Search

Your search keyword '"Tsuchitani, Shigeki"' showing total 127 results
Start Over Author "Tsuchitani, Shigeki"
127 results on '"Tsuchitani, Shigeki"'

6. Ultrathin amorphous carbon overcoats by filtered cathodic arc deposition

Author

Yamamoto, Takayuki, Hyodo, Hiroyuki, Tsuchitani, Shigeki, and Kaneko, Reizo

Subjects
Business, Electronics, Electronics and electrical industries
Abstract

We studied properties of 2- to 25-nm-thick tetrahedral amorphous carbon films produced by filtered cathodic arc deposition. We found that nitrogen doping was effective in controlling film properties. Both the amount of [sp.sup.3] bonding in the film and the hardness decreased with nitrogen incorporation. The adhesion of lubricant to the carbon film was improved by nitrogen doping. Tests of wear and corrosion on a nanometer scale showed the superior tribological and anticorrosion performance of tetrahedral amorphous carbon films over hydrogenated amorphous carbon films. Index Terms--Corrosion resistance, durability, filtered cathodic arc deposition, overcoat, tetrahedral amorphous carbon.

Published
2003

11. A novel microneedle device having flexible substrate and strong needles using PVA and gelatin

Author

Miki Hirofumi, Nishikata Ryota, and Tsuchitani Shigeki

Subjects
food.ingredient, Materials science, Fabrication, Biocompatibility, Nanotechnology, 02 engineering and technology, Substrate (printing), 021001 nanoscience & nanotechnology, 030226 pharmacology & pharmacy, Gelatin, 03 medical and health sciences, 0302 clinical medicine, medicine.anatomical_structure, food, Stratum corneum, medicine, 0210 nano-technology, Transdermal
Abstract

In recent years, Transdermal Drug Delivery System (TDDS) has been attracting rising attention. A problem in TDDS is that the drug need to be dosed will be forbidden by the stratum corneum of the epidermis (thickness about 20 μm). Microneedle is considered to be a promising technology to solve this problem [1]. But, there are still many other problems in the conventional technology, such as the fabrication cost, biocompatibility and the limitation of the dosage amount due to the small device area.

Published
2017

16. Nafion®-based polymer actuators with ionic liquids as solvent incorporated at room temperature.

Author

Kikuchi, Kunitomo and Tsuchitani, Shigeki

Subjects
*PHYSICS experiments, *IONIC liquids, *METAL-filled plastics, *POLYMERS, *SOLVENTS, *CURVATURE
Abstract

Nafion®-based ionic polymer-metal composites (IPMCs), with ionic liquids as solvent, were fabricated by exchanging counterions to ionic liquids at room temperature. Ion exchange is performed by only immersing IPMC in a mixture of de-ionized water and ionic liquids at room temperature for 48 h. The fabricated IPMCs exhibited a bending curvature the same as or larger than that of conventional IPMCs with ionic liquids, formed by ion exchange to ionic liquids at an elevated temperature up to about 100 °C, and also had long-term stability in operation in air, with a fluctuation smaller than 21% in bending curvature during a 180 min operation. The effective ion exchange to ionic liquids in the present method is probably due to an increase in diffusion speed of ionic liquids into IPMC by adsorption of water in a Nafion® membrane. It is a surprise that among IPMCs with ionic liquids 1-ethyl-3-methyl-imidazolium tetrafluoroborate, 1-buthyl-3-methyl-imidazolium tetrafluoroborate (BMIBF4), and 1-buthyl-3-methyl-imidazolium hexafluorophosphate (BMIPF6), IPMC with water-insoluble BMIPF6 exhibited a larger bending curvature than that IPMC with water-miscible BMIBF4. This might be due to effective incorporation of BMIPF6 into IPMC, since BMIPF6 has a higher affinity with IPMC than with water in the mixture of water and BMIPF6. From measurements of complex impedance and step voltage response of the driving current of IPMCs with ionic liquid, they are expressed by an equivalent circuit of a parallel combination of a serial circuit of membrane resistance of Nafion® and electric double layer capacitance at metal electrodes, with membrane capacitance of Nafion®, in a frequency range higher than about 0.1 Hz. The difference in magnitude of bending curvature in three kinds of IPMCs with ionic liquids is mainly due to the difference in bending response speed coming from the difference in the membrane resistance. [ABSTRACT FROM AUTHOR]

Published
2009
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results