Contrasting characteristics of pulsed and sinusoidal cold atmospheric plasma jets

Walsh, James L.; Shi, Jianjun; Kong, Michael G.

doi:10.1063/1.2198100

Cited by 284 publications

(186 citation statements)

References 16 publications

Supporting

Mentioning

170

Contrasting

Unclassified

Order By: Relevance

“…Details of the plasma jet have been given elsewhere. 17,18 For this study, the APGD jet was energized with a sinusoidal voltage source with a peak voltage of 4-8 kV and an excitation frequency of 30-45 kHz. Helium ͑99.9999%͒ was used as the working gas with its flow rate fixed at 5 slm, either alone or mixed with oxygen gas of varying flow rates.…”

Section: Methodsmentioning

confidence: 99%

Protein destruction by a helium atmospheric pressure glow discharge: Capability and mechanisms

Deng

Shi

Kong

2007

Journal of Applied Physics

Self Cite

173

108

View full text Add to dashboard Cite

Citation: DENG X.T., SHI, J.J. and KONG, M.G., 2007. Protein destruction by a helium atmospheric pressure glow discharge: capability and mechanisms.Journal of Applied Physics, 101 (7), article 074701, pp.1-9.Additional Information:• Biological sterilization represents one of the most exciting applications of atmospheric pressure glow discharges ͑APGD͒. Despite the fact that surgical instruments are contaminated by both microorganisms and proteinaceous matters, sterilization effects of APGD have so far been studied almost exclusively for microbial inactivation. This work presents the results of a detailed investigation of the capability of a helium-oxygen APGD to inactivate proteins deposited on stainless-steel surfaces. Using a laser-induced fluorescence technique for surface protein measurement, a maximum protein reduction of 4.5 logs is achieved by varying the amount of the oxygen admixture into the background helium gas. This corresponds to a minimum surface protein of 0.36 femtomole/ mm 2 . It is found that plasma reduction of surface-borne protein is through protein destruction and degradation, and that its typically biphasic reduction kinetics is influenced largely by the thickness profile of the surface protein. Also presented is a complementary study of possible APGD protein inactivation mechanisms. By interplaying the protein inactivation kinetics with optical emission spectroscopy, it is shown that the main protein-destructing agents are excited atomic oxygen ͑via the 777 and 844 nm emission channels͒ and excited nitride oxide ͑via the 226, 236, and 246 nm emission channels͒. It is also demonstrated that the most effective protein reduction is achieved possibly through a synergistic effect between atomic oxygen and nitride oxide. This study is a useful step toward a full confirmation of the efficacy of APGD as a sterilization technology for surgical instruments contaminated by prion proteins.

show abstract

Section: Methodsmentioning

confidence: 99%

Protein destruction by a helium atmospheric pressure glow discharge: Capability and mechanisms

Deng

Shi

Kong

2007

Journal of Applied Physics

Self Cite

173

108

View full text Add to dashboard Cite

show abstract

“…The electrical efficiency of pulsed atmospheric DBD is significantly higher than their conventional sinusoidal counterparts, partly due to the long plasma-off period that reduces power consumption 8,10,11 and partly due to larger electron temperature ͑discussed below͒. The averaged power is about 0.27 W, lower than that in sinusoidally excited DBD in atmospheric air.…”

mentioning

confidence: 99%

“…8 Recently, the use of submicrosecond voltage pulses has been shown to control effectively the GAT transition. [9][10][11][12] These submicrosecond pulsed atmospheric plasmas are glow discharges generated uniformly between two large parallel-plate electrodes and are different from pulsed corona discharges that are ineffective for large-scale surface treatment. 13 In this study, we report a 10 ns pulsed atmospheric air plasma and its uniform treatment of polypropylene films.…”

mentioning

confidence: 99%

10 ns pulsed atmospheric air plasma for uniform treatment of polymeric surfaces

Walsh

Kong

2007

Applied Physics Letters

Self Cite

174

View full text Add to dashboard Cite

This letter reports an experimental study of a 10ns pulsed dielectric barrier discharge in atmospheric air, excited with a train of 65ns voltage pulses at a repetition frequency of 5kHz. It is shown that these ultrashort pulses produce a homogenous discharge with very high electron density in excess of 1013cm−3 and low gas temperature, which are particularly desirable for uniform treatment of thermally sensitive polymer films. Their treatment of polypropylene films is found to introduce microscale surface patterns as well as various carbon-oxygen bonds, both useful for improving the hydrophilic properties of polymeric materials.

show abstract

“…A typical plasma jet consists of a capillary formed from a dielectric material through which a noble gas flows. A metallic electrode, excited using kHz sinusoidal or short duration high-voltage pulses [9,10], ionizes the flowing gas, resulting in a luminous plume that typically extends for several centimeters. A key advantage of the DBD jet configuration is that the reactive species generated in the capillary are effectively transported to a downstream sample where they are able to interact without compromising the stability of the device [11,12].…”

Section: Introductionmentioning

confidence: 99%

Chaos in atmospheric-pressure plasma jets

Walsh¹,

Iza²,

Janson³

et al. 2012

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

Abstract:We report detailed characterization of a low-temperature atmosphericpressure plasma jet that exhibits regimes of periodic, quasi-periodic and chaotic behaviors. Power spectra, phase portraits, stroboscopic section and bifurcation diagram of the discharge current combine to comprehensively demonstrate the existence of chaos, and this evidence is strengthened with a nonlinear dynamics analysis using two control parameters that maps out periodic, period-multiplication, and chaotic regimes over a wide range of the input voltage and gas flow rate. In addition, optical emission signatures of excited plasma species are used as the second and independent observable to demonstrate the presence of chaos and period-doubling in both the concentrations and composition of plasma species, suggesting a similar array of periodic, quasi-periodic and chaotic regimes in plasma chemistry. The presence of quasi-periodic and chaotic regimes in structurally unbounded low-temperature atmospheric plasmas not only is important as a fundamental scientific topic but also has interesting implications for their numerous applications. Chaos may be undesirable for industrial applications where cycle-tocycle reproducibility is important, yet for treatment of cell-containing materials including living tissues it may offer a novel route to combat some of the major challenges in medicine such as drug resistance. Chaos in low-temperature atmospheric plasmas and its effective control are likely to open up new vistas for medical technologies.2

show abstract

Contrasting characteristics of pulsed and sinusoidal cold atmospheric plasma jets

Cited by 284 publications

References 16 publications

Protein destruction by a helium atmospheric pressure glow discharge: Capability and mechanisms

Protein destruction by a helium atmospheric pressure glow discharge: Capability and mechanisms

10 ns pulsed atmospheric air plasma for uniform treatment of polymeric surfaces

Chaos in atmospheric-pressure plasma jets

Contact Info

Product

Resources

About