A jet-type low-temperature micro-plasma generator and its preparation method

Abstract

This invention provides a low-temperature micro-plasma jet generator and its preparation method, comprising: an ultrasonic jet generator for generating ultrasonic jets; and a micro-plasma generator for generating plasma; wherein the ultrasonic jet generator and the micro-plasma generator are integrated into a single, sheet-like structure. The ultrasonic jet generator is located in the middle of the micro-plasma generator, effectively enhancing the transverse wave effect of negative oxygen ions and ozone waveguides through the ultrasonic jet effect. This invention integrates the ultrasonic jet effect and the generation of low-temperature micro-plasma, effectively solving the problem of low transverse waveguide efficiency for the propagation of low-temperature negative oxygen ions and ozone. It can be used in plasma disinfection and sterilization scenarios, providing an effective approach for the miniaturized integrated manufacturing of related products.

Description

Technical Field

[0001] This invention relates to the field of disinfection and sterilization technology, specifically to a jet low-temperature micro-plasma generator and its preparation method. Background Technology

[0002] The main working principle of a plasma generator is to boost a low voltage to positive and negative high voltage through a boost circuit. The positive and negative high voltages are used to ionize the air (mainly oxygen) to generate a large number of positive and negative ions. The number of negative ions is greater than the number of positive ions (the number of negative ions is about 1.5 times the number of positive ions).

[0003] Currently, people usually wear functional masks to prevent bacteria, viruses and other pathogens in the air from entering their bodies through the respiratory tract. However, wearing masks for a long time can cause skin problems, such as mask face, and long-term wearing can also cause breathing discomfort and other problems, which bring inconvenience to people's lives. Therefore, many disinfection and sterilization products using plasma generators have emerged.

[0004] When existing plasma generators are used in the aforementioned disinfection products, the sterilization range is limited because the plasma generator is a static device operating in a passive sterilization mode. Traditional products primarily use fans, resulting in large sizes and making it impossible to manufacture products like sterilization cards. Furthermore, medical ultraviolet low-temperature plasma bedsore dressings and acne films need to be thin and have good air circulation to ensure sufficient oxygen for bedsores, acne, and other sores, generating enough negative oxygen ions and ozone to kill bacteria while expelling putrefactive gases from the wound. However, current plasma generators suffer from low-temperature free-state plasma propagation efficiency, leading to ineffective sterilization. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a jet low-temperature micro-plasma generator and its preparation method, realizing a small sheet-like product that can solve the problem of low propagation efficiency of low-temperature free-state plasma.

[0006] One aspect of the present invention provides a jet-type low-temperature micro-plasma generator, comprising:

[0007] Ultrasonic jet generator used to generate ultrasonic jets;

[0008] Microplasma generator for generating plasma;

[0009] Wherein: the ultrasonic jet generator and the micro-plasma generator are combined into an integral structure, which is sheet-shaped.

[0010] Optionally, the overall structure of the jet cryogenic microplasma generator includes:

[0011] Base;

[0012] The working electrode of the micro-plasma generator is disposed on the upper surface of the substrate;

[0013] The ultrasonic jet generator working electrode is located in the middle of the micro-plasma generator working electrode;

[0014] A bottom electrode disposed on the lower surface of the substrate;

[0015] in:

[0016] The substrate, the bottom electrode, and the working electrode of the micro-plasma generator constitute a micro-plasma generator;

[0017] The substrate, the ultrasonic jet working electrode, and the bottom electrode constitute the ultrasonic jet.

[0018] Optionally, a voltage is applied to the working electrode and the bottom electrode of the micro-plasma generator to generate high voltage that breaks down the air and ionizes it, forming a uniform high concentration of negative oxygen ions and ozone on the working electrode of the micro-plasma generator and dispersing it into the air, accompanied by ultraviolet radiation; the ultrasonic jet generator is located in the middle of the working electrode of the micro-plasma generator, and through the ultrasonic jet effect, a transverse wave is formed around the working electrode of the micro-plasma generator from the inside out, so that the negative oxygen ions and ozone formed by the micro-plasma generator can be rapidly propagated outward through the ultrasonic jet effect.

[0019] Optionally, the ultrasonic jet generator further includes one or more micropores located in the middle of the working electrode of the ultrasonic jet generator for the diffusion of the ultrasonic jet; when there are multiple micropores, they are uniformly arranged.

[0020] Optionally, the jet low-temperature micro-plasma generator is annular in shape, wherein: at least one of the substrate, the bottom electrode, and the working electrode of the micro-plasma generator is annular; the working electrode of the ultrasonic jet generator is circular and located in the middle of the working electrode of the annular micro-plasma generator;

[0021] Optionally, the jet low-temperature micro-plasma generator is a bridge-shaped plate, wherein: there are at least two substrates, bottom electrodes and micro-plasma generator working electrodes, and each substrate, bottom electrode and micro-plasma generator working electrode is connected to form a unit, forming two symmetrical units, and the two ends of the ultrasonic jet generator working electrode are respectively connected to one end of the two units to form a bridge shape.

[0022] Optionally, the pattern of the working electrode of the micro-plasma generator is designed according to the actual needs of use and is fabricated using MEMS patterning technology.

[0023] Another aspect of the present invention provides a method for preparing a jet-type low-temperature micro-plasma generator, comprising:

[0024] S1: Use software to draw the functional layer pattern, and draw the front and back sides for MEMS processing and the alignment symbols for aligning the multi-layer composite functional structure on the edge. Convert the pattern into a mask for MEMS process photolithography to meet the in-situ multiple processing of micron-level high-precision multi-layer composite structures of MEMS devices.

[0025] S2: Select a substrate as the substrate, prepare a transition layer on the substrate that has excellent bonding force with the metal and is not prone to cracking of the metal layer during thermal expansion and contraction, and then spray a layer of liquid photosensitive polymer material of uniform thickness on the transition layer, and dry the sprayed liquid photosensitive polymer material into a solid.

[0026] S3: Press the photomask obtained in S1 face to face onto the solid photosensitive polymer material obtained in S2, and use an ultraviolet light source to perform a photochemical reaction on the photosensitive polymer material that is not blocked by the photomask to obtain a photosensitive polymer material substrate.

[0027] S4: The photosensitive polymer substrate is placed in the photoresist developer to dissolve the part that needs to be removed, thereby forming the required electroforming three-dimensional micro-mold structure.

[0028] S5: The required back structure pattern, i.e., the bottom electrode, is first electroformed using an electrochemical micro-electroforming method on the three-dimensional micro-mold structure. Then, a slurry is coated, and finally the adhesive is removed to release the required bottom electrode structure layer.

[0029] S6: Prepare a composite substrate with lead holes, fabricate a patterned ceramic or ceramic-like film for bottom electrode protection on the composite substrate, align the pattern by pre-patterning alignment symbols on the outer side of the composite substrate and the upper surface of the substrate, and then complete the fabrication of the bottom electrode by isostatic pressing and high-temperature heat treatment.

[0030] S7: Using double-sided alignment overlay technology, the alignment symbol pre-placed on the outside of the composite substrate is aligned with the pattern alignment symbol on the front mask using the back alignment capability of the double-sided lithography machine. Repeat S2-S5 to prepare the micro-plasma working electrode and ultrasonic jet bonding layer pattern structure on the front side of the substrate. A skin-like bonding layer with good adhesion to the patterning paste is prepared on the substrate by sputtering process. Then, the micro-plasma working electrode and ultrasonic jet bonding layer paste is coated, and then the paste is quickly removed to form the front pattern structure of the device.

[0031] S8: The ultrasonic jet working electrode with a pre-prepared microporous structure is precisely positioned on the substrate at the set position by double-sided overlay patterning alignment. Then, isostatic pressing and high-temperature heat treatment are performed again. After that, glass glaze or ceramic glaze is coated on the micro-plasma working electrode to form a protective layer for the working electrode. This completes the fabrication of the entire device.

[0032] Optionally, before S1 above, the method further includes: drawing a multi-dimensional, multi-layer 3D structural schematic diagram of the device, simulating the rationality of the device's structural layout and performance to optimize its performance, and finally determining the interlayer structure and various materials for fabricating the device.

[0033] Compared with the prior art, the embodiments of the present invention have at least one of the following beneficial effects:

[0034] The above-mentioned jet low-temperature micro-plasma generator of the present invention can easily break down the cell walls of viruses and bacteria on the micro-plasma generation surface under the ultrasonic jet effect. At the same time, the combined effect of the negative oxygen ions and ozone strong oxidation of plasma and ultraviolet radiation greatly enhances the scope and efficiency of sterilization.

[0035] The above-mentioned jet-type low-temperature micro-plasma generator of the present invention is a small-sized sheet-like low-temperature micro-plasma generator. By using the same substrate (sharing the same base) for both the ultrasonic jet generator and the low-temperature micro-plasma generator, it integrates the ultrasonic jet effect and the generation of low-temperature micro-plasma into one, effectively solving the problem of low transverse waveguide efficiency for the propagation of low-temperature free-state plasma. It can be used in plasma disinfection and sterilization scenarios. Through micro-nano integrated manufacturing technology, a heterogeneous sheet-like structure is formed, which also provides an effective way for the miniaturized integrated manufacturing of related products.

[0036] The method for preparing the jet-type low-temperature micro-plasma generator of the present invention produces a micro-plasma working electrode (corona electrode) with a 3D structure, which is impossible to achieve with traditional methods. This corona electrode has a micro-nano composite needle-like structure, which not only effectively improves the plasma generation efficiency (i.e., the generation efficiency of negative oxygen ions and ozone), but also makes the formed plasma uniform and thick. It can form a micro-field emission effect and a micro-nano scale effect, that is, the energy required for ion formation at the micro-nano scale is reduced, which greatly reduces the power consumption of the device and makes it easy to ignite and form glow. Attached Figure Description

[0037] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0038] Figure 1 This is a schematic cross-sectional view of the overall structure of a jet-type low-temperature micro-plasma generator according to a preferred embodiment of the present invention;

[0039] Figure 2a , 2b These are front and rear views of an annular jet low-temperature micro-plasma generator.

[0040] Figure 3a , 3b These are the front and rear views of a bridged jet low-temperature micro-plasma generator;

[0041] Figure 4 This is a schematic diagram of a needle-like micro-nano composite structure in one embodiment of the present invention;

[0042] The markings in the diagram represent: 1. Ceramic or ceramic-like flexible membrane substrate; 2. Working electrode (upper electrode) of the micro-plasma generator; 3. Working electrode of the ultrasonic jet generator; 4. Lead solder joint of the working electrode of the micro-plasma generator; 5. Lead solder joint of the bottom electrode shared by the micro-plasma generator and the ultrasonic jet generator; 6. Ceramic or ceramic-like patterned circuit protective film that protects the bottom electrode; 7. Ceramic or ceramic-like film composite substrate that prevents leakage current from the bottom electrode; 8. Bottom electrode shared by the micro-plasma generator and the ultrasonic jet generator; 9. Lead solder joint of the working electrode of the ultrasonic jet generator; 10. Protective glaze for the working electrode of the micro-plasma generator; 11. Micropores for the ultrasonic jet generator. Detailed Implementation

[0043] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0044] Figure 1 This is a schematic diagram of the overall structure of a jet low-temperature micro-plasma generator according to a preferred embodiment of the present invention.

[0045] Reference Figure 1 As shown, in this embodiment, the jet cryogenic microplasma generator includes an ultrasonic jet generator for generating ultrasonic jets and a microplasma generator for generating microplasma, wherein the ultrasonic jet generator and the microplasma generator are combined into an integral structure, which is sheet-shaped.

[0046] This embodiment effectively solves the problem of low transverse waveguide efficiency in the propagation of low-temperature free-state plasma. Viruses and bacteria on the plasma generation surface are easily broken under the ultrasonic jet effect. At the same time, the combined effect of the negative oxygen ions and ozone strong oxidation of plasma and ultraviolet radiation greatly enhances the scope and efficiency of sterilization. In addition, the entire product is sheet-shaped and very small in size, which can be used to produce environmental disinfection products such as disinfection cards.

[0047] Reference Figure 1 As shown, in a preferred embodiment of the present invention, the overall structure of the low-temperature micro-plasma generator includes: a substrate 1; a micro-plasma generator working electrode 2 disposed on the upper surface of the substrate 1; an ultrasonic jet generator working electrode 3 located in the middle of the micro-plasma generator working electrode; and a bottom electrode 8 disposed on the lower surface of the substrate 1. In this embodiment, the sheet-like micro-plasma generator working electrode 2, the substrate 1, and the bottom electrode 8 constitute the micro-plasma generator; the ultrasonic jet generator working electrode 3, the substrate 1, and the bottom electrode 8 constitute the ultrasonic jet generator. These components are as follows: Figure 1 The integrated structure shown in Figure -3 is composed of multiple parts, and the overall structure is sheet-like.

[0048] In this preferred embodiment, the micro-plasma generator working electrode 2 and the ultrasonic jet generator working electrode 3 share the same substrate 1 and bottom electrode 8. The ultrasonic jet generator working electrode 3 is located in the middle of the micro-plasma generator working electrode 2. This jet effect creates a transverse wave around the micro-plasma generator working electrode 2, causing the high-density negative oxygen ions and ozone generated by the micro-plasma generator to propagate rapidly outwards. Voltage is applied to the micro-plasma generator working electrode 2 and the bottom electrode 8, breaking down the air through high voltage. This results in uniform high-density negative oxygen ions and ozone on the micro-plasma generator working electrode 2, which diffuse into the air, accompanied by ultraviolet radiation. This structure can be used to manufacture environmental disinfection products such as disinfection cards, and can also be used for local disinfection and sterilization of human or animal tissues. In this embodiment, the ultraviolet radiation occurs on the plasma working electrode. The gaseous positive ions in the plasma lack bound electrons, thus having empty energy levels—a potential well—if infinity is taken as the zero potential energy point, the energy corresponding to this energy level is a negative value. The electrons in the plasma are essentially free electrons and possess a certain kinetic energy; their energy is positive. During discharge, electrons collide with positive ions, and free electrons may fall into the potential well of the positive ions. The positive energy of the free electron minus the negative energy of the potential well equals a relatively large positive energy. One way for electrons to release this energy is by converting it into photons; high-energy photons are generally ultraviolet photons.

[0049] In the above embodiments, the substrate material is aluminum nitride, aluminum oxide, glass fiber, silicon carbide fiber, silicate fiber, polymer material such as polyimide, and other high dielectric constant materials.

[0050] like Figure 1As shown in Figure 3, in some embodiments, the ultrasonic jet generator further includes one or more micro-holes 11 located in the middle of the working electrode 3 of the ultrasonic jet generator for the diffusion of the ultrasonic jet; when there are multiple micro-holes 11, they are uniformly arranged, such as in a regular array, which is beneficial to the uniform diffusion of the ultrasonic jet.

[0051] like Figure 2a , 2b As shown, in a preferred embodiment, the jet low-temperature micro-plasma generator is annular, wherein: at least one of the substrate 1, the bottom electrode 8, and the micro-plasma generator working electrode 2 is annular; the ultrasonic jet generator working electrode 3 is circular and located in the middle of the annular micro-plasma generator working electrode.

[0052] like Figure 3a , 3b As shown, in a preferred embodiment, the jet cryogenic micro-plasma generator is a bridge-shaped plate, wherein: there are at least two substrates 1, bottom electrodes 8, and micro-plasma generator working electrodes 2. Each substrate 1, bottom electrode 8, and micro-plasma generator working electrode 2 is connected to form a unit, thereby forming two symmetrical units. The two ends of the ultrasonic jet generator working electrode 3 are respectively connected to one end of the two units, forming a bridge shape. Specifically, the substrate 1, bottom electrode 8, micro-plasma generator working electrode 2, and ultrasonic jet generator working electrode 3 can all adopt a square structure. The two opposite sides of the ultrasonic jet generator working electrode 3 are respectively connected to one side of each of the two square units formed by the substrate 1, bottom electrode 8, and micro-plasma generator working electrode 2, thereby forming a bridge-like connection structure between the two units and the ultrasonic jet generator working electrode 3 located in the middle.

[0053] Reference Figure 1 As shown in Figure -3, the jet low-temperature micro-plasma generator includes a substrate 1, a micro-plasma generator working electrode 2, an ultrasonic jet generator working electrode 3, and a bottom electrode 8. The specific connection method is as described in the above embodiments. In some specific embodiments, in order to obtain a jet low-temperature micro-plasma generator with better performance, the following are provided: the substrate 1 is made of ceramic or ceramic-like flexible film; a micro-plasma generator working electrode lead solder joint 4 is provided on the micro-plasma generator working electrode 2; a bottom electrode lead solder joint 5 shared by the micro-plasma generator and the ultrasonic jet generator is also provided below the bottom electrode 8; at the same time, a ceramic or ceramic-like patterned circuit protective film 6 is provided on the lower surface of the bottom electrode 8 to protect the bottom electrode; a ceramic or ceramic-like film composite substrate 7 is provided on the lower surface of the protective film 6 to prevent leakage of the bottom electrode; an ultrasonic jet generator working electrode lead solder joint 9 is provided on the ultrasonic jet generator working electrode 3; a micro-plasma generator working electrode protective glaze 10 is covered on the micro-plasma generator working electrode 2; and a micro-hole for the ultrasonic jet generator is located in the middle of the ultrasonic jet generator working electrode 3.

[0054] In the above embodiments of the present invention, the low-temperature micro-plasma is actually room-temperature plasma. Ordinary plasma ignites under high voltage, resulting in high temperatures on the plasma surface. Since nitrogen and oxygen are neighbors in the periodic table, this high temperature and high pressure easily produce nitrogen oxides, reducing the quality of ozone. However, the modified low-temperature micro-plasma can ignite in the atmosphere with a lower voltage, which not only reduces power consumption but also keeps the micro-plasma surface close to room temperature, thus being low-temperature. Furthermore, nitrogen has a triple bond structure, while oxygen has a two-bond structure. Since opening the triple bond requires higher energy (voltage), nitrogen oxides are less likely to form, effectively improving the purity (quality) of ozone. The innovation of this embodiment is that it combines the ultrasonic air jet and the plasma generator into one. Because the ultrasonic jet generator and the low-temperature micro-plasma generator can share the same metal bottom electrode 8 and ceramic or ceramic-like film substrate 1, it provides conditions for integrated design. The ultrasonic jet generator working electrode 3 and the substrate 1 and bottom electrode 8 can be metal and ceramic or metal and ceramic-like film to form an ultrasonic vibration piezoelectric device. The micro-plasma generator working electrode 2 and the substrate 1 and bottom electrode 8 form a low-temperature micro-plasma generator.

[0055] In the above embodiment, the ultrasonic jet generator working electrode 3 is disposed on the substrate 1, and the ultrasonic jet generator working electrode 3 is located in the middle of the micro-plasma generating surface. Utilizing the transverse waves generated from the inside out by the ultrasonic jet effect, the directional flow of air around the micro-plasma generator working electrode 2 is effectively promoted, allowing the negative oxygen ions and ozone generated by the disinfection sheet to rapidly propagate into the external air, efficiently expelling ionized oxygen (ozone) from the disinfection card and dispersing it into the air for disinfection. Traditionally, air convection is achieved primarily using fans. However, the weight, thickness, and volume of fans limit their integration into the disinfection card, especially the thickness. This embodiment uses the ultrasonic jet generator working electrode 3, the substrate 1, and the bottom electrode 8, which are lightweight, ultra-thin, and the diaphragm thickness for generating the jet transverse wave effect is less than 0.25 mm. Furthermore, the ceramic or ceramic-like substrate that forms the piezoelectric effect and the substrate of the micro-plasma generating sheet can be the same substrate, allowing for integrated manufacturing. Moreover, the thickness of the entire integrated device is less than 1 mm, typically around 0.5 mm. This reduces the weight, volume, and thickness of the entire disinfection card, providing effective support for its preparation.

[0056] In some embodiments, the ceramic substrate 1 can be made of aluminum nitride or silicon carbide fiber film / cloth. For example, unlike the traditional ceramic substrate 1 which uses aluminum oxide (Al2O3), this one uses aluminum nitride (AlN) or silicon carbide with high thermal and electrical conductivity, effectively improving thermal conductivity. Of course, other ceramic substrate materials can also be selected in other embodiments, and are not limited to aluminum oxide (Al2O3).

[0057] In some embodiments, the ultrasonic jet generator working electrode 3 and substrate 1, bottom electrode 8, and the low-temperature micro-plasma generator 2, substrate 1, and bottom electrode 8 are all stacked structures of metal and ceramic or ceramic-like materials. When the ultrasonic jet generator and the low-temperature micro-plasma generator are working, energy conversion occurs, and the ceramic substrate 1 layer generates heat. Conventional ceramic substrate 1 layers are typically made of aluminum oxide, while aluminum nitride and silicon carbide offer significantly better heat dissipation than aluminum oxide. Of course, other ceramic substrate materials can be selected in other embodiments, and are not limited to aluminum nitride and silicon carbide.

[0058] In some embodiments, the working electrode 3 of the ultrasonic jet is made of materials such as stainless steel or polyimide. For piezoelectric materials, the higher the hardness of the material, the higher the frequency can be. However, the working electrode 3 of the ultrasonic jet requires a large amplitude and a low frequency. Therefore, materials with good deformation capabilities, such as stainless steel and polyimide, are selected.

[0059] In another embodiment of the present invention, a method for preparing the jet low-temperature micro-plasma generator of the above embodiments is also provided, specifically including the following steps:

[0060] S1: Use software to draw the functional layer pattern, and draw the front and back sides for MEMS processing and the alignment symbols for aligning the multi-layer composite functional structure on the edge. Convert the pattern into a mask for MEMS process photolithography to meet the in-situ multiple processing of micron-level high-precision multi-layer composite structures of MEMS devices.

[0061] S2: Select a substrate as the substrate, prepare a transition layer on the substrate that has excellent bonding force with the metal and is not prone to cracking of the metal layer during thermal expansion and contraction, and then spray a layer of liquid photosensitive polymer material of uniform thickness on the transition layer, and dry the sprayed liquid photosensitive polymer material into a solid.

[0062] S3: Press the photomask obtained in S1 face to face onto the solid photosensitive polymer material obtained in S2, and use an ultraviolet light source to perform a photochemical reaction on the photosensitive polymer material that is not blocked by the photomask to obtain a photosensitive polymer material substrate.

[0063] S4: The photosensitive polymer substrate is placed in the photoresist developer to dissolve the part that needs to be removed, thereby forming the required electroforming three-dimensional micro-mold structure.

[0064] S5: The required back structure pattern, i.e., the bottom electrode, is first electroformed using an electrochemical micro-electroforming method on the three-dimensional micro-mold structure. Then, a slurry is applied, and finally the adhesive is removed to release the required structural layer of the bottom electrode 8.

[0065] S6: The composite substrate 7 with lead holes and the composite substrate on which a patterned bottom electrode protection ceramic or ceramic-like film is prepared are aligned by pre-patterning alignment symbols on the outer side of the composite substrate 7 and the upper surface of the substrate 1 using double-sided alignment technology. Then, the bottom electrode is prepared by isostatic pressing and high-temperature heat treatment. The high-temperature co-firing temperature is between 250-1500℃.

[0066] S7: Using double-sided alignment and overlay technology, the alignment symbol pre-placed on the outside of the composite substrate 7 is aligned with the pattern alignment symbol on the front mask using the back alignment capability of the double-sided lithography machine. Repeating S2-S5, a micro-plasma corona electrode and ultrasonic jet bonding layer pattern structure is prepared on the front side of the ceramic or ceramic-like film substrate 1. A skin-like bonding layer with good adhesion to the patterning paste is prepared on the ceramic or ceramic-like film substrate by sputtering process. Then, the micro-plasma working electrode and ultrasonic jet bonding layer paste are coated, and then the paste is quickly removed to form the front pattern structure of the device.

[0067] S8: The ultrasonic jet working electrode with a pre-prepared microporous structure is precisely positioned in the center of the ceramic or ceramic-like film, i.e., the ceramic substrate 1, by double-sided overlay patterning alignment. Then, isostatic pressing and high-temperature heat treatment are performed again. After that, glass glaze or ceramic glaze is coated on the micro-plasma working electrode as a protective glaze 10 to protect the working electrode. This completes the fabrication of the entire device.

[0068] Before S1 in the above embodiment, in order to better determine the structure, drawing tools such as CAD and Soildwords can be used to draw a multi-dimensional, multi-layer 3D structural schematic diagram of the device, so as to rationally plan the graphical functional layers and lead layout of each layer; using multi-physics simulation software such as COMSOL and ANSYS, the rationality of the device structure layout and performance can be simulated to optimize its performance, and finally determine the interlayer structure and various materials for fabricating the device.

[0069] The steps S2-S5 described above involve fabricating patterned functional materials on a ceramic substrate. The fabrication process of MEMS devices involves structuring functional materials (due to their thickness) to form a multilayer structure, thereby obtaining the functional device.

[0070] In the above embodiments of the present invention, because ceramics and metals have different coefficients of thermal expansion and their bonding strength is poor, they cannot be directly bonded. Therefore, a metal bonding layer with elasticity like skin and good adhesion is needed. Specifically, in some embodiments, the bonding layer is located between the substrate and the micro-plasma working electrode. The bonding layer is generally a chromium-copper composite structure layer, titanium metal, or titanium oxide layer. The skin-like bonding layer can be selected from nickel, chromium, molybdenum, tungsten, stainless steel, or polyimide materials. Considering factors such as processing, price, and performance, stainless steel is generally the most commonly used.

[0071] In the above embodiments of the present invention, the high-temperature heat treatment can be achieved using existing technologies. For example, co-fired multilayer ceramic substrates can be divided into two types: high-temperature co-fired multilayer ceramic (HTCC) substrates and low-temperature co-fired multilayer ceramic (LTCC) substrates. Compared with low-temperature co-fired ceramics, HTCC has advantages such as high mechanical strength, high wiring density, stable chemical properties, high heat dissipation coefficient, and low material cost. It has been widely used in heat-generating and packaging fields with higher requirements for thermal stability, lower requirements for high-temperature volatile gases, and higher requirements for sealing. High-temperature co-fired ceramics, abbreviated as HTCC, are integrated ceramics made by stacking unsintered cast ceramic materials together and sintering them at high temperatures (usually above 1200°C) to form multilayer devices. It features high printing resolution, one-time firing, controllable dielectric layer thickness, smooth surface, unlimited number of layers, and matching thermal expansion coefficient with silicon semiconductors.

[0072] Reference Figure 4 As shown, in the above embodiments of the present invention, the corona electrode has a micro-nano composite structure, which can be needle-shaped, columnar, or mushroom-shaped. In the above embodiments of the present invention, the corona electrode prepared by nano-transfer technology using micro-nano integrated manufacturing processes possesses a 3D structure, which is impossible to achieve using traditional methods. This type of corona electrode has a micron-scale needle-like structure, which not only effectively improves the generation efficiency of low-temperature plasma (i.e., the generation efficiency of ionized oxygen-ozone), but also makes the formed plasma uniform and thick. Viruses and bacteria on the plasma generation surface are easily broken down under the ultrasonic jet effect. Simultaneously, the combined effect of the negative oxygen ions and strong oxidizing effect of ozone, along with ultraviolet radiation, greatly enhances the scope and efficiency of sterilization.

[0073] In the above embodiments of the present invention, the ceramic or ceramic-like flexible membrane substrate is 500-1000 micrometers thick, the working electrode (upper electrode) of the micro-plasma generator is 50-100 micrometers thick, the working electrode of the ultrasonic jet generator is 125-450 micrometers thick, and the bottom electrode shared by the micro-plasma generator and the ultrasonic jet generator is 50-100 micrometers thick. Micrometer-scale materials can all be considered thick films; therefore, the fabrication of the entire device falls within the thick film category. The thick film fabrication technology of micro-nano integrated manufacturing forms a heterogeneous sheet structure, which also provides an effective way for the miniaturized integrated manufacturing of related products. Heterogeneous refers to a composite whole in which different materials are stacked and tightly bonded layer by layer; heterogeneous refers to a composite whole in which materials with different shapes and structures are stacked and tightly bonded layer by layer, such as… Figure 1 The numbers 1, 2, 3, and 8 in the original text.

[0074] Microplasma is a typical non-thermal equilibrium cryogenic plasma. Microplasma is usually confined to a limited spatial area, possessing some characteristics of conventional plasma. Although it is a microcosm of conventional plasma, the discharge size is reduced to the micrometer scale, allowing microplasma to typically operate under atmospheric pressure. This results in several new changes compared to conventional plasma, such as higher plasma density, better stability, and other new characteristics and advantages. The discharge conditions of DC discharge plasma follow Paschen's law, meaning the ignition voltage is determined by the product of gas pressure and electrode gap; the smaller this product, the lower the ignition voltage, the more stable the plasma discharge, and the higher the discharge efficiency. Microplasma discharge also follows Paschen's discharge condition, which determines the miniaturization of microplasma devices operating under atmospheric pressure, making them lightweight and portable. Furthermore, microplasma does not require the vacuum system used in conventional plasma, saving both cost and significant time in vacuum acquisition. From this perspective, microplasma is convenient, economical, and fast. In addition, micro-plasma discharge in high-pressure environments is mainly dominated by the three-body collision mechanism, which is not only conducive to the enhancement of radiation intensity, but also to the increase of discharge current density, thereby helping to increase plasma density.

[0075] The jet micro-plasma generator prepared according to the above embodiments of the present invention can be used in sheet-like disinfection products, such as disinfection cards that dynamically sterilize the surrounding air. This can directly replace wearing masks, relieving people of the inconvenience of wearing masks. The disinfection card, through the ultrasonic micro-plasma generator, can effectively kill bacteria, viruses, and other pathogens in the air. Furthermore, medical ultraviolet low-temperature plasma bedsore patches and acne films need to be thin and have good air circulation to ensure sufficient oxygen for the skin or tissue of bedsores, acne, and other sores. This allows for the formation of sufficient negative oxygen ions and ozone at the sore site to kill bacteria, while simultaneously expelling putrefactive gases from the wound. For these applications, a plasma generator with a jet effect is of even greater practical value.

[0076] In the above embodiments of the present invention, the ultrasonic jet generator and the low-temperature micro-plasma generator are integrated into one unit, which effectively solves the problem that the ionized oxygen formed by the low-temperature micro-plasma propagates slowly into the surrounding air. When applied to disinfection products, it can play a positive role in increasing the effective sterilization range, and at the same time provides an effective way for the miniaturized integrated manufacturing of related products.

[0077] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention. The preferred features described above can be used in any combination without conflict.

Claims

1. A jet-type low-temperature micro-plasma generator, characterized in that, include: Ultrasonic jet generator used to generate ultrasonic jets; Microplasma generator for generating plasma; in: The ultrasonic jet generator and the micro-plasma generator are combined into a single integrated structure, which is sheet-shaped. The overall structure of the jet-type low-temperature micro-plasma generator includes: Base; The working electrode of the micro-plasma generator is disposed on the upper surface of the substrate; The ultrasonic jet generator working electrode is located in the middle of the micro-plasma generator working electrode; A bottom electrode disposed on the lower surface of the substrate; in: The substrate, the bottom electrode, and the working electrode of the micro-plasma generator constitute a micro-plasma generator; The substrate, the ultrasonic jet ejector working electrode, and the bottom electrode constitute the ultrasonic jet ejector; A voltage is applied to the working electrode and the bottom electrode of the micro plasma generator to generate high voltage that breaks down the air and ionizes it. A uniform high concentration of negative oxygen ions and ozone is formed on the working electrode of the micro plasma generator and diffused into the air, accompanied by ultraviolet radiation. The ultrasonic jet generator is located in the middle of the working electrode of the micro-plasma generator. Through the ultrasonic jet effect, a transverse wave is formed around the working electrode of the micro-plasma generator from the inside out, which causes the negative oxygen ions and ozone generated by the micro-plasma generator to spread rapidly outward.

2. The jet-type low-temperature micro-plasma generator according to claim 1, characterized in that, The ultrasonic jet generator further includes one or more micro-holes located in the middle of the working electrode of the ultrasonic jet generator for the diffusion of ultrasonic jets; when there are multiple micro-holes, they are evenly arranged.

3. The jet-type low-temperature micro-plasma generator according to any one of claims 1-2, characterized in that, The jet-type low-temperature micro-plasma generator is annular in shape, wherein: at least one of the substrate, the bottom electrode, and the working electrode of the micro-plasma generator is annular; the working electrode of the ultrasonic jet generator is circular and located in the middle of the working electrode of the annular micro-plasma generator.

4. The jet-type low-temperature micro-plasma generator according to any one of claims 1-2, characterized in that, The jet low-temperature micro-plasma generator is a bridge-shaped plate, wherein: there are at least two substrates, bottom electrodes and micro-plasma generator working electrodes, and each substrate, bottom electrode and micro-plasma generator working electrode are connected to form a unit, forming two symmetrical units, and the two ends of the ultrasonic jet generator working electrode are respectively connected to one end of the two units to form a bridge shape.

5. The jet-type low-temperature micro-plasma generator according to any one of claims 1-2, characterized in that, The pattern of the working electrode of the micro-plasma generator is designed according to the actual needs of use and is fabricated using MEMS patterning technology.

6. A method for preparing a jet-type low-temperature micro-plasma generator according to any one of claims 1-5, characterized in that, include: S1: Use software to draw the functional layer pattern, and draw the front and back sides for MEMS processing and the alignment symbols for aligning the multi-layer composite functional structure on the edge. Convert the pattern into a mask for MEMS process photolithography to meet the in-situ multiple processing of micron-level high-precision multi-layer composite structures of MEMS devices. S2: Select a substrate as the substrate, prepare a transition layer on the substrate that has excellent bonding force with the metal and is not prone to cracking of the metal layer during thermal expansion and contraction, and then spray a layer of liquid photosensitive polymer material of uniform thickness on the transition layer, and dry the sprayed liquid photosensitive polymer material into a solid. S3: Press the photomask obtained in S1 face to face onto the solid photosensitive polymer material obtained in S2, and use an ultraviolet light source to perform a photochemical reaction on the photosensitive polymer material that is not blocked by the photomask to obtain a photosensitive polymer material substrate. S4: The photosensitive polymer substrate is placed in the photoresist developer to dissolve the part that needs to be removed, thereby forming the required electroforming three-dimensional micro-mold structure. S5: The required back structure pattern, i.e., the bottom electrode, is first electroformed using an electrochemical micro-electroforming method on the three-dimensional micro-mold structure. Then, a slurry is coated, and finally the adhesive is removed to release the required bottom electrode structure layer. S6: Prepare a composite substrate with lead holes, fabricate a patterned ceramic or ceramic-like film for bottom electrode protection on the composite substrate, align the pattern by pre-patterning alignment symbols on the outer side of the composite substrate and the upper surface of the substrate, and then complete the fabrication of the bottom electrode by isostatic pressing and high-temperature heat treatment. S7: Using double-sided alignment overlay technology, the alignment symbol pre-placed on the outside of the composite substrate is aligned with the pattern alignment symbol on the front mask using the back alignment capability of the double-sided lithography machine. Repeat S2-S5 to prepare the micro-plasma working electrode and ultrasonic jet bonding layer pattern structure on the front side of the substrate. A skin-like bonding layer with good adhesion to the patterning paste is prepared on the substrate by sputtering process. Then, the micro-plasma working electrode and ultrasonic jet bonding layer paste is coated, and then the paste is quickly removed to form the front pattern structure of the device. S8: The ultrasonic jet working electrode with a pre-prepared microporous structure is precisely positioned on the substrate at the set position by double-sided overlay patterning alignment. Then, isostatic pressing and high-temperature heat treatment are performed again. After that, glass glaze or ceramic glaze is coated on the micro-plasma working electrode to form a protective layer for the working electrode. This completes the fabrication of the entire device.

7. The method for preparing the jet-type low-temperature micro-plasma generator according to claim 6, characterized in that, Before S1 above, the process also includes: drawing a multi-dimensional, multi-layer 3D structural schematic diagram of the device, simulating the rationality of the device's structural layout and performance to optimize its performance, and finally determining the interlayer structure and various materials for fabricating the device.

8. The method for preparing the jet-type low-temperature micro-plasma generator according to claim 6, characterized in that, The microplasma working electrode is a corona electrode with a needle-like micro-nano composite structure.

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