Plasma fluid generator

Abstract

To provide a plasma fluid generator capable of stably generating a large amount of plasma-treated fluid without increasing manufacturing cost.SOLUTION: A plasma fluid generator includes: a plasma generation unit having electrode supporting dielectric 114, 126 provided on electrodes 110, 112, 122, 124 and between the electrodes and generating plasma in the electrode supporting dielectrics 114, 126 by applying an AC voltage to the electrodes; liquid-proof dielectric 116, 128 provided in the electrodes and preventing a fluid from entering the electrodes; and a fluid passage layer 106 provided between a pair of the liquid-proof dielectric separated from each other and through which the fluid flows.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a plasma fluid generating device that generates plasma fluids such as plasma water, plasma gas, and mixtures thereof. [Background technology]

[0002] In recent years, a technique called dielectric barrier discharge (DBD) has been developed in plasma processing technology, making it possible to generate low-temperature plasma at atmospheric pressure. As a result, the range of applications of plasma processing has expanded, and it is increasingly being used in a variety of applications. The purposes of plasma processing include sterilization, deodorization, surface modification, and decomposition of chemical substances. Furthermore, the substances that can be subjected to plasma processing can be solid, liquid, or gaseous.

[0003] Plasma water is generated by dissolving plasma-treated gas in a liquid such as water or by reacting it with water, but it is difficult to efficiently mix the plasma gas, which is a gas, with the liquid, such as water. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-129538 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, one method that has been considered is to apply a high voltage to electrodes placed in water, generate plasma directly under specific conditions, and then mix the gas that is produced with the surrounding water. However, with this method, the area in which plasma is generated is small, making it difficult to generate large amounts of plasma water (plasma fluid), and increasing production costs.

[0006] For example, when generating plasma in water, the impedance of the plasma changes significantly depending on the physical conditions around the electrode placed in the water. Stable plasma generation is achieved by controlling this change, but the larger the electrode, the greater the change in impedance. To maintain a stable plasma state, it is necessary to manipulate the output impedance of the high-voltage power supply to follow the sudden and large changes in impedance. This is extremely difficult, and increases the complexity and manufacturing costs. Furthermore, it is also difficult to achieve a compact device.

[0007] In this regard, a practical example uses two needle electrodes and applies a high voltage to the needle electrodes. This electrolyzes the tips of the needle electrodes, generating gas bubbles. These gas bubbles keep the tips of the needle electrodes out of contact with the water, allowing plasma to be generated. However, when using such needle electrodes, the plasma generation range is limited to the tips (points) of the needle electrodes, making it difficult to generate large amounts of plasma stably.

[0008] Another problem is the presence of liquid (such as water) around the part where high voltage is applied. Pure water does not conduct electricity, but if ions are present in the liquid, it becomes electrically conductive, and there is a risk that high voltage will be applied to unintended locations through the water. Furthermore, there is a risk of electric leakage or electric shock through the water. For this reason, it is necessary to somehow insulate the plasma generator from the liquid, but this is quite difficult in applications where the liquid is used directly. Even if this could be achieved, it would increase manufacturing costs.

[0009] The present invention has been made in consideration of the above points, and aims to provide a plasma fluid generating device that can produce plasma-treated fluid stably and in large quantities without increasing manufacturing costs. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the present invention is characterized by comprising: a plasma generating unit having at least a pair of electrode layers and a dielectric layer provided between the pair of electrode layers, which generates plasma in the dielectric layer by applying an AC voltage to the pair of electrode layers; a pair of fluid ingress prevention dielectrics provided above or below the at least pair of electrode layers, which prevent fluid from ingressing into the pair of electrode layers; and a fluid passage layer provided between the pair of fluid ingress prevention dielectrics spaced apart from each other, through which the fluid flows.

[0011] According to the present invention, most of the plasma is generated between the pair of electrodes, and some of the generated plasma passes through the fluid ingress prevention dielectric and appears on the surface of the fluid ingress prevention dielectric facing the fluid passage layer. The part of the plasma that appears on the surface of the fluid ingress prevention dielectric comes into contact with the fluid passing through the fluid passage layer, thereby bringing the fluid into contact with the plasma. In the present invention, a planar plasma generating unit can be used instead of a needle-shaped one, and a large surface area can be brought into contact with the fluid, making it easy to generate a large amount of plasma-treated fluid.

[0012] Furthermore, it is preferable that the pair of electrode layers have a first upper electrode layer and a second upper electrode layer arranged below the first upper electrode layer, and that a dielectric layer is arranged between the first upper electrode layer and the second upper electrode layer.

[0013] Furthermore, the pair of fluid ingress prevention dielectrics includes an upper fluid ingress prevention dielectric arranged above the fluid passage layer and a lower fluid ingress prevention dielectric arranged below the fluid passage layer, the pair of electrode layers includes a first upper electrode layer and a second upper electrode layer arranged above the upper fluid ingress prevention dielectric and a first lower electrode layer and a second lower electrode layer arranged below the lower fluid ingress prevention dielectric, the second upper electrode layer being arranged on the upper surface of the upper fluid ingress prevention dielectric and the second lower electrode layer being arranged on the lower surface of the lower fluid ingress prevention dielectric, and the second upper electrode layer and the second lower electrode layer being preferably set to the same potential.More preferably, for greater safety, the second upper electrode layer and the second lower electrode layer are set to the same ground potential.

[0014] Furthermore, it is preferable that the dielectric layer has a first dielectric layer provided on the first upper electrode layer side and a second dielectric layer provided on the second upper electrode layer side, and that an air layer through which air can pass is provided between the first dielectric layer and the second dielectric layer, which are separate and spaced apart from each other. [Effects of the Invention]

[0015] According to the present invention, a plasma fluid generator can be obtained that can stably produce a large amount of plasma-treated fluid without increasing manufacturing costs. Furthermore, unlike methods of generating plasma fluid by mixing gas and liquid, the present invention can directly process liquid without foaming. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 2 is a perspective view for explaining a plasma generating unit. [Figure 2] FIG. 2 is a perspective view for explaining a plasma generating unit. [Figure 3] FIG. 2 is a cross-sectional view for explaining a plasma generating unit. [Figure 4] FIG. 10 is a perspective view for explaining a plasma generating unit according to a first modified example. [Figure 5] FIG. 10 is a perspective view for explaining a plasma generating unit according to a second modified example. [Figure 6] FIG. 10 is a cross-sectional view illustrating a plasma generating unit according to a third modified example. [Figure 7] 1 is a perspective configuration diagram showing a plasma fluid generating device according to a first embodiment of the present invention. [Figure 8] FIG. 8 is a partially enlarged view illustrating the principle of plasma fluid generation using part A shown in FIG. 7. [Figure 9] FIG. 10 is a perspective view showing the configuration of a plasma fluid generating device according to a second embodiment of the present invention. [Figure 10] FIG. 10 is a perspective view showing a modified example of the plasma fluid generating device of FIG. [Figure 11]FIG. 10 is a perspective view showing the configuration of a plasma fluid generating device according to a third embodiment of the present invention. [Figure 12] FIG. 10 is a perspective view showing the configuration of a plasma fluid generating device according to a fourth embodiment of the present invention. [Figure 13] FIG. 13 is a partially enlarged schematic structural diagram of the plasma fluid generating device of FIG. [Figure 14] 10 is a schematic diagram of a spacer interposed between an upper electrode structure and a lower electrode structure. FIG. [Figure 15] FIG. 15 is a schematic diagram showing a first modified example of the spacer shown in FIG. [Figure 16] 15 is a schematic diagram showing a second modified example of the spacer shown in FIG. 14. FIG. [Figure 17] FIG. 13 is a perspective view showing a modified example of the plasma fluid generating device of FIG. [Figure 18] FIG. 1 is a schematic structural diagram showing a reference embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described in detail, but the embodiments of the present invention are not limited to the embodiments described below. Each embodiment and modified example can be applied in appropriate combination. Furthermore, directions such as "upper" and "lower" in the description are used for convenience of explanation and do not limit the directions of the present invention.

[0018] The plasma fluid generating device of this embodiment is configured to continuously plasma-treat fluids such as gases and liquids, and is equipped with a plasma generating unit having a multilayer structure including a dielectric layer, an electrode layer, and a mask layer (optional), and an AC power supply unit capable of applying an AC voltage between a pair of electrode layers. In dielectric barrier discharge, a dielectric layer is provided between two electrode layers, and by applying an AC voltage between the two electrode layers, plasma can be generated within the dielectric layer sandwiched between the two electrode layers. First, the plasma generating unit will be described.

[0019] <Basic structure of the plasma generation unit> As shown in Figures 1 and 2, the plasma generating unit 10 includes a dielectric layer 11, an upper electrode 12, a lower electrode 13, an upper mask layer 14, and a lower mask layer 15. The plasma generating unit 10 is a thin-film member and is flexible. For convenience, the dielectric layer 11 is expressed as a single dielectric, but it may also be a laminate of one or more dielectrics containing air. The mask layer is provided to protect the electrodes and improve the ease of assembly of the electrodes, and may be omitted. Furthermore, by appropriately selecting the thickness and position of the mask layer, excessive electric field concentration on the electrodes can be prevented, thereby extending the life of the electrodes.

[0020] As shown in Figures 1 to 3, the dielectric layer 11 is a layered member disposed between the upper electrode 12 and the lower electrode 13. The material of the dielectric layer 11 is an insulating material with a large breakdown voltage so as to prevent discharge between the upper electrode 12 and the lower electrode 13. Furthermore, since the material of the dielectric layer 11 will be exposed to the generated plasma, it is preferable that the material be durable against the active substances generated in the plasma. The material of the dielectric layer 11 is preferably a material selected from glass, ceramics, and synthetic resins. "Mainly" means that the component composition is 50 mass% or more (the same applies hereinafter). Note that, for convenience, the dielectric 11 is shown as a single dielectric in Figures 1 to 3, but it may also be a stack of multiple dielectrics including air.

[0021] Examples of glass include soda-lime glass (soda glass), borosilicate glass, quartz glass, lead glass, and oxide glass.

[0022] Synthetic resins include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include general-purpose resins such as polyolefin, polystyrene, polyvinyl acetate, polyurethane, polylactic acid, ABS resin, AS resin, acrylic resin, polyvinyl chloride, and polyvinylidene chloride; engineering plastics such as polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polyester, and cyclic polyolefin; polyphenylene sulfide, polysulfone, polyethersulfone, polyarylate, liquid crystal polymer, polyetheretherketone, polyimide, polyamideimide, polyetherimide, fluorine-based resin, unsaturated polyester resin, and polyurethane resin. Among these synthetic resins, silicone-based resins, polyimide-based resins, and Teflon®-based resins, which have excellent durability, are particularly preferred. The thickness of the dielectric layer 11 is not particularly limited, but is preferably 0.1 mm to 5.0 mm, more preferably 0.1 mm to 3.0 mm, and even more preferably 0.1 mm to 1.0 mm, in order to achieve lightweight and compactness.

[0023] As shown in FIGS. 2 and 3, the upper electrode (electrode layer) 12 and the lower electrode (electrode layer) 13 are layer members disposed on the front and back of the dielectric layer 11. The upper electrode 12 and the lower electrode 13 are each provided with a through-hole 16 penetrating in the thickness direction. In this embodiment, the through-holes 16 are oval in plan view, and five through-holes 16 are formed, but the shape and number are not limited. The through-holes 16 may be omitted, but the presence of the through-holes 16 makes it easier to generate plasma and facilitates the creation of a power supply circuit. Furthermore, contact with gas at the through-holes 16 enables plasma processing of the gas.

[0024] The upper electrode (electrode layer) 12 and the lower electrode (electrode layer) 13 are formed of a conductive material, and may be a metal plate (including metal foil), a conductive paint, a conductive polymer, a conductive film, etc. The thickness of the upper electrode 12 and the lower electrode 13 is not particularly limited, but is preferably 5 μm to 1.0 mm, more preferably 5 μm to 0.2 mm, and even more preferably 5 μm to 0.1 mm, respectively, in order to provide a flexible, lightweight, and compact processing device.

[0025] The dielectric layer 11, the upper electrode 12, and the lower electrode 13 may be laminated without using an adhesive, or may be bonded with an adhesive. The adhesive is preferably a material that is durable against active substances generated in plasma. Examples of adhesives include epoxy, acrylic, urethane, phenol, urea, silicone, cyanoacrylate, rubber, and vinyl acetate adhesives. Among these, silicone adhesives and UV-curable epoxy adhesives are preferred from the viewpoint of durability, with polyamide adhesives, polyimide adhesives, and silicone adhesives being more preferred. The thickness of the adhesive is preferably 0.01 to 0.2 mm, and more preferably 0.01 to 0.1 mm.

[0026] As shown in FIG. 3 , the upper mask layer 14 and the lower mask layer 15 are components disposed on the outer sides of the upper electrode 12 and the lower electrode 13, respectively. More specifically, the upper mask layer 14 is disposed on the upper surface of the upper electrode 12. The lower mask layer 15 is disposed on the lower surface of the lower electrode 13. The upper mask layer 14 and the lower mask layer 15 are each provided with through holes 17. In this embodiment, the through holes 17 are oval in shape, and five through holes 17 are formed, but the shape and number are not limited thereto. The through holes 17 may be omitted. Furthermore, for ease of manufacture, it is preferable that the through holes 17 be the same as the through holes 16, but this is not limiting.

[0027] 2 and 3, through holes 17 have the same shape as through holes 16 and are connected to each other. Through through holes 16 and 17, dielectric layer 11 is exposed to the outside. In other words, the surface of dielectric layer 11 is exposed to the outside at multiple locations where through holes 16 and 17 are formed. Hole walls (cross-sectional portions) 16a and 17a of through holes 16 and 17 are also exposed to the outside.

[0028] The upper mask layer 14 and the lower mask layer 15 are formed of an insulating material. The hardness of the upper mask layer 14 and the lower mask layer 15 is preferably equal to or less than that of the upper electrode 12 and the lower electrode 13. If the plasma generation unit 10 is manufactured using a thin material, it may be difficult to handle. However, providing the upper mask layer 14 and the lower mask layer 15 improves ease of handling. The upper mask layer 14 and the lower mask layer 15 also protect the thin conductor from mechanical and physical shocks during manufacture and use, as well as deterioration caused by the surrounding environment. They also provide mechanical protection against scratches that may occur during manufacture. Considering that the plasma generation unit 10 will be installed on an object to be attached, the upper mask layer 14 and the lower mask layer 15 preferably have a hardness that allows for easy installation along the object and also improves ease of handling. Furthermore, by dividing the dielectric layer 11 into two, the upper and lower structures of the plasma generating unit 10 can be made symmetrical. Manufacturing can be easily achieved by assembling the upper and lower structures and bonding them together in the center. In this case, the dielectric layer 11 is divided into three layers: the upper layer, the lower layer, and the adhesive layer, but can be considered electrically as a single dielectric.

[0029] The thicknesses of the upper mask layer 14 and the lower mask layer 15 are not particularly limited, but in order to provide a flexible, lightweight, and compact processing device, they are preferably 5 μm to 1.0 mm, more preferably 5 μm to 0.2 mm, and even more preferably 5 μm to 0.1 mm. The thicknesses of the upper mask layer 14 and the lower mask layer 15 may be set as appropriate, but in this embodiment they are formed to be larger than the thicknesses of the upper-layer electrode 12 and the lower-layer electrode 13.

[0030] The plasma generating unit 10 can be made very thin and flexible, which can lead to problems such as difficulty in handling during assembly. Furthermore, the upper electrode 12 and the lower electrode 13 are formed of conductive materials, such as conductive metals or conductive dielectrics. Metals, for example, can be corroded by liquids or gases. For example, the upper electrode 12 and the lower electrode 13 are oxidized by highly oxidizing gases and corroded by sulfuric acid or hydrochloric acid. Resin-based conductive materials can also be deteriorated by humidity or acid. Furthermore, the plasma generating unit 10 is installed to conform to the shape of the target object. However, if only the upper electrode 12 and the lower electrode 13 are installed without the upper mask layer 14 and the lower mask layer 15, thin metal electrodes can wrinkle or create gaps between the electrodes and the dielectric layer 11. Gaps between the upper electrode 12 and the lower electrode 13 and the dielectric layer 11 can cause abnormal or partial discharges.

[0031] In this regard, according to the present embodiment, the upper mask layer 14 and the lower mask layer 15 can protect the upper electrode 12 and the lower electrode 13, making the plasma generation unit 10 easier to handle and improving workability and assembly. Furthermore, the provision of the upper mask layer 14 and the lower mask layer 15 allows the plasma generation unit 10 to be installed on an object without forming wrinkles or gaps. Furthermore, when multiple pairs of electrodes are provided in a multi-stage configuration, the upper mask layer 14 and the lower mask layer 15 also serve as part of the dielectric constituting the barrier discharge, making it less likely that abnormal discharge will occur even if gaps are formed during installation. However, the upper mask layer 14 and the lower mask layer 15 are not particularly necessary for applications in which mechanical strength, electrode life, etc. are not a consideration. Furthermore, as long as the dielectric layer 11 sufficiently extends beyond the ends of the upper electrode 12 and the lower electrode 13, the upper mask layer 14 and the lower mask layer 15 are not necessarily required.

[0032] The outer edges of upper-layer electrode 12 and lower-layer electrode 13 may be sealed with an insulator (not shown) to prevent deterioration over time due to exposure to the outside world and to prevent discharge from occurring via the outer edges other than through-hole 16. When a resin or the like is used as the mask layer, this effect is achieved because the mask layer thinly extends over upper-layer electrode 12, lower-layer electrode 13, and also over the top and bottom surfaces of dielectric 11.

[0033] Similarly, the outer edges of the upper mask layer 14 and the lower mask layer 15 may be sealed with an insulator (not shown) to prevent their outer edges from being exposed to the outside world and reacting with external substances to deteriorate over time, and to prevent discharge from occurring through the outer edges other than the through holes 17.

[0034] Furthermore, an insulating layer (not shown) may be provided on the outside of the upper mask layer 14 and the lower mask layer 15 .

[0035] When the longitudinal direction of the through holes 16 and 17 is parallel to the gas flow direction, the resistance to the gas flow is small and the gas flows smoothly. On the other hand, when the longitudinal direction of the through holes 16 and 17 is perpendicular to the gas flow direction, the resistance to the gas flow is large, the gas flow is disturbed, and the gas is agitated.

[0036] The shape, number, and direction of the through holes 16, 17 relative to the gas flow can be selected appropriately depending on the purpose of the plasma processing, the effect of the plasma processing, etc. The shapes of the through holes may be different between the front and back sides of the plasma generating unit 10. Alternatively, the through holes may be provided on the front side of the plasma generating unit 10 and not on the back side.

[0037] <First Modification of Plasma Generation Unit> 4 is a perspective view for explaining a plasma generating unit according to a first modified example. The plasma generating unit 10A according to the first modified example differs from the basic structure described above in that it does not have an upper mask layer 14. As in the plasma generating unit according to the first modified example, the mask electrode (mask electrode layer) may be provided only on one side of the plasma generating unit 10A.

[0038] <Second Modification of Plasma Generation Unit> FIG. 5 is a perspective view illustrating a plasma generating unit according to a second modified example. The plasma generating unit 10B according to the second modified example differs from the basic structure described above in that it does not include the upper mask layer 14 and the lower mask layer 15. As in the plasma generating unit B according to the second modified example, the upper mask layer 14 and the lower mask layer 15 may be omitted. In other words, by configuring the plasma generating unit 10B with the dielectric layer 11, the upper electrode 12, and the lower electrode 13, it is possible to further reduce the size and the number of parts. Furthermore, by making the dielectric layer 11, the upper electrode 12, and the lower electrode 13 thin, the electrodes themselves can be made flexible, allowing them to be manufactured to fit curved surfaces.

[0039] Furthermore, as in the first and second modified examples, by omitting both or one of the upper mask layer 14 and the lower mask layer 15, the upper electrode 12 and the lower electrode 13 can be brought into direct contact with the gas, and the plasma and gas can be brought into contact at the ends of the electrodes, making it possible to easily extract the plasma gas (active species).

[0040] <Third Modification of Plasma Generation Unit> FIG. 6 is a cross-sectional view illustrating a plasma generating unit according to a third modified example. The plasma generating unit 10C according to the third modified example differs from the basic structure described above in that it does not include an upper mask layer 14 and a lower mask layer 15. Furthermore, the plasma generating unit 10C according to the third modified example does not have a monolithic dielectric layer, but is composed of an upper dielectric layer 18 and a lower dielectric layer 19, which are separated vertically and arranged facing each other. However, since air is also considered a type of dielectric, if the upper dielectric layer 18, air layer 20, and lower dielectric layer 19 are combined into a single dielectric layer 11, the structure is the same as that of the plasma generating unit 10B shown in FIG. 5. An upper electrode 12 is provided on the upper surface of the upper dielectric layer 18, and a lower electrode 13 is provided on the lower surface of the lower dielectric layer 19. An air layer 20 is provided between the upper dielectric layer 18 and the lower dielectric layer 19. In the third modified example, plasma can also be generated in the air layer 20.

[0041] First Embodiment Next, a plasma fluid generating device according to a first embodiment of the present invention will be described. Note that the "plasma fluid" used in the following embodiments refers to a fluid that is brought into contact with plasma and decomposed into the basic elements that make up the molecules of substances in the fluid. FIG. 7 is a perspective view showing the plasma fluid generating device according to the first embodiment of the present invention, and FIG. 8 is a partially enlarged view illustrating the principle of plasma fluid generation using part A shown in FIG. 7. The plasma fluid generating device 100 according to the first embodiment of the present invention is composed of an upper electrode structure 102, which is one plasma generating section, a lower electrode structure 104, which is the other plasma generating section, and a fluid-passing layer 106, which is a space provided between the upper electrode structure 102 and the lower electrode structure 104 and through which a fluid supplied from a fluid supply source (not shown) passes (flows).

[0042] The upper electrode structure 102 and the lower electrode structure 104 are disposed symmetrically to each other. The upper electrode structure 102 and the lower electrode structure 104 may have either a symmetrical structure or different structures. In consideration of manufacturing costs, a symmetrical structure is preferable. In addition, although water is illustrated as the fluid in FIGS. 7 and 8, the fluid is not limited to water, and may be any liquid, gas, or a mixture thereof.

[0043] The upper electrode structure 102 is composed of an upper-layer electrode mask 108 located at the top, a first upper-layer electrode 110 and a second upper-layer electrode 112 located below the upper-layer electrode mask 108, an upper electrode support dielectric 114 interposed between the first upper-layer electrode 110 and the second upper-layer electrode 112, and an upper liquid-proof dielectric 116 located below the second upper-layer electrode 112. In this embodiment, for convenience, the upper electrode support dielectric 114 is illustrated as a single dielectric, but it may also be a structure in which multiple dielectrics are stacked. In this case, the composite relative dielectric constant is calculated from the relative dielectric constants and thicknesses of the individual layers. The upper-layer electrode mask 108 corresponds to the upper mask layer 14 of the plasma generation unit 10 (see FIGS. 1 and 2) and has the same functions and effects as the upper mask layer 14. The upper electrode mask layer 108 may be omitted if necessary. The first upper-layer electrode 110 and the second upper-layer electrode 112 are provided with a plurality of parallel holes 118 penetrating through the electrode in the thickness direction. The holes 118 correspond to the through-holes 16 and 17 (see FIGS. 1 and 2) of the plasma generation unit 10 and have the same functions and effects as the through-holes 16 and 17. The holes 118 are not shown in FIGS. 7 and 8. The upper electrode structure 102 does not necessarily have to have the holes 118. The holes 118 are located opposite each other in FIGS. 9 to 11 and extend in a direction substantially perpendicular to the flow direction of the fluid passage layer 106, but may have any shape. The holes 118 may have a structure with extremely large holes, such as a mesh-like structure. The optimal size of the holes 118 depends on the frequency of the AC power supply and the characteristics of the upper electrode support dielectric 114, but is preferably approximately 0.1 mm to 20 mm. In addition, in this embodiment, hole 118 is shown as having a structure symmetrical to first upper layer electrode 110 and second upper layer electrode 112, but this is not limited to this. Also, in Figures 7 and 8, first upper layer electrode 110 and second upper layer electrode 112 are shown as having the same size (area), but this is not limited to this. In terms of reducing the leakage electric field on the fluid side, it is preferable that second upper layer electrode 112 facing the fluid side protrudes in a state covering first upper layer electrode 110.

[0044] The lower electrode structure 104 is composed of a lower-layer electrode mask 120 located at the bottom, a first lower-layer electrode 122 and a second lower-layer electrode 124 located above the lower-layer electrode mask 120, a lower electrode support dielectric 126 interposed between the first lower-layer electrode 122 and the second lower-layer electrode 124, and a lower liquid-proof dielectric 128 located above the second lower-layer electrode 124. The lower-layer electrode mask 120 is a member corresponding to the lower mask layer 15 of the plasma generation unit 10 (see FIGS. 1 and 2) and has the same functions and effects. The first lower-layer electrode 122 and the second lower-layer electrode 124 are provided with a plurality of parallel holes 130 penetrating through them in the thickness direction. The holes 130 may not be provided in the lower electrode structure 104. In the lower-layer electrode structure 104, as in the upper-layer electrode structure 102, the holes 130 are positioned opposite each other in FIGS. 7 and 8 and extend in a direction substantially perpendicular to the flow direction of the fluid passage layer 106, but any shape may be used. The holes 130 may also have an extremely large structure, such as a mesh-like structure. The optimal size of the holes 130 depends on the frequency of the AC power supply and the characteristics of the lower electrode support dielectric 126, but is preferably approximately 0.1 mm to 20 mm. In this embodiment, the holes 130 are shown as being symmetrical to the first lower-layer electrode 122 and the second lower-layer electrode 124, but this is not a limitation. In FIGS. 7 and 8, the first lower-layer electrode 122 and the second lower-layer electrode 124 are shown as having the same size (thickness), but this is not a limitation. In terms of reducing the leakage electric field on the fluid side, it is preferable to make second lower-layer electrode 124 facing the fluid side larger (thicker) than first lower-layer electrode 122.

[0045] The upper liquid-proof dielectric 116 and the lower liquid-proof dielectric 128 function as a "pair of fluid intrusion prevention dielectrics." The upper liquid-proof dielectric 116 and the lower liquid-proof dielectric 128 also prevent fluids from infiltrating the first upper-layer electrode 110 and the second upper-layer electrode 112, and the first lower-layer electrode 122 and the second lower-layer electrode 124, as well as corrosion, oxidation, deterioration, and mechanical damage to the electrodes. Furthermore, using a material with a smooth surface improves the cleanability of the plasma generation section. Furthermore, when handling medical or food fluids, using a material that complies with these standards allows for the handling of medical or food fluids.

[0046] 7 and 8 show the upper electrode structure 102 and the lower electrode structure 104 configured in a linear shape. However, if the upper electrode structure 102 and the lower electrode structure 104 are configured from a thin, flexible material, they can bend within a range that does not destroy the material. As a result, even if the electrode structure becomes large and bending occurs in the upper liquid-proof dielectric 116 and the lower liquid-proof dielectric 128, or even if a fluid is passed through the fluid-passing layer 106 and its central portion expands due to pressure, the first upper-layer electrode 110, the second upper-layer electrode 112, the first lower-layer electrode 122, and the second lower-layer electrode 124 can bend accordingly and absorb mechanical strain. In contrast, for example, a hard, plate-like electrode cannot absorb bending or strain and may cause cracks in the material.

[0047] The fluid passing layer 106 is formed by a space between the lower surface of the upper liquidproof dielectric 116 and the upper surface of the lower liquidproof dielectric 128. The first upper-layer electrode 110, the second upper-layer electrode 112, the first lower-layer electrode 122, and the second lower-layer electrode 124 are each electrically connected to one or more AC power supplies (not shown). In this embodiment, the upper liquidproof dielectric 116 and the lower liquidproof dielectric 128 are shown as a single layer, but the same effect can be obtained by stacking multiple dielectrics.

[0048] <Action and effect> The following describes the effects of the upper electrode structure 102 as an example, but the same effects as those of the upper electrode structure 102 can also be obtained with the lower electrode structure 104. In the upper electrode structure 102, plasma is generated between the first upper-layer electrode 110 and the second upper-layer electrode 112. More specifically, most of the plasma is generated in the upper electrode supporting dielectric 114 interposed between the first upper-layer electrode 110 and the second upper-layer electrode 112. In FIG. 7, the upper electrode supporting dielectric 114 is depicted as a single thin plate for convenience, but this is not limiting. For example, the upper electrode supporting dielectric 114 may be composed of multiple divided bodies. Furthermore, a space through which gas flows may be provided in the center of the multiple divided bodies.

[0049] Additionally, while first upper layer electrode 110 and second upper layer electrode 112 are illustrated as having the same shape for convenience, they do not necessarily have to be the same shape. Any structure that can uniformly distribute the electric field for plasma generation may be used, and the volume of the space may be increased or decreased. Furthermore, in order to reduce leakage of the plasma-generating electric field to the opposite side of upper liquid-proof dielectric 116, first upper layer electrode 110 may be a flat conductor without holes 118. Furthermore, for the same purpose, the shape and dimensions (dimensions in the width direction) of first upper layer electrode 110 may be larger or smaller than the shape and dimensions (dimensions in the width direction) of second upper layer electrode 112.

[0050] Furthermore, by appropriately selecting the thickness, relative dielectric constant, dielectric strength, etc. of the upper liquid-proof dielectric 116, the electric field leaks out to the opposite side of the electrode that generates plasma through the holes 118 provided in the second upper-layer electrode 112 and appears on the surface of the lower surface of the upper liquid-proof dielectric 116 facing the fluid-passing layer 106 (see the curved arrow in FIG. 8). In this embodiment, the plasma leaking out from the surface of the lower surface of the upper liquid-proof dielectric 116 is brought into contact with the fluid (liquid, gas, or a mixture thereof) flowing through the fluid-passing layer 106, thereby generating a plasma fluid.

[0051] Most of the plasma is generated between the first upper-layer electrode 110 and the second upper-layer electrode 112 (in the upper-electrode support dielectric 114) (see the straight arrow in FIG. 8 ). However, strong plasma is generated around the edges of the holes 118 and other portions of the second upper-layer electrode 112, and some of the plasma passes through the upper liquid-proof dielectric 116 and appears on the lower surface of the upper liquid-proof dielectric 116 (see the curved arrow in FIG. 8 ). By utilizing this, this embodiment realizes plasma electrodes in which the state of the fluid, such as conductivity and gas density, does not significantly affect the impedance between the plasma electrodes. In this embodiment, since the change in impedance due to the state of the fluid is small, larger electrodes can be used, allowing the plasma and gas to come into contact over a larger area. As a result, this embodiment can generate a large amount of plasma fluid (liquid, gas, or a mixture thereof).

[0052] Since plasma is generated mainly between the first upper-layer electrode 110 and the second upper-layer electrode 112, the plasma impedance does not change significantly even if the properties (e.g., permittivity, conductivity, filling rate, etc.) of the material on the opposite side of the upper liquid-proof dielectric 116 change. Therefore, in this embodiment, even if the fluid passing layer 106 provided between the upper liquid-proof dielectric 116 and the lower liquid-proof dielectric 128 is filled with a fluid such as water, the change in plasma impedance is slight, and the plasma does not disappear or abnormal discharge occurs, making it possible to stably generate a large amount of plasma fluid.

[0053] The AC power supply (not shown) is not particularly limited as long as it can apply an AC voltage of a predetermined voltage at a predetermined frequency to each electrode of the plasma generating unit, and any known power supply device can be used. The frequency of the AC voltage is preferably 50 Hz to 30 MHz, and more preferably 50 Hz to 100 kHz. The AC voltage is preferably 0.1 to 50 kV, and more preferably 0.2 to 10 kV.

[0054] Second Embodiment Next, a plasma fluid generating device according to a second embodiment of the present invention will be described. From the second embodiment onward, differences from the first embodiment will be mainly described. FIG. 9 is a structural diagram showing the potentials (+ pole, - pole) at a certain timing of an AC power supply unit (not shown). As shown in FIG. 9, in the plasma fluid generating device 200 according to this embodiment, by making the potential (- pole) of the second upper-layer electrode 112 and the potential (- pole) of the second lower-layer electrode 124 the same, even if a conductive material is present in the fluid passing layer 106 (space portion) sandwiched between the second upper-layer electrode 112 and the second lower-layer electrode 124, no current flows between the electrodes between the first upper-layer electrode 110 and the second upper-layer electrode 112, and between the electrodes between the first lower-layer electrode 122 and the second lower-layer electrode 124.

[0055] By setting the potentials of the second upper-layer electrode 112 and the second lower-layer electrode 124 equal to the ground potential, no current flows between the central fluid passage layer 106 and the ground potential. Therefore, even when high-voltage plasma is brought into contact with a liquid (fluid), no current flows between the liquid (fluid) and the ground potential. Therefore, there is no risk of electric leakage or shock through the liquid or fluid. This was a problem with systems that generate plasma directly in liquid, but this embodiment safely brings the application of a high voltage into contact with a conductive liquid, and further prevents electric leakage through the liquid. Even if the potentials of the second upper-layer electrode 112 and the second lower-layer electrode 124 are not set equal to the ground potential, the two potentials are the same, so no current flows through the fluid, and there are no operational problems. However, setting the potentials of the second upper-layer electrode 112 and the second lower-layer electrode 124 equal to the ground potential allows for safer operation.

[0056] Fig. 10 is a perspective view showing a plasma fluid generating device according to a modified example of this embodiment. The plasma fluid generating device 200a shown in Fig. 10 differs from this embodiment in that the first lower layer electrode 122 and the second lower layer electrode 124, which are arranged below the lower liquid-proof dielectric 128, are removed. Even when configured with such a pair of electrodes (first upper layer electrode 110, second upper layer electrode 112), the same effects as those of this embodiment shown in Fig. 9 can be obtained. Furthermore, the number of stages may be increased as necessary.

[0057] Third Embodiment Next, a plasma fluid generation device 300 according to a third embodiment of the present invention will be described. While the first to third embodiments are configured with a single upper electrode supporting dielectric 114 for convenience, the plasma fluid generation device 300 according to this embodiment differs in that the upper electrode structure 102 and the lower electrode structure 104 are each configured with a plurality of electrode supporting dielectrics. As shown in Fig. 11, in this embodiment, a first upper electrode supporting dielectric 302 is disposed on the lower surface of the first upper-layer electrode 110, and a second upper electrode supporting dielectric 304 is disposed on the upper surface of the second upper-layer electrode 112.

[0058] Furthermore, in this embodiment, a space (air layer) 306 through which gas (air) passes is provided between the first upper electrode supporting dielectric 302 and the second upper electrode supporting dielectric 304, thereby enabling plasma processing. The first upper electrode supporting dielectric 302 and the second upper electrode supporting dielectric 304 can have an appropriate thickness, for example, by bonding together a plurality of dielectrics. Note that the lower electrode structure 104, like the upper electrode structure 102, is provided with a first lower electrode supporting dielectric 305 and a second lower supporting dielectric 307, with a space 306 defined therebetween.

[0059] <Fourth embodiment> Next, a plasma fluid generating device 400 according to a fourth embodiment of the present invention will be described. The plasma fluid generating device 400 according to this embodiment differs from the first to third embodiments in that, in addition to the basic structure (upper electrode structure 102, lower electrode structure 104, fluid passing layer 106) configured in each of the first to third embodiments, a protective dielectric and a protective conductor (protective electrode) are additionally disposed for each electrode structure.

[0060] 12 and 13, in this embodiment, an upper-layer protective dielectric 402 is disposed on the upper surface of first upper-layer electrode mask 108a, and an upper protective conductor (upper protective electrode) 404 is disposed on the upper surface of this upper-layer protective dielectric 402. Furthermore, first upper-layer electrode mask 108a is disposed on the upper surface of first upper-layer electrode 110, and second upper-layer electrode mask 108b is disposed on the lower surface of second upper-layer electrode 112.

[0061] In this embodiment, lower protective dielectric 406 is disposed on the lower surface of first lower electrode mask 120a, and lower protective conductor 408 is disposed on the lower surface of lower protective dielectric 406. Furthermore, first lower electrode mask 120a is disposed on the lower surface of first lower electrode 122, and second lower electrode mask 120b is disposed on the upper surface of second lower electrode 124. Note that first upper electrode mask 108a, second upper electrode mask 108b, first lower electrode mask 120a, and second lower electrode mask 120b may each be omitted as necessary.

[0062] Furthermore, in this embodiment, the upper protective conductor 404 and the lower protective conductor 408 are each formed of a single plate-like conductor, but this is not limiting and they may be divided as necessary. In this case, it is advisable to connect the divided protective conductors with, for example, a capacitor, a resistor, an inductor, or a transformer so that they are at approximately the same potential.

[0063] Furthermore, the second upper-layer electrode 112 and the second lower-layer electrode 124 may have a structure in which holes are provided as necessary, or an electrode structure in which the holes are enlarged to reduce the amount of conductor, such as a mesh structure. In Fig. 12, the upper electrode structure 102 and the lower electrode structure 104 are parallel to each other, but the upper electrode structure 102 and the lower electrode structure 104 may also be arranged non-parallel so as to intersect.

[0064] In this embodiment, the plasma electrodes (first upper-layer electrode 110, second upper-layer electrode 112, first lower-layer electrode 122, second lower-layer electrode 124) are covered with protective dielectrics 402, 406 and protective conductors 404, 408, thereby confining the electric field at the plasma generating portion within the electrode structures 102, 104. The protective dielectrics 402, 406 and protective conductors 404, 408 are made sufficiently larger than the size (wall thickness) of the electrodes. By setting the protective conductors 404, 408 to a potential close to the ground side (earth side) or the potential applied to the surrounding circuits and elements, it is possible to prevent a high voltage from being directly applied to the hands or surrounding circuits even when the plasma electrodes are directly touched by hand or when elements, circuits, etc. are placed nearby.

[0065] In this embodiment, upper-layer electrode masks 108a, 108b and lower-layer electrode masks 120a, 120b are provided, but they may be omitted as necessary. The upper-layer protective dielectric 402 and the lower-layer protective dielectric 406 may be formed by combining one or more dielectrics including air. The upper protective conductor 404 and the lower protective conductor 408 may each be formed by a structure with holes or a mesh structure corresponding to the frequency of the high-frequency voltage power supply to be handled.

[0066] In this embodiment, in order to further prevent leakage of the electric field, a conductor, a conductor with holes, or a conductor with a mesh structure may be disposed on the side surfaces of the upper protective dielectric 402 and the lower protective dielectric 406, and a potential equal to or close to that of the upper protective conductor 404 and the lower protective conductor 408 may be applied to the conductors. For example, conductive paint or metal plating may be used for the conductors disposed on the side surfaces, thereby reducing manufacturing costs.

[0067] Furthermore, a spacer 410 or a positioning component for the upper electrode structure 102 and the lower electrode structure 104 may be interposed in the fluid passage layer 106 between the upper electrode structure 102 and the lower electrode structure 104. The spacer 410 may be disposed at both ends of the upper electrode structure 102 and the lower electrode structure 104 (both ends in a direction substantially perpendicular to the direction in which the fluid passes through the fluid passage layer 106) (see FIG. 14). In this case, the fluid flows from the front to the back of the drawing, or from the back to the front. Furthermore, a convex portion 414 may be provided in the center of the spacer 412, and a pair of recesses 416 with rectangular cross sections may be provided contiguous to the convex portion 414 to accommodate the upper electrode structure 102 and the lower electrode structure 104, respectively (see FIG. 15). Furthermore, in the spacer structure shown in Figure 14, the spacers 410 arranged on the left and right have the same length dimensions, but this is not limited to this, and spacers 418, 420 or positioning components with different length dimensions on the left and right may be provided in order to control the flow speed and direction of the fluid flowing through the fluid passage layer 106 (see Figure 16).

[0068] FIG. 17 shows a plasma fluid generator according to a modification of this embodiment. In this modification, the vertical separation distance between the upper electrode structure 102 and the lower electrode structure 104 is changed according to the direction in which the fluid flows through the fluid passing layer 106. For example, when the fluid flows from the right side to the left side of the fluid passing layer 106 shown in FIG. 17, the separation distance is shorter toward the left side, which is the fluid outlet, and the cross-sectional area of ​​the fluid passing layer 106 is narrower, thereby increasing the fluid flow rate. Note that FIG. 17 only shows the spacer 410 located at the back, and does not show the spacer 410 located at the front.

[0069] Furthermore, in a modified example, the activity of the plasma-treated gas can be increased by directly attaching an ultrasonic vibrator or the like to the protective conductors (protected electrodes) 404, 408 of the electrode structure. In the modified example, these components can be directly attached to the electrodes, which allows the overall device to be made smaller and less expensive.

[0070] <Reference embodiment> 18 is a cross-sectional structural schematic diagram showing a plasma fluid generating apparatus according to a reference embodiment of the present invention. A plasma fluid generating apparatus 500 according to this reference embodiment differs from the fourth embodiment in that an intermediate layer electrode (intermediate layer electrode layer) 506 is disposed at an intermediate position between an upper upper layer electrode (electrode layer) 502 and a lower lower layer electrode (electrode layer) 504, a first fluid-passing layer 106a is provided between an upper liquid-proof dielectric (one of the first fluid-preventing dielectrics) 116 and a first intermediate layer liquid-proof dielectric (one of the second fluid-preventing dielectrics) 508, and a second fluid-passing layer 106b is provided between a lower liquid-proof dielectric (the other of the first fluid-preventing dielectrics) 128 and a second intermediate layer liquid-proof dielectric (the other of the second fluid-preventing dielectrics) 510. In addition, in the reference embodiment, the upper surface of the intermediate layer electrode 506 is covered with an upper intermediate layer electrode mask 512, and the lower surface of the intermediate layer electrode 506 is covered with a lower intermediate layer electrode mask 514. The words in parentheses correspond to the invention-specifying features of the reference embodiment described below. Also, in Fig. 18, for convenience, the fluid passing through each of the first fluid passing layer 106a and the second fluid passing layer 106b is illustrated as "water," but this is not limited thereto and may be any of a liquid, a gas, or a mixture thereof.

[0071] <Issues of the reference embodiment> In the reference embodiment, the material structure between the electrodes, which determines the impedance of the plasma electrodes, changes depending on the state of the fluid passing through the first fluid passage layer 106a and the second fluid passage layer 106b. For example, when water such as tap water or well water passes through the first fluid passage layer 106a and the second fluid passage layer 106b, the space between the plasma generating electrodes is filled with a conductive material, and the impedance of the plasma generating electrodes decreases. Conversely, when the water is removed and the space within the first fluid passage layer 106a and the second fluid passage layer 106b becomes dry, the impedance of the plasma generating electrodes increases. This causes a large load fluctuation in the high-voltage power supply for generating plasma. For this reason, it is necessary to detect the state of the fluid passing through the first fluid passage layer 106a and the second fluid passage layer 106b in real time, or to detect the impedance between the plasma electrodes in real time. Furthermore, it is necessary to change the impedance of the high-voltage power supply for plasma generation based on this detection information to conditions for generating and maintaining plasma.

[0072] Furthermore, in the reference embodiment, a high voltage is applied to either the fluid passing through the first fluid passage layer 106a or the second fluid passage layer 106b, and there is a possibility of electric leakage through the fluid.

[0073] Furthermore, it is necessary to control the spacing between the plasma generating electrodes and the thickness of the dielectrics (upper liquid-proof dielectric 116, lower liquid-proof dielectric 128, first intermediate layer liquid-proof dielectric 508, second intermediate layer liquid-proof dielectric 510). Voltage is applied between the dielectrics sandwiched between them, the liquid-proof dielectric, the mask layer, and the fluid-passing layer through which the fluid passes. It is necessary to control these materials (for example, the dielectric constant, physical thickness, etc.). If these are not constant, it becomes difficult to provide a uniform electric field strength across the entire upper and lower electrode structure, resulting in uneven electric field strength and abnormal discharges in some areas.

[0074] Furthermore, when the entire electrode structure is bent, it is necessary to maintain a uniform gap between the electrodes, which makes the structure of the electrode structure complicated and leads to increased costs.

[0075] Furthermore, it is difficult to supply a uniform fluid throughout the entire electrode structure, which leads to increased costs. If the fluid is supplied unevenly, the discharge may be excessive in some areas, or the fluid may become diluted, making it impossible to obtain a uniform discharge.

[0076] <Effects of the Reference Embodiment> In the reference embodiment, for example, the middle layer electrode 506 is electrically connected to a high-voltage electrode that generates plasma, and the upper layer electrode 502 and the lower layer electrode 504 are electrically connected to an earth electrode (ground electrode). By adopting such a structure, the periphery of the plasma generation block is covered with the potential on the earth side, and can be safely touched with hands.

[0077] In the reference embodiment, the volume of fluid passing through the first fluid passage layer 106a and the second fluid passage layer 106b is increased, and a large amount of plasma fluid can be generated by the plasma generated by the plasma generating electrodes (the middle layer electrode 506 and the upper layer electrode 502, and the middle layer electrode 506 and the lower layer electrode 504). Furthermore, by appropriately selecting the fluid passing between the plasma electrodes (the first fluid passage layer 106a and the second fluid passage layer 106b), the plasma-treated gas can be smoothly dissolved into the fluid. As a result, in the reference embodiment, a highly concentrated plasma fluid containing a large amount of plasma-derived gas can be generated.

[0078] In the reference embodiment, the middle layer electrode 506 is the high-voltage electrode, and the upper layer electrode 502 and the lower layer electrode 504 are the ground electrodes, resulting in a structure in which the high-voltage middle layer electrode 506 is surrounded by the upper and lower ground electrodes 502 and 504, and the electric field exists in a narrow range. For this reason, in the reference embodiment, the upper protective conductor 404 and the lower protective conductor 408 are set to a potential close to ground, allowing the electrode structures 102 and 104 to be handled safely.

[0079] The following describes the invention-specifying features of the reference embodiment. "A plasma generating unit having a pair of electrode layers and an intermediate electrode layer provided between the pair of electrode layers, which generates plasma by applying AC voltages to the pair of electrode layers and the intermediate electrode layer, respectively; a pair of first fluid intrusion prevention dielectrics provided on the upper and lower layers of the pair of electrode layers, respectively, to prevent fluid from infiltrating into the pair of electrode layers; a pair of second fluid intrusion prevention dielectrics provided on the upper and lower layers of the intermediate electrode layer, respectively, to prevent fluid from infiltrating into the intermediate electrode layer; a first fluid-passing layer provided between one of the pair of first fluid-preventing dielectrics spaced apart from each other and one of the pair of second fluid-preventing dielectrics, through which the fluid flows; a second fluid-passing layer provided between the other of the pair of first fluid-preventing dielectrics spaced apart from each other and the other of the pair of second fluid-preventing dielectrics, through which the fluid flows; A plasma fluid generating device comprising:

[0080] Although the embodiment, modified examples, and reference embodiment of the present invention have been described above, appropriate design changes are possible within the scope of the present invention. [Explanation of symbols]

[0081] 100, 100a, 200, 300, 400, 400a Plasma fluid generator 102 Upper electrode structure 104 Lower electrode structure 106 Fluid passing layer 110 1st upper layer electrode 112 2nd upper layer electrode 114 Upper electrode support dielectric 116 Upper liquid-proof dielectric (dielectric to prevent fluid ingress) 122 1st lower layer electrode 124 2nd lower layer electrode 126 Lower electrode support dielectric 128 Lower liquid-proof dielectric (dielectric to prevent fluid ingress) 306 Space (air layer)

Claims

1. a plasma generating unit having at least a pair of electrode layers and a dielectric layer provided between the pair of electrode layers, and generating plasma in the dielectric layer by applying an AC voltage to the pair of electrode layers; a pair of fluid intrusion prevention dielectrics provided on the upper or lower layers of at least one of the pair of electrode layers, the dielectrics preventing fluid from infiltrating into the pair of electrode layers; a fluid passage layer provided between the pair of fluid intrusion prevention dielectrics spaced apart from each other, through which the fluid flows; A plasma fluid generating device comprising:

2. 2. The plasma fluid generating device according to claim 1, the pair of electrode layers includes a first upper electrode layer and a second upper electrode layer disposed below the first upper electrode layer, A plasma fluid generating device, characterized in that the dielectric layer is disposed between the first upper electrode layer and the second upper electrode layer.

3. 2. The plasma fluid generating device according to claim 1, the pair of fluid intrusion prevention dielectrics includes an upper fluid intrusion prevention dielectric disposed above the fluid passage layer and a lower fluid intrusion prevention dielectric disposed below the fluid passage layer, the pair of electrode layers includes a first upper electrode layer and a second upper electrode layer disposed on an upper layer of the upper fluid intrusion prevention dielectric, and a first lower electrode layer and a second lower electrode layer disposed on a lower layer of the lower fluid intrusion prevention dielectric, the second upper electrode layer is disposed on an upper surface of the upper fluid intrusion prevention dielectric; the second lower electrode layer is disposed on a lower surface of the lower fluid intrusion prevention dielectric; The plasma fluid generating device is characterized in that the second upper electrode layer and the second lower electrode layer are set to the same potential.

4. 4. The plasma fluid generating device according to claim 3, The plasma fluid generating device is characterized in that the second upper electrode layer and the second lower electrode layer are set to the same ground potential.

5. 3. The plasma fluid generating device according to claim 2, the dielectric layer includes a first dielectric layer provided on the first upper electrode layer side and a second dielectric layer provided on the second upper electrode layer side, A plasma fluid generating device characterized in that an air layer through which air passes is provided between the first dielectric layer and the second dielectric layer, which are separate and spaced apart from each other.

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