Electrical and Optical Characterization of Atmospheric-Pressure Helium Plasma Jets Generated With a Pin Electrode: Effects of the Electrode Material, Ground Ring Electrode, and Nozzle Shape

Hea Min Joh,Hae Ra Kang,Tae Hun Chung,Sun Ja Kim IEEE 2014 IEEE transactions on plasma science Vol.42 No.12

<P>This paper tests various design and operation parameters in atmospheric-pressure helium plasma jets generated with a pin electrode to provide a plasma environment well suited for material processing or biomedical applications. The effects of the pin electrode materials (Cu, W, and Al), the position, and the width of a ground ring electrode on the characteristics of the jets are studied. The inner quartz tube encompassing the pin electrode and two types of the outer quartz tubes (straight or tapered cylinder shape) are employed, and their effects are investigated. The electrical characteristics of the plasma jets are measured by current-voltage measurements and analyzed by the equivalent circuit model. The optical characteristics of the discharges are obtained by optical emission spectroscopy to identify various excited plasma species produced in the plasma jets. Optical emission spectra are also obtained at different positions along the coaxial direction. A variety of choices in design parameters and operation parameters are undertaken to determine optimal conditions and elucidate the properties of the plasma jets.</P>

Atmospheric Pressure Plasma Jet Composed of Three Electrodes: Application to Tooth Bleaching

Lee, Hyun Woo,Nam, Seoul Hee,Mohamed, Abdel-Aleam H.,Kim, Gyoo Cheon,Lee, Jae Koo WILEY-VCH Verlag 2010 Plasma Processes and Polymers Vol.7 No.3

<P>Three-electrode plasma jet system consisting of a perforated dielectric tube with two outer and one floating inner electrodes was developed and employed for tooth bleaching. Lowered gas breakdown voltage and increased discharge current were achieved by using the floating inner electrode. Optical emission spectra analysis showed that the rotational temperature of the second positive nitrogen bands was ≈290 K and vibrational temperature was ≈2 500 K, which means this plasma is in highly non-quilibrium state and nonthermal. The presence of excited He, N<SUB>2</SUB>, N<EM><SUB>2</SUB><SUP>+</SUP></EM> and O in the plasma plume was revealed. The plasma jet was used in combination with hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>) to remove stains from extracted teeth stained by either coffee or red wine. Combining the plasma jet and H<SUB>2</SUB>O<SUB>2</SUB> improved the bleaching efficacy by a factor of 3.1 (coffee) and 3.7 (red wine) compared with using H<SUB>2</SUB>O<SUB>2</SUB> alone.</P><P> <img src='wiley_img_2010/16128850-2010-7-3-4-PPAP200900083-gra001.gif' alt='wiley_img_2010/16128850-2010-7-3-4-PPAP200900083-gra001'> </P> <B>Graphic Abstract</B> <P>An atmospheric pressure plasma jet has attracted great interest in biomedical applications thanks to its simplicity of the design and its diverse capabilities. This study proposed a design of a safe and reactive, nonthermal atmospheric pressure plasma jet, and demonstrated that the plasma jet enhanced the tooth bleaching effect. We expect that this study can contribute to widening the application field of atmospheric pressure plasma. <img src='wiley_img_2010/16128850-2010-7-3-4-PPAP200900083-content.gif' alt='wiley_img_2010/16128850-2010-7-3-4-PPAP200900083-content'> </P>

A spectroscopic study of the effect of humidity on the atmospheric pressure helium plasma jets

Elsevier 2018 CURRENT APPLIED PHYSICS Vol.18 No.11

<P>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.</P>

Effective Surface Modification of a Germanium Layer by using an Atmospheric Pressure Plasma Jet with a Round Ended Nozzle

Min Kim,M. G. Kim,S. R. Kim,H. Y. Chung,J. G. Choi,조혜민,정태훈,Hyung Soo Kim,김용 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.5

We investigate the surface modification of a germanium epitaxial layer grown on a silicon substrate by means of an atmospheric-pressure plasma jet. The plasma jet contains a large density of highly reactive radicals, as confirmed by optical emission spectra. The plasma jet with a nozzle with a round end has a higher current level compared to cylindrical and pencil-shaped nozzles, indicating the usefulness of this plasma jet for semiconductor processing. Raman spectra reveal a significant modification of the germanium surface under exposure to an atmospheric pressure plasma jet even for 1 min. The first-order Raman peak at 320 cm−1 has an asymmetric shoulder on the lowfrequency side, which can be attributed to amorphization/oxidation of the germanium layer due to highly reactive radicals. The rapid surface change under short-time exposure indicates the practicality of the plasma jet for semiconductor processing.

A spectroscopic study of the effect of humidity on the atmospheric pressure helium plasma jets

한덕선 한국물리학회 2018 Current Applied Physics Vol.18 No.11

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.

Inactivation of Listeria monocytogenes on agar and processed meat surfaces by atmospheric pressure plasma jets

Lee, H.J.,Jung, H.,Choe, W.,Ham, J.S.,Lee, J.H.,Jo, C. Academic Press 2011 Food microbiology Vol.28 No.8

An apparatus for generating atmospheric pressure plasma (APP) jet was used to investigate the inactivation of Listeria monocytogenes on the surface of agar plates and slices of cooked chicken breast and ham. He, N<SUB>2</SUB> (both 7 L/min), and mixtures of each with O<SUB>2</SUB> (0.07 L/min) were used to produce the plasma jets. After treatment for 2 min with APP jets of He, He + O<SUB>2</SUB>, N<SUB>2</SUB>, or N<SUB>2</SUB> + O<SUB>2</SUB>, the numbers of L. monocytogenes on agar plates were reduced by 0.87, 4.19, 4.26, and 7.59 log units, respectively. Similar treatments reduced the L. monocytogenes inoculated onto sliced chicken breast and ham by 1.37 to 4.73 and 1.94 to 6.52 log units, respectively, according to the input gas used with the N<SUB>2</SUB> + O<SUB>2</SUB> mixture being the most effective. Most APP jets reduced the numbers of aerobic bacteria on the meat surfaces to <10<SUP>2</SUP> CFU/g, and the numbers remained below that level of detection after storage at 10 <SUP>o</SUP>C for 7 days. The results indicate that APP jets are effective for the inactivation of L. monocytogenes on sliced meats and for prolonging the shelf-life of such foods.

Surface Treatment of a Titanium Implant using a low Temperature Atmospheric Pressure Plasma Jet

이현영,옥정우,이호준,김규천,이해준 한국진공학회 2016 Applied Science and Convergence Technology Vol.25 No.3

The surface treatment of a titanium implant is investigated with a non-thermal atmospheric pressure plasma jet. The plasma jet is generated by the injection of He and O2 gas mixture with a sinusoidal driving voltage of 3 kV or more and with a driving frequency of 20 kHz. The generated plasma plume has a length up to 35 mm from the jet outlet. The wettability of 4 different titanium surfaces with plasma treatments was measured by the contact angle analysis. The water contact angles were significantly reduced especially for O2/He mixture plasma, which was explained with the optical emission spectroscopy. Consequently, plasma treatment enhances wettability of the titanium surface significantly within the operation time of tens of seconds, which is practically helpful for tooth implantation

생의학적 응용을 위한 상압 마이크로 플라즈마 Jet 제작

김선자,정태훈,박혜선,배세환 한국물리학회 2009 새물리 Vol.58 No.4

Atmospheric-pressure micro plasma jets driven by a radio-frequency wave of 13.56 MHz and by a low-frequency continuous wave of several kilohertz were fabricated and characterized. The feed gas was helium. The basic physical and chemical properties of the plasma jets, such as the current voltage (I-V) characteristics, the optical emission spectrum, the gas temperature, and the power deposition, were investigated. The device to produce the jets consisted of an ac-driven copper wire surrounded by a dielectric layer and a glass tube. With the addition of a ground ring electrode, the optical emission intensities of the O, OH, and NOγ species from the plasma plume and the plume temperature were enhanced. As an example of a biomedical application of microplasma jets, a bacterial inactivation experiment was performed. The plasma power (or applied voltage), the treatment time, and the pin-to-sample distance were varied, and the bacterial inactivation effects of these parameters were investigated. 상압 micro-plasma jet 장치를 제작하여 13.56 MHz RF power 혹은 수십 kHz high voltage를 pin electrode에 인가하여 플라즈마를 발생시켰다. 플라즈마 형성 가스로는 He을 사용하였다. 전류-전압 (I-V) 특성곡선, 광 방출 spectrum, 기체온도, power deposition 등과 같은 전기적, 광학적 특성들을 조사하였다. Jet 장치의 glass tube 출구 표면에 링 접지 전극 (grounded ring electrode)를 부착했을 때의 영향을 관찰하고 여러 control parameter를 변화시키면서 플라즈마 방전의 특성을 조사하였다. 링 접지전극이 부착되었을 때 플라즈마의 중성 기체온도가 증가하였고, 생체 sample에 생의학적 효과를 야기시키는 reactive species들인 O, OH, NOγ등의 농도가 증가함을 관찰하였다. 대장균 (Escherichia coli)을 배양하여 여러 operational parameter를 변화시켜 가며 발생시킨 플라즈마를 인가하여 사멸 처리하였다. 여러 방전 조건하에서 생성된 플라즈마의 노출시간과 인가전력 (혹은 인가전압) 그리고 pin electrode와 sample 사이의 거리에 따른 사멸률 (sterilization ratio)를 구하여 서로 비교하였다.

Surface Treatment of a Titanium Implant using a low Temperature Atmospheric Pressure Plasma Jet

Lee, Hyun-Young,Ok, Jung-Woo,Lee, Ho-Jun,Kim, Gyoo Cheon,Lee, Hae June The Korean Vacuum Society 2016 Applied Science and Convergence Technology Vol.25 No.3

The surface treatment of a titanium implant is investigated with a non-thermal atmospheric pressure plasma jet. The plasma jet is generated by the injection of He and $O_2$ gas mixture with a sinusoidal driving voltage of 3 kV or more and with a driving frequency of 20 kHz. The generated plasma plume has a length up to 35 mm from the jet outlet. The wettability of 4 different titanium surfaces with plasma treatments was measured by the contact angle analysis. The water contact angles were significantly reduced especially for $O_2/He$ mixture plasma, which was explained with the optical emission spectroscopy. Consequently, plasma treatment enhances wettability of the titanium surface significantly within the operation time of tens of seconds, which is practically helpful for tooth implantation.

900-MHz Nonthermal Atmospheric Pressure Plasma Jet for Biomedical Applications

Choi, Jun,Mohamed, Abdel-Aleam H,Kang, Sung Kil,Woo, Kyung Chul,Kim, Kyong Tai,Lee, Jae Koo WILEY-VCH Verlag 2010 Plasma Processes and Polymers Vol.7 No.3

<P>A portable microwave-excited atmospheric pressure plasma jet (APPJ) using a coaxial transmission line resonator is introduced for applications of plasma biomedicine. Its unique feature includes the portability and no need for matching network and cooling system with high power efficiency, operating at 900 MHz with low ignition power less than 2.5 W in argon at atmospheric pressure. The temperature at the downstream of the APPJ stays less than 47 °C (≈320 K) during 5 min of continuous operation. The optical emission spectrum of the APPJ shows various reactive radicals such as OH, NO, and O which are responsible for biomedicine. The APPJ was applied to investigate the acceleration of blood coagulation, which occurred within 20 s of plasma treatment in vitro and within 1 min in vivo. This is significantly faster than the natural coagulation.</P><P> <img src='wiley_img_2010/16128850-2010-7-3-4-PPAP200900079-gra001.gif' alt='wiley_img_2010/16128850-2010-7-3-4-PPAP200900079-gra001'> </P> <B>Graphic Abstract</B> <P>We have generated and characterized a 900-MHz nonthermal atmospheric pressure plasma jet (APPJ) based on a coaxial transmission line resonator (CTLR). The plasma generator needs no matching component and the overall device is palm-size. The typical power consumption is less than 5 W and the length of the APPJ longer than 5 mm. The temperature at the downstream of the APPJ is close to room temperature. These features make the CTLR APPJ more attractive for plasma biomedicine. <img src='wiley_img_2010/16128850-2010-7-3-4-PPAP200900079-content.gif' alt='wiley_img_2010/16128850-2010-7-3-4-PPAP200900079-content'> </P>