A tri-dimensional spacer fabric-based friction nanogenerator and a preparation method thereof

Abstract

The application relates to a friction nanogenerator based on a three-dimensional spacer fabric and a preparation method thereof, and belongs to the technical field of textiles.The friction nanogenerator based on the three-dimensional spacer fabric comprises a three-dimensional spacer fabric, the surface of the fiber of the three-dimensional spacer fabric is coated with a conductive metal layer by adopting an electrodeless electroless plating method, and the conductive metal layer is coated with a friction medium layer; the conductive metal is one or more of copper, nickel and silver.The friction nanogenerator based on the three-dimensional spacer fabric is a common electrode breathable friction nanogenerator based on a warp-knitted fabric structure, the plated copper electrodes of two devices both in a single electrode mode are shared by utilizing the original structure of the fabric, the process is reduced, and the processing electrode and structural construction cost are reduced.The friction nanogenerator can trigger the work of the two single electrode mode generators in stages under different pressing degrees, ensures certain output and service performance, and also provides a thought for structural innovation.

Description

Technical Field

[0001] This invention belongs to the field of textile technology, and particularly relates to a triboelectric nanogenerator based on a three-dimensional spacer fabric and its preparation method. Background Technology

[0002] With the advent of the Internet of Things (IoT) and artificial intelligence (AI) era, wearable devices have been widely applied in people's daily lives, greatly improving their quality of life. Currently, most electronic products rely primarily on traditional batteries, but these batteries are bulky, rigid, and complex, failing to meet the continuous use and wear requirements of wearable electronic products. In 2012, Wang Zhonglin's research group proposed a novel energy harvesting and self-powered sensing technology—the triboelectric nanogenerator (TENG). Based on the coupling effect of contact electrification and electrostatic induction, it is an energy conversion device that converts ubiquitous mechanical energy into electrical energy, potentially becoming an effective supplementary solution to avoid frequent battery replacements. Since human activities are primarily based on mechanical motion, harvesting ubiquitous and continuously available human mechanical energy is the most reliable and independent strategy for providing continuous power, regardless of climatic conditions or working environments. Textiles are indispensable materials in people's daily lives; they fit closely to the human body and can serve as friction materials for TENGs, facilitating the harvesting of human mechanical energy.

[0003] Patent CN103368450A discloses an insole utilizing a triboelectric nanogenerator, where the conductive layer is magnetron sputtered or vapor-deposited metal. This not only affects the breathability of the entire fabric device but also increases the cost of constructing an isolation layer between two adjacent friction layers. A three-dimensional spacer fabric with multiple intermediate fibers separates the upper and lower fabric layers, providing good elasticity for the entire fabric and sufficient separation space for the triboelectric nanogenerator (TENG). Utilizing its unique structure as a substrate or carrier, TENG integration and multi-field applications can be achieved. Liu et al. fabricated an integrated flexible contact-separated triboelectric nanogenerator based on a three-dimensional spacer fabric. Coating it with conductive materials reduces the fabric's elasticity, softness, moisture permeability, and breathability, decreasing the wearability of clothing made from this fabric. Zhu et al. used a fabric electrode composed of conductive yarns and a friction layer composed of dielectric yarns for a three-dimensional spacer power generation fabric; however, damage to the yarns during weaving affected its output. Therefore, in addition to maintaining the original conductivity, the fabric electrode in the TENG structure should also have certain properties such as softness, lightness, elasticity, washability and breathability. Electrodeless electroless plating method meets these requirements and does not significantly change the feel or texture of textiles.

[0004] Electrodeless electroless plating (ELD) is a non-electrolytic oxidation-reduction method for depositing metals in solution. ELD has become a promising metallization process for textiles and has been applied to fabric-based TENGs, but it has not yet been used in the electrode construction of three-dimensional spaced fabric TENGs. Zhao et al. fabricated fabric-based TENGs on an industrial sample loom, but the yarns are easily damaged during weaving, and there are certain requirements for the machine weaving of conductive yarns, such as length and strength parameters. Pu et al. used a laser mask method to ELD-plat a nickel film on one side of the exposed polyester fabric as the grid electrode of the TENG, while leaving the other side untreated. Although this maintained the original fabric insulation properties, the additional laser masking step was not conducive to the application of ELD in TENG construction.

[0005] Electrode construction based on three-dimensional spacer fabric TENGs reduces the original properties of the fabric. While ELD metallization of yarn and fabric can maintain some original properties, yarn weaving has machine requirements. Although direct fabric treatment does not have these requirements, if ELD is only performed on one side of the fabric, maintaining the original insulation properties of the other side requires other methods, increasing the TENG construction process. Furthermore, ELD has not yet been used for electrode construction of three-dimensional spacer fabric TENGs. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the problems of poor original properties of the fabric and high requirements for the machine when constructing the electrode structure of the three-dimensional spaced fabric TENG in the prior art.

[0007] To address the aforementioned technical problems, this invention provides a triboelectric nanogenerator based on a three-dimensional spacer fabric and its fabrication method. The electrode portion utilizes an ELD process to deposit metal on both sides of the fabric, effectively creating two electrode layers. Simultaneously generating triboelectric charges on both sides results in a greater amount of charge generated on one side, thus improving output to some extent. The three-dimensional spacer fabric consists of two layers. Constructing a single fabric electrode via ELD allows for two single-electrode modes of TENG, with the untreated fabric layer serving as a fixed triboelectric layer. The spacer structure of the three-dimensional spacer fabric also provides separation space for one of the modes.

[0008] The first objective of this invention is to provide a triboelectric nanogenerator based on a three-dimensional spacer fabric, comprising a three-dimensional spacer fabric, wherein one side of the three-dimensional spacer fabric is coated with a conductive metal layer on the fiber surface of the fabric by an electrodeless chemical plating method, and the conductive metal layer is coated with a triboelectric medium layer.

[0009] In one embodiment of the present invention, the conductive metal is one or more of copper, nickel and silver.

[0010] In one embodiment of the present invention, the friction medium layer is prepared by mixing a prepolymer and a curing agent.

[0011] In one embodiment of the present invention, the prepolymer is one or more of polydimethylsiloxane, silicone rubber and polytetrafluoroethylene resin; the curing agent is one or more of tetraethyl orthosilicate, propyl orthosilicate and isocyanate.

[0012] The second objective of this invention is to provide a method for preparing the aforementioned triboelectric nanogenerator based on three-dimensional spacer fabric, comprising the following steps:

[0013] S1. One side of the pretreated three-dimensional spacer fabric is successively immersed in organosilanic acid solution, grafted polymer brush solution and ammonium tetrachloropalladate solution to obtain the pretreated three-dimensional spacer fabric.

[0014] S2. A conductive metal layer is deposited on one side of the pretreated three-dimensional spacer fabric described in S1 using electrodeless chemical plating to obtain a fabric electrode.

[0015] S3. The fabric electrode described in S2 is immersed in a friction medium solution and then cured to obtain the triboelectric nanogenerator based on the three-dimensional spacer fabric.

[0016] In one embodiment of the present invention, in S1, the pretreatment is to perform alkali pretreatment and plasma-modified hydroxyl treatment on one side of the three-dimensional spacer fabric.

[0017] In one embodiment of the present invention, in S1, the organosilane solution is an ethanol solution of vinyltrimethoxysilane.

[0018] In one embodiment of the present invention, in S1, the grafted polymer brush solution is a methacryloyloxyethyltrimethylammonium chloride solution with potassium persulfate added as an initiator.

[0019] In one embodiment of the present invention, in S1, the reaction conditions in the grafted polymer brush solution are 70°C-80°C for 1-2 hours.

[0020] In one embodiment of the present invention, in S3, the curing is performed at 60°C-70°C for 1-2 hours.

[0021] A third objective of this invention is to provide a three-dimensional spaced fabric power supply device, including the aforementioned triboelectric nanogenerator.

[0022] The technical solution of the present invention has the following advantages compared with the prior art:

[0023] (1) The triboelectric nanogenerator based on three-dimensional spacer fabric described in this invention employs a method for manufacturing conductive fabrics that is selectively applied, low-cost, scalable, and maintains certain original fabric properties—electrodeless chemical plating. This method involves plating metal on both sides of a layer of the three-dimensional spacer fabric to form a shared electrode layer, thereby collecting energy from human movement on both sides of the fabric. Plating metal on both sides of the fabric can be considered as two electrode layers. When triboelectric charges are generated simultaneously on both sides, this will result in more triboelectric charges generated on one side, which can improve the output of a single-electrode TENG to a certain extent. Furthermore, metal wires are interlaced and sewn into the three-dimensional spacer fabric, acting as a means to draw out the induced charges on both sides of the copper-plated fabric.

[0024] (2) The triboelectric nanogenerator based on three-dimensional spacer fabric described in this invention can directly utilize existing three-dimensional spacer warp-knitted fabrics. The TENG manufacturing technology that integrates two common single-electrode modes of electrodeless chemical copper plating can not only collect energy from both sides of the fabric and reduce processing costs, but also provides sufficient separation space for one of the single-electrode modes of TENG, with its spacer yarns providing elastic recovery support for the metal-plated fabric electrodes to collect energy from both sides of the fabric.

[0025] (3) The triboelectric nanogenerator based on three-dimensional spacer fabric described in this invention is a shared-electrode breathable triboelectric nanogenerator based on a warp-knitted fabric structure. It utilizes the original structure of the fabric to share the copper-plated electrodes of two devices, both in single-electrode mode, reducing processing steps and lowering the cost of electrode fabrication and structural construction. Under different degrees of pressure, it can trigger the operation of the two single-electrode mode generators in a graded manner. While ensuring a certain output and performance, it also provides a new approach to structural innovation, namely, simultaneously constructing two devices on the same spacer fabric, achieving a potential function of graded response.

[0026] (4) The triboelectric nanogenerator based on three-dimensional spacer fabric described in this invention uses a layer of fabric with a porous structure in the three-dimensional spacer fabric. After electrodeless chemical copper plating and coating with a friction layer of PDMS, the transparent PDMS filling the pores is removed, which meets the certain requirements of the fabric for softness, lightness, elasticity, washability and breathability, and has the performance of practicality and compatibility with ordinary textiles. In addition, the untreated layer of fabric can be used as a fixed friction layer in one of the single-electrode modes, reducing the weaving cost of the fixed friction layer. Attached Figure Description

[0027] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0028] Figure 1 This is a flowchart illustrating the fabrication of a triboelectric nanogenerator based on a three-dimensional spacer fabric, as described in this invention.

[0029] Figure 2 The three-dimensional spacer fabric triboelectric nanogenerators of Embodiment 1 of the present invention are coated with different PDMS thicknesses, wherein a is 193 μm; b is 425 μm; c is 858 μm; and d is 1336 μm.

[0030] Figure 3 The output diagram of the three-dimensional spacer fabric triboelectric nanogenerator coated with different PDMS thicknesses in Test Example 1 of this invention is shown; where the left vertical axis represents the short-circuit current and the right vertical axis represents the open-circuit voltage.

[0031] Figure 4 Test Example 2 of this invention is a TENG intermittently lit LED coated with 425 μm thick PDMS; where a is before lighting and b is after lighting.

[0032] Figure 5 This is a graph showing the effect of frequency and extrusion position on output in Test Example 2 of the present invention; where a is the relationship between frequency and output; and b is the relationship between extrusion position and output.

[0033] Figure 6 This is a graph showing the effect of different fabric spacing thicknesses on the output in Test Example 2 of the present invention; where the left vertical axis represents the open-circuit voltage and the right vertical axis represents the short-circuit current.

[0034] Figure 7 The following is a performance test diagram of the three-dimensional spaced fabric triboelectric nanogenerator of the present invention, which is shown in Test Example 3 of the present invention; wherein, a is a comparison of air permeability during the treatment process; b is a comparison of output before and after water washing with pores retained; c is a durability test of open circuit voltage for 6500 cycles.

[0035] Figure 8 This is a simulation diagram of the triggering of a three-dimensional spaced fabric triboelectric nanogenerator in Test Example 3 of the present invention; wherein, a is a structural diagram of two single-electrode modes TENG; b is a working principle diagram of the two modes; and c is an output diagram. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0037] Example 1

[0038] Reference Figure 1 As shown, the triboelectric nanogenerator based on three-dimensional spacer fabric and its preparation method include the following steps:

[0039] (1) Pretreatment of three-dimensional spacer fabric substrate: one side of the warp-knitted three-dimensional polyester fabric with obvious holes is pretreated with 1M sodium hydroxide alkali for 1 hour, and the substrate is cleaned in a plasma cleaner for 5 minutes and then -OH is attached.

[0040] (2) Pretreatment of the three-dimensional spacer fabric substrate: The substrate with one side pretreated was silanized by immersing it in a 2% (v / v) ethanol solution of vinyltrimethoxysilane for 15 min to promote the polycondensation reaction between vinyltrimethoxysilane and -OH, followed by drying. The dried sample was then placed in a 20% (v / v) solution of methacryloyloxyethyltrimethylammonium chloride with 0.11 g / 100 mL potassium persulfate as the initiator, and treated in an oil bath at 80 °C for 1 h to perform in-situ free radical polymerization to form a polymer brush, followed by cleaning and drying. Subsequently, the dried polymer brush substrate was immersed in a 4×10 -3 After 15 minutes in a solution of M tetrachloroammonium palladium ((NH4)2PdCl4), the physically adsorbed ions were rinsed with deionized water.

[0041] (3) Metal deposition on the surface of a three-dimensional spacer fabric substrate: grafting PdCl4 2- The substrate with catalytically immobilized ions was immersed in a copper plating solution at 45°C in an oil bath to deposit copper. After the reaction stopped, the substrate was removed, washed, and dried. The copper plating solution consisted of a 1:1 ratio of solution A and solution B, where solution A was composed of sodium hydroxide (18.0 g / L). -1 Copper sulfate pentahydrate (19.5 g / L) -1 ) and potassium sodium tartrate (43.5 g / L) -1 The composition is as follows: Solution B is formaldehyde (14.5 mL). -1 Aqueous solution.

[0042] (4) Coating of friction material: In order to ensure that a certain thickness of PDMS is coated on the electrode, the PDMS prepolymer and tetraethyl orthosilicate curing agent with a mass ratio of 10:1 are mixed evenly and then dropped into a plastic culture dish of a certain volume. Then, the electrode side with copper wire sewn into it is immersed in the PDMS culture dish with the air bubbles removed, cured in an oven at 65°C for 2 hours, and then taken out to obtain a triboelectric nanogenerator based on three-dimensional spacer fabric.

[0043] Test Example 1

[0044] Reference Figure 2As shown, the study investigated the effect of PDMS thickness on output, including the following steps: Based on Example 1, to ensure a relatively consistent PDMS coating thickness on both sides of the conductive fabric, 1g, 1.5g, 2g, and 3g of de-bubbled and cured PDMS films were pre-prepared in circular plastic petri dishes with a bottom diameter of approximately 95mm and adhered to the outer side of copper-plated fabrics. Subsequently, 1g, 1.5g, 2g, and 3g of PDMS were sequentially placed in the same plastic petri dishes. After de-bubbling, the four previously coated copper-plated fabrics were sequentially placed into the same mass of PDMS. A 1g weight was placed on the top of the untreated fabric of the four spacer fabrics to allow the uncured PDMS to penetrate into the inner side of the copper-plated fabric, thus ensuring that the total PDMS coating thickness on both sides of the four copper-plated fabrics was 193μm, 425μm, 858μm, and 1336μm, respectively. By controlling the mass, three-dimensional spacer fabric triboelectric nanogenerators with different PDMS coating thicknesses were obtained, and the optimal PDMS thickness for achieving the highest output was found.

[0045] The test output is as follows Figure 3 As shown, the output increases with increasing thickness from 193μm to 425μm, but decreases after 425μm. Therefore, the optimal PDMS thickness is 425μm.

[0046] Test Example 2

[0047] The quantization of the brightness of a lamp based on frequency, i.e., the output magnitude, includes the following steps:

[0048] The TENG coated with 425 μm thick PDMS, as described in Test Example 1, was used for a lighting test. Test equipment included a linear motor providing periodic contact-separation motion to the sample at a specific frequency; an electrometer (Keithley 6514) and a multimeter (DMM7510) were used to measure open-circuit voltage and short-circuit current. The test output method involved fixing the sample to one end of the linear motor and a tin foil (as the positive electrode material relative to PDMS) to the other end. The copper wire connected to the sample was connected to the positive terminal of the multimeter, and its negative terminal was grounded. Results are as follows: Figure 4 As shown, pressing the sample at a frequency of approximately 1 Hz can intermittently light up 30 LEDs connected in series. The connection method is that the positive terminal of the first bulb is connected to the copper wire of the sample, and the negative terminal of the last bulb is grounded.

[0049] The device is fixed to one end of a linear motor, and the impact frequency is controlled by the speed of the other end. The brightness of the lamp is quantified by the output magnitude. Figure 5As shown in Figure a, at 1, 4, and 6 Hz, the output does not change significantly with increasing frequency. This indirectly indicates that higher frequency does not significantly optimize the output. However, the degree of compression of the device has a significant effect on the output. For example, when an 8mm thick fabric device is compressed to 8mm, 5mm, and 2mm, the output signal increases sequentially with increasing compression. Figure 5 b) This has potential applications for motion state detection and motion-oriented recognition.

[0050] Based on the fundamental operating mode of fabric-based TENGs, consistent with other TENGs, there are four basic modes: vertical contact separation, lateral sliding, single electrode, and independent layer mode. During operation, all require spatial gaps to ensure charge separation between the fabric electrode and the friction layer during the separation motion. Therefore, it is necessary to optimize the gap parameters, i.e., optimize the output based on the thickness of the three-dimensional spaced fabric TENG, such as... Figure 6 As shown, the electrical output was compared when the fabric thickness was 2, 3, 4, and 8 mm. Under the same conditions as in Test Example 1, the generated electrical signal increased with increasing thickness, therefore the fabric device thickness was optimized to 8 mm.

[0051] Test Example 3

[0052] The wearability performance of the triboelectric nanogenerator (TENG) prepared based on three-dimensional spacer fabric in Example 1 of this invention was tested.

[0053] Air permeability: The ability of air to pass through a fabric, measured in a test area and under a pressure of 20 cm. 2 Under the condition of 300 Pa, the air permeability tester (TEXTESTAG, FX 3300) was used to measure the rate at which the airflow passed vertically through the sample. The reference standard was GB-T 5453-1997 "Determination of air permeability of textile fabrics".

[0054] Washability: The reference standard is "GB-T 3921-2008 Textiles - Tests for color fastness to soaping - National Standard". The fabric sample is placed in the specified washing solution and rotated at 43°C by mechanical force to achieve the purpose of cleaning.

[0055] The results are as follows Figure 7 As shown, from Figure 7 It can be seen that the air permeability of the copper-plated fabric electrode decreased by only 6.1% compared to the original fabric, while the air permeability decreased significantly after coating with PDMS, with an air permeability of only 163 mm / s. From Figure 7 b shows that if the original pore structure is retained, i.e., the PDMS blocking the pores is removed, the air permeability reaches 2148.1 mm / s, retaining 65.4% of the original, thus ensuring a certain level of air permeability. Furthermore, from... Figure 7As can be seen from c, the output performance after retaining the hole and after water washing was compared with the original TENG. Although there was a certain decrease, it could still maintain good output. The subsequent durability open circuit voltage test also showed that it could maintain good output.

[0056] Figure 8 This is a simulation diagram of the triggering of the three-dimensional spacer fabric triboelectric nanogenerator of the present invention. Due to the spacer structure of the three-dimensional spacer fabric, the untreated positive electrode material (relative to PDMS) polyester yarn in a single-electrode mode is fixed. If the skin only performs cyclic contact separation movements on the treated fabric surface without causing the three-dimensional spacer fabric to deform as a whole, only one mode is triggered. Figure 8 a) This means that electrostatic charging only occurs when the PDMS comes into contact with the skin, while the fabric electrode only experiences electrostatic induction on one side. When the skin comes into contact with the fabric and the three-dimensional spacer is squeezed to a certain position, not only is the above-mentioned mode triggered, but also the PDMS wrapped in the inner layer of the fabric electrode and the untreated polyester yarn in the middle layer will each carry an equal amount of opposite charges after contact. Figure 8 b) This causes electrostatic induction to occur on both sides of the fabric electrode, thereby triggering two single-electrode modes. For example... Figure 8 As shown in Figure c, under the same pressure and frequency triggering conditions, the open-circuit voltage and short-circuit current of the two single-electrode modes will be three times that of one mode. This not only improves the output to a certain extent, but also provides a potential application for detecting the location of extrusion deformation during motion.

[0057] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a triboelectric nanogenerator based on a three-dimensional spacer fabric, characterized in that, Includes the following steps, S1. One side of the pretreated three-dimensional spacer fabric is successively immersed in organosilanic acid solution, grafted polymer brush solution and ammonium tetrachloropalladate solution to obtain the pretreated three-dimensional spacer fabric. S2. A conductive metal layer is deposited on one side of the pretreated three-dimensional spacer fabric described in S1 using electrodeless chemical plating to obtain a fabric electrode. S3. The fabric electrode described in S2 is immersed in a friction medium solution and then cured to obtain the triboelectric nanogenerator based on the three-dimensional spacer fabric.

2. The method for preparing a triboelectric nanogenerator based on a three-dimensional spacer fabric according to claim 1, characterized in that, In S1, the pretreatment involves alkali pretreatment and plasma-modified hydroxyl treatment on one side of the three-dimensional spacer fabric.

3. The method for preparing a triboelectric nanogenerator based on a three-dimensional spacer fabric according to claim 1, characterized in that, In S1, the organosilane solution is an ethanol solution of vinyltrimethoxysilane.

4. The method for preparing a triboelectric nanogenerator based on a three-dimensional spacer fabric according to claim 1, characterized in that, In S1, the grafted polymer brush solution is a methacryloyloxyethyltrimethylammonium chloride solution with potassium persulfate added as an initiator.

5. The method for preparing a triboelectric nanogenerator based on a three-dimensional spacer fabric according to claim 1, characterized in that, In S1, the reaction conditions in the grafted polymer brush solution are 70℃-80℃ for 1-2 hours.

6. The method for preparing a triboelectric nanogenerator based on a three-dimensional spacer fabric according to claim 1, characterized in that, In S3, the curing process involves curing at 60℃-70℃ for 1-2 hours.

Images