Self-driven electroluminescent liquid sensing system and preparation method thereof

Abstract

The invention discloses a self-driven electroluminescent liquid sensing system and a preparation method thereof, the sensing system comprises a substrate and an electrode layer on the substrate, and the electrode layer is also provided with an electroluminescent layer and a triboelectrification layer; the electroluminescent layer and the triboelectrification layer are respectively positioned on different sides of the electrode layer; the electroluminescent layer is immersed in the polar liquid, and when the liquid level fluctuates, the polar liquid fluctuates on the surface of the triboelectrification layer to generate alternating voltage output to drive the electroluminescent layer to emit light. According to the invention, the electroluminescent layer and the triboelectrification layer are arranged on the plane of the electrode layer, the electroluminescent layer is immersed in the polar liquid during use, and the liquid level of the polar liquid is located on the triboelectrification layer; when the liquid level fluctuates, the polar liquid fluctuates on the surface of the triboelectrification layer to generate alternating current voltage, and the alternating current voltage is output to drive the electroluminescent layer to emit light; the self-driven electroluminescent liquid sensing system disclosed by the invention is high in integration level, simple in structure and good in portability, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of electroluminescence, and in particular to a self-driven electroluminescence liquid sensing system and a preparation method thereof. Background Art

[0002] Electroluminescence is a photoelectric conversion phenomenon that has a wide range of applications in modern electronics, display technology, lighting industry, etc. Electroluminescent sensors based on the electroluminescence principle have the characteristics of surface luminescence, cold light source, long life and high stability compared with traditional photoelectric sensors.

[0003] Most AC electroluminescent sensors are powered by an external AC power supply. The reliance on an external AC power supply is not conducive to the reduction of the size and mobility of the sensor. When used for liquid sensing, the power supply and circuit waterproofing requirements are high, which limits the use environment and application areas of the sensor to a certain extent. In addition, the production and waste treatment of power supplies have brought tremendous pressure to the ecological environment. If the mechanical energy that is ubiquitous in nature, such as human walking, hand movement, wind energy, and water flow energy, can be collected to power electroluminescence, clean energy conversion and utilization can be realized, and self-driven electroluminescent sensing can be realized.

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

[0005] In order to solve 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 respectively located on different sides of the electrode layer;

[0007] The electroluminescent layer is immersed in a polar liquid, and when the liquid level fluctuates, the polar liquid fluctuates on the surface of the triboelectric layer to generate an AC voltage output to drive 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 an integral block, an interdigitated finger type, or a chessboard type;

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

[0010] Furthermore, the material of the substrate includes at least one of a polymer film, glass, organic glass, and a polymer plate. The polymer film belongs to a flexible substrate, and the polymer film can be a polyvinyl chloride (PVC) film, a polyethylene terephthalate (PET) film, a polycarbonate (PC) film, a polyethylene (PE) film, a polyimide (PI) film, etc. Glass (soda-lime glass, quartz glass), organic glass, and a polymer plate belong to a rigid substrate.

[0011] Furthermore, the material of the electrode layer includes at least one of conductive metal, indium tin oxide, and conductive polymer. The conductive metal may be gold, silver, or copper, and the microscopic morphology of the conductive metal may be nanowires, nanosheets, nanospheres, and the like.

[0012] Furthermore, the material of the electroluminescent layer includes an electroluminescent substance and a resin matrix. The resin matrix is ​​heat-curable, and after being mixed with the electroluminescent substance, it is coated on the electrode layer and heated and cured to form the electroluminescent layer.

[0013] Furthermore, the electroluminescent material includes ZnS:Cu, ZnS:Mn, SrAl 2 O 4 :Eu 2+ At least one of;

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

[0015] The mass ratio of the electroluminescent substance to the 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, aluminum oxide, 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 the light-emitting brightness.

[0018] Furthermore, the material of the triboelectric layer includes at least one of polytetrafluoroethylene or perfluoroethylene propylene copolymer. The material of the triboelectric layer is selected from a thin film material that is easy to transfer charge when in contact with liquid. The triboelectric layer and the electrode layer covered by it form a triboelectric generator component. When the liquid fluctuates, the mechanical energy of the liquid can be collected and converted into an AC voltage output to drive the area of ​​the electroluminescent layer in contact with the polar liquid to emit light.

[0019] The present invention also provides a method for preparing the above-mentioned self-driven electroluminescent liquid sensing system, comprising:

[0020] An electrode layer is prepared 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. The present invention arranges the electroluminescent layer and the triboelectric layer on the plane of the electrode layer. When in use, the electroluminescent layer is immersed in a polar liquid, and the liquid surface of the polar liquid is between the triboelectric layers. When the liquid surface fluctuates, the polar liquid fluctuates on the surface of the triboelectric layer to generate an AC voltage output to drive 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

[0026] Figure 2 A picture of the electrode layer prepared in Example 2 of the present invention is shown;

[0027] Figure 3 A picture of the self-driven electroluminescent liquid sensing system prepared in Example 2 of the present invention is shown;

[0028] Figure 4 A picture showing the self-driven electroluminescent liquid sensing system of Example 2 of the present invention fixed in still tap water;

[0029] Figure 5 The figure shows the AC voltage output of the generator component of the self-driven electroluminescent liquid sensing system of Example 2 of the present invention in fluctuating tap water;

[0030] Figure 6 A picture showing the luminous effect of the self-driven electroluminescent liquid sensing system of Example 2 of the present invention in fluctuating tap water;

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

[0032] Description of reference numerals:

[0033] 1. Substrate; 2. Electrode layer; 3. Electroluminescent layer; 4. Triboelectric layer. DETAILED DESCRIPTION

[0034] The endpoints and any values ​​of the ranges disclosed in the present 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in the present invention. The raw materials used in the present invention, unless otherwise specified, are conventional commercial products; the methods used in the present invention, unless otherwise specified, are conventional methods in the art.

[0035] The following will be combined with the specific embodiments of the present invention and the drawings of the specification to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work 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 comprises a substrate 1 and an electrode layer 2 on the substrate 1, wherein the electrode layer 2 is further provided with an electroluminescent layer 3 and a triboelectric layer 4; the electroluminescent layer 3 and the triboelectric layer 4 are respectively located on different sides of the electrode layer 2. The substrate 1 is a 5cm×3cm×2mm epoxy resin plate; the electrode layer 2 is a copper with a thickness of 500nm, and the shape of the electrode layer is a combination of block and chessboard; the electroluminescent layer 3 is a mixture of ZnS:Cu and epoxy resin glue with a thickness of 40μm (the mass ratio of ZnS:Cu and epoxy resin glue is 7:3); the triboelectric layer 4 is a perfluoroethylene propylene copolymer film with a thickness of 50μm. The triboelectric layer 4 and the electrode layer 2 covered by it form a triboelectric generator component, which can collect the mechanical energy of the liquid and convert it into an AC voltage output when the liquid fluctuates, driving the electroluminescent layer 3 to emit light in the area in contact with the polar liquid.

[0038] When in use, the electroluminescent layer 3 is immersed in a polar liquid, and the polar liquid is located on the triboelectric layer 4; when the liquid level fluctuates, the polar liquid fluctuates on the surface of the triboelectric layer 4 to generate an AC voltage output to drive the electroluminescent layer 3 to emit light.

[0039] Example 2

[0040] The preparation method of the self-driven electroluminescent liquid sensing system of Example 1 comprises the following steps:

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

[0042] Step 2: Electroplating is used to process a copper electrode layer with a thickness of 500 nm on the surface of a clean epoxy resin board. The electrode layer pattern is a combination of block double electrodes and chessboard double electrodes, such as Figure 2 As shown;

[0043] Step 3, ZnS:Cu and epoxy resin glue are mixed evenly in a mass ratio of 7:3 and coated on the checkerboard copper electrode layer area in step 2, and then dried in a constant temperature oven at 60°C to form a 40μm electroluminescent layer;

[0044] Step 4: Paste a 50 μm perfluoroethylene-propylene copolymer film on the block double electrode area of ​​the copper electrode layer to form a triboelectric layer, and a self-driven electroluminescent liquid sensing system can be obtained. Figure 3 shown.

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

[0046] like Figure 4 As shown, the electroluminescent layer is immersed in tap water, and the liquid surface of the tap water is located in the middle of the triboelectric layer. At this time, the tap water surface does not fluctuate, and the electroluminescent layer does not emit any light. The tap water is moved by hand to make the liquid surface fluctuate on the surface of the triboelectric layer, and the electroluminescent layer area can be observed to emit light. The output of the triboelectric generator component under water fluctuations is measured using an electrometer, and its AC voltage output is as follows Figure 5 As shown, the voltage can reach 60V. The luminous effect of the electroluminescent layer in a dark room is as follows Figure 6 As shown. Use the fiber optic spectrometer to focus on the luminous area and measure the spectrum as shown Figure 7 As shown, the luminescence peak is located at 520nm, which is in the visible green light region. When the fluctuation of the tap water stops, the luminescence stops.

[0047] Similarly, tap water was replaced with sodium chloride solutions (polar liquids) with mass fractions of 0.25%, 0.5%, 0.75% and 1%, and insulating oil (non-polar liquid). The results show that the electroluminescent layer can be observed to emit light when the liquid surface of sodium chloride solutions of different concentrations fluctuates; however, no luminescence phenomenon can be observed in insulating oil. This is because water and salt solutions are polar liquids, while insulating oil is a non-polar liquid. These results show that the self-driven electroluminescent liquid sensing system prepared by the present invention can be used for electroluminescent sensing of polar liquid media without an external power supply.

[0048] Example 3

[0049] It is basically the same as Example 2, the only difference being that in step 3, ZnS:Mn is used to replace ZnS:Cu.

[0050] Example 4

[0051] It is basically the same as Example 2, with the only difference being that: Step 3 is to mix ZnS:Cu, epoxy resin glue and barium titanate in a mass ratio of 4:2:4 and then apply it on the checkerboard copper electrode layer area of ​​Step 2, and then dry it 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 experiment as in Example 2. The results showed that the electroluminescent region of Example 3 produced visible orange light during the water wave process. The luminous 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 luminous brightness.

[0053] Comparative Example

[0054] It is basically the same as Example 2, the only difference being that step 4 is not included, that is, a 50 μm perfluoroethylene propylene copolymer film is not pasted on the block double electrode area of ​​the copper electrode layer, and there is no triboelectric layer.

[0055] The comparative electroluminescent layer is immersed in tap water, and no luminescence phenomenon is observed regardless of whether the water causes the liquid surface to fluctuate. Finally, the electroluminescent layer is connected to an AC power source to emit light. The results of Examples 2 to 4 and the comparative example show that the AC voltage generated by the fluctuation of the triboelectric layer surface of the polar liquid is sufficient to drive the self-driven electroluminescent liquid sensing system constructed by the present invention to emit light.

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

[0057] Finally, it should be noted that the above 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 aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in 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: The electrode layer is also provided with an electroluminescent layer and a triboelectric layer; The electroluminescent layer and the triboelectric layer are respectively located on different sides of the electrode layer; The electroluminescent layer is immersed in a polar liquid. When the liquid level fluctuates, the polar liquid fluctuates on the surface of the triboelectric layer to generate an AC voltage output to drive the electroluminescent layer to emit light.

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

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

4. The self-driven electroluminescent liquid sensing system according to claim 1, characterized in that: The material of the electrode layer includes at least one of conductive metal, indium tin oxide, and conductive polymer.

5. The self-driven electroluminescent liquid sensing system according to claim 1, characterized in that: The materials of the electroluminescent layer include electroluminescent substances and a 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, SrAl2O4:Eu 2+ At least one of; The resin matrix includes at least one of epoxy resin, acrylic resin, polyethylene resin, and polyvinylidene fluoride; The mass ratio of the electroluminescent substance to the resin matrix is ​​1:9 to 8:

2.

7. The self-driven electroluminescent liquid sensing system according to claim 5, characterized in that: The material of the electroluminescent layer also includes a high dielectric material; The high dielectric material includes at least one of barium titanate, aluminum oxide, 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 and 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 prepared 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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