polyamide PA fibers wound on the spool are wound onto Ag / PU material to form a triboelectric layer, and a coaxial PA / Ag / PU material is obtained, thus obtaining a triboelectric nanogenerator; (3) MXene supernatant was sprayed onto PA / Ag / PU material to obtain a triboelectric nanogenerator with MXene sprayed onto stretchable polyurethane fiber.
7. The preparation method according to claim 6, characterized in that, In step (3), the preparation method of MXene supernatant is as follows: After mixing and stirring lithium fluoride and hydrochloric acid, Ti3AlC2 is added to carry out the etching reaction. After the reaction is completed, the obtained solution is centrifuged, the supernatant is poured off, and centrifugation is continued until the pH of the supernatant poured off after centrifugation is 6. Ethanol is added to the centrifuge tube, and ultrasonic centrifugation is performed to obtain MXene supernatant.
8. The application of a triboelectric nanogenerator made of stretchable polyurethane fiber coated with MXene according to any one of claims 1 to 5 in wearable devices.
9. An application of a triboelectric nanogenerator made of stretchable polyurethane fiber coated with MXene according to any one of claims 1 to 5 in monitoring human motion signals, characterized in that, Triboelectric nanogenerators coated with MXene on stretchable polyurethane fibers are integrated into wearable devices through a weaving process to monitor human motion signals in real time.
10. The application according to claim 9, characterized in that, Triboelectric nanogenerators coated with MXene on stretchable polyurethane fibers are integrated into socks through a knitting process. Based on machine learning algorithms, the signals collected by FM-TENG are classified to recognize five human body movements: standing, walking slowly, walking normally, running, and jumping.