Marius Blajan

An endoscope fitted with dielectric barrier discharge‐generated microplasma was investigated for blood coagulation. Microplasma is a type of nonthermal plasma generated at atmospheric pressure that was used in plasma medicine applications. Dog blood samples were subjected to endoscopic microplasma treatment. Microplasma electrodes placed at the side and front part of the endoscope produced a coagulation effect, which increased with the increase of discharge voltage and treatment time. Microplasma was generated in environmental air using a negative pulse voltage Marx generator. The coagulation effect was quantified by analyzing the images taken before and after the microplasma treatment, and it could be attributed to reactive oxygen and nitrogen species. The thermal effect on the blood sample did not contribute to the coagulation process, as shown by the thermal images before and after microplasma treatments. The measured emission spectra confirmed the generation of reactive species in the microplasma. These species are likely involved in the observed coagulation effect.

Plasma medicine is a field of research that focuses on the sterilization of bacteria, wounds and cancer treatment, tissue regeneration and other biomedical applications using plasma. Dielectric barrier discharge microplasma was used for biomedical applications such as sterilization of bacteria and skin treatment for transdermal drug delivery. In this study, we investigated the feasibility of using microplasma for improving blood coagulation parameters. Blood samples collected from one dog and one cat were treated with microplasma, and the blood coagulation effect of this treatment was compared with the effect achieved by treating the blood with air flow only. The microplasma electrodes were energized using a negative pulse voltage power supply and environmental air was used as discharge gas. The microplasma treatment produced clear coagulation effects that increased proportionally with treatment time, discharge voltage and frequency. In contrast, the treatment with air flow only had no coagulation effects after the same treatment time as for the microplasma treatment. The observed blood coagulation effects induced by microplasma treatment could be attributed to the reactive oxygen and nitrogen species generated by microplasma. The blood sample subjected to microplasma treatment had a slight temperature increase (≈4 °C) confirming the nonthermal operation. In conclusion, this study shows promising results that suggest the potential of using microplasma treatment as a tool for improving blood coagulation parameters. Furthermore, microplasma’s suitability for portability and integration indicates the potential for developing a compact microplasma device tailored for use by first responders in cases of bleeding.

Plasma medicine is a field of research that focuses on the sterilization of bacteria, wounds and cancer treatment, tissue regeneration and other biomedical applications using plasma. Dielectric barrier discharge microplasma was used for biomedical applications such as sterilization of bacteria and skin treatment for transdermal drug delivery. In this research we have investigated the feasibility of microplasma use for blood coagulation. Blood from a dog and a cat was treated with microplasma and after the treatment the blood coagulation effect was observed. By comparison, the blood treated only with air flow did not coagulate after the same treatment time as for microplasma treatment. Microplasma electrodes were energized using a negative pulse voltage power supply and environmental air was used as discharge gas. An increase in the blood coagulation effect was observed with the increase of treatment time, discharge voltage and frequency. The blood coagulation process is attributed to the reactive oxygen and nitrogen species generated by microplasma. This research showed promising results that suggest the potential of using microplasma treatment as a tool for blood coagulation. Furthermore, the microplasma's suitability for portability and integration indicates the potential for developing a compact device tailored for use by first responders.

Dielectric-barrier-discharge microplasma has various applications such as flow control, surface treatment, air treatment, or biomedical applications. Microplasma was used for the inactivation of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Bacterial strains spread on Petri dishes containing Nutrient Agar were treated with microplasma and, after incubation, inhibition zones were observed. By comparison, the experiments carried out with the already-grown bacteria on the Petri dish did not show any inhibitory response. Environmental air was used as discharge gas. The reactive oxygen and nitrogen species mainly carry out the inactivation process. A negative pulse voltage energized the microplasma electrodes. The microplasma treatment was the most potent against S. aureus, followed by E. coli, and P. aeruginosa, which was the least susceptible bacteria from the tested strains. An increase in the inhibitory efficiency was observed with the increase in discharge voltage from −1.5 kV to −1.7 kV. This research proved the efficiency of microplasma in biological decontamination and provides valuable insights of the inactivation of bacteria carried out with a technology that is suitable for easy integration and portability.

Dielectric barrier discharge microplasma has various applications such as flow control, surface treatment, air treatment or biomedical applications. Microplasma was used for the inactivation of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Bacterial strains spread on Petri dishes containing Nutrient Agar were treated with microplasma and after incubation, inhibition zones were observed. By comparison, the experiments carried out with the already-grown bacteria on the Petri dish did not show any inhibitory response. Environmental air was used as discharge gas. The reactive oxygen and nitrogen species mainly carry out the inactivation process. A negative pulse voltage energized the microplasma electrodes. The microplasma treatment was the most potent against S. aureus, followed by E. coli, and P. aeruginosa, which was the least susceptible bacteria from the tested strains. An increase in the inhibitory efficiency was observed with the increase of discharge voltage from -1.5 kV to -1.7 kV. This research proved the efficiency of microplasma in biological decontamination and provides valuable insights of the inactivation of bacteria carried out with a technology that is suitable for easy integration and portability.

Dielectric barrier discharge microplasma has various industry applications such as surface treatment, NOx removal, flow control ore biomedical applications. Transdermal drug delivery procedure could be enhanced by microplasma. Along with this procedure skin treatment in order to remove harmful bacteria is necessary. One of these harmful bacteria which lives on human skin is Staphylococcus Aureus. Microplasma was used for the sterilization of Staphylococcus Aureus. Argon, oxygen and air were used as discharge gases. The sterilization process is mainly carried out by the reactive oxygen species. Thus the highest sterilization rates were obtained by using as discharge gas air or a mixture of argon and oxygen. The applied voltages were sine wave and pulse. In the case of sine wave the ozone generation is higher thus a pulse powered microplasma discharge is preferred.

Gaseous sulfur compounds are emitted from many facilities, such as wastewater facilities or biomass power plants, due to the decay of organic compounds. Gaseous dimethyl sulfide removal by ozone catalytic oxidation was investigated in this study. A Vacuum-Ultra-Violet (VUV) xenon excimer lamp of 172 nm was used for ozone generation without NOx generation, and activated carbon impregnated with iodic acid and H₂SO₄ was utilized as a catalyst. Performance assessment of dimethyl sulfide removal ability was carried out by a dynamic adsorption experiment. Empty-Bed-Contact-Time (EBCT), superficial velocity, concentration of dimethyl sulfide, temperature and humidity were set at 0.48 s, 0.15 m/s, 3.0 ppm, 25 °C and 45%, respectively. Without ozone addition, the adsorption capacity of impregnated activated carbon was 0.01 kg/kg. When ozone of 7.5 ppm was added, the adsorption capacity of impregnated activated carbon was increased to 0.15 kg/kg. Methane sulfonic acid, a reaction product of dimethyl sulfide and ozone, was detected from the activated carbon. The results suggest that the VUV and activated carbon impregnated with iodic acid and H₂SO₄ are workable for ozone catalytic oxidation for gas treatments.

The direct and indirect bactericidal effects of dielectric barrier discharge (DBD) cold atmospheric-pressure microplasma in an air and plasma jet generated in an argon-oxygen gas mixture was investigated on Staphylococcus aureus and Cutibacterium acnes. An AC power supply was used to generate plasma at relatively low discharge voltages (0.9–2.4 kV) and frequency (27–30 kHz). Cultured bacteria were cultivated at a serial dilution of 10⁻⁵, then exposed to direct microplasma treatment and indirect treatment through plasma-activated water (PAW). The obtained results revealed that these methods of bacterial inactivation showed a 2 and 1 log reduction in the number of survived CFU/mL with direct treatment being the most effective means of treatment at just 3 min using air. UV–Vis spectroscopy confirmed that an increase in treatment time at 1.2% O₂, 98.8% Ar caused a decrease in O₂ concentration in the water as well as a decrease in absorbance of the peaks at 210 nm, which are attributed NO₂⁻ and NO₃⁻ concentration in the water, termed denitratification and denitritification in the treated water, respectively.

Dielectric barrier discharge microplasma is a nonthermal plasma discharge at atmospheric pressure which due to the micrometer size dielectric layer between the grounded and high-voltage energized electrodes enables to drive the device at less than 1 kV. Microplasma is an economical and ecological alternative for conventional technologies used for NOx removal, indoor air cleaning, surface treatment of polymers, biomedical applications such as transdermal drug delivery, or as an actuator. In this chapter, microplasma applications such as indoor air purification, skin treatment for drug delivery, particle removal, and flow control are presented.