How APPJ Discharge Modes Define the Technology Landscape
Atmospheric pressure plasma jets sustain a controlled electrical discharge within or immediately downstream of a gas-flow conduit open to the atmosphere, propagating a plasma plume as a “guided streamer” or ionization wave that carries reactive oxygen and nitrogen species (RONS), UV photons, and charged particles to a target—all without requiring a vacuum chamber. The core technical literature identifies three principal discharge modes that underpin the entire field: dielectric barrier discharge (DBD) with coaxial electrode geometry, RF-driven micro-APPJ configurations, and nanosecond-pulsed DC configurations enabling air-based operation.
The DBD coaxial architecture—where a central metal electrode and outer cylindrical electrode are separated by a dielectric layer—is the dominant configuration in the patent record. The dielectric prevents arc transition, enabling stable, homogeneous glow discharge at ambient pressure. Working gases include noble gases (He, Ar) and admixtures with O₂ or N₂. VITO (Flemish Institute for Technological Research, Belgium) holds the most substantive cold APPJ coaxial design patents across Korean and Israeli jurisdictions.
Reactive oxygen and nitrogen species (RONS) are the chemically active components generated by atmospheric plasma jets—including atomic oxygen, ozone, hydroxyl radicals, and nitrogen oxides. RONS are responsible for the antimicrobial, surface-activation, and biological signalling effects that make APPJ technology valuable across biomedical, materials, and environmental applications.
RF-driven micro-APPJ configurations, operating typically at 13.56 MHz, sustain capacitively coupled discharges with excellent optical and diagnostic access. The μAPPJ geometry, extensively characterized at Ruhr University Bochum, produces a helium–oxygen effluent rich in atomic oxygen at concentrations up to 4.7 × 10¹⁵ cm⁻³ and ozone. These designs underpin the COST plasma jet, which functions as a de facto reference standard across European research institutions. A 2022 literature review from “Grigore T. Popa” University of Medicine and Pharmacy Iași frames APPJs as an “eco-friendly alternative to conventional physicochemical methods,” situating the field within a broader sustainability narrative.
The RF-driven micro-atmospheric pressure plasma jet (μAPPJ) geometry, characterized at Ruhr University Bochum, produces a helium–oxygen effluent with atomic oxygen concentrations up to 4.7 × 10¹⁵ cm⁻³ and forms the basis of the COST plasma jet reference standard used across European research institutions.
Three Decades of Innovation: From Thermal Arc to Flexible Cold Plasma
The APPJ patent record spans more than three decades, tracing a clear trajectory from high-power thermal arc devices toward low-temperature, non-thermal cold plasma configurations suited to biological and sensitive-material applications. This evolution reflects both fundamental advances in discharge physics and a broadening of addressable markets.
Pre-2000: Foundational Thermal Arc Era
Early plasma jet patents focused on thermal arc torches for spraying and chemical vapor deposition (CVD). Representative filings include a thermal plasma jet generator by Matsushita Electric Industrial Co. Ltd. (1997, Japan) and a high-power plasma jet generator by Arata Yoshiaki (1995, Japan), both targeting large-area coating deposition using high-current arc architectures. Fujitsu Ltd. filed a multi-nozzle thermal plasma jet generator (1995, Japan) for wide-area CVD film formation.
2004–2012: Emergence of Atmospheric-Pressure Non-Thermal Jets
VITO filed two coaxial DBD atmospheric-pressure plasma jet patents in the Israeli jurisdiction (2011 and 2012), with radially extended dielectric barriers enabling stable glow-mode discharge at ambient pressure. Dow Corning Ireland filed an atmospheric pressure plasma assembly patent in Korea (2004) incorporating substrate transport and atomizer integration for coating. Dalian University of Technology reported a 2D cold atmospheric plasma (CAP) jet array for large-area biomedical surface treatment in 2009—an early signal of multi-jet scaling strategies.
2015–2020: Flexible Sources, Multi-Jet Arrays, and Characterization Maturity
The University of Orléans filed a patent in Japan (2020) covering a method for generating multiple cold plasma jets at atmospheric pressure via secondary plasma multiplication through perforated substrates. Fuji Corporation filed an atmospheric pressure plasma generator (2019, Japan) integrating laser irradiation for plasma position visualization. DIFFER (Dutch Institute for Fundamental Energy Research) published simulation-validated interaction studies of kHz-pulsed APPJs with metallic targets in 2020.
2022–2025: Flexible Architectures, Long-Distance Transfer, and Active Devices
George Washington University published a 2023 review of flexible cold APPJ sources, including morphing arrays and ultra-flexible long tubes. Universidade Estadual Paulista (UNESP, Brazil) filed a patent in 2024 for an APPJ device achieving plasma transfer up to five meters via a conductor wire in a flexible plastic tube. Kobi Platech Co. Ltd. filed an atmospheric pressure plasma device for skin treatment (2022, Japan). Among the most recent filings in the dataset, Di Canto Gennaro’s electronic air plasma propulsion patents were active in the Italian jurisdiction in January and September 2025.
“Among the most recent filings in the dataset, flexible plasma delivery architectures capable of transferring plasma up to five meters via flexible tubing signal a decisive move toward point-of-care and endoscopic medical applications where rigid jet geometries are impractical.”
Where APPJ Technology Is Being Deployed: Six Application Domains
Atmospheric pressure plasma jet technology addresses six distinct application domains in this dataset, ranging from the largest cluster—biomedical and dermatology—to emerging areas including electronic air propulsion. The breadth of addressable markets is a defining characteristic of the field, and each domain carries distinct IP and regulatory dynamics.
Biomedical and Dermatology
The largest application cluster in this dataset. Cold APPJs generate RONS at temperatures safe for living tissue (below 50°C), enabling direct application to skin, wounds, and mucous membranes. The Kobi Platech atmospheric pressure plasma device (2022, Japan) targets skin cosmetic treatment with a dielectric-barrier remote configuration designed to avoid direct electrical stimulation. The UNESP long-distance transfer patent (2024, Brazil) explicitly targets medical and biological use cases. Instituto Tecnologico de Costa Rica (2015) reported a low-cost DBD reactor generating a cold argon plasma plume described as “suitable for use directly in contact with objects and delicate materials, including living tissue.” The University of Antwerp’s 2019 review of COST plasma jet applications covers plasma-liquid chemistry, sterilization, and pharmaceutical applications.
Cold atmospheric pressure plasma jets generate reactive oxygen and nitrogen species (RONS) at temperatures below 50°C, enabling direct application to living tissue for biomedical, wound healing, and cosmetic treatment applications without thermal damage.
Surface Modification and Materials Processing
Industrial surface treatment represents the established commercial backbone of the APPJ market. Korean filings from Changjo Engineering Co. Ltd. (2005, 2007) describe large-area atmospheric pressure plasma generators for substrate surface processing. The atmospheric pressure plasma assembly by Dow Corning Ireland (2004, Korea) integrates atomized liquid coating with plasma treatment for functional coating deposition. According to WIPO data on plasma technology filings, surface treatment and coating remain the highest-volume commercial application segment for atmospheric plasma systems globally.
Energy Harvesting and Storage
National Taiwan University (2015) describes ultrafast APPJ sintering of nanoporous oxide photoanodes and 3D reduced graphene oxide for dye-sensitized solar cells and flow batteries, with a 1-minute treatment improving flow battery energy efficiency. Ruhr-Universität Bochum (2016) reviews low-temperature atmospheric pressure plasma processes for third-generation photovoltaics, including perovskite and quantum dot cells. These results position APPJ as a rapid, low-temperature alternative to conventional thermal sintering in next-generation energy device fabrication.
Explore the full APPJ patent landscape, assignee profiles, and technology clusters in PatSnap Eureka.
Explore APPJ Patents in PatSnap Eureka →Environmental and Exhaust Gas Treatment
Northeast Forestry University (2020) reviewed atmospheric pressure plasma for diesel particulate matter treatment, covering plasma-assisted filter regeneration and simultaneous NOx and particulate removal. This positions APPJ systems as candidates for mobile emission control in automotive aftertreatment—a domain where the absence of vacuum infrastructure is a critical operational advantage. Standards bodies including ISO are actively developing frameworks for plasma-assisted emission control systems.
Ignition and Combustion Enhancement
AVIC Shenyang Engine Design and Research Institute (2013) demonstrated a continuous-plasma-jet igniter for aeroengine combustors, showing reliable altitude ignition performance dependent on inlet pressure and nozzle geometry. Air Force Engineering University (2018) proposed a multichannel discharge jet-enhanced spark ignition mode (MDJS) that increases arc discharge energy by up to 14.7% and penetration depth by 103% at high altitude—a result with direct implications for high-altitude relight capability in military and commercial aviation.
Air Force Engineering University demonstrated in 2018 that a multichannel discharge jet-enhanced spark ignition mode (MDJS) increases arc discharge energy by up to 14.7% and plasma penetration depth by 103% at high altitude compared to conventional spark ignition, with direct implications for aeroengine relight capability.
Electronic Air Plasma Propulsion
Di Canto Gennaro’s active Italian patents filed in January and September 2025 represent an emerging intersection of atmospheric plasma jet physics and air-breathing propulsion concepts, echoing Wuhan University’s microwave air plasma jet propulsion prototype from 2020. This application domain is the least mature in the dataset but carries high strategic interest given the convergence with electric aviation and space propulsion research. Research published through IEEE on plasma actuators and electroaerodynamic thrusters provides adjacent technical context for this emerging cluster.
Geographic and Assignee Patterns in the Global APPJ Patent Record
Japan dominates the patent filing count in this dataset, with active and inactive filings spanning thermal arc generators (Matsushita, Fujitsu, Ishikawajima Harima Heavy Industries), atmospheric pressure plasma generators (Fuji Corporation), plasma jet spark plugs (NGK Spark Plug Co. Ltd.), and cold APPJ mini-torch devices (Nadir S.r.l. via Japanese jurisdiction). Japanese assignees reflect both legacy thermal plasma and contemporary cold plasma activity.
Korea shows a cluster of surface treatment system patents from Choi Dae-Kyu (multiple filings 2005–2006) and Changjo Engineering Co. Ltd. (2005–2007), as well as VITO atmospheric-pressure plasma jet family filings. Korean large electronics—LG Electronics and Samsung Electronics—appear in the dataset but in display panel and CVD contexts rather than jet technology proper.
Europe is strongly represented in the research literature. Ruhr University Bochum (Germany) accounts for the most concentrated body of RF-APPJ diagnostic and simulation work (2007–2011). VITO (Belgium) holds the most substantive cold APPJ coaxial design patents across Korean and Israeli jurisdictions. University of Antwerp (Belgium) leads the COST plasma jet application literature. DIFFER (Netherlands) contributes simulation-experiment interaction studies. Universidade Estadual Paulista (Brazil) represents a notable emerging geography, filing a novel long-distance APPJ patent in 2024.
China contributes substantially through research literature from Huazhong University of Science and Technology (air APPJ, 2022), Dalian University of Technology (2D jet arrays, 2009), and AVIC (aerospace ignition, 2013), though fewer granted patents in this jurisdiction appear in the dataset. The United States appears primarily through research institutions—Ohio State University, George Washington University—in roadmap and review literature, with Fuji Corporation holding an active US design patent (2022) for equipment head geometry.
Innovation in APPJ technology is moderately distributed: no single assignee dominates all application verticals. VITO is the most concentrated patent holder specifically within cold APPJ device architecture; Fuji Corporation leads in commercial atmospheric pressure plasma equipment hardware; research institutions (Ruhr University Bochum, University of Antwerp, DIFFER) lead in fundamental diagnostics and reference standards.
Emerging Directions and Open IP Opportunities (2022–2025)
Five emerging directions are visible from the most recent filings and publications (2022–2025) in this dataset, each carrying distinct implications for R&D investment and IP strategy.
1. Long-Distance and Flexible Plasma Delivery
The 2024 UNESP patent for an APPJ device achieving plasma transfer up to five meters via a conductor wire in flexible plastic tubing signals a decisive move toward point-of-care and endoscopic medical applications where rigid jet geometries are impractical. Among retrieved results, this is the only patent specifically claiming flexible multi-meter plasma transfer, suggesting an open filing opportunity for medical device and robotics companies.
2. Air-Based APPJs Without Noble Gases
Huazhong University of Science and Technology’s 2022 ionization-driven air APPJ demonstrates that noble-gas-free operation in ambient air is achievable by controlling nozzle geometry and nanosecond-pulsed excitation, reducing consumable costs and enabling outdoor deployment. Freedom-to-operate in this architecture is narrowing, and R&D teams targeting cost-sensitive industrial deployments should conduct FTO analysis specifically on nanosecond-pulsed, air-fed jet configurations.
Huazhong University of Science and Technology demonstrated in 2022 that noble-gas-free atmospheric plasma jet operation in ambient air is achievable using nanosecond-pulsed DC excitation and controlled nozzle geometry, enabling lower operating costs and outdoor deployment without helium or argon feed gases.
3. Consumer Skin and Cosmetic Plasma Devices
The Kobi Platech atmospheric pressure plasma device patent (2022, Japan) reflects commercialization pressure from consumer health and aesthetics markets, with a dielectric-barrier remote-injection architecture designed to eliminate electrical stimulation risk. Regulatory strategy—rather than IP alone—will determine commercial velocity in this sector.
4. Electronic Air Plasma Propulsion
Di Canto Gennaro’s active Italian patents (January and September 2025) represent an emerging intersection of atmospheric plasma jet physics and air-breathing propulsion concepts, echoing Wuhan University’s microwave air plasma jet propulsion prototype from 2020. This is an early-stage but strategically significant domain given global interest in electric aviation and low-emission propulsion.
5. Data-Driven Plasma Science and Machine Learning-Coupled Controllers
The 2022 Plasma Roadmap (Ohio State University) explicitly identifies machine learning and data-driven methods as an emerging priority for APPJ process optimization and reactive species prediction. This suggests near-term IP activity in algorithm-coupled plasma controllers. Research published through Nature on machine learning applications in plasma physics provides the scientific underpinning for this emerging IP cluster.
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Monitor APPJ Innovation in PatSnap Eureka →Strategic Implications for R&D and IP Teams
The APPJ technology landscape presents a set of actionable strategic considerations for IP professionals, R&D leaders, and technology investors, derived directly from the patent and literature signals in this dataset.
- Freedom-to-operate in noble-gas-free architectures is narrowing. The Huazhong University air APPJ result and Nadir S.r.l.’s dual-excitation patent together signal that key enabling claims for ambient-air operation are being staked. R&D teams targeting outdoor or cost-sensitive industrial deployments should conduct FTO analysis specifically on nanosecond-pulsed, air-fed jet configurations.
- Long-distance and flexible delivery is an open IP space. Among retrieved results, only the 2024 UNESP patent specifically claims flexible multi-meter plasma transfer. The George Washington University review confirms demand for such architectures in medical applications. This represents a defensible filing opportunity for medical device and robotics companies.
- The COST plasma jet functions as a de facto reference standard. Any entrant to the research or diagnostic instrument market must differentiate against this well-characterized baseline. IP strategy should focus on application-specific performance claims rather than competing on fundamental discharge physics.
- Consumer and cosmetic market entry is accelerating. The Kobi Platech skin treatment device (2022, Japan) and similar designs reflect a path from clinical plasma medicine to consumer wellness. Regulatory strategy will determine commercial velocity in this sector.
- Multi-jet array scaling remains a key unresolved engineering challenge. The 2023 George Washington University review highlights lateral gradient and inter-jet interaction as unresolved problems for large-area uniform treatment. Assignees capable of solving this through hardware or real-time monitoring IP will hold a structural advantage in industrial surface treatment and additive manufacturing applications identified in the 2022 Plasma Roadmap.
“The 2022 Plasma Roadmap identifies data-driven plasma science, additive manufacturing, and electrification of chemical conversions as emerging priorities—signalling that APPJ technology is no longer confined to surface treatment but is entering systems-level integration roles.”
For teams conducting competitive intelligence on APPJ technology, the PatSnap patent analytics platform and PatSnap R&D intelligence tools provide structured access to the full assignee landscape, citation networks, and technology clustering across the global plasma jet patent corpus.