Plasma NANO mist generation device

Abstract

This plasma nano mist generation device comprises: a discharge tube into which a solution is injected, the discharge tube being configured from a dielectric; a liquid-feeding unit for feeding the solution into the discharge tube; an electrode provided within the discharge tube; a voltage application unit for applying a voltage to the electrode; a grounding electrode provided on the distal-end side of the electrode and on the outer periphery of the discharge tube, the grounding electrode being grounded within the device itself; and a control unit for controlling the liquid-feeding unit and the voltage application unit so as to feed the solution into the discharge tube and apply a voltage to the electrode such that dielectric barrier discharge occurs on the distal-end side of the electrode to generate a plasma nano mist.

Description

Plasma nanomist generator

[0001] The present disclosure relates to a plasma nano-mist generating device.

[0002] Atmospheric pressure plasmas are a key technology supporting many industrial innovations due to their ability to generate electric fields, optical radiation, heat, and reactive chemical species. In recent years, plasma systems have been explored for applications in medicine and biology as effective tools for wound healing (see, for example, WO 2011 / 071182) and cancer treatment (see, for example, "Nagatsu, M., Yang, E., Zhang, R., Zakudo, S., Ikuta, K., "Biomedical Applications of Plasma-Modified Nanoparticles," Surface Science, Vol. 34, No. 10, pp. 535-540, 2013").

[0003] These biomedical applications are mainly based on directly applying plasma-derived physical or chemical stimuli (such as ultraviolet light or reactive oxygen and nitrogen species) to the target object. While this is fine when the affected area is exposed, such as a wound, applying plasma directly to an internal lesion places a significant surgical burden on the patient.

[0004] On the other hand, there has been little research into biomedical technologies that indirectly utilize the effects of plasma. For example, if we could use plasma to manipulate the shape of drugs and medicinal solutions and promote their percutaneous absorption, this could lead to new developments in medical technology that reduces the burden on the entire body.

[0005] Nanoparticle drug delivery systems are crucial for enhancing transdermal drug absorption. Nanotechnology-based delivery systems enable drugs to penetrate the skin barrier, reach the target site in a stable state, and maintain their efficacy for a long period of time. Plasma-generated nanoparticles (e.g., "Nagatsu, M., Yang, E., Zhang, R., Sakudo, S., Ikuta, K., "Biomedical Applications of Plasma-Modified Nanoparticles," Surface Science, Vol. 34, No. 10, pp. 535-540, 2013" and "Michael, P., Lam, Y., Filipe, E.C. et al. Plasma polymerized nanoparticles effectively deliver dual siRNA and drug therapy in vivo. Sci Rep 10, 12836(2020). https: / / doi.org / 10.1038 / s41598-020-69591-x") can be used in such delivery systems.

[0006] However, these methods have the disadvantage of requiring complex chemical processes. If nano-sized particulate aggregates could be directly produced from aqueous or oily solutions containing drugs using a simple process, further development of transdermal drug delivery would be expected.

[0007] Electrostatic spraying is known as a technique for nanoparticleizing a solution (generating a nano-sized mist) using an electrical effect (see, for example, International Publication No. 2011 / 071182 and Japanese Patent Application Laid-Open No. 2019-058862). Another known technique involves generating a mist using an atomization mechanism such as an ultrasonic vibrator, followed by atmospheric pressure plasma treatment to improve transdermal absorption.

[0008] However, the electrospray method has the drawback that the target side must be grounded to form a closed circuit and a high voltage must be applied, and the target itself must be included in the high voltage system.

[0009] Furthermore, the mist generation method using ultrasonic waves has the drawback of requiring an atomization mechanism such as an ultrasonic vibrator.

[0010] An object of the present disclosure is to provide a plasma nano-mist generating device that can generate nano-sized mist with a simple configuration.

[0011] The plasma nano-mist generating device according to the first aspect includes a discharge tube made of a dielectric and into which a solution is injected, a liquid delivery unit that delivers the solution into the discharge tube, an electrode provided within the discharge tube, a voltage application unit that applies a voltage to the electrode, a ground electrode that is provided on the tip side of the electrode and on the outer periphery of the discharge tube and is grounded within the device, and a control unit that controls the liquid delivery unit and the voltage application unit so that the solution is delivered to the discharge tube and a voltage is applied to the electrode, so that a dielectric barrier discharge is generated on the tip side of the electrode to generate a plasma nano-mist.

[0012] In the plasma nano-mist generating device according to the first aspect, the electrode may be a needle electrode or a cylindrical electrode.

[0013] In the plasma nano-mist generating device according to the first aspect, the electrode may be a needle electrode.

[0014] The plasma nano-mist generating device according to the first aspect may be configured to include an air blowing unit that blows air into the discharge tube.

[0015] Furthermore, in the plasma nano-mist generating device according to the first aspect, the control unit may be configured to control the voltage application unit so that a voltage set based on a correspondence relationship between the type of solution, the outer diameter of the discharge tube, the outer diameter of the electrode, and the voltage to be applied to the electrode is applied to the electrode, the correspondence relationship being a predetermined correspondence relationship that is a generating condition under which the plasma nano-mist can be generated.

[0016] Furthermore, in the plasma nano-mist generating device according to the first aspect, the control unit may control the voltage application unit so that the voltage set based on the correspondence relationship between the type of the solution, the outer diameter of the discharge tube, the outer diameter of the electrode, the voltage applied to the electrode, and the liquid feed rate of the solution is applied to the electrode, which is a correspondence relationship that is predetermined as a generation condition under which the plasma nano-mist can be generated, and may also control the liquid feed unit so that the solution is fed at the liquid feed rate that is set based on the correspondence relationship.

[0017] According to the present disclosure, there is an effect that nano-sized mist can be generated with a simple configuration.

[0018] 6A is a diagram illustrating the configuration of a plasma nano-mist generating device. FIG. 6B is a diagram illustrating a streamer as seen from below the discharge tube. FIG. 6C is an exploded view of the discharge unit. FIG. 6D is a cross-sectional perspective view of the discharge unit. FIG. 6E is a diagram illustrating the correspondence relationship between the outer diameter of the electrode, the applied voltage, and the liquid feed rate into the solution when the outer diameter of the discharge tube is 8 mm, showing the conditions under which plasma nano-mist can be generated. FIG. 6F is a diagram illustrating the correspondence relationship between the outer diameter of the electrode, the applied voltage, and the liquid feed rate into the solution when the outer diameter of the discharge tube is 8 mm, showing the preferred conditions under which plasma nano-mist can be generated. FIG. 6G is a diagram illustrating nano-mist generated by a plasma nano-mist generating device. FIG. 6H is an enlarged view of a portion of FIG. 6A. FIG. 6H is a diagram illustrating the correspondence relationship between the outer diameter of the electrode, the applied voltage, and the liquid feed rate into the solution when the outer diameter of the discharge tube is 10 mm, showing the conditions under which plasma nano-mist can be generated. FIG. 6H is a diagram illustrating the correspondence relationship between the outer diameter of the electrode, the applied voltage, and the liquid feed rate into the solution when the outer diameter of the discharge tube is 10 mm, showing the preferred conditions under which plasma nano-mist can be generated. 1 is a diagram showing the correspondence relationship between the outer diameter of the electrode, the applied voltage, and the solution feed rate when the outer diameter of the discharge tube is 15 mm, and showing the conditions under which plasma nano-mist can be generated. FIG. 2 is a diagram showing the correspondence relationship between the outer diameter of the electrode, the applied voltage, and the solution feed rate when the outer diameter of the discharge tube is 15 mm, and showing the preferred conditions under which plasma nano-mist can be generated. FIG. 3 is a diagram showing discharge characteristics for each solution and for each solution feed rate. FIG. 4 is a diagram showing the relationship between the feed rate of ultrapure water and electrical conductivity. FIG. 5 is a diagram showing the relationship between the feed rate of phosphate-buffered saline and electrical conductivity. FIG. 6 is a diagram showing the relationship between the amount of hydrogen peroxide solution generated and the feed rate. FIG. 7 is a diagram showing the relationship between the amount of nitrite ions generated and the feed rate. FIG. 8 is a diagram showing the relationship between the amount of nitrate ions generated and the feed rate. FIG. 9 is a diagram showing the configuration of a plasma nano-mist generating device equipped with a blower. FIG. 10 is a diagram showing the correspondence relationship between the outer diameter of the discharge tube, the outer diameter of the electrode, and the applied voltage when the solution is ultrapure water or phosphate-buffered saline, and showing the conditions under which plasma nano-mist can be generated. 1 is a diagram showing the relationship between the outer diameter of the discharge tube, the outer diameter of the electrode, and the applied voltage when the solution is ultrapure water or phosphate buffered saline, and showing the conditions under which plasma nano-mist can be generated.

[0019] Hereinafter, an example of an embodiment of the present disclosure will be described with reference to the drawings.

[0020] 1A shows a configuration diagram of a plasma nano-mist generator 10 according to this embodiment. As shown in FIG. 1A, the plasma nano-mist generator 10 includes a discharge unit 20, a liquid delivery unit 30, a voltage application unit 40, and a control unit 50.

[0021] As shown in Figures 2 and 3, the discharge unit 20 includes a discharge tube 21 and an electrode 22. The electrode 22 may be, for example, a needle electrode or a cylindrical electrode. The needle electrode has an outer diameter (diameter) of, for example, less than 2 mm, and the cylindrical electrode has an outer diameter of, for example, 2 mm or more and 5 mm or less. The electrode 22 is inserted into a through-hole of a socket 23 made of, for example, PLA resin (polylactic acid). The socket 23 is fitted into the discharge tube 21, so that the tip of the electrode 22 is positioned within the discharge tube 21.

[0022] The discharge tube 21 is made of a dielectric material such as borosilicate glass, and the outer periphery of the discharge tube 21 is covered with a polyimide film tape 24.

[0023] The tip of the electrode 22 and the outer periphery of the discharge tube 21 are covered with a ground electrode 25 made of, for example, aluminum (Al). The ground electrode 25 is grounded within the plasma nanomist generating device 10. In other words, the ground electrode 25 is grounded within the device itself and forms a closed circuit, so there is no need to ground it on the side to which the plasma nanomist is to be supplied, which increases safety compared to when using electrostatic spraying.

[0024] The other end of the electrode 22 is connected to a syringe pump 31 of the liquid delivery unit 30, which will be described later. The electrode 22 has a hollow structure, into which a solution is injected from the syringe pump 31.

[0025] The liquid sending unit 30 sends the solution into the discharge tube 21. Specifically, the liquid sending unit 30 includes a syringe pump 31 that sends the solution, and a drive unit 32 that drives the syringe pump 31.

[0026] The voltage application unit 40 applies a voltage to the other end of the electrode 22. The voltage application unit 40 includes a power supply unit 41, a transformer 42, and a high-voltage amplifier 43. The power supply unit 41 supplies an AC voltage of 100 V. The transformer 42 transforms the AC voltage supplied from the power supply unit 41 into a predetermined AC voltage. The high-voltage amplifier 43 amplifies the AC voltage supplied from the transformer 42 to a high voltage of, for example, several kV to 10-odd kV, and applies it to the other end of the electrode 22. The frequency of the voltage applied to the other end of the electrode 22 is, for example, about 10 kHz.

[0027] The control unit 50 controls the drive unit 32 of the solution delivery unit 30 and the voltage application unit 40 so that the solution is delivered to the discharge tube 21 and a voltage is applied to the other end of the electrode 22, so that a dielectric barrier discharge, more specifically a corona-like dielectric barrier discharge, is generated on the tip side of the electrode 22 to generate a plasma nanomist. Here, the plasma nanomist refers to particles produced by plasma with a diameter of less than 1 μm, i.e., nanometer-sized particles.

[0028] The solution injected from syringe pump 31 into electrode 22 becomes charged as it passes through electrode 22, and interacts with plasma generated at the tip of electrode 22 to generate nanomist. Note that any liquid delivery means other than a syringe pump may be used as long as it can deliver the liquid at a desired speed. For example, a piezo micropump or the like may be used to deliver the liquid continuously.

[0029] The principle of nanomist generation will be explained below. Streamers ST, as shown in Figures 1A and 1B, are generated from the tip of electrode 22 toward ground electrode 25. When a high AC voltage is applied to electrode 22, the discharge tube 21, which is a dielectric in front of electrode 22, and the layer of air between electrode 22 and discharge tube 21 are charged, and an inverse electric field is formed between the tip of electrode 22, where the charge becomes locally large, and the surface of discharge tube 21 closest to the tip of electrode 22. As a result, the streamers ST generated by the high electric field are limited, and a discharge space without sparks is obtained.

[0030] The streamer ST is a strongly ionized discharge path that occurs when a discharge in air begins. When electrodes are placed in the atmosphere and the voltage exceeds a certain value, electrons gain energy from the electric field and travel toward the anode, forming an electron avalanche. Large positive ions resulting from ionization are left behind in the avalanche, and a strong electric field due to space charge is generated at the anode, the head of the electron avalanche. Light emitted from the avalanche attracts the ionized electrons. The streamer ST is a plasma, and at its tip, a cloud of positive ions moves at high speed toward the other electrode. In addition, the tip of the positive ion cloud emits strong light, forming a photoionized region near the streamer ST. Because the streamer ST is unstable in discharge forms such as spark discharge, it is stabilized by the dielectric barrier discharge described above.

[0031] Furthermore, when the liquid is sent through the electrode 22, it is charged by a high voltage and atomized by so-called Coulomb repulsion at the tip of the electrode 22. When the atomized droplets come into contact with the streamer ST, which is a strongly ionized discharge path, further ionization occurs, and the droplets are highly atomized to become a nanomist.

[0032] Since the plasma nano-mist generating device 10 has the above-described configuration, it does not require an atomization mechanism such as an ultrasonic vibrator, and can generate plasma nano-mist with a simple configuration.

[0033] Whether or not plasma nanomist can be generated depends on the type of solution, the outer diameter of the discharge tube 21, the outer diameter of the electrode 22, the voltage applied to the electrode 22, and the solution transfer speed.

[0034] Therefore, the control unit 50 controls the voltage application unit 40 so that a voltage set based on table data representing the correspondence between the type of solution, the outer diameter of the discharge tube 21, the outer diameter of the electrode 22, the voltage applied to the electrode 22, and the solution delivery rate, which is a predetermined correspondence relationship that serves as a generation condition for plasma nanomist generation, is applied to the electrode 22. The control unit 50 also controls the drive unit 32 of the liquid delivery unit 30 so that the solution is delivered at the delivery rate set based on the table data. This generates plasma nanomist. The generated plasma nanomist can be used in a wide range of applications, such as medical and cosmetic applications. Furthermore, the generated plasma nanomist is electrically charged, improving wettability.

[0035] 4 shows the correspondence relationship between the voltage (kV) applied to the electrode 22, the solution feed rate (μL / min), and the outer diameter (mm) of the electrode 22 when the outer diameter (mm) of the discharge tube 21 is 8 mm. The solution is ultrapure water (UPW), and the solution is also ultrapure water in the cases of FIGS. 5 to 10 described below.

[0036] As shown in FIG. 4, when the applied voltage is P (kV), the solution feed rate (μL / min) is S, and the outer diameter (mm) of the electrode 22 is D, plasma nanomist can be generated by satisfying the conditions below, preferably satisfying all of the following formulas (1) to (3):

[0037] 7≦P≦17.5...(1) 0<S<500...(2) 0.25≦D≦5...(3)

[0038] Figure 5 shows the optimum conditions among the conditions for generating the plasma nanomist shown in Figure 4. Here, the optimum conditions refer to conditions under which the phenomenon of droplets (droplets) being generated from the discharge tube 21 does not occur. As shown in Figure 5, the range of the optimum conditions is narrower than the range of conditions for generating the plasma nanomist shown in Figure 4.

[0039] Figures 6A and 6B show images of mist generated by the plasma nanomist generator 10 using ultrapure water as the solution, taken with a digital camera using a 10x microscope lens at an ISO sensitivity of 8000 and a shutter speed of 1 / 8000 seconds. Figure 6A shows an image of the generated mist, while Figure 6B is an enlarged view of a portion of the area enclosed by the white frame in Figure 6A. Figure 6B confirms that the generated mist is smaller than the minimum pixel size (2150 nm x 2150 nm) of the camera used to take the image, and that the generated mist is in the micro to nano size range of 2.15 μm or less.

[0040] FIG. 7 shows the correspondence between the voltage (kV) applied to the electrode 22, the solution feed rate (μL / min), and the outer diameter (mm) of the electrode 22 when the outer diameter (mm) of the discharge tube 21 is 10 mm.

[0041] As shown in FIG. 7, the range of conditions under which plasma nano-mist can be generated is narrower than when the outer diameter (diameter, mm) of the discharge tube 21 in FIG. 4 is 8 mm.

[0042] Fig. 8 shows the preferable conditions among the conditions under which the plasma nano-mist can be generated shown in Fig. 7. As shown in Fig. 8, the range of the preferable conditions is narrower than the range of the conditions under which the plasma nano-mist can be generated shown in Fig. 7.

[0043] FIG. 9 shows the correspondence between the voltage (kV) applied to the electrode 22, the solution feed rate (μL / min), and the outer diameter (mm) of the electrode 22 when the outer diameter (mm) of the discharge tube 21 is 15 mm.

[0044] As shown in Figure 9, the range of conditions under which plasma nanomist can be generated is narrower than when the outer diameter (diameter, mm) of the discharge tube 21 in Figure 4 is 8 mm and when the outer diameter (diameter, mm) of the discharge tube 21 in Figure 7 is 10 mm.

[0045] Fig. 10 shows the preferable conditions among the conditions under which the plasma nano-mist can be generated shown in Fig. 9. As shown in Fig. 10, the range of the preferable conditions is narrower than the range of the conditions under which the plasma nano-mist can be generated shown in Fig. 9.

[0046] Furthermore, whether or not a solution tends to become mist depends on its conductivity. That is, the more conductive the solution, the more likely it is to become mist, and the less conductive the solution, the less likely it is to become mist.

[0047] FIG. 11 shows the results of measuring the voltage and current applied to electrode 22, i.e., the results of measuring the discharge characteristics, for three types of solutions: ultrapure water (UPW), phosphate buffered saline (PBS), and castor oil (CO). The solution flow rate was changed to 10 μL / min, 50 μL / min, and 100 μL / min. As shown in FIG. 11, the discharge characteristics differ depending on the solution. The difference in the discharge characteristics of the solutions means that the conductivity of the solutions differs, and therefore the likelihood of them becoming mist differs.

[0048] FIG. 12 shows the results of measuring the conductivity of ultrapure water when the ultrapure water flow rate was changed to 50 (μL / min), 100 (μL / min), and 1000 (μL / min).

[0049] 13 shows the results of measuring the conductivity of phosphate buffered saline when the solution delivery rate was changed to 50 μL / min, 100 μL / min, and 1000 μL / min. As shown in FIGS. 12 and 13, different types of solutions have different conductivity. In other words, the tendency to become mist differs.

[0050] Therefore, by controlling the voltage applied to the electrode 22 and the speed at which the solution is sent depending on the type of solution, it is possible to appropriately turn the solution into nano-mist.

[0051] Furthermore, due to the interaction between the plasma generated at the tip of the electrode 22 and the solution, for example, hydrogen peroxide solution (H ２ O ２ ), nitrite ion (NO ２ － ), and nitrate ions (NO ３ － ) and other reactive chemical species that have disinfecting and germicidal effects.

[0052] FIG. 14 shows the results of measuring the amount (mg / L) of aqueous hydrogen peroxide dissolved in ultrapure water (UPW) by changing the solution flow rate (μL / min) when the solution was ultrapure water.

[0053] FIG. 15 shows the results of measuring the amount of nitrite ions (mg / L) dissolved in ultrapure water (UPW) by changing the solution flow rate (μL / min) when the solution was ultrapure water.

[0054] FIG. 16 shows the results of measuring the amount of nitrate ions (mg / L) dissolved in ultrapure water (UPW) by changing the solution flow rate (μL / min) when the solution was ultrapure water.

[0055] 14 to 16, it can be seen that the amount of reactive chemical species varies depending on the type of reactive chemical species. If it is desired to suppress the generation of reactive chemical species, a scavenger may be mixed into the solution.

[0056] 17, a configuration may be adopted in which a blower 60 is provided to blow air into the discharge tube 21. This makes it easier to send the generated plasma nano-mist to the outside of the discharge tube 21.

[0057] In addition, although the discharge tube 21 is set facing downward in FIG. 1A, it is also possible to install the discharge tube 21 facing upward or sideways.

[0058] Furthermore, when it is desired to generate a large amount of nano-mist, a bundle of a plurality of discharge tubes 21 and electrodes 22 can be used.

[0059] 17, in the case of a configuration in which air is blown into the discharge tube 21, or in the case of the configuration shown in Fig. 1A with the discharge tube 21 facing upward, the solution sending speed does not affect droplet generation. In this case, the control unit 50 controls the voltage application unit 40 so that a voltage set based on table data representing predetermined correspondences as conditions for generating plasma nanomist, which table data represents correspondences among the type of solution, the outer diameter of the discharge tube 21, the outer diameter of the electrode 22, and the voltage applied to the electrode 22, is applied to the electrode 22.

[0060] FIG. 18 shows the correspondence between the outer diameter (mm) of the discharge tube 21, the outer diameter (G) of the electrode 22, and the applied voltage (kV) in ultrapure water and phosphate buffered saline as conditions for generating plasma nanomist.

[0061] 19 shows the correspondence between the outer diameter (mm) of the discharge tube 21, the outer diameter (G) of the electrode 22, and the applied voltage (kV) for castor oil. Fig. 20 shows a gauge conversion table showing the correspondence between the gauge (G), outer diameter (mm), inner diameter (mm), and wall thickness (mm).

[0062] 18 and 19, the white areas are areas where plasma nano-mist is not generated, and the other areas are areas where the conditions are such that plasma nano-mist can be generated. Also, because an applied voltage of more than 17.5 kV will damage the discharge tube 21, the applied voltage must be 17.5 kV or less. As shown in Figures 18 and 19, it can be seen that the conditions for generating plasma nano-mist differ when the solution is ultrapure water or phosphate buffered saline and when the solution is castor oil.

[0063] The above has described in detail an embodiment of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure.

[0064] For example, the solution is not limited to ultrapure water, castor oil, and phosphate-buffered saline, but may also include, for example, methanol, ethanol, 1-propanol, 2-propanol, butanol, fragrances (both oil-based and water-based), pigment-based inks, and dye-based inks. Specific examples of fragrances include essential oils and volatile oil-based fragrances, and the components may be fragrances dissolved in alcohol, carbon disulfide, petroleum ether, or fatty oils. Pigment-based inks and dye-based inks may use inks that use, for example, vegetable oil derivatives as the main component. For pigment-based inks, it is possible to easily turn pigment-based inks dissolved in organic solvents into nanomists.

[0065] The disclosure of Japanese Patent Application No. 2022-057334 is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Claims

1. a discharge tube made of a dielectric material and into which a solution is injected; A liquid delivery unit that delivers the solution into the discharge tube; an electrode provided in the discharge tube and capable of delivering the solution; A voltage application unit that applies a voltage to the electrodes; a ground electrode provided on the tip side of the electrode and on the outer periphery of the discharge tube, the ground electrode being grounded within the device itself; A control unit that controls the solution delivery unit and the voltage application unit so that the solution is delivered to the discharge tube and a voltage is applied to the electrode so that a dielectric barrier discharge is generated at the tip side of the electrode to generate a plasma nanomist; A plasma nanomist generating device equipped with the device.

2. The electrode is a needle electrode or a cylindrical electrode. The plasma nano-mist generating device according to claim 1.

3. The electrode is a needle electrode. The plasma nano-mist generating device according to claim 2.

4. A blower for blowing air into the discharge tube The plasma nano-mist generating device according to claim 1 .

5. The control unit controls the voltage application unit so that a voltage set based on a correspondence relationship between the type of the solution, the outer diameter of the discharge tube, the outer diameter of the electrode, and a voltage applied to the electrode is applied to the electrode, the correspondence relationship being a predetermined correspondence relationship as a generation enabling condition for generating the plasma nano mist. The plasma nano-mist generating device according to claim 1.

6. The control unit controls the voltage application unit so that the voltage set based on a correspondence relationship between the type of the solution, the outer diameter of the discharge tube, the outer diameter of the electrode, the voltage applied to the electrode, and a liquid delivery speed of the solution, which is a correspondence relationship previously determined as a generating condition for generating the plasma nano mist, and controls the liquid delivery unit so that the solution is delivered at the liquid delivery speed set based on the correspondence relationship. The plasma nano-mist generating device according to claim 1.

7. The liquid delivery rate is greater than 0 μL / min and less than 500 μL / min. The plasma nano-mist generating device according to claim 6.

8. The solution is any one of ultrapure water, castor oil, and phosphate buffered saline; The outer diameter of the discharge tube is 8 mm or more and 15 mm or less, The outer diameter of the electrode is 0.25 mm or more and 5 mm or less, The voltage is equal to or greater than 7 kV and equal to or less than 17.5 kV. The plasma nano-mist generating device according to any one of claims 1 to 7.