Preparation method of self-healing wide-temperature-range friction nanogenerator type self-powered biomechanical sensor

Abstract

This invention discloses a method for preparing a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor. The steps are as follows: 1) Preparing FCT composite aerogel, specifically: a) Adding fish gelatin to an acetic acid solution of chitosan and mixing to form a composite colloid, wherein the mass ratio of chitosan to fish gelatin is 1:2; b) Introducing two-dimensional Ti3C2T into the above composite colloid. x The material, added at 1%–20% of the chitosan mass, was stirred evenly at room temperature; c) the above mixed solution was cured at -75–-85 °C for 11–12 h, and freeze-dried to obtain FCT composite aerogel; 2) the FCT composite aerogel obtained in step 1) was used as a positive friction layer to prepare a triboelectric nanogenerator. The constructed self-powered biomechanical sensor can realize self-powered sensing applications such as fingertip tapping recognition, gait recognition, voice recognition, and respiratory monitoring.

Description

Technical Field

[0001] This invention belongs to the field of sensors, specifically relating to a method for preparing a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor. Background Technology

[0002] The demand for wearable electronic devices continues to grow in scenarios such as health monitoring, human-computer interaction, motion assessment, and rehabilitation assistance. However, existing systems mostly rely on rechargeable batteries for power, which suffers from limited battery life, increased size and weight, and the need for frequent charging and maintenance, affecting skin comfort and the feasibility of continuous monitoring. Self-powered biomechanical sensors, as a passive sensing solution, can directly convert mechanical stimuli such as pressure, tension, bending, shearing, and tactile sensations into electrical signals without an external power source. They can also utilize energy from human movement for local energy compensation, thus supporting low-power, long-term online signal acquisition and event recognition. The amplitude, frequency, and waveform characteristics of their output can be mapped to stimulus intensity, rhythm, and contact method, making them suitable for applications such as gait and posture monitoring, joint activity assessment, touch command input, and interactive feedback. Existing methods for implementing self-powered devices include piezoelectricity, thermoelectricity, and triboelectricity. Among these, triboelectric and electrostatic induction-based solutions have relatively simple structures but are sensitive to interface conditions. After repeated deformation, friction and wear, or localized damage, devices are prone to output attenuation and signal drift. Temperature fluctuations can alter material mechanics and interfacial charge behavior, leading to decreased repeatability and limiting wide-temperature-range applications. Existing material systems often struggle to simultaneously achieve flexibility, wear resistance, and self-healing, and are prone to hardening, cracking, or rapid attenuation of interfacial charges at low and high temperatures, resulting in insufficient long-term service life. Therefore, there is an urgent need for a self-powered biomechanical sensor with both self-healing capabilities and wide-temperature-range adaptability, along with its fabrication method, to improve stability and reliability under long-term cyclic operating conditions and enhance signal consistency. Summary of the Invention

[0003] In view of this, the present invention provides a method for fabricating a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor. Specifically, the present invention provides the following technical solution:

[0004] 1. A method for fabricating a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor, comprising the following steps:

[0005] 1) Preparation of FCT composite aerogel, the specific steps are as follows:

[0006] a) Add fish gelatin to the acetic acid solution of chitosan and mix to form a composite colloid. The mass ratio of chitosan to fish gelatin is 1:2.

[0007] b) Introducing two-dimensional Ti3C2T into the above composite colloid xThe amount of material added is 1% to 20% of the mass of chitosan, and it is stirred evenly at room temperature;

[0008] c) The above mixed solution was cured at -75 ~ -85 ℃ for 11 ~ 12 h and freeze-dried to obtain FCT composite aerogel;

[0009] 2) The FCT composite aerogel obtained in step 1) is used as the positive friction layer to prepare a triboelectric nanogenerator.

[0010] Furthermore, the amount added in step b) is 4% of the mass of chitosan.

[0011] Further, step 2) specifically involves: assembling the FCT composite aerogel onto the surface of an indium tin oxide conductive film substrate, using a copper wire as a signal outlet, assembling the polydimethylsiloxane film onto the surface of an aluminum foil or aluminum sheet, using a copper wire as a signal outlet, leading out the two electrodes respectively and constructing a complete dual-electrode conductive path, thereby obtaining a triboelectric nanogenerator based on FCT aerogel and polydimethylsiloxane film.

[0012] Furthermore, the preparation method of the polydimethylsiloxane film is as follows: take polydimethylsiloxane adhesive and polydimethylsiloxane curing agent and mix them at a mass ratio of 10:1. After stirring thoroughly until uniform, let it stand to degas until there are no obvious bubbles in the system. Coat the degassed polydimethylsiloxane mixture evenly on the bottom of a smooth petri dish. Place the coated petri dish at 80°C for heat curing for 2 hours to allow the polydimethylsiloxane to fully crosslink. After curing, cool to room temperature and peel off from the substrate to obtain the polydimethylsiloxane film.

[0013] Furthermore, the two-dimensional Ti3C2T described in step 1) x The preparation method of the material is as follows: Lithium fluoride (LiF) is added to hydrochloric acid solution and stirred until fully dissolved. Titanium aluminum carbide (Ti3AlC2) is then added, and the reaction is stirred at 35 °C for 24 h. After the reaction, the product is centrifuged and repeatedly washed with deionized water until the pH of the washing solution is close to neutral. The washed precipitate is then ultrasonically exfoliated under an argon atmosphere. The ultrasonically treated solution is centrifuged, the supernatant is collected, and freeze-dried to obtain two-dimensional Ti3C2T. x Material.

[0014] Furthermore, the concentration of the hydrochloric acid solution is 9 mol / L.

[0015] Furthermore, the mass ratio of LiF to Ti3AlC2 is 1:1.

[0016] The beneficial effects of this invention are as follows: This invention uses HCl and LiF to construct a liquid phase etching system to etch Ti3AlC2 and obtain two-dimensional Ti3C2T. xMaterials. A composite matrix was formed by combining fish gelatin and chitosan and then incorporating Ti3C2T. x FG / CS / Ti3C2T was prepared by freeze-curing and freeze-drying. x The ternary composite aerogel, denoted as FCT composite aerogel, is used as the positive friction layer of a triboelectric nanogenerator. It can generate a stable electrical output under external mechanical stimulation and can be used to construct a self-powered biomechanical sensor. The triboelectric nanogenerator using the FCT composite aerogel as the positive friction layer has an open-circuit voltage as high as 155.8 V and a peak power density of 714.69 mW / m³. 2 The device can self-heal and restore stable electrical output after mechanical damage with the assistance of trace amounts of deionized water. Simultaneously, the device maintains stable electrical performance within a temperature range of −80 ℃ to 60 ℃. Based on the differences in electrical output under different pressures, the constructed self-powered biomechanical sensor can realize self-powered sensing applications such as fingertip tapping recognition, gait recognition, voice recognition, and respiratory monitoring. Attached Figure Description

[0017] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided:

[0018] Figure 1 The figure shows the test results of the open-circuit voltage (Voc) generated by the triboelectric nanogenerator when FCT composite aerogel is used as the positive friction layer;

[0019] Figure 2 Figure 1 shows the test results of the open-circuit voltage (Voc) output performance of the FCT-FP-T aerogel triboelectric nanogenerator and the CT-FP-T aerogel triboelectric nanogenerator.

[0020] Figure 3 Figure showing the test results of open-circuit voltage (Voc) output performance of FCT-FP-T aerogel triboelectric nanogenerator after treatment at 60℃ and -80℃ or self-healing of mechanical damage.

[0021] Figure 4 The figure shows the power density output performance test results of the FCT-FP-T aerogel triboelectric nanogenerator.

[0022] Figure 5 The figure shows the test results of the FCT-FP-T aerogel triboelectric nanogenerator-type self-powered biomechanical sensor. Detailed Implementation

[0023] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0024] Example 1

[0025] 1. Preparation of FG / CS / Ti3C2Tx -1 ternary composite aerogel (FCT-1 aerogel), the steps are as follows:

[0026] 1) Take 40 mL of 9 mol / L hydrochloric acid (HCl) solution, add 2 g of lithium fluoride (LiF), and stir for 5 min to dissolve it completely. Then, slowly add 2 g of aluminum carbide (Ti3AlC2) powder to the above solution and stir the reaction at 35 ℃ for 24 h. After the reaction is complete, centrifuge the reaction product at 4000 rpm and wash repeatedly with deionized water until the pH of the washing solution is close to neutral. Place the washed precipitate under an argon atmosphere and sonicate for 1 h. Centrifuge the sonicated solution at 4000 rpm for 1 h, collect the supernatant and freeze-dry it to obtain Ti3C2T x powder.

[0027] 2) Weigh 1 g of chitosan (CS) and dissolve it in 20 mL of 0.17 mol / L acetic acid solution. Stir magnetically until a homogeneous solution is formed. Add 2 g of fish gelatin (FG) and continue stirring for 2 h to obtain a CS / FG composite colloid. Add 10 mg of Ti3C2T to the above composite colloid. x The powder (0.5 mg / mL) was stirred for 2 h at room temperature to ensure uniform dispersion. The mixture was transferred to a custom mold and cured at -80 °C for 12 h, followed by freeze-drying to obtain FG / CS / Ti3C2T. x -1 composite aerogel, denoted as FCT-1 aerogel.

[0028] 2. The following steps were taken to prepare a triboelectric nanogenerator based on FCT-1 aerogel:

[0029] 1) Mix polydimethylsiloxane (PDMS) base adhesive and PDMS curing agent at a mass ratio of 10:1, stir thoroughly until homogeneous, and allow to stand to degas until no obvious bubbles remain in the system. Evenly coat the degassed PDMS mixture onto the bottom of a smooth petri dish. Place the coated petri dish at 80℃ for heat curing for 2 hours to allow complete cross-linking of the PDMS. After curing, cool to room temperature and peel off from the substrate to obtain the PDMS film.

[0030] 2) The FCT-1 aerogel prepared in Example 1 was assembled onto the surface of an indium tin oxide (ITO) conductive film substrate, with a copper wire serving as the signal outlet. The PDMS film was then assembled onto an aluminum foil or sheet, again with a copper wire serving as the signal outlet. The two electrodes were then led out to construct a complete two-electrode conductive path, resulting in a triboelectric nanogenerator based on the FCT-1 aerogel and PDMS film, denoted as FCT-P-1.

[0031] Example 2

[0032] 1. Preparation of FG / CS / Ti3C2T x -2 ternary composite aerogel (FCT-2 aerogel), the steps are as follows:

[0033] 1) Preparation of Ti3C2T x Powder, same as in Example 1.

[0034] 2) Weigh 1 g of chitosan and dissolve it in 20 mL of 0.17 mol / L acetic acid solution, stirring magnetically until a homogeneous solution is formed. Add 2 g of fish gelatin and continue stirring for 2 h to obtain the CS / FG composite colloid. Add 20 mg of Ti3C2T to the above composite colloid. x The powder (1 mg / mL) was stirred for 2 h at room temperature to ensure uniform dispersion. The mixture was then transferred to a custom mold and cured at -80 °C for 12 h, followed by freeze-drying to obtain FG / CS / Ti3C2T. x -2 composite aerogel, denoted as FCT-2 aerogel.

[0035] 2. The following steps were taken to prepare a triboelectric nanogenerator based on FCT-2 aerogel:

[0036] 1) Prepare PDMS film, same as in Example 1.

[0037] 2) The FCT-2 aerogel prepared in Example 2 was assembled onto the surface of an ITO conductive film substrate, with a copper wire serving as the signal outlet. The PDMS film was then assembled onto an aluminum foil or aluminum sheet, again with a copper wire serving as the signal outlet. The two electrodes were then led out to form a complete two-electrode conductive path, resulting in a triboelectric nanogenerator based on the FCT-2 aerogel and PDMS film, denoted as FCT-P-2.

[0038] Example 3

[0039] 1. Preparation of FG / CS / Ti3C2T x -3 ternary composite aerogel (FCT-3 aerogel), the steps are as follows:

[0040] 1) Preparation of Ti3C2T x Powder, same as in Example 1.

[0041] 2) Weigh 1 g of chitosan and dissolve it in 20 mL of 0.17 mol / L acetic acid solution, stirring magnetically until a homogeneous solution is formed. Add 2 g of fish gelatin and continue stirring for 2 h to obtain the CS / FG composite colloid. Add 40 mg of Ti3C2T to the above composite colloid. xThe powder (2 mg / mL) was stirred for 2 h at room temperature to ensure uniform dispersion. The mixture was then transferred to a custom mold and cured at -80 °C for 12 h, followed by freeze-drying to obtain FG / CS / Ti3C2T. x -3 composite aerogel, denoted as FCT-3 aerogel.

[0042] 2. The following steps were taken to prepare a triboelectric nanogenerator based on FCT-3 aerogel:

[0043] 1) Prepare PDMS film, same as in Example 1.

[0044] 2) The FCT-3 aerogel prepared in Example 3 was assembled onto the surface of an ITO conductive film substrate, with a copper wire serving as the signal outlet. The PDMS film was then assembled onto an aluminum foil or aluminum sheet, again with a copper wire serving as the signal outlet. The two electrodes were then led out to form a complete two-electrode conductive path, resulting in a triboelectric nanogenerator based on the FCT-3 aerogel and PDMS film, denoted as FCT-P-3.

[0045] Example 4

[0046] 1. Preparation of FG / CS / Ti3C2T x -4 ternary composite aerogel (FCT-4 aerogel), the steps are as follows:

[0047] 1) Preparation of Ti3C2T x Powder, same as in Example 1.

[0048] 2) Weigh 1 g of chitosan and dissolve it in 20 mL of 0.17 mol / L acetic acid solution, stirring magnetically until a homogeneous solution is formed. Add 2 g of fish gelatin and continue stirring for 2 h to obtain the CS / FG composite colloid. Add 100 mg of Ti3C2T to the above composite colloid. x The powder (5 mg / mL) was stirred for 2 h at room temperature to ensure uniform dispersion. The mixture was then transferred to a custom mold and cured at -80 °C for 12 h, followed by freeze-drying to obtain FG / CS / Ti3C2T. x -4 composite aerogel, denoted as FCT-4 aerogel.

[0049] 2. The following steps were taken to prepare a triboelectric nanogenerator based on FCT-4 aerogel:

[0050] 1) Prepare PDMS film, same as in Example 1.

[0051] 2) The FCT-4 aerogel prepared in Example 4 was assembled onto the surface of an ITO conductive film substrate, with a copper wire serving as the signal outlet. The PDMS film was then assembled onto an aluminum foil or sheet, again with a copper wire serving as the signal outlet. The two electrodes were then led out to form a complete two-electrode conductive path, resulting in a triboelectric nanogenerator based on the FCT-4 aerogel and PDMS film, denoted as FCT-P-4.

[0052] Example 5

[0053] 1. Preparation of FG / CS / Ti3C2T x -5 ternary composite aerogel (FCT-5 aerogel), the steps are as follows:

[0054] 1) Preparation of Ti3C2T x Powder, same as in Example 1.

[0055] 2) Weigh 1 g of chitosan and dissolve it in 20 mL of 0.17 mol / L acetic acid solution, stirring magnetically until a homogeneous solution is formed. Add 2 g of fish gelatin and continue stirring for 2 h to obtain the CS / FG composite colloid. Add 200 mg of Ti3C2T to the above composite colloid. x The powder (10 mg / mL) was stirred for 2 h at room temperature to ensure uniform dispersion. The mixture was then transferred to a custom mold and cured at -80 °C for 12 h, followed by freeze-drying to obtain FG / CS / Ti3C2T. x -5 composite aerogel, denoted as FCT-5 aerogel.

[0056] 2. The following steps were taken to prepare a triboelectric nanogenerator based on FCT-5 aerogel:

[0057] 1) Prepare PDMS film, same as in Example 1.

[0058] 2) The FCT-5 aerogel prepared in Example 5 was assembled onto the surface of an ITO conductive film substrate, with a copper wire serving as the signal outlet. The PDMS film was then assembled onto the surface of an aluminum foil or sheet, again with a copper wire serving as the signal outlet. The two electrodes were then led out to form a complete two-electrode conductive path, resulting in a triboelectric nanogenerator based on the FCT-5 aerogel and PDMS film, denoted as FCT-P-5.

[0059] Example 6

[0060] 1. Preparation of FG / CS / Ti3C2T x A triboelectric nanogenerator-type self-powered biomechanical sensor (FCT-FP-T) based on -5 ternary composite aerogel (abbreviated as: FCT composite aerogel).

[0061] 1) Mix PDMS base adhesive and PDMS curing agent at a mass ratio of 10:1, stir thoroughly until homogeneous, and allow to stand to degas until no obvious bubbles remain in the system. Coat the degassed PDMS mixture evenly onto the surface of sandpaper with different mesh sizes, the sandpaper being 500 mesh. Heat-cur the coated composite system at 80°C for 2 hours to allow complete cross-linking of the PDMS. After curing, cool to room temperature and peel off from the sandpaper substrate to obtain a PDMS film with a microstructured surface. Place the PDMS film in an oxygen plasma treatment system for surface activation, with a single-sided treatment time set to 100 s. Immediately after surface activation, place the PDMS film into a sealed container containing a small amount of 1H,1H,2H,2H-perfluorooctyltrichlorosilane (FOTS) for vapor-phase self-assembly deposition, and maintain the container at 40°C for 4 hours to obtain a surface-functionalized PDMS film, denoted as FPDMS.

[0062] 2) Take the aerogel FCT-3 prepared in Example 3 and assemble it on the surface of an ITO conductive film substrate, using a copper wire as the signal outlet. Assemble the above-mentioned FPDMS film on the surface of an aluminum foil or aluminum sheet, also using a copper wire as the signal outlet. Lead out the two electrodes respectively and construct a complete two-electrode conductive path to obtain a triboelectric nanogenerator based on FCT aerogel and FPDMS film, denoted as FCT-FP-T, which also serves as a self-powered biomechanical sensor.

[0063] Comparative Example 1

[0064] 1. Preparation of CS / Ti3C2T x Binary composite aerogel (CT aerogel), the steps are as follows:

[0065] 1) Preparation of Ti3C2T x Powder, same as in Example 1.

[0066] 2) Weigh 1 g of chitosan and dissolve it in 20 mL of 0.17 mol / L acetic acid solution, stirring magnetically until a homogeneous solution is formed. Then add 40 mg of Ti3C2T to the solution. x The powder (2 mg / mL) was stirred at room temperature for 2 h to ensure uniform dispersion. The mixture was transferred to a custom mold and cured at -80 °C for 12 h, followed by freeze-drying to obtain CS / Ti3C2T. x Composite aerogel, denoted as CT aerogel.

[0067] 2. The following steps were taken to prepare a triboelectric nanogenerator based on CT aerogel:

[0068] 1) Mix PDMS base adhesive and PDMS curing agent at a mass ratio of 10:1, stir thoroughly until homogeneous, and allow to stand to degas until no obvious bubbles remain in the system. Coat the degassed PDMS mixture evenly onto the surface of sandpaper with different mesh sizes, specifically 500 mesh. Heat-cur the coated composite system at 80°C for 2 hours to ensure complete cross-linking of the PDMS. After curing, cool to room temperature and peel off from the sandpaper substrate to obtain a PDMS film with a microstructured surface. Place the PDMS film in an oxygen plasma treatment system for surface activation, with a single-sided treatment time set to 100 seconds. Immediately after surface activation, place the PDMS film into a sealed container containing a small amount of FOTS for vapor phase self-assembly deposition, and maintain the container at 40°C for 4 hours to obtain a surface-functionalized PDMS film, denoted as FPDMS.

[0069] 2) Take the CT aerogel obtained in step 1) of Comparative Example 1, assemble it on the surface of an ITO conductive film substrate, and use a copper wire as a signal outlet. Assemble the above-mentioned FPDMS film on the surface of an aluminum foil or aluminum sheet, and similarly use a copper wire as a signal outlet. Lead out the two electrodes respectively and construct a complete two-electrode conductive path to obtain a triboelectric nanogenerator based on CT aerogel and FPDMS film, denoted as CT-FP-T.

[0070] Test Example 1

[0071] The open-circuit voltage (Voc) output performance of the FCT aerogel triboelectric nanogenerators (FCT-P-1 ~ FCT-P-5) prepared in Examples 1 to 5 was tested.

[0072] FCT aerogel, serving as the positive friction layer of the device, is assembled onto the surface of an ITO conductive film substrate and connected to the test circuit via lead wires. A linear motor test system and a Keithley 6517B electrometer are used as the test system. The positive and negative friction layers are fixed to the two back plates of the linear motor, respectively, forming a contact-separation working mode in the vertical direction. Periodic contact and separation are achieved under programmable drive to simulate the device's operation under external mechanical stimulation and to complete the conversion of mechanical energy into electrical energy. The electrometer is used to collect and record the device's electrical output signals. During testing, the positive friction layer and its back electrode are fixed to the left end of the linear motor, and its lead wires are connected to the electrometer. The negative friction layer and its back electrode are fixed to the right end of the linear motor, and its lead wires are connected to the electrometer. After completing the electrode connections, the linear motor motion parameters are set, using periodic contact-separation motion at a frequency of 1.5 Hz as the excitation method.

[0073] During the testing process, the open-circuit voltage Voc generated by the triboelectric nanogenerator when the FCT composite aerogel was used as the positive friction layer in Examples 1-5 was collected and recorded in real time using LinMot software and an electrometer, so as to conduct performance screening.

[0074] Figure 1 The graph shows the test results of the open-circuit voltage (Voc) generated by the triboelectric nanogenerator when FCT composite aerogel is used as the positive friction layer. From... Figure 1 It can be seen that:

[0075] While keeping the other preparation and testing conditions consistent, Ti3C2T was prepared separately. x Samples of 10 mg, 20 mg, 40 mg, 100 mg and 200 mg were added and assembled into devices for electrical testing, and their open-circuit voltage output was recorded.

[0076] Test results show that, with Ti3C2T x As the dosage increased from 10 mg to 20 mg, the device voltage output showed an increasing trend. When Ti3C2T... x When the addition amount was 40 mg, the voltage output further increased and reached approximately 70 V. Subsequently, when Ti3C2T x When the dosage was further increased to 100 mg, the voltage output dropped to approximately 60 V. When the dosage was further increased to 200 mg, the voltage output continued to decrease compared to the 100 mg condition. When the dosage was too high, Ti3C2T… x Excessive stacking of nanosheets obstructs conductive pathways, leading to a decrease in charge transport efficiency. Therefore, Ti3C2T x The optimal dosage is 40 mg.

[0077] Test Example 2

[0078] The open-circuit voltage (Voc) output performance of the FCT-FP-T aerogel triboelectric nanogenerator prepared in Example 6 and the CT-FP-T nanotriboelectric nanogenerator prepared in Comparative Example 1 were tested. The test system and excitation method were the same as in Example 1. During the test, CS / Ti3C2T was acquired and recorded in real time using LinMot software and an electrometer. x Composite aerogel with FG / CS / Ti3C2T x The open-circuit voltage Voc generated by the triboelectric nanogenerator when the composite aerogel is used as the positive friction layer.

[0079] Figure 2 The graph shows the test results of the open-circuit voltage (Voc) output performance of the FCT-FP-T aerogel triboelectric nanogenerator and the CT-FP-T aerogel triboelectric nanogenerator. From... Figure 2 It can be seen from this:

[0080] FG / CS / Ti3C2T x The Voc output generated when ternary composite aerogel is used as a positive friction layer is significantly higher than that of CS / Ti3C2T. x Binary composite aerogel. Among them, CS / Ti3C2T... x When the binary composite aerogel is used as a positive friction layer, it generates an open-circuit voltage of 108.83 V; FG / CS / Ti3C2T x When the ternary composite aerogel is used as a positive friction layer, it can generate an open-circuit voltage of 155.8 V. Compared with the one without FG, the performance of the ternary composite aerogel of the present invention is improved by 41.83%.

[0081] Test Example 3

[0082] The open-circuit voltage (Voc) output performance of the FCT-FP-T aerogel triboelectric nanogenerator prepared in Example 6 was tested after treatment at 60℃ and -80℃ or after mechanical damage self-healing. The test steps are as follows:

[0083] 1) The FCT-3 composite aerogel was subjected to high-temperature and low-temperature treatments. High-temperature treatment involved placing the sample at 60℃ for 24 hours, and low-temperature treatment involved placing the sample at -80℃ for 24 hours. After treatment, the sample was brought back to room temperature. Subsequently, the electrical output was tested using the same test system and excitation method as in Test Example 1 to compare the changes in the open-circuit voltage (Voc) output signal before and after the wide-temperature treatment, thereby evaluating its wide-temperature adaptability and output stability.

[0084] 2) The FCT-3 composite aerogel was cut to form a fracture interface. A small amount of deionized water was then sprayed onto the cut surface to induce slight hydration of the fracture interface. The two cut parts were then butt-bonded at room temperature and held together for approximately 30 seconds to allow the sample to self-heal and return to a continuous whole. After self-healing, electrical output testing was performed using the same testing system and excitation method as in Test Example 1 to compare the changes in the open-circuit voltage (Voc) output signal of the device after self-healing of mechanical damage, thereby evaluating its ability to recover electrical performance after self-healing.

[0085] Figure 3 The graph shows the open-circuit voltage (Voc) output performance test results of the FCT-FP-T aerogel triboelectric nanogenerator after treatment at 60℃ and -80℃ or self-healing of mechanical damage. From... Figure 3 It can be seen from this:

[0086] FG / CS / Ti3C2T xWhen used as a positive friction layer, the composite aerogel generates an open-circuit voltage of 155.8 V; after treatment at 60℃, the open-circuit voltage is 155.5 V, with a retention rate of 99.8%; after treatment at -80℃, the open-circuit voltage is 155.6 V, with a retention rate of 99.8%; after self-healing from mechanical damage, the open-circuit voltage is 152.1 V, with a retention rate of 97.6%. This demonstrates excellent wide-temperature adaptability and self-healing properties.

[0087] Test Example 4

[0088] The power density output performance of the FCT-FP-T aerogel triboelectric nanogenerator prepared in Example 6 was tested.

[0089] The test platform and excitation method are the same as in Test Example 1. The two ends of the triboelectric nanogenerator under test are respectively led out and connected to an external load resistor. The load resistor has a value ranging from 1 MΩ to 500 MΩ, and is switched sequentially using a resistance box. An electrometer is connected across the load resistor to measure the output voltage signal U and the output current I in real time. During the test, a linear motor is used to make the device perform periodic contact-separation movements at a preset frequency, and the voltage waveform within a stable period is collected under each load resistor condition. Under each load resistor R condition, the output power P is calculated based on the measured output voltage U and output voltage I, using the formula P = UI / S, where S is the effective working area. The effective working area used in the test is 4 cm². 2 The power densities corresponding to various load resistors in the range of 1 MΩ to 500 MΩ are statistically analyzed and compared. The load resistor corresponding to the maximum power density is taken as the optimal matching load for the device, and this maximum value is taken as the peak power density characterization result of the device.

[0090] Figure 4 The graph shows the power density output performance test results of the FCT-FP-T aerogel triboelectric nanogenerator. From... Figure 4 It can be seen from this:

[0091] With an external load of 90 MΩ, the triboelectric nanogenerator exhibits a power output of 714.69 mW / m. 2 The peak power density is higher than that of other aerogel-based triboelectric nanogenerators published in recent years.

[0092] Test Example 5

[0093] The self-powered biomechanical sensing performance of the FCT-FP-T aerogel triboelectric nanogenerator prepared in Example 6 was tested.

[0094] Wearable devices are constructed by attaching the FCT-FP-T as the basic structure to a flexible polyethylene terephthalate (PET) substrate. Utilizing the flexibility and conformability of the PET substrate, the devices can adapt to multiple joints and curved surfaces of the human body, including the throat, soles of the feet, and abdomen. The wearable devices are fixed to these different locations, and the electrical output signals generated by the devices under natural human movement or specific action stimuli are recorded on the same test platform and under the same signal acquisition conditions for functional verification. In the tapping recognition test, stimulation is generated by continuous tapping, and the corresponding electrical output waveform characteristics are collected and recorded to distinguish different tapping patterns. In the gait recognition test, the device is attached to the sole of the foot, and electrical output signals are collected during the volunteer's walking or gait changes. The periodic waveform characteristics and amplitude changes are used for gait recognition. In the speech recognition test, the device is attached to the throat area as a speech signal acquisition module, collecting the corresponding electrical output signals when the volunteer speaks and using them for speech recognition. In the respiratory monitoring test, the device is attached to the abdomen and electrical output signals are collected during the volunteer's natural breathing. The respiratory status is monitored based on the changes in electrical signals corresponding to the periodic deformation caused by breathing.

[0095] Figure 5 The test results are for the FCT-FP-T aerogel triboelectric nanogenerator type self-powered biomechanical sensor.

[0096] from Figure 5 As can be seen from (a):

[0097] The voltage waveform triggered by a fingertip tap exhibits a clear transient peak response, with each tap corresponding to a single sharp peak, the peak appearing at the same time as the tap. As the tapping force increases, the peak height increases synchronously with a steeper rise edge, reflecting stronger instantaneous contact pressure. Different tap intervals correspond to the time distance between peaks; the signal returns to the baseline quickly and exhibits good repeatability, indicating that the device can be used to distinguish and identify tapping intensity and rhythm.

[0098] from Figure 5 As can be seen from (b):

[0099] In gait recognition testing, both walking and running produce stable periodic voltage responses, with waveform peaks and troughs corresponding to the gait period, reflecting the foot's landing and takeoff processes. Compared to walking, the voltage peak amplitude is significantly larger during running, with sharper peaks and more dramatic waveform fluctuations, indicating higher impact loads and deformation rates. The amplitude differences and periodic characteristics between different movement modes are clearly distinguishable and can be used to identify movement intensity and gait type.

[0100] from Figure 5 As can be seen from (c):

[0101] After the FCT-FP-T was attached and fixed to the volunteer's throat, when the subject clearly pronounced the target word "Self-Drive," the device's output voltage waveform showed regular changes closely related to vocal cord vibration. The fluctuations corresponding to different syllables during phonation were clearly distinguishable, and the waveform exhibited stable characteristics in duration, peak amplitude, and pulse density, reflecting differences in syllable length, intensity, and vibration frequency. This signal originates from the microscale contact separation effect induced by vocal cord vibration, realizing the conversion of biomechanical energy into an electrical signal.

[0102] from Figure 5 As can be seen from (d):

[0103] When the device is attached to the abdomen, the periodic fluctuations in the abdomen caused by breathing are stably converted into a continuous voltage waveform, exhibiting clear segmentation characteristics between the inhalation and exhalation phases. During inhalation, the waveform gradually rises to a peak, and during exhalation, the waveform gradually falls back to the baseline, with the alternation of peaks and troughs corresponding to a complete respiratory cycle. The waveform amplitude and slope change with the depth and frequency of breathing, indicating that the device can capture the respiratory rhythm and intensity in real time, achieving self-powered respiratory monitoring.

[0104] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A method for fabricating a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor, characterized in that, The steps are as follows: 1) Preparation of FCT composite aerogel, the specific steps are as follows: a) Add fish gelatin to the acetic acid solution of chitosan and mix to form a composite colloid. The mass ratio of chitosan to fish gelatin is 1:

2. b) Introducing two-dimensional Ti3C2T into the above composite colloid x The amount of material added is 1% to 20% of the mass of chitosan, and it is stirred evenly at room temperature; c) The above mixed solution was cured at -75 ~ -85 ℃ for 11 ~ 12 h and freeze-dried to obtain FCT composite aerogel; 2) The FCT composite aerogel obtained in step 1) is used as the positive friction layer to prepare a triboelectric nanogenerator.

2. The method for fabricating a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor according to claim 1, characterized in that, The amount added in step b) is 4% of the mass of chitosan.

3. The method for fabricating a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor according to claim 1, characterized in that, Step 2) Specifically, FCT composite aerogel is assembled on the surface of an indium tin oxide conductive film substrate, and a copper wire is used as a signal outlet. Polydimethylsiloxane film is assembled on the surface of an aluminum foil or aluminum sheet, and a copper wire is used as a signal outlet. The two electrodes are led out respectively and a complete dual-electrode conductive path is constructed to obtain a triboelectric nanogenerator based on FCT aerogel and polydimethylsiloxane film.

4. The method for fabricating a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor according to claim 3, characterized in that, The preparation method of the polydimethylsiloxane film is as follows: polydimethylsiloxane adhesive and polydimethylsiloxane curing agent are mixed at a mass ratio of 10:1, stirred thoroughly until uniform, and then allowed to stand to degas until there are no obvious bubbles in the system. The degassed polydimethylsiloxane mixture is then uniformly coated onto the bottom of a smooth petri dish. The coated petri dish is then placed at 80°C for heat curing for 2 hours to allow the polydimethylsiloxane to fully crosslink. After curing, the mixture is cooled to room temperature and peeled off from the substrate to obtain the polydimethylsiloxane film.

5. The method for fabricating a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor according to claim 1, characterized in that, Step 1) The two-dimensional Ti3C2T x The preparation method of the material is as follows: Lithium fluoride (LiF) is added to hydrochloric acid solution and stirred until fully dissolved. Titanium aluminum carbide (Ti3AlC2) is then added, and the reaction is stirred at 35 °C for 24 h. After the reaction, the product is centrifuged and repeatedly washed with deionized water until the pH of the washing solution is close to neutral. The washed precipitate is then ultrasonically exfoliated under an argon atmosphere. The ultrasonically treated solution is centrifuged, the supernatant is collected, and freeze-dried to obtain two-dimensional Ti3C2T. x Material.

6. The method for fabricating a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor according to claim 5, characterized in that, The concentration of the hydrochloric acid solution is 9 mol / L.

7. The method for fabricating a self-healing, wide-temperature-range triboelectric nanogenerator-type self-powered biomechanical sensor according to claim 4, characterized in that: The mass ratio of LiF to Ti3AlC2 is 1:1.

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