Browsing by Author "Lin, Zhi-Hua"

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A Cold Planar Nitrogen-Based Atmospheric-Pressure Dielectric Barrier Discharge Jet With Enhanced UV Emission and Radical Generation Using Short Electrodes
(2016-12)
Cheng, Kuang-Yao
;
Yang, Yi-Wei
;
Lin, Zhi-Hua
;
Liao, Guo-Chun
;
Liu, Chih-Tung
In this paper, a planar nitrogen-based atmospheric-pressure dielectric barrier discharge (DBD) jet with enhanced UV emission and radical generation, and much lower power consumption and gas temperature using shorter electrodes as compared with a previously developed DBD jet is presented. The highest UV intensity (five times larger) and radical generation (two times larger) in the DBD jet region are found to occur when the electrode length is 1 cm. Corresponding jet gas temperature and power consumption are 31 degrees C and 39 W, respectively. The 1-cm DBD jet was used to treat polylactide film for enhancing its hydrophilic properties. The results show that a contact angle of 28.4 degrees could be obtained with a residence time of 4 s. The resulting 1-cm DBD jet may provide an efficient surface treatment tool for delicate industrial and biomedical devices/materials.
A Cold Planar Nitrogen-Based Atmospheric-Pressure Dielectric Barrier Discharge Jet With Enhanced UV Emission and Radical Generation Using Short Electrodes
(2016-12-01)
Cheng, Kuang-Yao
;
Yang, Yi-Wei
;
Lin, Zhi-Hua
;
Liao, Guo-Chun
;
Liu, Chih-Tung
In this paper, a planar nitrogen-based atmospheric-pressure dielectric barrier discharge (DBD) jet with enhanced UV emission and radical generation, and much lower power consumption and gas temperature using shorter electrodes as compared with a previously developed DBD jet is presented. The highest UV intensity (five times larger) and radical generation (two times larger) in the DBD jet region are found to occur when the electrode length is 1 cm. Corresponding jet gas temperature and power consumption are 31 degrees C and 39 W, respectively. The 1-cm DBD jet was used to treat polylactide film for enhancing its hydrophilic properties. The results show that a contact angle of 28.4 degrees could be obtained with a residence time of 4 s. The resulting 1-cm DBD jet may provide an efficient surface treatment tool for delicate industrial and biomedical devices/materials.
Atomic Oxygen and Hydroxyl Radical Generation in Round Helium-Based Atmospheric-Pressure Plasma Jets by Various Electrode Arrangements and Its Application in Sterilizing Streptococcus mutans
(2014-12-01)
Liu, Chih-Tung
;
Wu, Ching-Jung
;
Yang, Yi-Wei
;
Lin, Zhi-Hua
;
Wu, Jong-Shinn
The reactive chemical species generated in an atmospheric-pressure plasma jet (APPJ), such as hydroxyl radical and atomic oxygen, are generally regarded as the major sources for several biomedical applications. In this paper, we propose an APPJ with a 25-kHz high-voltage powered stainless steel tube fixed inside a quartz tube and an aluminum grounded electrode that is wrapped around the quartz tube. The results show that the radical intensities of atomic oxygen and hydroxyl radical, gas temperature, and power absorption increase with increasing distance of discharge gap distance under the same applied voltage. Increasing the width of grounded electrode increases gas temperature and causes higher power absorption but only slight change of radical generation. We have applied the APPJ with the conditions of highest radical generation (grounded electrode width = discharge gap distance = 15 mm) for effectively sterilizing Streptococcus mutans within 15 s, which shows a highly potential application for root canal disinfection.
DEVELOPMENT AND CHARACTERIZATION OF A PORTABLE ATMOSPHERIC-PRESSURE ARGON PLASMA JET FOR STERILIZATION
(2016)
Lin, Zhi-Hua
;
Wu, Jong-Shinn
;
Tschang, Chen-Yon Tobias
;
Su, Chi-Feng
;
Wu, Tuoh
In this study, we would like to develop a portable round argon atmospheric-pressure plasma jet (APPJ) which can be applied for general use of bacteria inactivation. The APPJ was characterized electrically and optically, which include measurements of absorption power, gas temperature and optical properties of plasma generated species. Measured OH* number density at 5 mm downstream was estimated to be 5.8 x 10(15) cm(3) and the electron density and electron temperature were estimated to be 2.4 x 10(15) cm(-3) and 0.34 eV, respectively, in the discharge region. This APPJ was demonstrated to effectively inactivate E. coli within seconds of treatment, which shows its great potential in the future use of general bacteria inactivation and sterilization.
Effect of Ground and Floating Electrode on a Helium-Based Plasma Jet and Its Applications in Sterilization and Ceramic Surface Treatment
(2016-12)
Liu, Chih-Tung
;
Cheng, Kuang-Yao
;
Lin, Zhi-Hua
;
Wu, Ching-Jung
;
Wu, Jane-Yii
In this paper, we compare the helium-based atmospheric pressure plasma jets (APPJs) with power-ground (PG) and power-floating (PF) configurations by using optical analysis. We find that the PG jet traps plasma between two electrodes (discharge region); thus, the hydroxyl radical intensity is significantly strong in discharge region; however, the plasma intensity in downstream region is relatively weak as compared with that of PF configuration. In contrast, using the APPJ with PF configuration, the hydroxyl radical and nitric oxide are approximately two and three times stronger, respectively, in the downstream region, even though the gas temperature and power consumption are lower. The PF jet successfully eradicates S. mutans and decreases water contact angle by similar to 40 within 15-s treatment, which demonstrates higher efficient than that of PG jet, and shows highly potential for dental filling demand.
Effect of Ground and Floating Electrode on a Helium-Based Plasma Jet and Its Applications in Sterilization and Ceramic Surface Treatment
(2016-12-01)
Liu, Chih-Tung
;
Cheng, Kuang-Yao
;
Lin, Zhi-Hua
;
Wu, Ching-Jung
;
Wu, Jane-Yii
In this paper, we compare the helium-based atmospheric pressure plasma jets (APPJs) with power-ground (PG) and power-floating (PF) configurations by using optical analysis. We find that the PG jet traps plasma between two electrodes (discharge region); thus, the hydroxyl radical intensity is significantly strong in discharge region; however, the plasma intensity in downstream region is relatively weak as compared with that of PF configuration. In contrast, using the APPJ with PF configuration, the hydroxyl radical and nitric oxide are approximately two and three times stronger, respectively, in the downstream region, even though the gas temperature and power consumption are lower. The PF jet successfully eradicates S. mutans and decreases water contact angle by similar to 40 within 15-s treatment, which demonstrates higher efficient than that of PG jet, and shows highly potential for dental filling demand.
Production Enhancement of Reactive Oxygen and Nitrogen Species at Interface of Helium Plasma Jet and Agar
(2016-12)
Liu, Chih-Tung
;
Wu, Ching-Jung
;
Lin, Zhi-Hua
;
Wu, Jane-Yii
;
Wu, Jong-Shinn
Even though atmospheric-pressure plasma jet (APPJ) has been shown highly effective in many biomedical applications because of reactive oxygen/nitrogen species (RONS) generated in the discharge, free jet region, and at the interfacial region with the treated surface. However, most of the studies characterized APPJ only in either discharge or free jet region. In this paper, we measured optical emissions of RONS in free jet and plasma/surface interfacial regions of a helium-based dielectric barrier discharge APPJ. The results show that the emissions caused by RONS (nitric oxide, hydroxyl radical, and atomic oxygen) are enhanced 3-5 times at plasma/surface interfacial region as compared with those of free jet region. Some typical sterilization experiments using the current helium-based APPJ show that this helium-based APPJ effectively kills the oral bacteria (S. mutans) in 15 s, which was caused by the cell wall disruption. We believe that measuring the properties at plasma/surface interfacial region is more important than in the free jet region in characterizing APPJ for most realistic applications.
Production Enhancement of Reactive Oxygen and Nitrogen Species at Interface of Helium Plasma Jet and Agar
(2016-12-01)
Liu, Chih-Tung
;
Wu, Ching-Jung
;
Lin, Zhi-Hua
;
Wu, Jane-Yii
;
Wu, Jong-Shinn
Even though atmospheric-pressure plasma jet (APPJ) has been shown highly effective in many biomedical applications because of reactive oxygen/nitrogen species (RONS) generated in the discharge, free jet region, and at the interfacial region with the treated surface. However, most of the studies characterized APPJ only in either discharge or free jet region. In this paper, we measured optical emissions of RONS in free jet and plasma/surface interfacial regions of a helium-based dielectric barrier discharge APPJ. The results show that the emissions caused by RONS (nitric oxide, hydroxyl radical, and atomic oxygen) are enhanced 3-5 times at plasma/surface interfacial region as compared with those of free jet region. Some typical sterilization experiments using the current helium-based APPJ show that this helium-based APPJ effectively kills the oral bacteria (S. mutans) in 15 s, which was caused by the cell wall disruption. We believe that measuring the properties at plasma/surface interfacial region is more important than in the free jet region in characterizing APPJ for most realistic applications.
Wound Healing in Streptozotocin-Induced Diabetic Rats Using Atmospheric-Pressure Argon Plasma Jet
(2018-08-15)
Cheng, Kuang-Yao
;
Lin, Zhi-Hua
;
Cheng, Yu-Pin
;
Chiu, Hsien-Yi
;
Yeh, Nai-Lun
In this study, we used an argon-based round atmospheric-pressure plasma jet (APPJ) for enhancing wound healing in streptozotocin (STZ) induced diabetic rats. The APPJ was characterized by optical emission spectroscopy. We induced Type 1 and Type 2 diabetes in rats with different amounts of STZ combined with normal and high-fat diets, respectively. The wound area ratio of all the plasma-treated normal and diabetic groups was greatly reduced (up to 30%) compared with that of the untreated groups during healing. Histological analysis revealed faster re-epithelialization, collagen deposition, less inflammation, and a complete skin structure in the plasma-treated groups was found as compared with the untreated control groups. In addition, the new blood vessels of plasma-treated tissues decreased more than untreated tissues in the middle (Day 14) and late (Day 21) stages of wound healing. The plasma-treated wounds demonstrated more transforming growth factor beta (TGF-beta) expression in the early stage (Day 7), whereas they decreased in the middle and late stages of wound healing. The levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) increased after plasma treatment. In addition, plasma-treated water had a higher concentration of hydrogen peroxide, nitrite and nitrate when the plasma treatment time was longer. In summary, the proposed argon APPJ based on the current study could be a potential tool for treating diabetic wounds.
Wound Healing in Streptozotocin-Induced Diabetic Rats Using Atmospheric-Pressure Argon Plasma Jet (vol 8, 12214, 2018)
(2018-08-29)
Cheng, Kuang-Yao
;
Lin, Zhi-Hua
;
Cheng, Yu-Pin
;
Chiu, Hsien-Yi
;
Yeh, Nai-Lun