• Current Applied Physics
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• v.18 no.11
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• pp.1375-1380
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• 2018

Atmospheric-pressure plasma has a great potential in many applications due to its simplicity rather than low pressure plasmas. In material processing, biomedical applications, and many other applications, the input power, gas flow rate, and the geometry of electrode have been mainly considered and studied as important external parameters of atmospheric-pressure plasma control. Besides, since the atmospheric-pressure plasmas are typically generated in an open air, the relative humidity is difficult to control and can change day by day. Therefore, the relative humidity cannot be ignored for plasmas. Thus, in this work, the atmospheric-pressure plasma jet was characterized by changing relative humidity, and it was found that the increase in electron density and OH radicals are due to Penning ionization between helium metastable and water vapors at higher humidity condition.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.357-357
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• 2012

The doping process of the solar cell has been used by furnace or laser. But these equipment are so expensive as well as those need high maintenance costs and production costs. The atmospheric pressure plasma doping process can enable to the cost reduction. Moreover the atmospheric pressure plasma can do the selective doping, this means is that the atmospheric pressure plasma regulates the junction depth and doping concentration. In this study, we analysis the atmospheric pressure plasma doping compared to the conventional furnace doping. the single crystal silicon wafer doped with dopant forms a P-N junction by using the atmospheric pressure plasma. We use a P type wafer and it is doped by controlling the plasma process time and concentration of dopant and plasma intensity. We measure the wafer's doping concentration and depth by using Secondary Ion Mass Spectrometry (SIMS), and we use the Hall measurement because of investigating the carrier concentration and sheet resistance. We also analysis the composed element of the surface structure by using X-ray photoelectron spectroscopy (XPS), and we confirm the structure of the doped section by using Scanning electron microscope (SEM), we also generally grasp the carrier life time through using microwave detected photoconductive decay (u-PCD). As the result of experiment, we confirm that the electrical character of the atmospheric pressure plasma doping is similar with the electrical character of the conventional furnace doping.

• The Journal of the Korean dental association
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• v.52 no.12
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• pp.783-794
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• 2014

Since the introduction of non-thermal atmospheric pressure plasma in the field of the dentistry, numerous applications have been investigated. Especially with its advantages over existing vacuum plasma in terms of portability, low cost, and non-thermal damage, it can be directly applied in the oral cavity, giving number of potentials for dental application. First, possible application of non-thermal atmospheric pressure plasma in the field of dentistry is relation to dental caries and periodontal diseases. Teeth and alveolar bones are one of the strongest bony structures in our body, but it cannot be regenerated when they are damaged by dental caries or periodontal disease. Hence many studies to prevent such diseases have been carried out, though no perfect solution has been found yet. With recent studies of modifying surfaces through non-thermal atmospheric pressure application that can prevent attachment of bacteria, or studies on bactericidal effects of non-thermal atmospheric pressure plasma can be applied here to prevent oral pathogen and 'biofilm' attachment to the surface of teeth or directly eliminate the dental caries/periodontal disease causing germs. Secondly, non-thermal atmospheric pressure application will be useful on the surface of dental implant. It is well known that the success of dental implant surgery depends on the process known as 'osseointegration' that result from osteoblast attachment, proliferation and differentiation. As the application of non-thermal atmospheric pressure plasma on the surface of dental implant just before its introduction by the chair-side of dental surgery. Despite its long history, the generation of non-thermal atmospheric pressure plasma has been greatly increased with its application in dentistry.

• Korean Journal of Agricultural Science
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• v.45 no.1
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• pp.94-104
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• 2018

Nitrite is an essential additive for cured meat product. Plasma is ionized gas and reactive nitrogen species in plasma can be infused into meat batter and subsequently generate nitrites by reaction with water molecules after plasma treatment. However, the increase of nitrite in meat batter is limited with direct treatment of atmospheric pressure cold plasma because of the increase of meat batter temperature. Therefore, this study investigated the influence of indirect treatment of atmospheric pressure cold plasma on the physicochemical properties of meat batter. Meat batter was indirectly treated with plasma at 1.5 kW for 60 min. The pH of meat batter decreased while the temperature increased with plasma treatment time. The total aerobic bacterial count of meat batter was not affected by plasma treatment. The nitrite content of meat batter was increased to 377.68 mg/kg after 60 min of plasma treatment. The residual nitrite content of cooked meat batter also increased with plasma treatment time. The CIE $a^*$-value of cooked meat batter increased. As plasma treatment time increased, lipid oxidation tended to increase and protein oxidation significantly increased. According to these results, the indirect treatment of atmospheric pressure cold plasma can be used as a new curing method for replacing synthetic nitrite salts.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.155.1-155.1
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• 2013

The goals of this study are to elucidate the plasma effects on DNA molecules to apply some plasma based applications and also to find out the mechanisms of plasma-induced DNA damage in biomolecule. Nonthermal atmospheric pressure plasma has much potential for medical, agricultural and food applications for the future. The atmospheric pressure plasma jet (APPJ) contains radicals, charged particles, low energy electrons, excited molecules and UV light. It has been started doing experiments using APPJ at the early 21th. And some recent results showed that APPJ has a possibility to apply to new fields like mentioned above. But it is kind of at the very early stages of plasma based application. It is definitely necessary much of theoretical and experimental studies to further understanding to use nonthermal atmospheric pressure plasma in biomedical, agriculture and food parts. Here we introduce a new experimental system to study plasma effects on biomolecules. And we will show some recent results of LEE-induced DNA damage using electron irradiation apparatus under ultra-high vacuum.

• Biomolecules & Therapeutics
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• v.22 no.6
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• pp.477-490
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• 2014

Non-thermal atmospheric-pressure plasma, also named cold plasma, is defined as a partly ionized gas. Therefore, it cannot be equated with plasma from blood; it is not biological in nature. Non-thermal atmospheric-pressure plasma is a new innovative approach in medicine not only for the treatment of wounds, but with a wide-range of other applications, as e.g. topical treatment of other skin diseases with microbial involvement or treatment of cancer diseases. This review emphasizes plasma effects on wound healing. Non-thermal atmospheric-pressure plasma can support wound healing by its antiseptic effects, by stimulation of proliferation and migration of wound relating skin cells, by activation or inhibition of integrin receptors on the cell surface or by its pro-angiogenic effect. We summarize the effects of plasma on eukaryotic cells, especially on keratinocytes in terms of viability, proliferation, DNA, adhesion molecules and angiogenesis together with the role of reactive oxygen species and other components of plasma. The outcome of first clinical trials regarding wound healing is pointed out.

• Textile Coloration and Finishing
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• v.19 no.4
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• pp.38-46
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• 2007

Surface properties of the plasma treated fabric were changed while maintaining its bulk properties. Surface of plasma treated fabric take charge of enhanced adhesion by surface etching, surface activity. The water repellency coating Poly(Ethylene Terephthalate) fabric was treated with atmospheric pressure plasma using various parameters such as Argon gas, treatment time, processing power. Morphological changes by atmospheric pressure plasma treatment were observed using field emmission scanning electron microscopy(FE-SEM) and the zeta-potential measurement, contact angle measurement equipment. At the atmospheric pressure plasma treatment time of 150 sec, the power of 800W, the best wettability and peel strength were obtained. And we confirmed the possibility of industrial application by using atmospheric plasma system.

• Journal of the Semiconductor & Display Technology
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• v.8 no.2
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• pp.15-21
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• 2009

Atmospheric pressure plasma equipment was successfully applied to the flip chip BGA manufacturing process to improve the uniformity of flux printing process. The problem was characterized as shrinkage of the printed flux layer due to insufficient surface energy of the flip chip BGA substrate. To improve the hydrophilic characteristics of the flip chip BGA substrate, remote DBD type atmospheric pressure plasma equipment was developed and adapted to the flux print process. The equipment enhanced the surface energy of the substrate to reasonable level and made the flux be distributed over the entire flip chip BGA substrate uniformly. This research was the first adaptation of the atmospheric pressure plasma equipment to the flip chip BGA manufacturing process and a lot of possible applications are supposed to be extended to other PCB manufacturing processes such as organic cleaning, etc.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.268-268
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• 2012

Atmospheric pressure microwave induced plasmas are used to excite and ionize chemical species for elemental analysis, for plasma reforming, and for plasma surface treatment. Microwave plasma differs significantly from other plasmas and has several interesting properties. For example, the electron density is higher in microwave plasma than in radio-frequency (RF) or direct current (DC) plasma. Several types of radical species with high density are generated under high electron density, so the reactivity of microwave plasma is expected to be very high [1]. Therefore, useful applications of atmospheric pressure microwave plasmas are expected. The surface characteristics of SUS304 stainless steel are investigated before and after surface modification by microwave plasma under atmospheric pressure conditions. The plasma device was operated by power sources with microwave frequency. We used a device based on a coaxial transmission line resonator (CTLR). The atmospheric pressure plasma jet (APPJ) in the case of microwave frequency (880 MHz) used Ar as plasma gas [2]. Typical microwave Pw was 3-10 W. To determine the optimal processing conditions, the surface treatment experiments were performed using various values of Pw (3-10 W), treatment time (5-120 s), and ratios of mixture gas (hydrogen peroxide). Torch-to-sample distance was fixed at the plasma edge point. Plasma treatment of a stainless steel plate significantly affected the wettability, contact angle (CA), and free energy (mJ/$m^2$) of the SUS304 surface. CA and ${\gamma}$ were analyzed. The optimal surface modification parameters to modify were a power of 10 W, a treatment time of 45 s, and a hydrogen peroxide content of 0.6 wt% [3]. Under these processing conditions, a CA of just $9.8^{\circ}$ was obtained. As CA decreased, wettability increased; i.e. the surface changed from hydrophobic to hydrophilic. From these results, 10 W power and 45 s treatment time are the best values to minimize CA and maximize ${\gamma}$.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.56.2-56.2
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• 2015

Nonthermal Atmospheric Pressure Plasmas and their Applications to Plasma Bioscience and Medicines have been introduced for next generation human healthcare's quantum developments. Various kinds of nonthermal atmospheric pressure plasmas have been introduced and their electron temperature and plasma densities along with reactive oxygen and nitrogen species have been diagnosed and analyzed for biological cell interactions, especially, used in Plasma Bioscience Research Center (PBRC), Korea. Herein, we have also introduced the plasma-initiated ultraviolet photolysis, which might be a generation mechanism for the reactive oxygen and nitrogen species (RONS) intracellular and extracellular regions inside the liquid when the plasma has been bombarded onto the water. Finally we have investigated the interactions of these RONS with the various cancer cells resulting in apoptotic cell death.