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Herein, we describe a new flexible atmospheric pressure plasma jet device composed of hollow-core optical fibers and introduce two potential applications of the device: endoscopic plasma treatment and decomposition of aqueous phosphorus compounds. The proposed device is 1.6 m long and highly flexible, has a small probe size of several hundred micrometers, and spatially separates the plasma jet from the electrical input, making it very suitable for treatment through the biopsy channel of a conventional endoscope. Because the wire electrode of the fabricated atmospheric pressure plasma jet device is thoroughly isolated inside the hollow of the optical fiber, the device produces a plasma column in an identical discharge state regardless of external environmental conditions. As a result, the device can operate safely and steadily in highly humid environments, such as underwater, which can be utilized to decompose phosphorus compounds in fresh water. [ABSTRACT FROM AUTHOR]

Polyaniline (PANI) was synthesized from liquid aniline, a nitrogen-containing aromatic compound, through the atmospheric pressure (AP) plasma process using a newly designed plasma jet array with wide spacing between plasma jets. To expand the area of the polymerized film, the newly proposed plasma jet array comprises three AP plasma jet devices spaced 7 mm apart in a triangular configuration and an electrodeless quartz tube capable of applying auxiliary gas in the center of the triangular plasma jets. The vaporized aniline monomer was synthesized into a PANI film using the proposed plasma array device. The effects of nitrogen gas addition on the morphological, chemical, and electrical properties of PANI films in AP argon plasma polymerization were examined. The iodine-doped PANI film was isolated from the atmosphere through encapsulation. The constant electrical resistance of the PANI film indicates that the conductive PANI film can achieve the desired resistance by controlling the atmospheric exposure time through encapsulation. [ABSTRACT FROM AUTHOR]

In this study, we describe an atmospheric pressure plasma jet (APPJ) device made of four-bore tubing operable in inhospitable humid environments and introduce two potential applications of liquid material processing: decomposition of aqueous phosphorus compounds and solution-plasma polymerization. A four-bore tube was used as the plasma transfer conduit and two diagonal bores contained metal wires. In the proposed APPJ device, the metal wires serving as electrodes are completely enclosed inside the holes of the multi-bore glass tube. This feature allows the APPJ device to operate both safely and reliably in humid environments or even underwater. Thus, we demonstrate that the proposed electrode-embedded APPJ device can effectively decompose aqueous phosphorus compounds into their phosphate form by directly processing the solution sample. As another application of the proposed APPJ device, we also present the successful synthesis of polypyrrole nanoparticles by solution plasma polymerization in liquid pyrrole. [ABSTRACT FROM AUTHOR]

When a tissue slice pretreated with gold nanoparticles is irradiated with a focused 532-nm continuous wave laser, desorption is observed to be uniform and stable, and its shape is sharp and steep. However, since the desorbed molecules are still electrically neutral particles in atmospheric pressure (AP), additional procedure of ionizing them is necessary for AP mass spectrometry (AP-MS) analysis. Therefore, the authors have combined an electrospray device with a simple chamber connected to the airflow-assisted particle transport equipment mounted at the mass spectrometer inlet. Subsequent ionization processes using an electrospray device enable the detection of several types of diacylglycerol molecules above 500 Da, which cannot be detected with the use of AP plasma jets. The authors also developed a remote AP-MS using a long and flexible sampling probe and a fiber laser with a slight modification of the proposed AP desorption and ionization method. [ABSTRACT FROM AUTHOR]

Abstract: Atmospheric pressure plasmas have been used as a therapy for cancer. However, the fairly large size and rigidity of present plasma-delivery systems obstructs the precise treatment of tumors in harder-to-reach internal organs such as the lungs, pancreas, and duodenum. In order to improve the targeted delivery of plasmas a highly flexible microplasma jet device is fabricated using a hollow-core optical fiber with an inner diameter of either 15μm, 55μm, or 200μm. Described herein, based on this device, are results on lung carcinoma therapy using a microplasma cancer endoscope. Despite the small inner diameter and the low gas flow rate, the generated plasma jets are shown to be sufficiently effective to induce apoptosis, but not necrosis, in both cultured mouse lung carcinoma and fibroblast cells. Further, the lung carcinoma cells were found to be more sensitive to plasma treatment than the fibroblast cells based on the overall plasma dose conditions. This work enables directed cancer therapies using on highly flexible and precise hollow optical fiber-based plasma device and offers enhancements to microplasma cancer endoscopy using an improved method of plasma targeting and delivery. [Copyright &y& Elsevier]

Abstract: The authors describe a proposed 15-μm-sized, single-cellular-level, and cell-manipulatable microplasma jet device with a microcapillary glass tip and its potential in the development of cancer treatment therapies. The electrical and optical properties of the plasma jets and preliminary apoptosis results of cultured murine tumor cells and non-tumor fibroblast cells treated with the plasma jets are presented. The generated plasma jet was stable and enabled the treatment of cultured cells in cell culture plates regardless of the small inner diameter and low gas flow rate. The microplasma jet was observed inducing apoptosis in cultured murine melanoma tumor cells in a dose-dependent manner. Furthermore, the percentage of apoptotic cells of murine melanoma tumor cells induced by this plasma device was approximately 2.5 times bigger than that of murine fibroblast cells as indicated by an Annex V apoptosis assay. The apoptosis in cultured murine tumor cells by the 15-μm-sized single-cellular-level and cell-manipulatable microplasma jet device was also observed using an in situ apoptosis assay. We report on a novel microplasma jet device with the advantages of single-cellular-level and single cell-manipulatable plasma treatment with precise and solid stimuli. This highly precise plasma medicine, which enables new directed cancer therapies can be combined with current cell manipulation and cell culturing technologies without much difficulty. [ABSTRACT FROM AUTHOR]

New nanostructured conducting porous polythiophene (PTh) films are directly deposited on substrates at room temperature (RT) by novel atmospheric pressure plasma jets (APPJs) polymerization technique. The proposed plasma polymerization synthesis technique can grow the PTh films with a very fast deposition rate of about 7.0 μm·min−1 by improving the sufficient nucleation and fragment of the thiophene monomer. This study also compares pure and iodine (I2)-doped PTh films to demonstrate the effects of I2 doping. To check the feasibility as a sensing material, NO2-sensing properties of the I2-doped PTh films-based gas sensors are also investigated. As a result, the proposed APPJs device can produce the high density, porous and ultra-fast polymer films, and polymers-based gas sensors have high sensitivity to NO2 at RT. Our approach enabled a series of processes from synthesis of sensing materials to fabrication of gas sensors to be carried out simultaneously. [ABSTRACT FROM AUTHOR]

A newly designed atmospheric pressure plasma jet that can generate plasma without an external power line for use in an inhospitable humid environment is proposed. A four-bore tube is employed as the delivery conduit, and wire electrodes are inserted into two diagonal hollows. As the wire electrodes are completely isolated inside the hollows of the multibore glass tube, there is no contact with the environment at the end of the device where the jet is produced. Two identical plasma plumes can be generated not only in the ambient air but also under water, thereby enabling tissue and wound treatments in a humid environment, such as oral medicine and endodontic care. [ABSTRACT FROM PUBLISHER]

The plasma jet-to-jet coupling behavior between two plasma jet arrays is investigated. A plasma array structure consisting of two plasma jet arrays and a double electrode configuration is used as an ambient plasma source and shown to generate a strong plasma emission. Since the proposed plasma device is able to generate an intense plasma emission without any external ground electrode, it is a promising tool for surface treatments and modifications that require a strong discharge process, regardless of the dielectric property of the target material. [ABSTRACT FROM PUBLISHER]

A new plasma array jet with an additional ring-type focusing electrode is proposed to obtain an extended and intense Ar plasma jet focused on a central glass tube at atmospheric pressure. To investigate the role of the ring-type electrode, the sinusoidal voltages of 9 kV and frequency of 30 kHz were applied to three different electrode configurations, such as only ring-type electrode, only probe-type electrodes, and both the ring- and probe-type electrodes. As a result, the ring-type electrode is confirmed to play a significant role in spatially focusing the charge particles ignited by the exposed probe-type electrodes, thereby producing a stable and intense Ar plasma jet under atmospheric pressure. [ABSTRACT FROM PUBLISHER]

The authors describe an intense plasma plume from atmospheric-pressure plasma jet array devices. Here, outer plasma plumes, produced by this device, were sucked into the centered plasma plume at the ends of the tubes and merged with the centered plume. The intense plasma jet is possible through jet-to-jet coupling in eight-quartz-tube arrays. To describe this coupling, optical properties of the intense plasma jet are compared with those of a single tubing plasma jet. The optical intensity from the intense plasma jet by jet-to-jet coupling was approximately three times larger than that of a conventional single plasma jet under identical driving and gas conditions. [ABSTRACT FROM AUTHOR]

ZnO nanowire arrays on polyethylene terephthalate substrate were characterized, in terms of surface energy, by the honeycomb structured plasma jets for biosensors. A rapid hydrothermal synthesis is carried out to grow ZnO nanowires by a variable power microwave sintering system. The optical emission spectra of the honeycomb structured plasma jet array show that excited OH, \N2, \N2^{+}, He, and O exist in the plasma jet array and the many gaseous species in the air participated in the plasma process. Surface modification by atmospheric plasma resulted in reduced contact angles from 111.23^\circ to 8.70 ^\circ as a function of plasma duration time. [ABSTRACT FROM AUTHOR]

A dual atmospheric-pressure plasma jet using a theta-shaped tube has been proposed for generating the plasma jet with multigases. Two individual plasma plumes of He and Ar were generated and focused at a certain point. When the gas flow ratio was 3:1 between the Ar and He gases, the dual plasma plume exhibited the longest focal distance from the nozzle, and it was sustaining as a well-balanced state. The optical emission spectra of the plasma plume showed that the merged plasma plume had both excited He and Ar species. [ABSTRACT FROM AUTHOR]

Atmospheric-pressure microplasma jets from a linear array of five hollow-core optical fibers are described. All plasma plumes from the array were quite narrow but long enough to apply the direct treatments to a very small object. The optical intensities from five individual plasma jets were also stable and had a good uniformity. The variation of the optical intensities of individual plasma plumes was within 15%. This plurality of the small-sized plasma jets can be utilized to target some groups of different cells simultaneously in an in vitro biomedical application. [ABSTRACT FROM AUTHOR]

A flexible atmospheric pressure microplasma jet device utilizing a 200-\mu \m hollow-core optical fiber was developed in order to trigger the apoptosis of cultured tumor cells and determine the feasibility of plasma endoscopy. As determined by in situ apoptosis assay, the TUNEL assay, this flexible microplasma jet induced cultured murine tumor cells to undergo apoptosis. In addition, the apoptosis was induced to a greater extent in B16F0 tumor cells than in CL.7 cells for the same plasma dose. [ABSTRACT FROM AUTHOR]

The authors describe an intensified plasma jet from a honeycomb structural plasma jet array at atmospheric pressure. Despite an equally distributed gas flow, the outermost tubes did not produce strong individual plumes. Rather, the plasma plumes were drawn into the central plume, which was, in turn, amplified. As a result, the optical intensity from the 19-array plasma jet was nearly twice greater than that from a conventional single plasma jet at the maximum plasma emission condition of each device under identical applied voltages. [ABSTRACT FROM AUTHOR]