PDMS / PTFE (Polydimethylsiloxane / Polytetrafluoroethylene) friction nano-generator based on biological topological structure and preparation method of PDMS / PTFE friction nano-generator

Abstract

The invention discloses a PDMS / PTFE (Polydimethylsiloxane / Polytetrafluoroethylene) friction nano-generator based on a biological topological structure and a preparation method thereof. The PDMS / PTFE friction nano-generator is prepared by uniformly mixing PDMS, a PDMS curing agent, PTFE, ethanol, n-hexane and a substrate (such as wings of leaves, butterflies, dragonflies and cicadas) with the biological topological structure under a heating condition. The PDMS / PTFE friction nano-generator based on the biological topological structure can significantly improve the electric signal output performance, and has the advantages of efficient energy conversion, stable structure, wide environmental adaptability, simple preparation process, low cost and the like. The friction nanometer generator can be widely applied to the fields of energy collection, self-powered sensing, wearable equipment and the like, is suitable for various complex environments, and is easy for large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical fields of biomaterial preparation and biomedical applications, and particularly to a PDMS / PTFE triboelectric nanogenerator based on a biological topological structure and a preparation method thereof. Background Art

[0002] With the rapid development of the Internet of Things, wearable electronic devices, and self-powered sensing technologies, the demand for efficient and sustainable micro energy harvesting devices has become increasingly urgent. Triboelectric nanogenerators (TENGs) have attracted much attention because they can convert ambient mechanical energy into electrical energy and show great potential in the fields of energy harvesting, human-machine interaction, and intelligent sensing. Currently, the performance optimization of TENGs mainly relies on the screening of triboelectric materials and the design of surface structures. Polydimethylsiloxane (PDMS) and polytetrafluoroethylene (PTFE), as typical triboelectric materials, are widely used due to their high electron affinity, chemical stability, and processability. However, traditional planar-structured PDMS / PTFE triboelectric nanogenerators still have problems such as low energy conversion efficiency and insufficient output signal stability, and their performance is prone to decay especially in complex environments (such as humidity changes and dynamic contact frequency fluctuations).

[0003] In recent years, researchers have attempted to improve the performance of TENGs through bionic strategies, such as mimicking the microstructures on the lotus leaf surface to enhance hydrophobicity, or drawing on animal skin textures to increase the contact area. However, existing bionic designs are mostly limited to single-scale structures (such as micron-scale protrusions or grooves), and the utilization of natural biological multi-level topological structures (such as fractal geometry, hierarchical folds, porous networks) is still insufficient. In addition, traditional preparation processes (such as photolithography and template imprinting) are costly, have complex steps, and are difficult to accurately replicate the complex features of biological topologies. For example, a PDMS surface micro-column array TENG based on laser etching can improve the output charge density, but its preparation relies on expensive equipment, and the structural rigidity is prone to cause long-term contact fatigue failure. Some other studies have improved the electrical properties of materials by doping nanoparticles (such as carbon nanotubes and graphene), but the introduced foreign interfaces may reduce the material homogeneity and even cause mechanical property degradation. Therefore, developing a TENG technology with high-efficiency energy conversion, environmental robustness, low cost, and scalable preparation still faces challenges.

[0004] Through its unique micro-nano topography and surface properties, the topological structure can effectively increase the contact area and charge transfer efficiency of the triboelectric nanogenerator, thereby significantly enhancing the electrical signal output. At the same time, the flexibility and biocompatibility of the bionic design reduce the risk of mechanical damage to biological tissues by the device and enhance the biosafety. In addition, the environmental adaptability and self-cleaning properties of the biological structure also improve the durability and stability of the device, making it more potential for applications in complex environments. For example, Patent CN118449391A discloses a triboelectric nanogenerator based on a scale structure. By subjecting the MXene / CMC solution to pre-freezing and freeze-drying to form an aerogel layer, impregnating and drying a nylon fabric to form a composite fabric, cutting and sewing it into a bionic scale layer, and printing electrode materials on the other side of the aerogel layer, a triboelectric nanogenerator based on a scale structure is finally constructed. Due to the too large gaps in its surface structure, the loss of charge transfer makes it unstable, and its preparation steps are also relatively cumbersome, not suitable for mass production. Another example is that Patent CN119410002A discloses a highly elastic SBS-tea powder friction layer, its preparation method and application in a triboelectric nanogenerator. Using hydroxylated SBS and tea powder as raw materials, an SBS-tea powder film is prepared for use in a triboelectric nanogenerator. The waste tea powder is used to increase the number of H atoms in the friction layer, providing more electrons for the highly electronegative F atoms of PTFE, thus increasing the electrical output characteristics of the triboelectric nanogenerator. However, due to the relatively small particle size of the tea powder and possible hydrophobicity, its dispersibility in the polymer matrix may be poor, so it cannot be well dispersed on the surface of the film, resulting in incomplete surface contact of the film, and thus causing charge loss and poor stability. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a PDMS / PTFE triboelectric nanogenerator based on a biological topological structure and its preparation method. The prepared triboelectric nanogenerator has the advantages of significant improvement in electrical signals, safety, non-toxicity, good biocompatibility, low cost and simple operation, providing an important reference for the design and development of various wearable devices.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions: A preparation method of a PDMS / PTFE triboelectric nanogenerator based on a biological topological structure, comprising the following steps: Step (1): Dissolve PTFE in ethanol and vortex mix to obtain solution S1; Step (2): Add the PDMS matrix to n-hexane and stir at room temperature to obtain solution S2; Step (3): Pour solution S1 into solution S2, heat and stir to mix evenly to obtain solution S3; Step (4): Pour solution S3 into a culture dish with a substrate having a biological topological structure to obtain solution S4; Step (5): Add the PDMS curing agent into solution S4 and stir at room temperature to obtain solution S5; Step (6): Dry and peel solution S5 to obtain the PDMS / PTFE triboelectric nanogenerator based on the biological topological structure.

[0007] In a preferred embodiment: In solution S1 of step (1), the mass fraction of PTFE is 0.01~1 wt%, the mass fraction of ethanol is 0.1~20 wt%, and the vortex time is 0.5~1 h.

[0008] In a preferred embodiment: In solution S2 of step (2), the concentration of PDMS is 0.01~10 g / mL, the stirring temperature is 10~25 °C, and the stirring time is 0.5~2 h.

[0009] In a preferred embodiment: In step (3), pour solution S1 into solution S2 and heat and stir, the stirring temperature is 80~100 °C; the stirring time is 4~6 h.

[0010] In a preferred embodiment: In solution S4 of step (4), pour solution S3 into a substrate culture dish with a biological topological structure, and the biological topological structure includes the wings of a leaf, a butterfly, a dragonfly or a cicada.

[0011] In a preferred embodiment: In step (5), the concentration of the PDMS curing agent is 0.001~0.1 g / mL.

[0012] In a preferred embodiment: In step (6), solution S5 is dried in an oven at 70~85 °C for 2~3 h and then peeled off.

[0013] The present invention also provides a PDMS / PTFE triboelectric nanogenerator based on a biological topological structure, which is prepared by using the preparation method of a PDMS / PTFE triboelectric nanogenerator based on a biological topological structure as described above.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) A series of PDMS / PTFE triboelectric nanogenerators prepared by the present invention have excellent charge generation ability. By precisely imprinting the topological structures of butterfly, leaf, dragonfly and cicada wings on the surface of the PDMS / PTFE film through a simple and efficient hot-melt method, not only the contact area of the microstructure is significantly increased, the triboelectric effect is enhanced, but also the hot-melt method, as a green and low-energy processing technology, avoids complex chemical treatment processes, which is in line with the concept of sustainable development. This efficient and environmentally friendly preparation method further improves the performance of the triboelectric nanogenerator and reduces the production cost at the same time, having broad application potential.

[0015] (2) By introducing surface microstructures with different topologies and utilizing the bionic design of natural organisms, the present invention successfully increases the contact area of the friction surface. The larger surface particle size and structural features enhance the friction effect, thereby significantly improving the acquisition efficiency of electrical signals and the charge transfer speed. This improvement mechanism is based on the enhancement of the contact force at the contact interface by the topology, further promoting the electron transfer process and providing the triboelectric nanogenerator with more efficient electrical energy conversion ability. Therefore, this design provides a more stable and accurate signal acquisition solution for wearable devices. Especially under dynamic movement conditions, it can continuously and stably provide energy for sensors, having important application value.

[0016] (3) The PDMS / PTFE triboelectric nanogenerator based on the biological topology structure prepared in the present invention fully considers the excellent biological safety and good biocompatibility of PDMS and PTFE, ensuring the safe application of the generator in wearable devices. The PDMS / PTFE material has a wide application foundation. Because it is non-toxic, non-irritating, has strong durability and good stability, it shows excellent biocompatibility in the human contact environment. The prepared triboelectric nanogenerator not only has a high electrical signal acquisition ability, but also has stable performance under dynamic conditions, is suitable for long-term wearing, and has the advantages of simple preparation process, low cost and easy large-scale production, showing broad application prospects, especially in the fields of wearable devices and intelligent sensors. Description of the Drawings

[0017] Figure 1 It is the test result of the infrared absorption spectrum of the PDMS / PTFE triboelectric nanogenerator prepared in Example 1 of the present invention; Figure 2 It is the scanning electron microscope images of the PDMS / PTFE triboelectric nanogenerators based on the natural biological topology structures prepared in Examples 1 - 5 of the present invention; Figure 3 It is the voltage test results of the PDMS / PTFE triboelectric nanogenerators based on the natural biological topology structures prepared in Examples 1 - 5 of the present invention; Figure 4 It is the current test results of the PDMS / PTFE triboelectric nanogenerators based on the natural biological topology structures prepared in Examples 1 - 5 of the present invention; Figure 5 It is the cytotoxicity test result of the PDMS / PTFE triboelectric nanogenerator prepared in Example 1 of the present invention. Detailed Embodiments

[0018] The present invention will be further described below with reference to the drawings and embodiments.

[0019] It should be noted that the following detailed description is illustrative and aims to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application pertains.

[0020] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application; as used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0021] Example 1 A preparation method of a PDMS / PTFE triboelectric nanogenerator based on the biological topological structure in nature, comprising the following steps: (1) Dissolve 35 mg of PTFE in 3 ml of ethanol, and vortex mix to obtain solution S1, where the concentration of PTFE is 0.01167 g / ml and the concentration of ethanol is 0.789 g / ml; (2) Add 3.9 g of PDMS matrix to 0.5 ml of n-hexane; stir at a temperature of 20 °C for 1 h to obtain solution S2, where the concentration of PDMS matrix is 7.8 g / ml and the concentration of n-hexane is 0.6548 g / ml; (3) Heat and stir solutions S1 and S2 at 85 °C for 4 h to mix them evenly to obtain solution S3; (4) Pour S3 into a petri dish containing a blank substrate to obtain solution S4; (5) Add 0.39 g of PDMS curing agent to solution S4, and stir at 20 °C for 1 h to obtain solution S5; (6) Dry solution S5 at 80 °C for 4 h and then peel it off to obtain the PDMS / PTFE triboelectric nanogenerator.

[0022] Example 2 A preparation method of a PDMS / PTFE triboelectric nanogenerator based on the biological topological structure in nature, comprising the following steps: (1) Dissolve 40 mg of PTFE in 3.2 ml of ethanol, and vortex mix to obtain solution S1, where the concentration of PTFE is 0.01250 g / ml and the concentration of ethanol is 0.800 g / ml; (2) Add 3.8 g of PDMS matrix to 0.55 ml of n - hexane; stir at 20 °C for 1 h to obtain solution S2, where the concentration of PDMS matrix is 6.91 g / ml and the concentration of n - hexane is 0.6600 g / ml; (3) Heat and stir solutions S1 and S2 at 85 °C for 4 h to mix them evenly to obtain solution S3; (4) Pour S3 into a petri dish containing a leaf substrate to obtain solution S4; (5) Add 0.38 g of PDMS curing agent to solution S4 and stir at 20 °C for 1 h to obtain solution S5; (6) Dry solution S5 at 80 °C for 4 h and then peel it off to obtain a PDMS / PTFE triboelectric nanogenerator based on the leaf topological structure.

[0023] Example 3 A preparation method of a PDMS / PTFE triboelectric nanogenerator based on the topological structure of natural organisms includes the following steps: (1) Dissolve 45 mg of PTFE in 3.4 ml of ethanol and vortex - mix to obtain solution S1, where the concentration of PTFE is 0.01324 g / ml and the concentration of ethanol is 0.810 g / ml; (2) Add 3.7 g of PDMS matrix to 0.60 ml of n - hexane; stir at 20 °C for 1 h to obtain solution S2, where the concentration of PDMS matrix is 6.17 g / ml and the concentration of n - hexane is 0.6650 g / ml; (3) Heat and stir solutions S1 and S2 at 85 °C for 4 h to mix them evenly to obtain solution S3; (4) Pour S3 into a petri dish containing a butterfly wing substrate to obtain solution S4; (5) Add 0.37 g of PDMS curing agent to solution S4 and stir at 20 °C for 1 h to obtain solution S5; (6) Dry solution S5 at 80 °C for 4 h and then peel it off to obtain a PDMS / PTFE triboelectric nanogenerator based on the butterfly wing topological structure.

[0024] Example 4 A preparation method of a PDMS / PTFE triboelectric nanogenerator based on the topological structure of natural organisms includes the following steps: (1) Dissolve 50 mg of PTFE in 3.6 ml of ethanol and vortex - mix to obtain solution S1, where the concentration of PTFE is 0.01389 g / ml and the concentration of ethanol is 0.820 g / ml; (2) Add 3.6 g of PDMS matrix to 0.65 ml of n - hexane; stir at 20 °C for 1 h to obtain solution S2, where the concentration of PDMS matrix is 5.54 g / ml and the concentration of n - hexane is 0.6700 g / ml; (3) Heat and stir solutions S1 and S2 at 85 °C for 4 h to mix them evenly to obtain solution S3; (4) Pour S3 into a petri dish containing a dragonfly wing substrate to obtain solution S4; (5) Add 0.36 g of PDMS curing agent to solution S4 and stir at 20 °C for 1 h to obtain solution S5; (6) Dry solution S5 at 80 °C for 4 h and then peel it off to obtain a PDMS / PTFE triboelectric nanogenerator based on the topological structure of butterfly wings.

[0025] Example 5 A preparation method of a PDMS / PTFE triboelectric nanogenerator based on the topological structure of natural organisms includes the following steps: (1) Dissolve 55 mg of PTFE in 3.8 ml of ethanol and vortex - mix to obtain solution S1, where the concentration of PTFE is 0.01447 g / ml and the concentration of ethanol is 0.830 g / ml; (2) Add 3.5 g of PDMS matrix to 0.70 ml of n - hexane; stir at 20 °C for 1 h to obtain solution S2, where the concentration of PDMS matrix is 5.54 g / ml and the concentration of n - hexane is 0.6750 g / ml; (3) Heat and stir solutions S1 and S2 at 85 °C for 4 h to mix them evenly to obtain solution S3; (4) Pour S3 into a petri dish containing a cicada wing substrate to obtain solution S4; (5) Add 0.36 g of PDMS curing agent to solution S4 and stir at 20 °C for 1 h to obtain solution S5; (6) Dry solution S5 at 80 °C for 4 h and then peel it off to obtain a PDMS / PTFE triboelectric nanogenerator based on the topological structure of cicada wings.

[0026] Performance measurement Use the triboelectric nanogenerators prepared in Examples 1 - 5 for the triboelectric nanogenerator performance test experiment. It can be seen from Table 1 that: the triboelectric nanogenerators prepared by the present invention have an obvious improvement in electrical signals during voltage testing, and at the same time, the prepared materials can adhere to the skin, which is expected to provide a reference for the insufficient and unstable electrical signals of wearable devices.

[0027] Table 1 Voltage test data of the triboelectric nanogenerator prepared by the present invention Table 2 Current test data of the triboelectric nanogenerator prepared by the present invention Current (nA) Example 1 41.3 Example 2 57.5 Example 3 70.8 Example 4 84.3 Example 5 98.7 It can be seen from the current test results in Table 2 that the triboelectric nanogenerator prepared by the present invention has an obvious improvement in the electrical signal during the current signal test.

[0028] Scanning electron microscopy test: The morphology of the hydrogel was studied using a scanning electron microscope (SEM). Before observation, the freeze-dried samples were coated with a thin gold conductive layer using a sputter coater. Then, the surface structure of the film was detected using a Nova NanoSEM 230 (FEI Company, Hillsboro, OR, USA). Different film topologies were found.

[0029] Electrical signal test experiment: Samples of pure PDMS / PTFE and PDMS / PTFE triboelectric nanogenerators with different topologies (leaf, butterfly wing, dragonfly wing, cicada wing) were fixed on the rotating shaft of an electric motor. The initial settings of the electric motor were to apply a force of 5 N and a frequency of 5 Hz, and the initial distance between the sample and the electric motor was 5 cm. A digital source meter (Keithley 2450 model) was connected to the sample to measure the voltage and current generated by friction in real time.

[0030] Cytotoxicity test: In a 96-well plate, the material was placed in the wells, and 100.0 µL of LO2 cell suspension (density = 5000 cells mL -1 ) was added, and the cells were cultured at 37 °C in a humid atmosphere of 5% CO2 for 1, 3, and 7 days, and the medium was changed every other day. At a predetermined time interval, the original medium in the wells of the cell culture plate was removed, 100.0 µL of fresh serum-free medium (containing 10% CCK-8 reagent) was added to each well, and the cells were cultured at 37 °C for 45 minutes. Cells inoculated in a 96-well plate without the extraction medium served as the positive control group. The absorbance was measured at 450 nm using a microplate reader (model 550, Bio-Rad, Hercules, CA, USA).

Claims

1. A method for preparing a PDMS / PTFE triboelectric nanogenerator based on a biotopological structure, characterized in that: The following steps are involved: Step (1): dissolving PTFE in ethanol and vortex mixing to obtain solution S1; Step (2): adding the PDMS matrix into n-hexane and stirring at room temperature to obtain a solution S2; Step (3): pouring solution S1 into solution S2, heating, stirring and mixing to obtain solution S3; Step (4): pouring solution S3 into the culture dish with the biological topological structure to obtain solution S4; Step (5): adding PDMS curing agent to solution S4 and stirring at room temperature to obtain solution S5; Step (6): drying the solution S5 and then peeling it off to obtain the PDMS / PTFE friction nanogenerator based on the biotopological structure.

2. The method for preparing a PDMS / PTFE triboelectric nanogenerator based on a biotopological structure according to claim 1, characterized in that: In the solution S1 of step (1), the mass fraction of PTFE is 0.01-1 wt %, the mass fraction of ethanol is 0.1-20 wt %, and the vortex time is 0.5-1 h.

3. The method for preparing a PDMS / PTFE triboelectric nanogenerator based on a biotopological structure according to claim 1, characterized in that: In the solution S2 of step (2), the concentration of PDMS is 0.01-10 g / mL, the stirring temperature is 10-25° C., and the stirring time is 0.5-2 h.

4. The method for preparing a PDMS / PTFE triboelectric nanogenerator based on a biotopological structure according to claim 1, characterized in that: Step (3) Pour solution S1 into solution S2 and heat and stir. The stirring temperature is 80-100°C and the stirring time is 4-6 h.

5. The method for preparing a PDMS / PTFE triboelectric nanogenerator based on a biotopological structure according to claim 1, characterized in that: In the solution S4 of step (4), the solution S3 is poured into a base culture dish with a biological topological structure, wherein the biological topological structure includes leaves, butterfly, dragonfly or cicada wings.

6. The method for preparing a PDMS / PTFE triboelectric nanogenerator based on a biotopological structure according to claim 1, characterized in that: The concentration of the PDMS curing agent in step (5) is 0.001-0.1 g / mL.

7. The method for preparing a PDMS / PTFE triboelectric nanogenerator based on a biotopological structure according to claim 1, characterized in that: In step (6), the solution S5 is dried in an oven at 70-85° C. for 2-3 hours and then peeled off.

8. A PDMS / PTFE triboelectric nanogenerator based on biological topological structure, characterized in that: The nanogenerator is prepared by the method for preparing a PDMS / PTFE friction nanogenerator based on a biotopological structure as described in any one of claims 1 to 7.

Images