Characteristics of 2.45 GHz Surface-Wave-Sustained Argon Discharge for Bio-Medical Applications

Abstract

Cold atmospheric plasma (CAP) applications in various fields, such as biology, medicine and agriculture, have significantly grown during recent years. Many new types of plasma sources operating at atmospheric pressure in open air were developed. In order to use such plasmas for the treatment of biological systems, plasma properties should fulfil strong requirements. One of the most important is the prevention from heating damage. That is why in many cases, the post-discharge region is used for treatment, but the short living particles in the active discharge zone and reactions with them are missed in that case. We use the active region of surface-wave-sustained argon plasma for biological systems treatment. The previous investigations showed good bactericidal, virucidal, seeds germination and decontamination effects at a short treatment time, but the discharge conditions for bio-medical applications need specific adjustment. A detailed theoretical and experimental investigation of the plasma characteristics and their possible optimization in order to meet the requirements for bio-medical applications are presented in this paper. The length of the plasma torch, the temperature at the treatment sample position and the microwave radiation there are estimated and optimized by the appropriate choice of discharge tube size, argon flow rate and microwave power.

Effect of Cold Plasma on the Germination and Seedling Growth of Durum Wheat Genotypes

“…When the discharge tube is shortly outside the surfatron, the electromagnetic wave continues traveling along the plasma-air interface, producing the plasma torch in the open space in this way (Figure 1). Usually, the plasma gas temperature T g of the torch is above 100 • C and depending on the electromagnetic wave power can reach 5000 • C. At low wave power (12 W in our case) and appropriate discharge conditions, the temperature of the plasma is below 40 • C [25], and at such conditions the microwave torch can be used as a CAP source. The treated samples are inside the active plasma-sustaining region in the plasma torch but not in an afterglow region.…”

The Effect of Low-Temperature Microwave Plasma on Wound Regeneration in Diabetic Rats

“…This makes it valuable in applications where accurate temperature measurements are critical. Determination of the treated area's temperature and monitoring it during the in vivo treatments was performed with a Testo 865 infrared camera (produced by Testo SE & Co. KGaA, Titisee-Neustadt, Germany) as investigated in [27]. We measured the reflected radiation from a tilted 45-degree mica plate.…”

A Simple and Stable Atmospheric Pressure Electrodeless Water Vapor Microwave Plasma Torch

“…One of the problems is that the strong chemical reaction between the active atoms produced by microwave plasma and the surface of the metal electrodes will lead to electrode corrosion, which will limit the service life of plasma devices [18,19]. Therefore, many studies have proposed electrodeless discharge devices to overcome the problem of electrode poisoning caused by electrode discharge [20], such as surface-wave-sustained discharges [21][22][23], microwave plasma jets [24], plasma guns [25], etc. However, when we apply liquid water to these devices, many additional devices are often added to generate water vapor plasma, such as heating and evaporation equipment or vacuum sealing device.…”