Kashiwa, Japan
Kashiwa, Japan

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Akaike S.,Tsurumi University | Kobayashi D.,Tokyo Institute of Technology | Aono Y.,Tokyo Institute of Technology | Hiratsuka M.,Nanotec Corporation | And 3 more authors.
Diamond and Related Materials | Year: 2016

In orthodontics, it is important to reduce the static friction between brackets and wires in order to enable easy tooth movement. The goal of the present study was to deposit diamond-like carbon (DLC), fluorine-doped DLC (F-DLC), and silicon-doped DLC (Si-DLC) coatings onto the slot surface in stainless steel orthodontic brackets using the plasma-enhanced chemical vapor deposition (PECVD) method and to characterize the frictional property between the coated bracket and wire under dry and wet conditions. In order to characterize DLC-, F-DLC- or Si-DLC-coated surface, XPS, the surface roughness and surface wettability of three deferent surfaces were measured. A nanoindentation test and a scratch test were performed in order to measure the hardness and adhesiveness, respectively, of DLC-, F-DLC- or Si-DLC coatings. The static friction between DLC-, F-DLC-, Si-DLC-coated brackets and 0.019 × 0.025-in stainless steel (SS) orthodontic wires was measured for several angulations under dry and wet conditions using a universal testing machine equipped with a custom-made friction-testing device. The F 1s or Si 2p and Si 2s peaks were observed for F-DLC (27.8 at.%:F) or Si-DLC (26.8 at.%:Si), respectively. There were no significant differences in the surface roughness of the slot surface of the bracket among the four types of specimens. The F-DLC was significantly hydrophobic and Si-DLC was significantly hydrophilic as compared to DLC. Doping the DLC with fluorine or silicon caused the surface hardness to decrease significantly. The results of the present study indicate that DLC, F-DLC and Si-DLC coatings provided a significant reduction in static friction. Among the coatings examined herein, F-DLC-coated bracket exhibited the significantly lowest static friction between the bracket and wire under the wet condition, which was lower than that under the dry condition. The F-DLC coating is highly promising as a means of promoting effective tooth movement and shortening treatment time for orthodontic treatments. © 2015 Elsevier B.V. All rights reserved.

Akaike S.,Tsurumi University | Hayakawa T.,Tsurumi University | Kobayashi D.,Tokyo Institute of Technology | Aono Y.,Tokyo Institute of Technology | And 3 more authors.
Dental Materials Journal | Year: 2015

In orthodontics, a reduction in static friction between the brackets and wire is important to enable easy tooth movement. The aim of this study was to examine the effects of a homogeneous diamond-like carbon (DLC) coating on the whole surfaces of slots in stainless steel orthodontic brackets on reducing the static friction between the brackets and the wire. The DLC coating was characterized using Raman spectroscopy, surface roughness and contact angle measurements, and SEM observations. Rectangular stainless steel and titanium-molybdenum alloy wires with two different sizes were employed, and the static friction between the brackets and wire was measured under dry and wet conditions. The DLC coating had a thickness of approximately 1.0 μm and an amorphous structure was identified. The results indicated that the DLC coating always led to a reduction in static friction. © 2015, Japanese Society for Dental Materials and Devices. All rights reserved.

Hiratsuka M.,Nanotec Corporation | Tanaka A.,Nanotec Corporation
Journal of the Vacuum Society of Japan | Year: 2015

Diamond-like carbon (DLC) films have attractive properties such as low friction, anti-wear, high hardness, and anti-corrosion. Such DLC films have been fabricated with various deposition methods such as magnetron sputtering, ion plating, filtered arc deposition, and plasma-enhanced chemical vapor deposition. The properties such as low friction in vacuum, electrical conductivity, hydrophobicity, and heat resistance can be added to DLC films by the modification of conventional deposition methods, or the doping of foreign elements. These DLC films can be applied to tribological parts in vacuum environment, dies for plastic moldings, inspection components of semiconductors, components of solar cells, and devices of medical engineering. Modified deposition techniques can also fabricate DLC films to large-scale machine components. © 2015, Vacuum Society of Japan. All rights reserved.

Takatsu M.,Nihon University | Asai T.,Nihon University | Hiratsuka M.,NANOTEC Corporation
IEEJ Transactions on Fundamentals and Materials | Year: 2014

A magnetized coaxial plasma gun (MCPG) has been studied in the context of nuclear fusion research, for particle and magnetic helicity injection and spheromak formation through electromagnetically accelerated magnetized plasmoid. On the other hand, most of physical vapor deposition (PVD) techniques have been developed for surface modification and new substance composition in field of electric-appliance, material, semiconductor, etc. However, in the conventional methods, conditions of deposition are limited by productive efficiency and thermal load to the substrate. We proposed a novel PVD method by utilizing electromagnetic acceleration of MCPG. In this study, we deposited Al films on SiO2by the method, and evaluated the deposition rate and the adhesion strength. We confirmed the adhesion strength of about 2.1 times higher than the conventional method. This method can deposit a thin film with high adhesion strength by electromagnetically accelerating particles. © 2014 The Institute of Electrical Engineers of Japan.

Hiratsuka M.,Tokyo University of Science | Hiratsuka M.,Nanotec Corporation | Azuma A.,Nanotec Corporation | Nakamori H.,Nanotec Corporation | And 2 more authors.
Surface and Coatings Technology | Year: 2013

High-power impulse magnetron sputtering (HIPIMS) technologies have great potential for material processing and surface modification of substrates. A diamond-like carbon (DLC) film is deposited using HIPIMS technology varying source voltage, pulse duration, and repetition rate. An extraordinary increase in the deposition rate is found. The deposition rate is 2.6 times greater than that expected on the basis of the proportional relationship between the deposition rate and the consumed power in the plasma lower than 40kW. When the repetition rate is varied, the deposition rate increases proportionally with the repetition rate less than 400Hz, while the deposition rate at 1500Hz is a factor of 1.3 times greater than that expected by the proportional relationship. The high deposition rate under these conditions may originate from the heat generated by the increased power consumption, which may be enough to volatilize the metal component according to its vapor pressure. The density of the carbon species emitted by this heating is estimated to be on the order of 1012cm-3. Because of the significant increase in the deposition rate, the ion current density at the substrate increases under identical power consumption, which gives an identical sputtering yield. Therefore, an additional factor to the magnetron sputtering may cause the significant increase in the deposition rate. © 2012 Elsevier B.V.

Tada H.,Tokyo Denki University | Mabuchi Y.,Tokyo Denki University | Hibino M.,Tokyo Denki University | Ohgoe Y.,Tokyo Denki University | And 12 more authors.
Transactions of Japanese Society for Medical and Biological Engineering | Year: 2014

Diamond-Like Carbon (DLC) films have excellent properties such as hemocompatibility, biocompatibility, and in-vivo stability. However, the properties of DLC films strongly depend on deposition conditions, fabrication equipments and deposition methods. To produce required films, a manufacture method and a preparation condition have to be carefully selected. In this study, biocompatibility of DLC films deposited by several kinds of equipments was estimated by the cell culture, and the correlation with DLC film surface state was investigated. By several kind of equipment, 19 types of DLC films were deposited on PS dish. We estimated biocompatibility and surface states for these films. We found that there was no correlation between biocompatibility of DLC films and the result of XPS, or that of contact angle measurements. However, there was strong correlation between biocompatibility and hardness test. This result shows hardness test becomes one of the useful methods to evaluate the biocompatibility of DLC films. © 2014, Japan Soc. of Med. Electronics and Biol. Engineering. All rights reserved.

Ohgoe Y.,Tokyo Denki University | Hirakuri K.K.,Tokyo Denki University | Saitoh H.,Nagaoka University of Technology | Nakahigashi T.,Nissin Electric Co. | And 5 more authors.
Surface and Coatings Technology | Year: 2012

In this study, various kinds of diamond-like carbon (DLC) films were classified in terms of their biological responses (specifically the number of adhering cells). Forty three kinds of DLC samples that had been deposited on Si substrate by various physical vapor deposition (PVD) and chemical vapor deposition (CVD) system equipment were obtained at random from coating companies, universities, and public organizations in Japan. Mouth fibroblasts (NIH-3T3) were used to estimate the cellular responses on the DLC samples. During the cell culture, 12 of the DLC samples were peeled off from the Si substrates. As a result, the remaining 31 DLC samples with a wide range of properties were classified into four groups in terms of their number of adhering cells. Group 1 (high density, low sp 2 content, and low hydrogen contents) and Group 2 (low or medium density, high sp 2 content, and low hydrogen contents) had a low number of adhering cells. Group 3 (medium density, and medium sp 2 content, and relatively high hydrogen contents) and Group 4 (low sp 2 content, low density, and a wide range of hydrogen contents) had a wide range of number of adhering cells. Especially, 7 DLC samples in Group 4 had good cell growth. It was shown that this classification is one of the design criteria of DLC film deposition for biomaterials regardless of the various deposition system equipment. It is expected that ordinary DLC users can carefully select a DLC film for specific applications to medical devices using the classification. © 2012 Elsevier B.V.

Nano Tec Co. and Samsung | Date: 2012-02-09

An apparatus for producing electrolytic reducing water with excellent reducing ability and a pH that is maintained neutral by combining advantages of a conventional water purifier and a conventional alkaline ionized water device.

Nanotec Co. | Date: 2014-07-16

An excellent and high-grade carbon film is formed on a surface of a material to be processed at a high speed. A film forming vacuum chamber includes: a substrate to which a predetermined voltage is applied by substrate voltage applying means in a vacuum chamber that can be depressurized to a predetermined degree of vacuum; and a plasma generating source that has at least one carbon raw material substrate that is arranged to face the substrate, forms plasma from an atmosphere for discharge generation introduced into the vacuum chamber based on adjustment electric power output to the carbon raw material substrate by a pulse power supply on the carbon raw material substrate, and discharges electricity together with a carbon raw material from the carbon raw material substrate toward the material to be processed that is held on the substrate, a carbon film is processed and formed on a surface of the material to be processed by a sputtering method, the pulse power supply and the substrate voltage applying means are connected to an oscillation apparatus for a gate signal by a mechanism that adjusts an initial voltage, and each of the pulse power supply and the substrate power supply has an adjustment circuit that controls each of a pulse width, delay timing from application of a voltage to a target to application of a substrate voltage, a frequency, and a voltage in a predetermined range.

Samsung and Nano Tec Co. | Date: 2012-10-10

An apparatus for producing electrolytic reducing water with excellent reducing ability and a pH that is maintained neutral by combining advantages of a conventional water purifier and a conventional alkaline ionized water device.

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