A self-driven electroluminescent liquid sensing system and its preparation method

Abstract

This invention discloses a self-driven electroluminescent liquid sensing system and its fabrication method. The sensing system includes a substrate and an electrode layer on the substrate. An electroluminescent layer and a triboelectric layer are also disposed on the electrode layer. The electroluminescent layer and the triboelectric layer are located on different sides of the electrode layer. The electroluminescent layer is immersed in a polar liquid. When the liquid surface fluctuates, the polar liquid fluctuates on the surface of the triboelectric layer, generating an AC voltage output that drives the electroluminescent layer to emit light. This invention places the electroluminescent layer and the triboelectric layer on the plane of the electrode layer. In use, the electroluminescent layer is immersed in a polar liquid, with the liquid surface located on the triboelectric layer. When the liquid surface fluctuates, the polar liquid fluctuates on the surface of the triboelectric layer, generating an AC voltage output that drives the electroluminescent layer to emit light. This self-driven electroluminescent liquid sensing system has high integration, a simple structure, good portability, and broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of electroluminescence technology, and in particular to a self-driven electroluminescent liquid sensing system and its preparation method. Background Technology

[0002] Electroluminescence is a photoelectric conversion phenomenon with wide applications in modern electronics, display technology, and the lighting industry. Compared with traditional photoelectric sensors, electroluminescent sensors based on the principle of electroluminescence have the characteristics of surface emission, cold light source, long lifespan, and high stability.

[0003] Most AC electroluminescent sensors rely on external AC power supplies. This dependence hinders sensor miniaturization and portability, and when used for liquid sensing, it imposes stringent waterproofing requirements on the power supply and wiring, thus limiting the sensor's operating environment and application areas. Furthermore, the production and disposal of these power supplies place significant pressure on the environment. If we could harvest ubiquitous mechanical energy from nature—such as the energy from walking, hand movements, wind, and water flow—to power electroluminescence, we could achieve clean energy conversion and utilization, enabling self-driven electroluminescent sensing.

[0004] Therefore, it is necessary to improve the structure of electroluminescent sensors so that they can sense liquids without an external power source. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention provides a self-driven electroluminescent liquid sensing system, comprising a substrate and an electrode layer on the substrate, wherein the electrode layer is further provided with an electroluminescent layer and a triboelectric layer.

[0006] The electroluminescent layer and the triboelectric layer are located on different sides of the electrode layer, respectively.

[0007] The electroluminescent layer is immersed in a polar liquid. When the liquid surface fluctuates, the polar liquid fluctuates on the surface of the triboelectric layer, generating an AC voltage output that drives the electroluminescent layer to emit light. The polar liquid includes water, salt solution, ethanol, glycerol, propylene glycol, formamide, etc.

[0008] Furthermore, the thickness of the electrode layer is 20 nm to 1 μm; the structure of the electrode layer can be integral block, interdigitated, or checkerboard.

[0009] The thickness of the electroluminescent layer is 20–200 μm.

[0010] Furthermore, the substrate material includes at least one of polymer film, glass, plexiglass, and polymer sheet. Polymer film is a flexible substrate and can be polyvinyl chloride (PVC) film, polyethylene terephthalate (PET) film, polycarbonate (PC) film, polyethylene (PE) film, polyimide (PI) film, etc. Glass (soda-lime glass, quartz glass), plexiglass, and polymer sheet are rigid substrates.

[0011] Furthermore, the electrode layer is made of at least one of a conductive metal, indium tin oxide, and a conductive polymer. The conductive metal can be gold, silver, or copper, and its microstructure can be nanowires, nanosheets, nanospheres, etc.

[0012] Furthermore, the material of the electroluminescent layer includes an electroluminescent substance and a resin matrix. The resin matrix can be cured by heating, and after being mixed with the electroluminescent substance, it is coated onto the electrode layer and cured by heating to form an electroluminescent layer.

[0013] Furthermore, the electroluminescent material includes ZnS:Cu, ZnS:Mn, and SrAl2O4:Eu. 2+ At least one of them;

[0014] The resin matrix includes at least one of epoxy resin, acrylic resin, and polyethylene resin;

[0015] The mass ratio of electroluminescent material to resin matrix is ​​1:9 to 8:2.

[0016] Furthermore, the material of the electroluminescent layer also includes a high-dielectric material;

[0017] The high-dielectric material includes at least one of barium titanate, alumina, quartz, beryllium oxide, spinel, sapphire, garnet ferrite, potassium arsenide, titanium dioxide, and polytetrafluoroethylene. The high-dielectric material is used to increase the dielectric constant of the light-emitting layer and improve its brightness.

[0018] Furthermore, the material of the triboelectric layer includes at least one of polytetrafluoroethylene or perfluoroethylene-propylene copolymer. The triboelectric layer is selected from thin film materials that readily undergo charge transfer upon contact with the liquid. The triboelectric layer and the electrode layer it covers form a triboelectric generator component. When the liquid fluctuates, it can collect the liquid's mechanical energy and convert it into an alternating current voltage output, driving the area of ​​the electroluminescent layer in contact with the polar liquid to emit light.

[0019] This invention also provides a method for preparing the above-mentioned self-driven electroluminescent liquid sensing system, including,

[0020] An electrode layer is fabricated on a substrate, and then an electroluminescent layer and a triboelectric layer are processed on the electrode layer to obtain a self-driven electroluminescent liquid sensing system.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. In this invention, an electroluminescent layer and a triboelectric layer are disposed on the plane of the electrode layer. In use, the electroluminescent layer is immersed in a polar liquid, with the surface of the polar liquid positioned between the triboelectric layers. When the liquid surface fluctuates, the polar liquid fluctuates on the surface of the triboelectric layers, generating an AC voltage output that drives the electroluminescent layer to emit light.

[0023] 2. The self-driven electroluminescent liquid sensing system of the present invention has high integration, simple structure, good portability, and broad application prospects. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of the structure of the self-driven electroluminescent liquid sensing system in Embodiment 1 of the present invention is shown;

[0026] Figure 2 An image of the electrode layer prepared in Embodiment 2 of the present invention is shown;

[0027] Figure 3 An image of the self-driven electroluminescent liquid sensing system prepared in Embodiment 2 of the present invention is shown;

[0028] Figure 4 The image shows a self-driven electroluminescent liquid sensing system of Embodiment 2 of the present invention fixed in still tap water;

[0029] Figure 5 The AC voltage output of the generator component in fluctuating tap water is shown in Embodiment 2 of the present invention, which is a self-driven electroluminescent liquid sensing system.

[0030] Figure 6 The image shows the luminescence effect of the self-driven electroluminescent liquid sensing system of Embodiment 2 of the present invention in fluctuating tap water;

[0031] Figure 7 The spectrum of the self-driven electroluminescent liquid sensing system of Embodiment 2 of the present invention is shown in the electroluminescent layer region of fluctuating tap water.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Substrate; 2. Electrode layer; 3. Electroluminescent layer; 4. Triboelectric layer. Detailed Implementation

[0034] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of various ranges, the endpoint values ​​of various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention. Unless otherwise specified, the raw materials used in this invention are conventional commercially available products; the methods used in this invention, unless otherwise specified, are conventional methods in the art.

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] like Figure 1 As shown, a self-driven electroluminescent liquid sensing system includes a substrate 1 and an electrode layer 2 on the substrate 1. An electroluminescent layer 3 and a triboelectric layer 4 are further disposed on the electrode layer 2. The electroluminescent layer 3 and the triboelectric layer 4 are located on different sides of the electrode layer 2. The substrate 1 is a 5cm × 3cm × 2mm epoxy resin board; the electrode layer 2 is 500nm thick copper, and its shape is a combination of block and checkerboard patterns; the electroluminescent layer 3 is a 40μm thick mixture of ZnS:Cu and epoxy resin (ZnS:Cu to epoxy resin mass ratio 7:3); the triboelectric layer 4 is a 50μm thick perfluoroethylene-propylene copolymer film. The triboelectric layer 4 and the electrode layer 2 it covers form a triboelectric generator component. When the liquid fluctuates, it can collect the liquid's mechanical energy and convert it into an AC voltage output, driving the area of ​​the electroluminescent layer 3 in contact with the polar liquid to emit light.

[0038] In use, the electroluminescent layer 3 is immersed in a polar liquid, at which point the polar liquid is located on the triboelectric layer 4; when the liquid surface fluctuates, the polar liquid fluctuates on the surface of the triboelectric layer 4 to generate an AC voltage output that drives the electroluminescent layer 3 to emit light.

[0039] Example 2

[0040] The preparation method of the self-driven electroluminescent liquid sensing system in Example 1 is as follows:

[0041] Step 1: Clean and dry the surface of a 5cm×3cm×2mm epoxy resin board to serve as the base.

[0042] Step 2: A 500nm thick copper electrode layer is electroplated onto the clean epoxy resin board surface. The electrode layer pattern is a combination of blocky double electrodes and checkerboard double electrodes, such as... Figure 2 As shown;

[0043] Step 3: Mix ZnS:Cu and epoxy resin adhesive at a mass ratio of 7:3 and coat the checkerboard copper electrode layer area in Step 2. Then dry it in a constant temperature oven at 60℃ to form a 40μm electroluminescent layer.

[0044] Step 4: A 50μm thick perfluoroethylene-propylene copolymer film is adhered to the bulk dual-electrode region of the copper electrode layer to form a triboelectric layer, thus obtaining a self-driven electroluminescent liquid sensing system, such as... Figure 3 As shown.

[0045] The prepared self-driven electroluminescent liquid sensing system was fixed on the wall of a water tank to illustrate its sensing method:

[0046] like Figure 4 As shown, when the electroluminescent layer is immersed in tap water with the water level in the middle of the triboelectric layer, the water surface remains still, and the electroluminescent layer shows no light emission. However, when the tap water is stirred to create ripples on the surface of the triboelectric layer, light emission can be observed in the electroluminescent layer area. The output of the triboelectric generator component under these water ripples is measured using an electrometer, and its AC voltage output is as follows: Figure 5 As shown, the voltage can reach 60V. The luminescence effect of the electroluminescent layer in a dark room is as follows: Figure 6 As shown. A fiber optic spectrometer is used to align with the emitting region, and the spectrum is measured as follows. Figure 7 As shown, the emission peak is located at 520nm, which is in the visible green light region. When the fluctuation of the tap water stops, the emission also stops.

[0047] Similarly, tap water was replaced with sodium chloride solutions (polar liquids) at mass fractions of 0.25%, 0.5%, 0.75%, and 1%, respectively, and insulating oil (non-polar liquid). The results showed that electroluminescence was observed in all sodium chloride solutions of different concentrations when the liquid surface was disturbed; however, no luminescence was observed in the insulating oil. This is because water and salt solutions are polar liquids, while insulating oil is a non-polar liquid. These results demonstrate that the self-driven electroluminescent liquid sensing system prepared in this invention can be used for electroluminescent sensing in polar liquid media without an external power source.

[0048] Example 3

[0049] It is basically the same as Example 2, except that ZnS:Mn is used instead of ZnS:Cu in step 3.

[0050] Example 4

[0051] The process is basically the same as in Example 2, except that in step 3, ZnS:Cu, epoxy resin adhesive, and barium titanate are mixed evenly in a mass ratio of 4:2:4 and then coated onto the checkerboard copper electrode layer area in step 2. The mixture is then dried in a constant temperature oven at 60°C to form a 40μm electroluminescent layer.

[0052] The self-driven electroluminescent liquid sensing systems prepared in Examples 3 and 4 were subjected to the same sensing experiments as in Example 2. The results showed that the electroluminescent region of Example 3 emitted visible orange light during water ripples. The luminescence intensity of Example 4 was higher because barium titanate is a high-dielectric material, which can increase the dielectric constant of the luminescent layer and improve the luminescence brightness.

[0053] Comparative Example

[0054] The example is basically the same as Example 2, except that step 4 is not included, that is, a 50μm perfluoroethylene propylene copolymer film is not pasted on the blocky dual electrode area of ​​the copper electrode layer, and there is no triboelectric layer.

[0055] When the comparative electroluminescent layer was immersed in tap water, no light emission was observed regardless of whether the water caused surface ripples. Only when an AC power source was connected to the top of the electroluminescent layer did light emission occur. The results of Examples 2-4 and the comparative example demonstrate that the AC voltage generated by surface ripples of the polar liquid's triboelectric layer is sufficient to drive the self-driven electroluminescent liquid sensing system constructed in this invention to emit light.

[0056] In summary, this invention places the electroluminescent layer and the triboelectric layer on the electrode plane. In use, the electroluminescent layer is immersed in a polar liquid, with the surface of the polar liquid located on the triboelectric layer. When the liquid surface fluctuates, the polar liquid fluctuates on the surface of the triboelectric layer, generating an AC voltage output that drives the electroluminescent layer to emit light. The self-driven electroluminescent liquid sensing system of this invention has high integration, a simple structure, good portability, and broad application prospects.

[0057] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-driven electroluminescent liquid sensing system, comprising a substrate and an electrode layer on the substrate, characterized in that, An electroluminescent layer and a triboelectric layer are also disposed on the electrode layer; The electroluminescent layer and the triboelectric layer are located on different sides of the electrode layer, respectively. The electroluminescent layer is immersed in a polar liquid. When the liquid surface fluctuates, the polar liquid fluctuates on the surface of the triboelectric layer, generating an AC voltage output that drives the electroluminescent layer to emit light. When the liquid sensing system detects liquid, the electroluminescent layer is located below the liquid surface, and the triboelectric layer is located between the gas and liquid interfaces.

2. The self-driven electroluminescent liquid sensing system according to claim 1, characterized in that, The thickness of the electrode layer is 20 nm to 1 μm; The thickness of the electroluminescent layer is 20~200μm.

3. The self-driven electroluminescent liquid sensing system according to claim 1, characterized in that, The substrate material includes at least one of polymer film, glass, plexiglass, and polymer sheet.

4. The self-driven electroluminescent liquid sensing system according to claim 1, characterized in that, The electrode layer is made of at least one of conductive metals, indium tin oxide, and conductive polymers.

5. The self-driven electroluminescent liquid sensing system according to claim 1, characterized in that, The electroluminescent layer is made of electroluminescent material and resin matrix.

6. The self-driven electroluminescent liquid sensing system according to claim 5, characterized in that, The electroluminescent material includes ZnS:Cu, ZnS:Mn, and SrAl2O4:Eu. 2+ At least one of them; The resin matrix includes at least one of epoxy resin, acrylic resin, polyethylene resin, and polyvinylidene fluoride; The mass ratio of electroluminescent material to resin matrix is ​​1:9 to 8:

2.

7. The self-driven electroluminescent liquid sensing system according to claim 5, characterized in that, The electroluminescent layer also includes a high-dielectric material; The high dielectric material includes at least one of barium titanate, alumina, quartz, beryllium oxide, spinel, sapphire, garnet ferrite, potassium arsenide, titanium dioxide, and polytetrafluoroethylene.

8. The self-driven electroluminescent liquid sensing system according to claim 1, characterized in that, The material of the triboelectric layer includes at least one of polytetrafluoroethylene or perfluoroethylene-propylene copolymer.

9. A method for preparing a self-driven electroluminescent liquid sensing system according to any one of claims 1 to 8, characterized in that, include, An electrode layer is fabricated on a substrate, and then an electroluminescent layer and a triboelectric layer are processed on the electrode layer to obtain a self-driven electroluminescent liquid sensing system.

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