Multi-jet cold atmospheric plasma (CAP) device

Abstract

Multi-nozzle Cold Atmospheric Plasma (CAP) devices are disclosed. One CAP device includes a cylindrical body with multiple injectors arrange in a radial direction of the cylindrical body and a gas injector connected to each of the multiple injectors. Each of the gas injectors include a cathode, and an anode is formed on a surface of the cylindrical body. Other CAP devices include multiple flexible tubes attached to a hollow chamber, each of the flexible tubes including a ring anode positioned at an opposite end of the flexible tube from the chamber. Other CAP devices include a gas inlet rod within a movable ring. Sliding the movable ring along the gas inlet rod changes the direction of multiple tube assemblies and thus, the direction of the plasma. The CAP devices may provide decontamination of different surfaces, for example PPE and other medical tools or devices.

Description

[0001] MULTI-JET COLD ATMOSPHERIC PLASMA (CAP) DEVICE

[0002] GOVERNMENT LICENSE RIGHTS

[0003] This invention was made with government support under Grant No. 1747760 awarded by the National Science Foundation. The government has certain rights in the invention.

[0004] RELATED APPLICATION

[0005] This application claims the benefit of U.S. Provisional Application No. 63 / 540,209, filed September 25, 2023, the entire contents of which are incorporated herein by reference. The references cited in the provisional application are also hereby incorporated by reference in their entireties herein.

[0006] BACKGROUND

[0007] Cold atmospheric plasma (CAP) has emerged as a promising tool in combating antibiotic-resistant bacterial infections, including those caused by methicillin-resistant Staphylococcus aureus (MRSA). MRSA and other antibiotic-resistant bacteria pose a significant and growing threat to public health worldwide. These pathogens are responsible for a multitude of infections that are increasingly difficult to treat due multi-drug resistance. The need for innovative and effective antimicrobial modalities remains urgent to global healthcare.

[0008] CAP, also referred to as non-thermal or low-temperature plasma, is a partially ionized gas composed of ions, electrons, and neutral particles at near-room temperature. This unique state of matter exhibits potent antimicrobial and antifungal properties. CAP is a valuable tool in the fight against resistant pathogens such as MRSA. CAP is generated by applying an electric field to an inert gas (often a mixture of air, helium, or argon) resulting in the formation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) among other reactive particles. These reactive species are highly effective at disrupting microbial cells. They can damage cellular membranes, proteins, and nucleic acids, ultimately leading to cell death. The non-thermal nature of CAP ensures that it can be used on heat-sensitive surfaces and tissues without causing thermal damage, distinguishing it from traditional sterilization methods that rely on high temperatures. Several studies have demonstrated the effectiveness of CAP in treating MRSA infections. For example, CAP has been reported to reduce MRSA populations on infected wounds, treat chronic wounds infected with MRSA-that reduced bacterial load and also promoted wound healing, likely due to the anti-inflammatory properties of the plasma. Beyond MRSA, CAP has been shown to be effective against a wide range of bacterial pathogens. For instance, CAP has achieved substantial reductions in bacterial populations such as Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus epidermidis . CAP has also been studied for decontaminating surfaces contaminated wdh Bacillus subtilis spores, as a model organism for studying sporeforming bacteria. The CAP was shown to effectively inactivate some bacterial spores, which are known for their resistance to conventional decontamination methods. Such studies suggest that CAP may be particularly useful in settings where spore-forming pathogens pose a significant risk, such as healthcare and food processing environments.

[0009] During the COVID- 19 pandemic, the decontamination of personal protective equipment (PPE) was critical due to global shortages. Single-use PPE (e.g., surgical respirators, masks, and gowns) are disposable and typically not decontaminated for reuse. During the COVID pandemic, disinfection of PPE included the use of chemical and physical treatments such as hydrogen peroxide vapor, which is effective but can degrade material integrity over time. Hydrogen peroxide vapor is a strong oxidizer that can damage the material and fabric of PPE, reducing its integrity and effectiveness. Ozone, which is powerful oxidative agent, may be used but requires humidity which may compromise the barrier integrity of PPE. Also, ultraviolet (UV) radiation, particularly UV-C light, can inactivate pathogens but may also weaken PPE materials, and UV-C light has limited penetration. Autoclaving, or steam sterilization, can be highly effective for certain types of equipment, but Autoclaving is not suitable for heat-sensitive materials. Micro wave-generated steam may also be used but requires careful control to avoid material damage. Additionally, chemical detergents like Alconox, a detergent widely used for cleaning laboratory glassware, may be employed to decontaminate PPE, but may not achieve the necessary level of microbial inactivation alone, because Alconox is often combined with other methods.

[0010] The above methods have limitations that may compromise the structural integrity or effectiveness of PPE. These limitations highlight the need for alternative decontamination methods like CAP that preserve the integrity of PPE without causing significant material degradation while ensuring effective microbial inactivation. CAP offers several advantages over these traditional methods. The application of CAP is a dry process, which reduces the risk of material degradation while maintaining the structural integrity of treated surfaces. Additionally, the rapid action of CAP allows for faster decontamination compared to other methods, which is crucial in environments like hospitals and food processing plants where PPE is essential to worker or patient safety. CAP may effectively decontaminate PPE without causing significant damage to the material, making it a promising alternative to chemical and moisture-based disinfectants.

[0011] The antimicrobial action of CAP is primarily attributed to the generation of ROS and RNS, which induce oxidative stress in bacterial cells. These reactive species can oxidize lipids in cell membranes, leading to increased permeability and cell lysis. Additionally, these reactive species can cause direct damage to DNA, RNA, and proteins, disrupting essential cellular functions and ultimately leading to cell death.

[0012] Safety is a critical consideration for any new antimicrobial treatment. Studies have shown that CAP can be applied safely to human tissues without causing significant damage. For example, CAP treatments have been determined to not cause cytotoxic effects in mammalian cells, suggesting that it could be used for treating infections in clinical settings. Moreover, the ability to precisely control the application of CAP ensures that it can target pathogens without harming surrounding healthy tissues.

[0013] The potential applications of CAP extend beyond treating bacterial infections in humans. Research regarding different health benefits through CAP includes exploring its use in oncology, veterinary medicine, and agriculture. For example, CAP may be used to treat antibiotic-resistant infections in animals, thereby reducing the spread of resistance genes. CAP has also been shown to effectively reduce bacterial load on the skin of animals without causing adverse effects, indicating its potential for treating skin infections in veterinary practice.

[0014] CAP could play a role in enhancing food safety by decontaminating food products and processing surfaces. The ability of CAP to inactivate a wide range of pathogens, including bacteria, viruses, and fungi, makes it a versatile tool for ensuring the microbial safety of food products. Furthermore, CAP technology could be integrated into packaging processes to extend the shelf life of perishable goods by reducing microbial contamination.

[0015] Despite the promising potential of CAP, several challenges must be addressed to facilitate its widespread adoption. One major challenge is the need for standardized protocols to ensure consistent and effective treatment outcomes. Variations in plasma generation methods, treatment times, and gas compositions may affect the efficacy of CAP, necessitating rigorous standardization and optimization. Additionally, the mechanisms by which CAP interacts with microbial cells and host tissues require further elucidation to optimize its use and minimize any potential adverse effects.

[0016] CAP represents a promising and versatile tool for combating antibiotic-resistant bacterial infections, including those caused by MRSA. Its unique properties, including broad-spectrum antimicrobial activity, rapid action, and non-thermal nature, make it an attractive alternative to traditional antimicrobial and decontamination methods. The successful application of CAP in both clinical and environmental settings highlight its potential to address critical challenges in public health and safety. As research continues to advance our understanding of CAP, its integration into routine antimicrobial practices could significantly enhance our ability to manage resistant infections and improve infection control measures across various domains.

[0017] SUMMARY

[0018] The present disclosure provides different designs for multi-nozzle CAP devices that may provide antimicrobial and antifungal treatments, as well as decontamination of different surfaces, such as PPE and other medical tools and / or devices. However, the device can be used for any suitable application other than decontamination.

[0019] In one aspect, embodiments related to a CAP device that includes a cylindrical body with multiple injectors arrange in a radial direction of the cylindrical body and a gas injector connected to each of the multiple injectors. Each of the gas injectors include a cathode. The device includes an anode formed on a surface of the cylindrical body, where the surface includes multiple ceramic openings for each of the multiple injectors.

[0020] In some embodiments, the cylindrical body is an annulus and the surface of the cylindrical body forming the anode in on an interior surface of the annulus. In other embodiments, the device includes a fan oriented to blow parallel to an axis of the cylindrical body and arranged on one end of the cylindrical body. The device also includes a ground with a honeycomb structure. The ground is disposed on the other end of the cylindrical body, and plasma exits the device through the honeycomb structure. The ground may provide an axial electric field to facilitate the flow of the plasma through the honeycomb. Also, the surface of the cylindrical body forming the anode may be angled to direct an output of the multiple injectors towards the ground.

[0021] In another aspect, embodiments relate to a CAP device including multiple flexible tubes attached to a hollow chamber, each of the flexible tubes including a ring anode positioned at an opposite end of the flexible tube from the chamber.

[0022] In some embodiments, the CAP device may include a conical shaped cathode comprising a gas inlet to the hollow chamber.

[0023] In other embodiments, the CAP device may include a chamber with a door, a base plate, and one or more vents. Such devices may include a gas mix housing inlet attached to the chamber, and a Y-shaped gas mixer outside of the chamber operatively attached to the gas mix housing inlet. The gas inlet of the conical shaped cathode is inside the chamber and operatively attached to the gas mix housing inlet.

[0024] In some embodiments, the CAP device includes an enclosure with the hollow chamber. The enclosure is divided to form the hollow chamber and a circuit housing. The device includes a gas inlet on a surface of the enclosure operably connected to the hollow chamber and a cathode incorporated into the surface of the enclosure with the gas inlet. A removable covering is located on a side of the enclosure to provide access the circuit housing. The multiple flexible tubes are disposed on a side of the enclosure opposite of the circuit housing.

[0025] In another aspect, embodiments are related to a CAP including a gas inlet rod within a movable ring. The movable ring is connected to multiple connecting rods each with movable joints. Multiple tube assemblies are connected to each of the multiple connecting rods. Each of the tube assemblies include a flexible tube with a ring anode near a plasma exit of the flexible tube, a gas inlet, and a cathode disposed at the end of the tube assembly connected to the connecting rod. Sliding the movable ring along the gas inlet rod changes the direction of plasma at the plasma exit of the flexible tube. In some embodiments, the CAP device includes a base plate attached to an end of the gas inlet rod and a circuit housing comprising an integrated circuit with a voltage source for supplying a voltage to each cathode and anode of the multiple tube assemblies.

[0026] BRIEF DESCRIPTION OF THE FIGURES

[0027] FIG. 1 illustrates a multi -plasma jet system in accordance with one or more embodiments herein.

[0028] FIGS. 2A-2B illustrate an annular multi-plasma device in accordance with one or more embodiments herein. FIG. 2A is a schematic of the annular multi-plasma device in accordance with embodiments, and FIG. 2B illustrates the plasma output of the annular multi-plasma device according to embodiments.

[0029] FIGS. 3A-3C illustrate different perspectives of a multi-plasma device in accordance with one or more embodiments herein.

[0030] FIGS. 4A-4C illustrate a flexible tube multi-plasma device in accordance with one or more embodiments herein. FIG. 4A shows the components of a flexible tube multi-plasma device according to embodiments, FIG. 4B illustrates an assembled flexible tube multi-plasma device, and FIG. 4C is a side view of FIG. 4B.

[0031] FIGS. 5A-5B demonstrate an example of multi-plasma chamber device utilizing flexible tubes device in accordance with one or more embodiments herein. FIG. 5A shows the components of the device, and FIG. 5B illustrates an assembled multi-plasma device utilizing flexible tubes in accordance with embodiments.

[0032] FIGS. 6A-6B illustrate demonstrate an example of multi-plasma device utilizing flexible tubes device in accordance with one or more embodiments herein. FIG. 5A shows the components of the device, and FIG. 5B illustrates an assembled multi-plasma device utilizing flexible tubes in accordance with embodiments.

[0033] FIGS. 7A-7E illustrate an adjustable multi-plasma device in accordance with one or more embodiments herein. Figure 7A-7B provide different perspectives of an adjustable multi-plasma device, and FIG. 7C shows details of the tube and anode. FIG. 7D shows components of an adjustable multi-plasma device in accordance with embodiments. FIG. 7E illustrates adjustment of the multi-plasma jets in an adjustable multi -plasma device in accordance with embodiments. FIG. 8 demonstrates an example system using an adjustable multi-plasma device in accordance with one or more embodiments herein.

[0034] FIG. 9A is a perspective exploded view of a multi-plasma device having a distributor.

[0035] FIG. 9B is a cutaway perspective view of the device of FIG. 9A.

[0036] FIG. 9C is a cutaway perspective view of the device of FIG. 9A from a distal end.

[0037] FIG. 9D is a cutaway side view of the device of FIG. 9A.

[0038] FIG. 9E is a cutaway top view of the housing of FIG. 9 A.

[0039] FIG. 9F is a perspective cutaway top view of the housing of FIG. 9A.

[0040] DETAILED DESCRIPTION

[0041] In describing the preferred embodiments of the present disclosure illustrated in the drawings, specific terminology is resorted to for the sake of clarity. However, the present disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.

[0042] GENERAL MULTI-PLASMA JET SYSTEM 100 (FIG. 1)

[0043] FIG. 1 illustrates a general multi -plasma jet system 100 having a circuit or circuit housing 110, gas chamber 116, an array of one or more jets 102 in accordance with embodiments, here shown as a 5x1 array. Each jet 102 is an elongated tube 106 with a hollow center, a tube distal end and a tube proximal end. The tube proximal end is positioned inside of the gas chamber 116. The tube 106 extends outside of the gas chamber 116, and the tube distal end is outside of the gas chamber 116.

[0044] The tube 106 has an open tube proximal end with a tube proximal end opening and an open tube distal end with a tube distal end opening. An elongated cathode or cathode rod 104 is arranged at or near the proximal opening of the tube 106 and forms an inner electrode with an electrode distal end and an electrode proximal end. The cathode 104 is at least partially located inside of the tube 106, and as shown extends from outside of the tube 106 to inside the tube 106. Accordingly, the cathode proximal end is outside of the tube 106 and exposed inside of the gas chamber 116 at the tube proximal end. The cathode 104 extends partially into the tube 106 at the proximal end opening, but does extend completely through the tube 106. A support fixture 105 is positioned inside the tube 106 at the tube proximal end. The support fixture 105 holds the cathode 104 in position. In one embodiment, the support fixture 105 can include a center opening through which cathode 104 can pass, ensuring it remains stable while allowing the necessary components of the cathode 104 to extend through the tube. The fixture 105 also allows gas to pass from the chamber 116 into and through the tube 106 and exit the distal tube opening as plasma 120.

[0045] An anode 108 is positioned at or near the exit of each jet 102 at or near the tube distal end opening. The anode 108 can be a ring shape that extends around the tube at or near the tube distal end. In the embodiment shown, the anode 108 is beyond the cathode 104, so that the cathode 104 is not positioned inside of the anode ring 108. The presence of the cathode in the tube and anode outside the tube prevents breakdown of gas between the electrodes and focuses the plasma generation in the region where Helium gas is flowing.

[0046] The circuit 110 can be, for example, an integrated circuit that includes a voltage source 112, as well as other electronic components, such as timers and voltage regulators (not shown). The circuit 110 is shown outside of the gas chamber 116 and outside of the jet tube 106, but can also be positioned at least partially in the tube 106. The circuit 110 has a first lead that is electrically coupled to the cathode proximal end of the cathode 104 and a second lead that is electrically coupled to the anode 108. It will be recognized that embodiments are not limited to inner electrodes, and the cathode 104 need not be positioned inside the jet tube 106.

[0047] In embodiments, an inert gas 114, such as helium, and atmospheric air is introduced into a gas chamber 116 via a gas inlet 118. The gas 114 enters the tube 106, travels through the tube 106 and exits as plasma 120. The integrated circuit in the circuit housing 110 facilitates precise control over the frequency and discharge voltage of the plasma jet system 100. A high electric field is formed between the anode 108 and the cathode 104 while the noble gas flows via the gas inlet 118 to generate cold plasma 120 from each of the multiple jets 102. The tubes 106 are linear and extend parallel to one another, with the tube proximal ends all arranged within the same gas chamber 116 and aligned with one another. The tube distal ends are also aligned with one another, and have a cold plasma jet output that are all directed at different angles toward a same target or specimen 101. The multiple jets 102 provide greater coverage of the target 101. FIG. 1 illustrates a general multi -pl asm a jet system 100 using an inner electrode as the cathode 104. In other embodiments, for example, the jet tubes 106 need not be parallel to one another, but can be positioned about the target 101 at different angles. As explained below, other embodiments provide different geometries of the chambers and configurations of the anodes and cathodes: for example, annular shaped multi-jet devices (FIGS. 2-3), devices with flexible jet tubes (FIGS. 4-6), and radial to axial adjustable CAP devices (FIGS. 7-8). NNULAR MULTI-PLASMA JET DEVICE 200 (FIG. 2)

[0048] FIGS. 2A-2B illustrate a non-limiting example annular multi-plasma device 200 in accordance with one or more embodiments herein. FIG. 2A is a schematic of the annular multiplasma device 200 in accordance with embodiments, and FIG. 2B illustrates the plasma output of the annular multi-plasma device 200 according to embodiments. The device 200 includes a housing 220 with a single piece unitary solid main housing body 222 and a housing cover or plate 209. The main housing body 222 is a solid metal having an annular ring shape with an inner housing wall 226, an outer housing wall 228, a housing bottom and a housing top having the housing cover 209. The inner housing wall 226 defines an open housing center or region 215.

[0049] One or more through-holes 207 are formed completely through the solid housing body 222, and extend radially inward from the outer housing wall 228 to the inner housing wall 226 toward the center of the housing body 222 at the center region 215. In the example embodiment of FIG. 2A, there are four through-holes 207 positioned equally about the outer circumference of the main housing body 222, every ninety (90) degrees. Of course, more or fewer through-holes 207 can be provided.

[0050] An inlet or jet 202 is orthogonally arranged in each of the through-holes 207 at the outer housing wall 228, for a total of four inlets 202 in the embodiment of FIG. 2. The inlets 202 extend radially inward from an exterior side of the annular device 200 towards the interior center of the annulus of the device 200. The jets 202 have a proximal end that couples with the through- hole 207, for example the jet proximal end can have external threads and the through-hole 207 can have internal threads that threadably mate with the external threads of the jet 202 to form a gas-tight couple. The jets 202 have an elongated tube-like structure with external circumferential ribs. The jets 202 have a jet distal end that mates with a gas hose or pipe to deliver the air / gas mixture 217 to the jets 202. The jets 202 extend orthogonally outward from the outer surface of the outer housing wall 222 of the device 200. One of ordinary skill in the art will appreciate that the number of through-holes 207 and jets 202, and the radius of the annular device 200 may be varied in accordance with specific applications.

[0051] In these embodiments, an air / gas mixture 217 is introduced into the system 200 through a gas pipe to a gas injector 218, for example a gas pipe or hose (e.g., rubber tube or hose) that is securely connected to the jet inlet 202. The gas injector 218 may be coupled to or threaded onto the jet 202. The injector 218 includes a ring electrode 204 that serves as the cathode in the device 200. The ring electrode 204 has a ring center opening that receives the injector 218 therethrough, so that the ring electrode 204 extends around the injector 218. The gas injector 218 and / or the ring electrode 204 can be coupled to the jet distal end of the jet 202, or can extend about the jet 202, for example at or near the jet distal end or at an intermediate portion of the jet 202 between the jet distal end and the jet proximal end. Though the anode 204 is shown about the injector 218, in other embodiments, the anode 204 can be placed about the jet 202 and not the injector 218.

[0052] An AC electric field is established between the ring electrode 204 and an anode 208 generates a plasma stream that moves radially inwards. In these embodiments, the inner housing wall 226 of the annulus device 200 forms the anode 208. A thin ceramic layer or coating can be placed at the inner walls of the through-holes 207, as well as optionally at the inner walls of the gas injector 218 and jet 202. The ceramic material operates as an insulator that prevents loss of current and provides thermal insulation for the jet 202, though other insulators can be used.

[0053] The device 200 includes a ground cover plate 209 that forms an electrode to generate electric fields that interacts with the four plasma jets 202 to facilitate plasma extraction for treatment purposes. Thus, the injector 218, jet 202, through-holes 207 are in flow communication with each other. The air / gas mixture 217 is received at the injector 218, passes through the jet 202 into the through-hole 207. The gas is expelled out of the proximal end of the through-holes 207 at the inner housing wall 226 and into the open center region 215, as the plasma jets. An insulator thin ring plate 211 (e.g., Teflon) is positioned between the main housing body 220 and the cover plate 209 to provide a standoff / insulation between the anode inner wall 208 and the ground cover plate 209, so that the anode and ground are electrically disconnected. The cover plate 209 and the insulator plate 211 have the same inner and outer diameter and shape as the main housing body 222, and are fixed to the top surface of the main housing body 222 of the device 200 using a number of fasteners 213, such as screws. The screws, as shown, can be of sufficient length to also mount the device to a support structure, such as a movable system.

[0054] Referring to FIG. 2B, within the center 215 of the device 200, a high electric field region is formed due to the interaction of the four plasma jets 202, resulting in the creation of a region 215 with a significantly elevated plasma density. The presence of a high-density plasma region 215 is crucial for the generation of intense reactive oxygen and nitrogen species, which are vital for CAP treatment processes. The entire center 215 gets filled with plasma as the plasma distributes due to the electric filed.

[0055] The circuit configuration for embodiments of FIGS. 2A-2B is a single plasma jet circuit that controls all of the jets 202. Using a single circuit may necessitate amplification of the input voltage to reach levels of lOkVs or higher. Alternatively, multiple circuits can be employed to individually control one or more of the jets and the associated output intensity.

[0056] Ionization may be enhanced by reducing the inner diameter of the anode 208. Additionally, the frequency of the input AC electric field may be optimized to maximize the production of reactive species at the highest intensities. In addition to the generation of UV light and the reactive species, the device 200 may emit electromagnetic waves as in traditional plasma jets. Such devices may have applications in cancer treatment, wound healing, bacteria treatments, and surface decontaminations.

[0057] As shown, the main housing body 222 has a substantial width, which provides a longer flow path for the Helium to be fully developed at the plasma exit of the through-hole 207. In other embodiments, the main body 222 can be a thin circular plate with mounting features such as fasteners or openings, and with longer jet tubes 202. The circular plate is a mounting support that holds the jet tubes 202 in a desired position, and the longer jet tubes 202 provide a longer flow path for the Helium to develop. CONICAL MULTI-PLASM JET DEVICE 300 (FIG. 3)

[0058] FIGS. 3A-3C illustrate different perspectives of another multi-plasma device 300 in accordance with one or more embodiments herein. The device 300 includes a housing 320 with a hollow single-piece unitary main housing body 322 and a circular cover plate 324. The main housing body 322 has a housing side wall 308, closed bottom, and an open top that receives the cover plate 309, which collectively define an open interior space. The main housing body has a conical shape (a circle cross-section) that is tapered outward with a smaller housing proximal end and a larger housing distal end that is enclosed by the cover plate 309. The housing proximal end can have a straight portion that is linear and not tapered outward.

[0059] The housing side wall 308 forms an anode, and the cover plate 309 forms a ground. One or more jet connectors 302 are formed about the conical housing body 322, and orthogonally coupled to the housing side wall 308. In addition, one or more openings 324 are formed in the cover plate 309. Thus, gas enters through the connectors 302, forms the plasma at the interior space of the main body 322, and the plasma exits through the openings 324 to expel a plasma jet 305. A strong electric field forms due to the four jets interacting in the hollow housing, and an electric field is formed between the openings 324 and the jets.

[0060] Similar to the embodiments of FIG. 2, the device 300 includes a gas injector 318 with a ring electrode 304 that serves as the cathode in the device 300 as shown in FIG. 3A. The example device 300 includes one or more (here shown as four) jets 302 arranged transversely inwards and orthogonally at the outside of the housing, and are directed inward towards the center of the device 300. The system introduces a mixture of air and inert gas 317 via the gas injector 318 using a secure connection between the gas pipe and the injector 318.

[0061] The interplay of the AC electric field established between cathode 304 and the anode 308 results in the creation of a plasma stream that moves radially inward. The gas injector 318 is intricately threaded into the anode 308, and both the inner walls of the gas injector 318 and the anode hole 307 are lined with ceramic material. The ceramic material in the anode hole 307 prevents any loss of current and provides effective thermal insulation.

[0062] Within the interior central region of the device 300, the interaction of the multiple plasma jets 302 gives rise to a pronounced high electric field volume, ultimately forming a zone characterized by a substantially elevated plasma density. Referring to FIG. 3B, the ground cover plate 309 is a honeycomb design electrode with openings 324 that creates an electric field axially with the multiple plasma jets. In these embodiments, the radial plasma jets may be inclined, e.g., at 20-degree angle, towards the ground 309.

[0063] Referring to FIG. 3C, the device includes a fan 330 to cool the anode housing side wall 308 and create steady flow of plasma jet extraction via honey-comb structure in the ground cover plate 309. The design of the structure may be optimized for specific applications using flow simulations.

[0064] An insulator thin ring plate 311 (e.g., Teflon) is positioned between the main housing body 320 and the cover plate 309 to provide a standoff / insulation between the anode wall 308 and the ground cover plate 309, so that the anode and ground are electrically disconnected. The cover plate 309 and the insulator plate 311 are fixed to the main housing body 322 of the device 300 using a number of fasteners, such as screws.

[0065] Similar to embodiments of FIG. 2, the overall circuit configuration may take the form of a single, plasma jet circuit, which may necessitate the amplification of the input voltage to levels of lOkVs or higher. Alternatively, multiple circuits may be employed to individually control each of the jets and precisely manage their intensity. To further enhance ionization, the inner diameter of the anode can be reduced, and the frequency of the input AC electric field may be finely tuned and optimized to maximize the production of reactive species at the associated peak intensities.

[0066] FLEXIBLE TUBE MULTI-PLASMA JET DEVICE 400 (FTG. 4)

[0067] FIGS. 4A-4C illustrate a flexible tube multi-plasma device 400 in accordance with one or more embodiments herein. FIG. 4A shows the components of a flexible tube multi-plasma device 400 according to embodiments, and FIGS. 4B, 4C illustrate an assembled flexible tube multi-plasma device 400.

[0068] The device 400 includes a single-piece unitary mounting plate 404 and one or more flexible tubes 402 that may be adjusted and formed to direct the output plasma. The mounting plate 404 has mounting plate housing body that includes a front mounting plate wall 412 with a front mounting plate surface, a rear mounting plate wall 414 with a rear mounting plate surface opposite the front mounting plate surface 412, and a side mounting plate wall 413 between the front wall 412 and the rear wall 414. The side wall 413 is tapered outwardly from the front wall 412 to the rear wall 414. One or more rear openings are formed at the rear surface of the rear wall 414 that form gas outlets. The mounting plate 404 is electrically conductive, such as metal, and is used as a cathode.

[0069] A gas inlet 417 is formed at the front surface 412. The gas inlet 417 is a circular wall that projects forward from the front surface 412.

[0070] One or more connector adaptors 410 are coupled to the rear openings in the rear surface of the rear wall 414. The connector adaptors 410 couple the flexible tubes 402 to the rear wall 414. For example, the tube connector 410 can have external threads that threadably mate with the internal threads of the rear opening. Or, the tube 402 can be made of a pliable rubber that forms a friction fit about the outer surface of the adaptor wall. In other embodiments, a rear connector can be positioned about the rear openings of the rear wall 414. The rear connector can be a circular wall (similar to the gas inlet 417) that projects rearward from the rear mounting plate surface 414. For example, the rear connector can be externally threaded and threadably mate with internal threads on the tubes 402. In the embodiment shown, four adaptors 410 are formed about the rear surface 414, though other suitable positions and numbers can be provided.

[0071] The mounting plate housing body is hollow to form an open interior space that is gas proof and retains gas. Gas is received through the inlet 417, into the hollow interior space where it mixes and forms the plasma, and exits out of the rear gas outlets, into the flexible tubes 402. The gas forms plasma between the anode 408 and the cathode 405.

[0072] A high electric field is formed between a ring anode 408 positioned at the end of the flexible tube 402 and the cathode 404, such as by attaching electrical leads to the anode 408 and cathode 404 and applying a voltage differential thereto. The electric field is applied while the gas flows via the gas inlet 417 to generate the cold plasma 401. The flexible tubes 402 are used to achieve flexibility by moving the exit nozzles of the tubes 402 in the plasma device 400. In these embodiments, a conical shaped cathode 404 includes a hollow chamber with the gas inlet 417. The cathode 404 attaches each of the flexible tubes 402 to the hollow chamber of the cathode 404, for example using a one-quarter (0.25) inch National Pipe Taper (NPT) connector 405. A transformer-based voltage step up circuit may be used to generate AC discharge voltages above 6 kV to create the cold plasma produced from the flexible tubes 402. In such embodiments, the operation frequency may be in the range of 10-20 kHz using an AC wave as an input signal.

[0073] MULTI-PLASMA CHAMBER 500 (FIG. 5)

[0074] FIGS. 5A-5B demonstrate an example of multi-plasma chamber device assembly 500 utilizing the flexible tube device 400 shown in FIG. 4. FIG. 5A shows the components of the chamber device, with the flexible tube device 400 disconnected from the mixing housing 540. And FIG. 5B illustrates an assembled multi-plasma chamber device utilizing flexible tubes, with the flexible tube device 400 connected to the mixing housing 540, in accordance with embodiments. The chamber device 500 includes a plasma chamber or plasma chamber housing 530, gas mixing housing 540, and flexible tube assembly 400. In the example embodiment shown, the plasma chamber 530 has a cuboid shape with four chamber side walls, a chamber top wall, and a chamber bottom wall. However, other suitable shapes can be utilized. A door 532 is provided in one of the four chamber side walls. One or more vents 542 can be provided in one or more of the chamber walls to facilitate air circulation within the chamber 530. A base plate 534 can optionally be provided on the bottom wall to hold a specimen or target, such as on a petri dish, that is to be treated with plasma.

[0075] The gas mixing housing 540 is coupled to the outside (or inside) of one of the chamber walls of the gas chamber 530. The gas mixing housing 540 is shown as a cuboid shape with an open interior space, a gas mixing housing inlet 540, and a gas mixing housing outlet 544. However, other suitable shapes can be provided. A Y-shaped gas mixer 536 is connected to the gas mix housing inlet 540. The Y-shaped gas mixer 536 has a first gas inlet 537 and a second gas inlet 538 and a combined gas outlet. The combined gases from the Y-shaped gas mixer 536 enter the interior space of the gas mixing housing 540. The gas mixer 536 and gas mixing housing 540 mix the first gas (air) and second gas (noble gas) at a desired mix ratio at the gas mixing housing outlet 544.

[0076] As best shown in FIG. 5B, the flexible tube device 400 has an inlet 417 that is coupled to the gas mixing housing outlet 544. Multiple flexible tubes 402 are attached to the cathode 404 as in the embodiments of FIG. 4. The flexible tube device 400 receives the mixed gas via the flexible tube device inlet from the gas mixing housing outlet 544, and passes the gas through the tube housing into the multiple flexible tubes 402. Accordingly, the Y-mixer 536, gas mixing housing 540, tube device 400 and tubes 402 are in flow communication, so that gas passes from the Y-mixer 536 into the gas mixing housing 540, and to the flexible tubes 404. The cathode 404 (which includes the gas inlet 417) is attached to the gas mix housing inlet 540 on the inside of the chamber 530. The gas mixture becomes plasma between the anode 408 and the cathode mounting plate 400, after voltage application and electrical breakdown, gas is ionized and form a plasma jet.

[0077] Thus, the Y-connector 538 mixes the air 537 and noble gas 538. The Y-connector 538 can connect to the distal side of the gas housing 540 outside the gas chamber 530, and the mounting plate 400 inlet can couple to the opposite proximal side of the gas housing 540 inside the gas chamber 530 (via an opening in the gas chamber 530), so that the gas from the Y- connector enters the interior of the gas mixing housing 540 so the gas can disperse, then travels into the mounting plate 400. In other embodiments, the Y-connector 538 can extend through the gas mixing housing 540 (or the gas mixing housing 540 is not provided) and the Y-connector can directly connect to the inlet of the mounting plate 400 via an opening in the gas chamber 530.

[0078] In these embodiments, a high electric field is formed between the anode 408 and the cathode 404 while the noble gas flows via the mixer 536, gas mix housing inlet 540, and inlet 417 to generate cold plasma at the output (e.g., exit nozzles) of the flexible tubes 402. The flexible tubes 402 allow the exit nozzles to be moved into various desired positions about the target specimen that is placed inside the chamber 530, such as on the base plate 534, for treatment by plasma that is emitted from the ends of the tubes 402. In embodiments, the plasma chamber 530 may be constructed with multiple cathodes 404, each with multiple flexible tubes 402 for decontamination and / or biological experiments. A transformer-based voltage step up circuit may be used to generate AC discharge voltages above 6kV to create the cold plasma. The operation frequency may be in the range of 10-20 kHz using an AC wave as an input signal.

[0079] MULTI-PLASMA FLEXIBLE TUBE DEVICE 600 (FIG. 6)

[0080] FIGS. 6A-6B illustrate another example of a flexible tube multi-plasma device or assembly 600 in accordance with one or more embodiments herein. FIG. 6A shows the components of the device 600, and FIG. 6B illustrates an assembled multi-plasma device 600 utilizing the flexible tubes 602 in accordance with embodiments.

[0081] The gas chamber assembly 600 includes a gas chamber 631 and flexible tubes 602 (similar to tubes 402 in FIGS. 4-5). The gas chamber 631 has a cuboid shape with four chamber side walls, a chamber top wall, and a chamber bottom wall. However, other suitable shapes can be utilized. The gas chamber 631 has a gas inlet 617 that receives gas from a gas source. The gas inlet 617 can be a circular wall that is positioned about an opening in one of the gas chamber walls. Enclosure 600 is divided diagonally by a partition or separating wall to separate the circuit housing 610 from the gas chamber 631. A window can optionally be provided in at least one of the gas chamber walls to allow the user to see the plasma inside the gas chamber 631. The gas chamber 631 and circuit housing 610 are combined in the same integral assembly 600 to provide a portable device that can directly plug into a power source and gas inlet. In some embodiments, the circuit housing 610 can be separate from the gas chamber 631. Cathode 604 is incorporated into the top of enclosure 600 at the gas inlet 617. The cathode 604 is not charged. A Faraday cage is provided inside the circuit housing 610. The cage at least partially (or fully) surrounds the circuit inside the circuit housing 610 to shield RF coming from the circuit. A removable lid or cover 632 is arranged on a side of enclosure 600 to access the circuit housing 610.

[0082] One or more chamber outlet openings 634 are provided in one or more of the chamber walls. The flexible tubes 602 including a ring anode 608, similar to those shown in the previous figures, are attached to the gas chamber 631 on the side of the enclosure 600 opposite of the circuit housing 610. The flexible tubes 602 may be attached to the gas chamber 631 for example using a one-quarter (0.25) inch NPT connector 605. For example, the connector 605 can have external threads that are threadably mated to the chamber outlet openings 634. Other embodiments may include an outlet opening coupler (similar to the gas inlet 617) formed about the outlet openings 634, and the tube connector 605 can couple with the outlet opening coupler.

[0083] Accordingly, the gas inlet 617 is in flow communication with the gas chamber 630, which is in flow communication with the tubes 602. Thus, gas flows from the gas inlet 617 into the interior space of the gas chamber 630 where it mixes (if needed), and exits as a plasma out of the gas outlets 634 into the tubes 602. The exit end of the tubes 602 eject the plasma, such as through a nozzle. The gas becomes plasma between the ring anode 608 and the cathode housing body 604.

[0084] A high electric field is formed between anode 604 and cathode 608 while a noble gas flows via the gas inlet 617 to generate the cold plasma. The flexible tubes 602 allow flexibility by moving the exit nozzles of the plasma device. The enclosure 600 includes the necessary circuit for the plasma device and the circuit is shielded using a removable shielding 632. The slanting design of the gas chamber 631 enables effective noble gas transfer through the mounting holes for the flexible tubes 602. A transformer-based voltage step up circuit may be used to generate AC discharge voltages above 6 kV to create the cold plasma, and the operation frequency may be in the range of 10-20 kHz with AC wave as an input signal.

[0085] ADJUSTABLE MULTI-PLASMA DEVICE 700 (FIGS. 7A-7E, 8)

[0086] FIGS. 7A-7E illustrate an adjustable multi-plasma device 700 in accordance with one or more embodiments herein. FIG. 7A provides a perspective of an adjustable multi-plasma device 700, and FIGS. 7B-7C show the components of an adjustable multi-plasma device 700 in accordance with embodiments. FIGS. 7D-7E illustrate adjusting the multi -pl asm a jets in the adjustable multi-plasma device 700 in accordance with embodiments. The adjustable device 700 that is configured to move between a first radial configuration (FIG. 7C) and a second axial configuration (FIG. 7D).

[0087] The device 700 includes a frame or support assembly 702 that has a center support rod 710, a base plate 720, a movable adjustment support ring 730, one or more connecting rods 740, and one or more tube assemblies 750. A target specimen 704 (FIGS. 7D, 7E) can be positioned at or on the base plate 720. Or, referring to FIG. 8, the outward-facing surface of the base plate 720 can face the specimen 704 can be positioned at a distance from the specimen 704. A first gas (e g., air) travels through the center support rod 710 to the base plate 720, and a second gas (e.g., inert gas, such as Helium) travels in a tube through or along the tube assemblies 750 to emit a plasmon output 760 from distal ends of the tube, directed toward the specimen 704.

[0088] The support rod 710, adjustment support ring 730, connecting rods 740, and tube assemblies 750 cooperate to move the device 700 between a first radial configuration (FIG. 7D), and an axial configuration (FIG. 7E). In the radial configuration (FIG. 7D), the top of the tube assemblies 750 is substantially coplanar with, or in a parallel plane with, the top planar surface 721 of the base plate 720. In that manner, the plasmon output 760 projects from the outer perimeter of the base plate 720 radially inward across the top surface 721 of the base plate 720 and toward the center of the base plate 720 and slightly above the base plate 720 plane.

[0089] In the axial configuration (FIG. 7E), the top of the tube assemblies extends at an acute angle to the top planar surface 721 of the base plate 720 (in some embodiments from zero degrees (in a parallel plane) to approximately 75 degrees, with respect to the top surface 721 of the base plate 720). Thus, the plasmon output 760 projects outward from the top surface 721 of the base plate 720 at an angle.

[0090] Accordingly, the device provides a full range of motion of the plasmon output 760 to permit all angles and sides of a target 704 to be impacted by the plasmon output 760. In addition, a motor can be provided to rotate the device 700 so that the plasmon output 760 can be rotated with respect to the target 704 to provide even greater coverage.

[0091] The center support rod 710 is elongated and hollow, with a longitudinal axis, center support rod distal end 712 and a center support rod proximal end 714. A first gas (e.g., air) tube has a first tube distal end and a first tube proximal end. The first tube proximal end has a first gas inlet at the proximal end 714 of the support rod 710, and receives a gas hose that communicates gas from a pressurized gas source to the gas inlet. The first gas tube can extend through the center of the support rod 710 and the first tube distal end can couple at the base plate 720 and the air is emitted from one or more openings (here shown as a single opening) in the center of the base plate 720.

[0092] In the embodiment shown, the base plate 720 is a circular thin plate with an outwardfacing surface and an inward-facing surface. The base plate 720 is affixed at the distal end 712 of the support rod 710, and is configured to support the tube assemblies 750 and the connecting rods 740. A central hub 722 is positioned at the middle of the plate 720 and projects out from the inward surface of the plate 720 toward the proximal end 714. The central hub 722 has a center opening that receives and couples to the distal end 712 of the support rod 710, such as by a fastener, adhesive, or being integrally formed. The center opening has the same shape as at least the distal end 712 of the center support rod 710, which is a circle in the embodiment shown. The central hub 722 fixedly couples the base plate 720 to the distal end 712 of the support rod 710, whereby the inward (or proximal) surface of the base plate 720 faces the proximal end 714 of the rod 710 and the outward (or distal surface). In that position, the base plate 720 supports the connecting rods 740 and the tube assemblies 750.

[0093] The base plate 720 has one or more base plate coupling members 724 that are positioned about the inward surface of the plate 720. The base plate coupling members 724 are situated toward the outer edge of the plate 720, and project outward from the inward surface of the plate 720. In the embodiment shown, the coupling member 724 is a pair of thin base plate tabs, each with a base plate coupling opening. The tabs 724 are positioned to extend radially outward from the central hub 722, with the coupling opening being transverse to the outer edge of the plate 720. Each pair of tabs 724 are positioned parallel to each other and separated to form a base plate coupling receiving channel therebetween that receives and rotatably couples with an end of one of the tube assemblies 750.

[0094] The movable adjustment ring 730 is a short sleeve having a central ring through-hole 732 and one or more ring coupling members 734. The adjustment ring 730 has a ring inner surface at the through-hole 732, and a ring outer surface. The adjustment ring through-hole 732 slidably receives the center support rod 710. The adjustment ring through-hole 732 is sized to be slightly larger than the support rod outer surface, so that the adjustment ring 730 can freely slide up and down with respect to the center support rod 710, toward / away from the support rod distal end 712 and toward / away from the support rod proximal end 714. The base plate 720 operates as a stop to prevent the adjustment ring 730 from coming off of the support rod distal end 712. In one embodiment, the adjustment ring 730 can move the entire length of the support rod 710 from the distal end 712 to the proximal end 714; though in other embodiments the adjustment ring 730 can only slide a portion of the support 710 due to restrictions of the connecting rods 740 and / or tube assemblies 750.

[0095] The ring coupling members 734 are formed about the ring outer surface. In the embodiment shown the ring coupling member 734 is a thin ring tab that projects outward from the ring outer surface, and has a ring coupling opening. The tab 734 is positioned to extend along the longitudinal axis of the support rod 710, with the ring coupling opening being transverse with the longitudinal axis of the support rod 710. As best shown in FIG. 7D, the ring outer surface can have flat sides, such as to form a hexagonal or octagonal shape, and a pair of tabs 734 are positioned on opposite flat sides. Each pair of tabs 734 are positioned parallel to each other and separated to form an adjustment coupling receiving channel therebetween that receives and rotatably couples with an end of one of the connecting rods 740 to form one or more first rotatable joints 706 that rotatable couples the adjustment ring 730 and the connecting rod 740.

[0096] The connecting rods 740 are solid elongated rods and can have any suitable shape, such as a flat rectangular shape as best shown in FIG. 7D. The connecting rods 740 form connectors that are cross-support members and have a connecting rod distal end 742 and a connecting rod proximal end 744. The connecting rod distal end 742 has a connecting rod distal end coupling member, and the connecting rod proximal end 744 has a connecting rod proximal end coupling member. The connecting rod distal end coupling member can be a connecting rod distal end through-hole that rotatably couples with a respective tube assembly 750. The connecting rod proximal end coupling member can be a connecting rod proximal end through-hole that rotatably couples the connecting rod proximal end 744 with the adjustment support ring 730. For example, the connecting rod proximal end 744 is received in the adjustment tab channel between the adjustment tabs. A fastener (e.g., nut and bolt or screw or rivet) is then passed through the connecting rod proximal end through-hole and the pair of adjustment tab through-holes 732 to rotatably couple the connecting rod proximal end through-hole with the adjustment tab through- holes 732, to form the first rotatable joint 706.

[0097] The tube assembly 750 includes a tube support beam member 752, a flexible tube 753, a cathode 754, gas inlet 756, and a ring anode 758 (FIG. 7C). The tube support beam 752 is an elongated rigid member with a beam top, beam bottom, beam distal end and a beam proximal end. The beam 752 can have any suitable shape, such as a rectangular shape. A U-shaped channel member 757 is coupled to or formed with the beam 752, and has a channel distal end and a channel proximal end. The channel member 757 has a beam channel base and two beam channel side walls. The channel base is coupled to the beam bottom of the support beam 752, such as by fastener or adhesive or being integrally formed therewith. The two beam channel side walls extend along the longitudinal length of the beam support 752, and outward from the beam channel base and the beam support 752. A beam channel 755 is formed between the two beam channel side walls. In the embodiment best shown in FIG. 7 A, the beam 752 is shorter than the channel member 757. The beam proximal end can substantially align and be flush with the channel member proximal end. The channel distal end extends further than the beam distal end, so that the channel distal end can rotatably couple with the base plate 720 and the channel 757 and beam 752 can rotate with respect to the base plate 720 without obstruction by the tube 753 or the beam 752.

[0098] The support channel distal end has a support channel distal end coupling member 759, and the support channel proximal end has a support channel proximal end coupling member 759. The support channel distal end coupling member 759 can be a support channel distal end through-hole that rotatably couples with the base plate coupling member 724. For example, the support channel distal end is received in the base plate tab channel between the base plate tab members. A fastener (e.g., nut and bolt or screw or rivet) is then passed through the support channel proximal end through-hole 759 and the pair of the base plate tab through-holes to rotatably couple the support channel proximal end through-hole with the base plate tab through- holes, to form one or more second rotatable joints 707 that rotatably couple the base plate 720 with the tube assemblies 750.

[0099] The support channel proximal end coupling member 759 can be a support channel proximal end through-hole that rotatably couples with the connecting rod coupling member 746. For example, the connecting rod distal end is received in the support plate channel 755 between the support plate channel side walls. A fastener (e.g., nut and bolt or screw or rivet) is then passed through the support channel proximal end through-holes and the connecting rod through- hole 746 to rotatably couple the support channel proximal end through-hole with the connecting rod through-hole 746, to form one or more third rotatable joints 708 that rotatably couple the connecting rods 740 and the tube assemblies 750.

[0100] A second flexible gas tube 753 is coupled to the beam top of the support beam 752. The second flexible gas tube 753 can optionally be received through an optional rigid tube housing 751 that is elongated and has a circular cross section. The tube housing 751 is hollow with a central bore that receives a second flexible gas tube 753. The second flexible gas tube 753 has a second tube distal end and a second tube proximal end. A second gas (e.g., an inert gas, noble gas) inlet is provided at the second tube proximal end, and receives a gas hose that communicates gas from a pressurized gas source to the gas inlet. The second tube distal end can be flush with or extend beyond the tube support beam distal end of the tube support beam 752. In the embodiment show, the flexible tube 753 extends outside of the tube housing 751 and the distal end can have a ring cathode and bend to direct the jet plasma, and the proximal tube end extends outside of the tube housing 751 to have a ring anode and mate with a tube from a gas source. In other embodiments, a rigid tube housing 751 is not provided, and instead the flexible tube can be directly mounted to the top surface of the support beam, such as by fasteners or the like. In other embodiments, a flexible tube 753 is not provided, and gas can travel through the rigid tube housing 751 that is integral to the support beam.

[0101] The ring anode 758, as best shown in FIG. 7C, is positioned at or near the exit of the second tube distal end of the second flexible tube 753 from which the plasma exits the tube 753. The second tube proximal end of the tube assembly 750 includes the noble gas inlet 756 and the cathode 754. The tube 753 has a plasmon output 760 that is expelled parallel to the longitudinal axis of the tube support beam 752. The second tube distal end, as well as the tube support beam distal end, are at or near the perimeter of the base plate 720, so that the plasmon output from the second tube 753 extends onto the base plate 720, where the target sample is located.

[0102] Referring to FIGS. 7D-7E, the device 700 can be moved between a radial configuration (FIG. 7D) and an axial configuration (FIG. 7E). In the radial configuration (FIG. 7D), the adjustment support ring 730 is slid as far up on the support rod 710 as possible, which is at a distance from the support bar distal end and the base plate 720, as shown. Further movement is prevented by the connecting rods 740 and the tube assemblies 750. The connecting rods 740 and the tube assemblies 750 can have different lengths or the same lengths. In the radial configuration, the connecting rods 740 and tube assemblies 750 are in an outward position and form an acute angle therebetween at the third rotatable joint 708 and larger angles to be formed at the first and second rotatable joints 706, 707. As the adjustment ring 730 moves outward toward the center support rod proximal end 714, the connecting rods 740 and tube assemblies 750 move inward toward the center support rod 710, which forms an obtuse angle at the third rotatable joint 708 between the connecting rods 740 and the tube assemblies 750 and sharply acute angles at the first and second rotatable joints 706, 707 between the adjustment ring 730 and the connecting rods 740 and between the base plate 720 and the tube assemblies 750, respectively.

[0103] In addition, as the movable ring 730 slides along the center support rod 710, the first rotatable joint 706, second rotatable joint 707, and third rotatable joint 708 rotate and the angle of the tube assemblies 750 and the flexible tubes 753 to change. That changes the angle or position between the tube assemblies 750 and the top planar surface 721 of the base plate 720. As the user pushes the ring 732 upward (toward the center support rod distal end 712), the ring 732 pushes the connecting rods 740 outward, which in turn pushes the tube assembly proximal end upward and the tube assembly distal end downward toward the base plate top surface 721, so that the plasma exit end of the tube 753 points radially inwardly at the base plate top surface 721 and the plasma jet projects radially inward at the base plate to surface 721.

[0104] In addition, that allows the plasma jets 760 to be adjusted between a radial configuration and an axial configuration. More specifically, as shown in FIG. 7C, when the movable ring 730 is closer to the base plate 720, the output plasmon 760 is more radial. As shown in FIG. 7D, when the movable ring 730 is positioned farther from the base plate 720, the output plasma 760 is more axial (i.e., rotates outward with respect to the top surface 721 of the base plate 720). Both the cathode 754 and the anode 758 are fixed to the support beam 752, with the cathode 754 at the distal end of the support beam and the anode 758 at the proximal end of the support beam. Accordingly, the cathode 754 and the anode 758 remain at a fixed position with respect to each other as the support structure 702 is moved between the radial position and the axial position, so that the emitted plasma jet remains constant in the radial position and the axial position. The air out the tube through the base plate opening, mixes with the Helium from the tube 753 of the tube assembly 750, to form cold plasma. The flow through plate can cool the plasma further, especially if we go to high discharge power / voltages, and improves ionization and increases in reactive species.

[0105] It is noted that the connecting rods 740 and tube assemblies 750 are shown as rectangular in shape, with the thickness facing to the center support rod 710 and the width orthogonal to the center support rod 710. In addition, while four sets of connector rods 740 and tube assemblies 750 are shown, more or less sets can be provided. In addition, the center support rod 710, connecting rods 740 and tube assemblies 750 (including the tubes 753, channel 757, and support beam 752) are linear. However, any suitable number, shape and configuration can be utilized, within the spirit and scope of this disclosure.

[0106] A transformer-based voltage step up circuit may be used to generate AC discharge voltages above 6 kV to create the cold plasma. The operation frequency may be in the range of 10-20 kHz with AC wave as an input signal. With the embodiments of FIG. 7, samples, such as a petri dish, may be placed on the base plate 720, and the movable ring may be adjusted to apply the plasma to the sample. The plasma may also be pointed towards a sample such as in the system shown in FIG. 8.

[0107] FIG. 8 illustrates a cold plasma system 700 using an adjustable multi-plasma device in accordance with one or more embodiments. The system 700 includes an anode 758 positioned near the exit of each tube assembly 750. The cathode 754 and anode 108 are coupled to a circuit housing 810 that includes an integrated circuit that includes a voltage source 812, as well as other electronic components, such as timers and voltage regulators (not shown). The integrated circuit in the circuit housing 810 facilitates precise control over the frequency and discharge voltage of the system 700.

[0108] In embodiments, an inert gas 814, such as Helium, and air 874 is introduced into the tube assembly 750 which includes the cathode 754. A high electric field is formed between the anode 758 and the cathode 754 to generate cold plasma 760 from each of the tube assemblies 750. In some embodiments, only air 874 enters the main tube 710, and Helium 814 enters the tubes 753 of the tube assemblies 750. However, in other embodiments, the air 874 and Helium 814 can be premixed before entering the main tube 710 and / or the tube assembly 750. Gas plasma initiates between the cathode 754 and the anode 758.

[0109] Similar to FIG. 7, a movable ring 730 is used to adjust the radial / axial direction of the output plasma 820. Further, the system 700 may include a gas inlet at the support rod 710 that supplies air 874 through the rod 710 and the base plate 720. The supplied air 874 may further help direct the plasma 760 and help control the temperature of the sample to which the plasma 760 is applied. Embodiments may also include an additional plasma jet using the gas inlet rod 710. Such embodiments would include an additional anode / cathode pair and use a ceramic hole to insulate the base plate (similar to previous embodiments). As shown, the air and / or inert gas 874, 814 are directed into the center rod 710 and / or the flexible tubes 753 of the tube assembly 750. The base plate 720 is positioned at a predetermined distance from the target 704, which distance can change as the device 700 moves between the radial and axial configurations, or which distance can remain fixed.

[0110] In some embodiments, Optical Emission Spectroscopy (OES) may be used with a multiplasmajet system for a comprehensive analysis and / or control of an emitted spectra of the plasma. The OES spectra may exhibit significant peaks associated with different reactive oxygen species (ROS) and reactive nitrogen species (RNS). For example, peaks at 297 nm (oxygen, 02), 308.9 nm (hydroxyl radicals, OH), 311.24 nm (nitric oxide, NO), 337.13 nm (nitrogen, N2), 357.69 nm (N2), 375.54 nm (N2), 380.49 nm (N2), 391.44 nm (N2+), 399.84 nm (N2), 405.94 nm (N2), 427.81 nm (N2+), 706.519 nm (helium, He), and 777.194 nm (atomic oxygen, O) may be measured using OES. These emissions can provide a spectroscopic fingerprint of the CAP jet's chemical constituents.

[0111] OES may also be used to measure emissions at different locations relative to the multiple plasma jets and the sample to potentially establish a spatial distribution and / or relative concentration of ROS and RNS present during CAP application. This spatial variation of reactive species concentration may have significant implications for understanding the effectiveness of CAP in various applications, particularly in the context of targeted biological and chemical processes. OES emissions may be instrumental optimizing the reactive species composition for different applications, as well as the voltage applied, frequency used, amount of inert gas used, and gas / air flowrates.

[0112] It is further noted that the device 700 of FIGS. 7, 8 can be operated manually or automatically, such as by a motor. And, connector arms 740 and adjusting ring 730 need not be provided, but instead the direction of the tube assembly 750 can be moved in other suitable manners, such as by a motor. Or tube assemblies are no needed, but the flexible tubes (e.g., FIG> 4) can be moved in an automated or manual fashion. In other embodiments, multiple radially- extending tubes 753 can be provided, and multiple axially-extending tubes 753 can be provided, and selectively operated turn ON or OFF so that a radial jet, axial jet, or both radial and axial jets are used simultaneously.

[0113] In some embodiments, a cold atmospheric plasma (CAP) device generates a plasma for use on a target. The device has a gas tube for conveying an inert gas, said gas tube having a distal end forming a plasma exit arranged at a first direction to the target. A cathode is fixedly coupled to said gas tube a first distance from said distal end. An anode is fixedly coupled to the gas tube at a second distance from the distal end greater than the first distance. And, an apparatus moves the gas tube from a first direction to a second direction. Though the apparatus is shown in the example embodiment as connecting rods 740, tube apparatus 750, and adjustment ring 730, other suitable means can be utilized.

[0114] MULTI-PLASMA DEVICE WITH DISTRIBUTOR 900 (FIG. 9)

[0115] Turning to FIGS. 9A-9F, a multi-plasma assembly 900 is shown having one or more flexible tubes 902 and a single-piece unitary multi -plasma distribution housing 910. The tubes 902 are similar to those shown and described in earlier embodiments (e.g., FIGS. 4-6), and include a ring anode 904 at or near a tube distal end and a connector 906 at a tube proximal end. A plasma jet exits from the tube distal end, which can optionally include a nozzle.

[0116] The multi-plasma distribution housing 910 has a housing proximal end portion, a housing distal end portion 916, and an intermediate portion 914 therebetween. A slightly tapered gas inlet 913 is provided at the proximal end of the distal end portion 916. The intermediate portion 914 includes a tapered cone-shaped neck 912 and a main body 915. The neck 912 is formed at the distal end of the gas inlet 913. The neck 912 tapers outward to the main body 915.

[0117] The main body 915 has a linear exterior wall, and various internal walls that define one or more elongated internal plasma jet tubes 920, including a central jet tube 921 and one or more side jet tubes 923. The internal central jet tube 921 has a circular cross-section that extends from a small distributor opening 934 at the very proximal leading end of a central distributor 934 feature, and widens to the distal end 916 of the housing 910. The central jet tube 921 does not have any blades. As best shown in FIG. 9E, the internal side plasma jet tubes 923 generally have an offset semi-ring or arc cross-section shape, with a curved arc inner wall and a curved arc outer wall, and straight side walls 922. The exit openings 928 of the jet tubes 920 are approximately equal in size to each other. As best shown in FIG. 9F, the side walls 922 of the jet tubes 920 are thin gas distributor blades, or vanes, or partition walls 922 that separate the jet tubes 923 from one another. The jet tubes also have an open tube interior space 924, and a plasma exit opening 928. A blunt body distributor 930 is positioned within the neck 912 and / or main body 915. The distributor 930 has a rounded head shape that is slightly oblong or oval with a leading end facing the housing proximal end, to form an extended U-shape. The distributor blades 922 are positioned within the jet tubes 920. The blades 932 form a divider wall that separates the internal jet tubes 920. The leading portion of the side walls 922 can optionally be angled in a same direction to distribute the gas into the internal jet tube 920 and also mix, circulate, and / or disperse the gas.

[0118] The distributor 930 guides the gas received at the gas inlet 913 into one of the multiple jet tubes 920, and out through the plasma exit 928 at the housing distal end of the housing 910 end portion 916. As further shown, the housing distal end portion 916 can be tapered inward so that the jet tube distal end is tapered to be narrowed and define a more precise plasma jet at the plasma exit 928.

[0119] A flexible tube 902 is coupled to the plasma exit opening 928. For example, the tube connector 906 can have external threads that threadably couple with the plasma jet exit 928. Thus, the gas inlet 913 is in flow communication with the neck 912, which is in flow communication with the main body 915, which is in flow communication with the jet tubes 920, which is in flow communication with the flexible tubes 902. Accordingly, gas from a pressurized gas source enters the gas inlet 913 and continues into the neck interior space of the neck 912. At that point, the gas comes into contact with the distributor 930, which deflects the gas equally into each of the multiple side jet tubes 923, and through the distributor opening 934 into the central tube 921. The gas travels through the jet tubes 920, and exits through the plasma exit 928 into the flexible tubes 902. It continues through the flexible tubes 902 and exits through the plasma tube exit at the distal end of the tube. The gas becomes plasma between the anodes 904 and the cathode housing 910. The neck interior, distributor, and blades help mix the gas and distribute and spread the gas into the multiple jet compartments 920. The device 900 is a cold plasma device. The housing 910 is made of metal and used as a cathode electrode. A high electric field is formed between the ring anode 904 and the cathode housing 910, while the noble gas flows via the gas inlet to generate cold plasma. The flexible tubes 902 are used to achieve flexibility is moving the exit nozzles of the plasma device. The cathode includes the gas inlet, blunt body and blade gas distributor. The body and the blade distributes the incoming noble / Helium into 4 zones that later connects with flex tube assembly via one-quarter (0.25) inch NPT connector. Anode rings 904 are placed at the end of the tube and plasma is generated. A transformer-based voltage step up circuit is used to generate AC discharge voltages above 6kV to create the cold plasma. The operation frequency is in the range of 10-20 kHz with AC wave as an input signal. The target can be placed at the plasma flexible tube exits, or in a petri dish with cells for treatment with MJ-V4.

[0120] CONCLUSION

[0121] It is noted that the housings (and in particular the anodes, cathodes, and grounds) are generally made of a rigid conductive material such as metal, except as noted (such as the insulative layers). In the embodiments shown and described, the plasma is formed in any suitable manner, such as between the anode and the cathode by a high electric field that is formed by the anode and cathode. An electric lead can be connected to the anode and cathode to apply a voltage differential that generates and controls the electric field. It will be appreciated that the location and position of the cathode and anode can be changed depending on the application, within the spirit and scope of the present disclosure. The flexible tubes can be made of insulative material (except for the anode ring, which is conductive). In some embodiments, the distance from the anode to the cathode is from about 2-6cm, and the electric field is 6,000-12,000 AC volts. The diameter of the flexible tubes is approximately 1cm (1 / 4 inch diameter), and 5cm in length. The flexible tubes bend, but do not expand and contract since a change in the length of the flexible tube would change the electric field. In addition, though the embodiments have been shown and described for cold plasma and for disinfection, other suitable uses can be made other than for cold plasma and other than disinfection.

[0122] In addition, while the devices have been shown and described as delivering both an inert gas (that forms a gas plasma) an air (to disperses the jet plasma and increase the density of the gas plasma), it is noted that air need not be delivered and the device need not include components for delivering air.In addition, it is noted that the drawings may illustrate, and the description and claims may use geometric or relational terms, such top, bottom, external, inward, outward, distal, proximal, rectangular, center, central, planar, flat, linear, oblong, curved, circular, etc. These terms are not intended to limit the disclosure and, in general, are used for convenience to facilitate the description based on the examples shown in the figures. In addition, the geometric or relational terms may not be exact. For instance, walls may not be exactly perpendicular or parallel to one another because of, for example, roughness of surfaces, tolerances allowed in manufacturing, etc., but may still be considered to be perpendicular or parallel.

[0123] The description and drawings of the present disclosure provided in the paper should be considered as illustrative only of the principles of the disclosure. The disclosure may be configured in a variety of ways and is not intended to be limited by the preferred embodiments. Numerous applications of the disclosure will readily occur to those skilled in the art. Therefore, it is not desired to limit the disclosure to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the disclosure.

Claims

CLAIMS1 . A Cold Atmospheric Plasma (CAP) device comprising: a gas inlet rod within a movable ring, the movable ring connected to multiple connecting rods each with movable joints; multiple tube assemblies each connected to one of the multiple connecting rods, wherein each tube assembly comprises: a tube having a plasma exit at a distal end of the tube; an anode near the plasma exit of the tube; a gas inlet and a cathode disposed at a proximal end of the tube assembly connected to the connecting rod; wherein sliding the movable ring along the gas inlet rod changes a direction of the plasma exit of the tube.

2. The CAP device of claim 1, further comprising: a base plate attached to an end of the gas inlet rod; and an opening in the base plate for emitting gas from the end of the gas inlet rod.

3. The CAP device of claim 1 or 2, further comprising: a circuit housing comprising an integrated circuit with a voltage source for supplying a voltage to each cathode and anode of the multiple tube assemblies.

4. The CAP device of any one of claim 1-3: wherein said gas inlet rod has an end positioned at a center of the plasma exit of the tube of the multiple tube assemblies; and further comprising a first radial direction in which the plasma exit of the tube is directed radially inward toward the end of the gas inlet rod, and a second axial direction in which the plasma exit of the tube is directly axially outward with respect to the end of the gas inlet rod.

5. The CAP device of any one of claims 1 -4, said multiple tube assemblies each further comprising a support beam, and wherein said tube, said cathode and said anode are each coupled to said support beam.

6. The CAP device of any one of claims 1-5, wherein said multiple tube assemblies and said multiple connecting rods move outward to position the plasma exit of the tube in a radial direction, and move inward to position the plasma exit of the tube in an axial direction.

7. The CAP device of any one of claims 1, 3-6, further comprising: a base plate attached to an end of the gas inlet rod; each of said multiple connecting rods having a first connecting end rotatably coupled to said movable ring, and a second connecting end; each of said multiple tube assemblies having a first tube end rotatably coupled to said second connecting end, and a second tube end coupled to said base plate.

8. A cold atmospheric plasma (CAP) device for generating a plasma for use on a target, the device comprising: a gas tube for conveying an inert gas, said gas tube having a distal end forming a plasma exit arranged at a first direction to the target; a cathode fixedly coupled to said gas tube a first distance from said distal end; an anode fixedly coupled to said gas tube at a second distance from said distal end greater than the first distance; and an apparatus for moving said gas tube from a first direction to a second direction.

9. A Cold Atmospheric Plasma (CAP) device comprising: multiple flexible tubes attached to a hollow chamber, each flexible tube comprising a ring anode positioned at an opposite end of the flexible tube from the chamber.

10. The CAP device of claim 9, further comprising: a conical shaped cathode comprising a gas inlet to the hollow chamber.

11. The CAP device of claim 9 or 10, further comprising: a chamber comprising a door, a base plate, and one or more vents; a gas mix housing inlet attached to the chamber; a Y-shaped gas mixer outside of the chamber operatively attached to the gas mix housing inlet, wherein the gas inlet of the conical shaped cathode is inside the chamber and operatively attached to the gas mix housing inlet.

12. The CAP device of any one of claims 9-11, further comprising: an enclosure comprising the hollow chamber, wherein the enclosure is divided to form the hollow chamber and a circuit housing; a gas inlet on a surface of the enclosure operably connected to the hollow chamber; a cathode incorporated into the surface of the enclosure with the gas inlet; and a removable covering on a side of the enclosure providing access the circuit housing, wherein the multiple flexible tubes are disposed on a side of the enclosure opposite of the circuit housing.

13. The CAP device of claim 9, further comprising an integral housing having a gas input and multiple jet tubes, each jet tube having an exit opening coupled with one of the multiple flexible tubes.

14. The CAP device of claim 13, wherein said housing comprises a cathode.

15. The CAP device of claim 13 or 14, further comprising a distributor inside said housing configured to divert gas into one of the multiple jet tubes.

16. The CAP device of any one of claims 13-15, further comprising a ledge configured to disrupt flow inside the jet tubes.

17. A Cold Atmospheric Plasma (CAP) device comprising: a cylindrical body comprising multiple injectors arrange in a radial direction of the cylindrical body; a gas injector connected to each of the multiple injectors, each gas injector comprising a cathode; and an anode formed on a surface of the cylindrical body, the surface comprising multiple ceramic openings for each of the multiple injectors.

18. The CAP device of claim 17, wherein the cylindrical body is an annulus and the surface of the cylindrical body forming the anode in on an interior surface of the annulus.

19. The CAP device of claim 17 or 18, the device further comprising: a fan oriented to blow parallel to an axis of the cylindrical body and arranged on one end of the cylindrical body; and a ground comprising a honeycomb structure, the ground disposed on the other end of the cylindrical body, wherein plasma exits the device through the honeycomb structure.

20. The CAP device of claim 19, wherein plasma exits the device through the honeycomb structure using an axial electric field formed with the ground.

21. The CAP device of claim 19, wherein the surface of the cylindrical body forming the anode is angled to direct an output of the multiple injectors towards the ground.

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