21P-119
Fabrication of Line Type Atmospheric Pressure Plasma Jet
by Dielectric Barrier Discharge
誘電体バリア放電ライン型大気圧プラズマジェットの作製
Hideki Yajima1, Takenori Hayakawa1, Izumi Serizawa1,Kotaro Ogawa2, Hiroshi Furuta2, Akimitsu Hatta3
矢島英樹1，早川壮則1，芹澤和泉1，小川広太郎2，古田寛2，八田章光2
1

ORC Manufacturing Co., Ltd., 2Kochi University of Technology
1
株式会社オーク製作所，2高知工科大学

We have been developing a line shaped atmospheric pressure plasma jet device which can eject line shaed
plasma plume excited by dielectric barrier discharge. The device consists of a pair of glass plates with asmall discharge gap and electrodes adhered to the outside of the glass plates. It has been succeeded toexcite uniform line shaped N2, Ar and He plasma ejected into the ambient air by optimizing theconfiguration of electrodes for each gas. To confirm the effective irradiation profiles, the line plasmas wereirraditaed to KI-starch gel. It was found that the N2 plasma made a uniformly irradiation image while Arand He plasmas made nonuniform profiles. A possible reason for the nonuniform profile by Ar and He
plasmas is direct discharges passing throuth the target to the electrical ground other than the electrodes.

1. Introduction
When the electrode of the atmospheric pressureplasma jet is exposed to electric discharge, it issputtered and the irradiation object is
contaminated with the electrode material.
Therefore, in applications that may be affected bycontamination, such as surface modification ofcell culture dish, it is desirable to avoid
contamination by the electrode material.
The purpose of this study is to fabricate theatmospheric pressure plasma jet device which caneject line shaped plasma (line type atmosphericpressure plasma jet) for processing of a wide areasuch as surface modification of a petri dishwithout electrode material contamination.

KI-starch gel (irradiation distance) to 5 mm, 10 mm
and 15 mm. The irradiation time was varied
depending on the type of gas and irradiation
distance. The KI-starch gel was prepared by adding
0.5 wt% agarose to an aqueous solution containing
0.3 wt% potassium iodide and 0.5 wt% starch.

2. Experimental
A rectangular discharge cell, as shown in Fig.1,
was prepared using two non-alkaline glass plates(Eagle XG, Corning Inc.) having a thickness of 0.3
mm and glass frit (LS-3075, Nippon Electric GlassCo., Ltd.). The inside dimension of the cell wasaround 32 mm in width and around 1.1 mm inheight. A line type atmospheric pressure plasma jet
was excited by copper tape electrodes placed on theoutside of the glass plates.
N2, Ar or He gas was supplied at a flow rate of20 L/min, and a 25 kHz sinusoidal wave voltage at
10kVp-p was applied to the electrode for generationof plasma.
In order to evaluate the irradiation shape andirradiation area of the plasma, we used KI-starchgel[1]. The experiments were conducted bychanging the distance from the plasma outlet to theFig.1. Structure and photograph of rectangular tube

Glass frit~1.1mm~32mm

Glass plate(t = 0.3mm)

3. Results and Discussions
By optimizing the configuration of the electrodes
for each discharge gas, line shaped N2, Ar and He
plasma was successfully appeared (Fig. 2). The
length of the N2, Ar plasma was around 10 mm andHe plasma was around 5 mm.

N2N2Discharge gasArHe30mm

5mm~10mm

Ar30mm1mm

101510mm

1mm

10mm

Irradiation distance (mm)

530mm

5mm

~10mm

Fig.3. Irradiation shapes ofline type atmospheric pressure plasma jets

He30mm5mm

30mm~5mm

Fig.2. Structure and photographs ofline type atmospheric pressure plasma jets

The plasma jets were irradiated on the KI-starch
gel and the results are shown in Fig.3. It wasconfirmed that the N2 plasma was uniformly
irradiated even if the irradiation distance waschanged. However, Ar and He plasma became
nonuniform. It is assumed to be due to partial
discharge occurring between the irradiation object
and plasma density distribution near the partial
discharge being nonuniform. In the case of N2
plasma, it is believed that a homogeneous plasma
has been ejected since it is discharged inside therectangular tube and the generated plasma is
extruded by the gas flow.

4. Summary
A line type atmospheric pressure plasma jethaving an inner dimension of a discharge cellaround 32 mm in width and around 1.1 mm inheight was using non-alkali glass plate and glass fritand placing an electrode on the outside of therectangular discharge cell. By flowing N2, Ar or Hegas at a flow rate of 20 L/min and applying a 25
kHz sinusoidal wave voltage at 10kVp-p to the
optimized electrode for placement, line shaped
plasma was successfully ejected. The irradiation
shape of the plasma jets was visualized using
KI-starch gel, and it was confirmed that N2 plasma
can be uniformly irradiated. On the other hand, Arand He plasma became nonuniform. It is assumed
to be due to partial discharge occurring between theirradiation object.
In the case of N2 plasma, the line typeatmospheric pressure plasma jet capable oftreating a width of around 30 mm could be
realized without contamination. Therefore, forexample, the surface modification of a 30 mm
cell culture dish can be expected.

References[1] T. Kawasaki, K. Kawano, H. Mizoguchi, Y. Yano, K.
Yamashita, M. Sakai, T. Shimizu, G. Uchida, K.
Koga, and M. Shiratani: IEEE Trans. Plasma Sci. 42(2014) 2482.