What plasma activated water is and how it works
Plasma activated water is produced when non-thermal atmospheric pressure plasma — generated through electrical discharges — interacts with liquid water, creating a solution enriched with reactive oxygen and nitrogen species (RONS). The resulting liquid contains hydrogen peroxide (H₂O₂), hydroxyl radicals (•OH), nitrite (NO₂⁻), nitrate (NO₃⁻), superoxide anions, and ozone (O₃), each contributing to PAW’s potent antimicrobial and biostimulatory effects.
The foundational mechanism is consistently described across sources: plasma discharge at the gas-liquid interface produces RONS through UV photolysis of water molecules and gas-phase chemistry, which then dissolve into the liquid phase. These changes induce measurable physicochemical transformations — PAW exhibits significantly reduced pH (as low as 2.5–3.0), elevated oxidation-reduction potential (ORP), increased electrical conductivity, and — as recently characterised by Drexel University’s C and J Nyheim Plasma Institute (2023) — reduced surface tension and altered viscosity compared to untreated water.
RONS are the active chemical agents in PAW. They include hydrogen peroxide (H₂O₂), hydroxyl radicals (•OH), nitrite (NO₂⁻), nitrate (NO₃⁻), superoxide anions, and ozone (O₃). Their combined oxidative action is responsible for PAW’s antimicrobial, antiviral, and biostimulatory properties. Concentrations can be tuned by adjusting plasma source type, pulse polarity, and treatment duration — a capability demonstrated using DC-pulse-driven helium plasma jets at Osaka City University.
The technology is gaining momentum as a chemical-free, eco-friendly alternative to conventional disinfectants. According to research published across institutions including the World Health Organization-aligned food safety community and reviewed by bodies such as FAO, chemical-free sanitisation pathways are under increasing scrutiny for food and water applications. PAW sits at the intersection of plasma physics, food science, and environmental engineering — a convergence that explains both the breadth of its application landscape and the distributed nature of its global research base.
Plasma activated water (PAW) exhibits a pH as low as 2.5–3.0, elevated oxidation-reduction potential, increased electrical conductivity, and reduced surface tension compared to untreated water, as a result of reactive oxygen and nitrogen species generated by non-thermal atmospheric pressure plasma discharge.
Four dominant PAW generation technologies compared
PAW generation technology clusters into four distinct approaches, each with different scalability, chemistry control, and application suitability profiles. Dielectric barrier discharge (DBD) reactors are the most widely documented in the research literature; plasma jets and gliding arc systems offer fine chemical tunability; hydrodynamic cavitation plasma jets (HCPJ) address industrial-scale volumetric production; and microwave or radio-frequency systems provide an alternative pathway particularly suited to agricultural deployment.
Dielectric Barrier Discharge (DBD) Reactors
DBD systems apply high-voltage electrical energy across a dielectric material in contact with water or gas above water, producing stable, large-area discharges suitable for scaling. Huazhong University of Science and Technology developed a DBD array capable of treating 1,000 mL of tap water in one hour, reducing pH from 8.10 to 2.54 and achieving greater than 5-log E. coli reduction. The University of Sydney directly compared a dielectric barrier discharge-diffuser (DBDD) reactor to a bubble spark discharge (BSD) reactor, finding the DBDD achieved greater than 6-log CFU bacterial reduction within one minute.
Plasma Jet and Gliding Arc Systems
Plasma jets and gliding arc configurations direct ionised gas streams onto or above a liquid surface, generating PAW through gas-phase RONS transfer. The Instituto Tecnológico de Aeronáutica (Brazil) used a gliding arc plasma system to evaluate PAW antimicrobial activity against S. aureus, E. coli, and C. albicans, demonstrating that stirred (dynamic) conditions produce more chemically uniform PAW (pH 3.53, ORP 215 mV). Osaka City University employed a DC-pulse-driven helium plasma jet to finely tune H₂O₂, NO₂⁻, and NO₃⁻ concentrations through pulse polarity and width variation, establishing a chemical tailoring capability that is directly relevant to application-specific PAW formulation.
Hydrodynamic Cavitation Plasma Jets (HCPJ)
For volumetric production beyond laboratory scale, hydrodynamic cavitation plasma jets have been demonstrated to generate PAW at flow rates of several m³/h. The Czech Academy of Sciences showed complete inactivation of algae and cyanobacteria within 72 hours using HCPJ-generated PAW, underscoring industrial water treatment potential. Technische Universiteit Eindhoven (Netherlands) patented a combined thermal and non-thermal plasma reactor using a water vortex configuration with recirculation, enabling continuous PAW generation — the only active EP-jurisdiction reactor patent identified in this dataset.
Microwave and Radio-Frequency Plasma Systems
Microwave-induced and radio-frequency (RF) plasma systems represent a distinct generation pathway, particularly relevant for agricultural PAW production. Mari State University (Russia, 2022) developed a microwave setup for PAW generation, confirming linear dependence of H₂O₂ and NO₃⁻ concentrations on treatment time — providing reliable quality control markers for agricultural applications. Bung Hatta University (Indonesia, 2020) demonstrated RF plasma at 0.16 MHz for drinking water production from rainwater, extending the technology’s reach to resource-constrained settings.
Explore the full patent landscape for plasma activated water reactor technologies in PatSnap Eureka.
Search PAW Patents in PatSnap Eureka →Application domains: food, agriculture, medicine, and water
PAW’s application landscape spans four primary domains — food safety, agriculture, medicine, and water purification — each at a different stage of maturity and each presenting distinct commercialisation dynamics. Food safety and agricultural applications carry the strongest near-term signals; medical and water treatment applications face higher regulatory and cost barriers but represent larger long-term markets.
Food Safety and Fresh Produce
The dominant commercial application signal in the dataset is food decontamination. PAW has been validated against key foodborne pathogens including L. monocytogenes, E. coli, and Salmonella enterica on fresh produce including fruit, vegetables, and meat. The University of Sydney demonstrated in-situ PAW treatment as a competitive sanitiser for cucurbit fruit. North Carolina State University extended PAW application to seafood safety through plasma-activated simulated seawater (PASW) for oyster depuration, with documented reductions in total coliform and E. coli in live oysters during static depuration. Multiple reviews confirm PAW’s ability to extend shelf life without thermal damage — a critical differentiator from heat-based decontamination methods.
Plasma activated water has been validated against foodborne pathogens including L. monocytogenes, E. coli, and Salmonella enterica on fresh produce including fruit, vegetables, and meat, and extends shelf life without thermal damage, according to multiple peer-reviewed studies including research from the University of Sydney (2023) and the University of Brasilia (2022).
Agriculture and Plant Science
PAW is documented as a biostimulant for seed germination, root growth, and disease resistance. Russian institutions are particularly active in this domain: the Federal Scientific Agroengineering Center VIM (2023) deployed portable PAW generators for spruce and strawberry stimulation, and Mari State University (2022) confirmed PAW efficacy for cotton, wheat, and strawberry cultivation. The Institute of High Current Electronics SB RAS (2019) identified optimal energy input modes for PAW production in agricultural contexts. Polish institutions — Warsaw University of Life Sciences and Krakow University of Agriculture — also contributed systematic reviews of PAW’s properties in the context of microbial and plant science applications (both 2022).
“The finding that PAW retains 6-log bactericidal activity after 18 months at ultra-low temperatures opens a distinct product category: pre-made, storable PAW formulations for distribution to end users in agriculture, healthcare, and food processing — analogous to liquid disinfectant markets, but without regulatory residue concerns.”
Medical and Dental Applications
PAW and plasma-activated liquids (PAL) are emerging in oncology, wound care, dentistry, and targeted infection control. Xi’an Jiaotong University (China, 2021) demonstrated PAW’s ability to inactivate the SARS-CoV-2 spike protein via receptor-binding domain (RBD) modification. Korean researchers designed a plasma-activated water vaginal cleaning device for bacterial vaginosis treatment (2020). Code Steri Co., Ltd. (Korea) holds an active KR patent for a dual-type plasma steriliser platform for rooms and medical instruments using RONS-enhanced disinfectant solutions (2021). Dental applications reviewed by UNESP (Brazil, 2022) confirmed PAW utility for oral biofilm control, root canal disinfection, and whitening — all areas where chemical-free alternatives face strong clinical demand, as noted in research published by institutions affiliated with Nature‘s biomedical portfolio.
Water Purification and Wastewater Treatment
Industrial-scale water treatment applications include peat water purification (Indonesia Water Institute), treatment of contaminated rainwater, and retrofitting chlorination plants with plasma technology. The University of Pretoria (South Africa, 2023) conducted a cost-benefit analysis of plasma versus chlorination and ozonation for tertiary wastewater treatment, concluding that retrofitting is feasible but energy optimisation is critical. Cold plasma was also applied to SARS-CoV-2 inactivation in wastewater streams (G. B. Pant University, India, 2021). An Iranian patent filing for a plasma desalination system (IR, 2022) represents an early signal that PAW-adjacent plasma technologies may be explored for water scarcity applications, a domain of increasing concern according to UN Water.
Innovation timeline: from lab concept to commercial signals
The PAW field exhibits a clear three-phase trajectory across the publication dataset spanning 2009 to 2025, moving from foundational mechanistic research through application diversification to early commercialisation signals. Understanding this arc is essential for positioning IP strategy relative to the technology’s maturity curve.
Early Conceptual Stage (pre-2016): Foundational research established the basic mechanisms of plasma-liquid interaction, antimicrobial efficacy, and initial reactor concepts. Work from Loughborough University as early as 2009 identified plasma-liquid systems as an emerging biomedical tool. By 2015, prototype industrial reactor designs for wastewater purification were being proposed by Instituto Tecnológico de Costa Rica. The University of Liverpool demonstrated a solar-powered portable plasma device for microbial decontamination in 2016.
Development and Diversification Stage (2017–2021): The period 2019–2021 marks a sharp expansion in application diversity. Foundational stability studies demonstrating PAW’s bactericidal properties over 18 months of storage were published by Technological University Dublin (2020). The Czech Academy of Sciences demonstrated mass-production feasibility using hydrodynamic cavitation plasma jets (2020). Technische Universiteit Eindhoven filed the key active reactor patent in the EP jurisdiction (2021).
Application Scaling Stage (2022–present): The most recent filings (2022–2024) reflect commercialisation signals: Korean steriliser platforms for medical devices (2021), cold plasma applicators by ColdPlasmaTech GmbH (JP, 2024), and agricultural PAW technology deployed for crop stimulation (Russia, 2023). The dataset includes a pending BR patent by Velico Medical (2025) and an active IR plasma desalination patent (2022), indicating expanding geographic reach.
The majority of PAW innovation documentation in this dataset takes the form of peer-reviewed literature rather than granted patents, suggesting the field remains in a pre-commercial IP consolidation phase — particularly outside of reactor hardware and medical device applications. Active granted patents are sparse: one EP (Technische Universiteit Eindhoven, reactor system, 2021), one KR (Code Steri Co., Ltd., medical steriliser, 2021), and one JP (ColdPlasmaTech GmbH, plasma applicator, 2024).
Active granted patents for plasma activated water generation reactors are sparse across global jurisdictions as of 2025. The most significant active reactor patent in this dataset is held by Technische Universiteit Eindhoven in the EP jurisdiction (2021), covering a combined thermal and non-thermal plasma reactor with a water vortex configuration. This suggests significant freedom to operate for teams developing novel PAW reactor configurations.
Five emerging directions shaping PAW’s next phase
Based on the most recent filings and publications (2022–2025) in this dataset, five directional signals define where PAW innovation is heading. These are not speculative projections — each is grounded in documented research activity or active patent filings.
1. In-Situ and Portable PAW Generation
The shift from centralised laboratory PAW production toward portable, on-demand systems is accelerating. RMIT University (2022) demonstrated a nanoscale zinc oxide nanorod-based device combining plasma generation and aerosol dispensing in a single miniaturised unit. The Federal Scientific Agroengineering Center VIM (2023) deployed portable glow discharge generators for field agricultural use. ColdPlasmaTech GmbH filed a cold plasma applicator patent in Japan (2024, active), targeting surface treatment applications.
2. PAW Stability Enhancement and Storage Optimisation
Long-term storage viability is emerging as a commercial enabler. Technological University Dublin demonstrated 6-log bacterial reduction after 18 months of PAW storage at −150°C. Russian researchers at the Federal Scientific Agroengineering Center VIM (2023) explored polyvinylpyrrolidone (PVP) polymer additives to extend PAW shelf life for agricultural use. These findings open a distinct product category: pre-made, storable PAW formulations analogous to liquid disinfectant markets, but without regulatory residue concerns.
3. Antiviral Applications
Post-COVID-19, PAW’s antiviral capability has attracted new research investment. Xi’an Jiaotong University (2021) showed PAW inactivates the SARS-CoV-2 receptor-binding domain, establishing a mechanistic basis for broader antiviral claims. This aligns with the growing interest in non-chemical disinfection documented by WHO infection prevention guidelines.
4. Physicochemical Property Engineering
Drexel University (C and J Nyheim Plasma Institute, 2023) published the first systematic characterisation of PAW’s physical properties — surface tension reduction, viscosity changes, and contact angle modification — unlocking new application domains in heat transfer, surface wetting, and nucleate boiling enhancement. This represents a significant conceptual expansion: PAW is no longer defined solely by its antimicrobial chemistry but by its full suite of altered physical properties.
5. Plasma Desalination
An Iranian patent filing for a plasma desalination system (IR, 2022) represents an early, speculative signal that PAW-adjacent plasma technologies may be explored for water scarcity applications beyond conventional treatment. While this remains a nascent signal within this dataset, the convergence of plasma technology and desalination aligns with the water security priorities identified by international bodies including UN Water.
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Monitor PAW Innovation in PatSnap Eureka →Strategic implications for IP teams and R&D leaders
The PAW technology landscape presents several actionable strategic opportunities, each grounded in the specific gaps and signals identified across patent and literature records in this dataset. IP strategists and R&D leaders should consider the following implications when allocating resources and planning filing strategies.
IP White Space in Reactor Hardware
Within this dataset, active granted patents for PAW generation reactors are sparse — notably the Technische Universiteit Eindhoven EP patent. R&D teams designing novel DBD configurations, hydrodynamic cavitation systems, or integrated portable generators may find significant freedom to operate and file defensible IP, particularly in EP, US, and CN jurisdictions. The gap between published research and granted patents is the clearest signal of pre-consolidation opportunity in this field.
Agricultural Scale-Up is Near-Term
With multiple independent research groups across Russia, Brazil, and Australia validating PAW’s seed germination and crop protection benefits, and with portable generator technology emerging, agricultural PAW represents the most proximate commercialisation pathway outside of food safety. IP strategists should monitor the intersection of PAW chemistry formulation and precision agriculture delivery systems — a combination not yet covered by active patents in this dataset.
Antiviral and Medical Device Convergence
The demonstrated efficacy of PAW against the SARS-CoV-2 spike protein, combined with active commercial steriliser patents in Korea and Germany, signals a convergence between PAW and the medical device and infection control market. Regulatory classification of PAW-generating devices will be a critical gating factor — a dynamic familiar to teams navigating FDA and CE marking pathways for novel disinfection technologies.
Energy Efficiency is the Primary Scaling Barrier
The University of Pretoria’s 2023 cost analysis flagged plasma’s high operating costs as the primary obstacle to industrial water treatment deployment. Innovations combining PAW with renewable energy sources — as demonstrated by solar-powered plasma devices from the University of Liverpool — are strategically relevant for both cost reduction and sustainability credentials. This is particularly relevant as energy cost benchmarking becomes a standard component of environmental, social, and governance (ESG) assessments across industrial sectors.
The University of Pretoria’s 2023 cost-benefit analysis of plasma versus chlorination and ozonation for tertiary wastewater treatment concluded that retrofitting existing plants with plasma technology is feasible, but that energy optimisation is critical — identifying high operating costs as the primary obstacle to industrial-scale plasma activated water deployment.