2021/05/15 更新

写真a

タケヤス ノブユキ
武安 伸幸
TAKEYASU Nobuyuki
所属
自然科学学域 准教授
職名
准教授
外部リンク

学位

  • 博士(工学) ( 2001年2月   九州大学 )

研究分野

  • ナノテク・材料 / ナノ材料科学

学歴

  • 九州大学    

    1995年4月 - 2001年2月

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  • 九州大学   工学部  

    1991年4月 - 1995年3月

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経歴

  • 岡山大学   大学院自然科学研究科   准教授

    2012年9月 - 現在

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  • 大阪大学   フォトニクス先端融合研究センター   特任講師

    2010年9月 - 2012年9月

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  • 理化学研究所   ナノフォトニクス研究室   基礎科学特別研究員

    2003年10月 - 2006年9月

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  • 九州大学   今坂研究室   NEDO地域コンソーシアム研究開発事業 博士研究員

    2001年4月 - 2003年2月

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論文

  • Comparison of hot carrier generation between self-assembled gold and silver nanoparticle arrays tailored to the same hybrid plasmon resonance 査読

    Tetsuya Fujita, Yuki Takeuchi, Kenzo Yamaguchi, Taka-aki Yano, Takuo Tanaka, Nobuyuki Takeyasu

    Journal of Applied Physics128 ( 12 ) 123104 - 123104   2020年9月

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    担当区分:責任著者   掲載種別:研究論文(学術雑誌)   出版者・発行元:AIP Publishing  

    DOI: 10.1063/5.0020403

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  • Isolation and identification of the antimicrobial substance included in tempeh using Rhizopus stolonifer NBRC 30816 for fermentation. 査読 国際誌

    Masahiro Ito, Takashi Ito, Hideyuki Aoki, Koshi Nishioka, Tsugumi Shiokawa, Hiroko Tada, Yuki Takeuchi, Nobuyuki Takeyasu, Tadashi Yamamoto, Shogo Takashiba

    International journal of food microbiology325   108645 - 108645   2020年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In this study, we focus on the antimicrobial properties of tempeh, a soybean fermented food, against oral bacteria. Tempeh showed antimicrobial activity against dental caries pathogenic bacterium Streptococcus mutans at a final concentration of 1 mg/mL. An antimicrobial substance contained in tempeh was present in the 100 kDa or greater fraction generated by ultrafiltration, but it was found not to be proteinaceous by native-PAGE, SDS-PAGE and protein degradation tests. Next, when the fraction was purified with an ODS column, the 80% and 100% methanol eluates showed antimicrobial activity against S. mutans. The 100% methanol eluate was further subjected to a 2nd column purification, and isolation of the target was confirmed by HPLC. When the isolated material was analyzed by ESI-MS, the m/z was 279.234. Further analysis by Raman spectroscopy revealed a peak similar to linoleic acid. This substance also possessed antimicrobial properties equivalent to linoleic acid.

    DOI: 10.1016/j.ijfoodmicro.2020.108645

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  • Hot Carrier Generation in Two-Dimensional Silver Nanoparticle Arrays at Different Excitation Wavelengths under On-Resonant Conditions 査読

    Yuki Takeuchi, Antoine Violas, Tetsuya Fujita, Yasuaki Kumamoto, Mircea Modreanu, Takuo Tanaka, Katsumasa Fujita, Nobuyuki Takeyasu

    The Journal of Physical Chemistry C124 ( 25 ) 13936 - 13941   2020年6月

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    担当区分:責任著者   掲載種別:研究論文(学術雑誌)   出版者・発行元:American Chemical Society (ACS)  

    DOI: 10.1021/acs.jpcc.0c04034

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  • Plasmon-mediated chemical transformation from alkane to alkene on a silver nanoparticle array under 532 nm excitation 査読

    Takeuchi Yuki, Fujita Tetsuya, Takeyasu Nobuyuki

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS21 ( 14 ) 7502 - 7507   2019年4月

  • Hydrophobic assembly of gold nanoparticles into plasmonic oligomers with Langmuir-Blodgett film 査読

    Ikegami Shiho, Yamaguchi Kenzo, Tanaka Takuo, Takeyasu Nobuyuki, Kaneta Takashi

    JAPANESE JOURNAL OF APPLIED PHYSICS57 ( 12 )   2018年12月

  • Extraction of three-dimensional silver nanostructures with supercritical fluid 査読

    Natsuo Taguchi, Nobuyuki Takeyasu, Satoshi Kawata

    Applied Physics Express11 ( 2 )   2018年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Japan Society of Applied Physics  

    In a previous report, a self-growing approach was proposed for fabricating complex silver nanostructures, where silver dendrites were grown at silver nanoseeds in silver ion solution owing to plasmonic heating with ultraviolet light. Structures were deformed or destroyed when they were extracted with acetone and dried in air. In this Letter, we discuss the use of supercritical carbon dioxide fluid for the nondestructive extraction of nanostructures. We show the experimental results and discuss the laser power dependence of resultant structures. Another experiment was performed for nanostructure growth inside an agarose gel as a matrix. Silver nanostructures were immobilized without damage in an agarose skeleton network.

    DOI: 10.7567/APEX.11.025201

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  • Enhanced collection efficiency of vesicles in a suspension by optical pressure using gold nanoparticles 査読

    Takashi Kaneta, Mai Kuboi, Nobuyuki Takeyasu

    Proceedings of SPIE - The International Society for Optical Engineering10712   2018年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE  

    We developed a method to collect micro- and nano-vesicles on a glass substrate using the optical pressure of a laser beam. The laser beam was focused on the glass substrate which sandwiches a suspension containing micro- or nano-sized vesicles prepared by a phospholipid. The optical pressure generated at the interface of the medium and the vesicles accelerated the vesicles to form aggregates on the glass surface. Two types of glass substrates, hydrophilic and aminated ones, showed no difference in the adsorption property of the vesicles. Time to be required for collecting a certain amount of the vesicles was inversely proportional to the concentration of the vesicles. To enhance the collection efficiency, gold nanoparticles were added to the suspension of the vesicles. We found that gold nanoparticles reduced the collection time as short as 1/10-times.

    DOI: 10.1117/12.2317724

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  • Enhanced Optical Collection of Micro- and Nanovesicles in the Presence of Gold Nanoparticles 査読

    Mai Kuboi, Nobuyuki Takeyasu, Takashi Kaneta

    ACS Omega3 ( 3 ) 2527 - 2531   2018年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:American Chemical Society  

    We describe a process for collecting micro- and nanovesicles on a glass substrate using the optical pressure of a laser beam. The laser beam was focused on a glass substrate that sandwiched a solution containing vesicles prepared using a phospholipid. The optical pressure generated at the surface of the vesicles pulled them into the center of the beam where they formed an aggregate on the glass surface. The vesicles prepared with a buffer solution were successfully collected via adsorption onto the glass surface, whereas the vesicles prepared with pure water exhibited no such tendency. The time required to collect a certain amount of vesicles was inversely proportional to their concentration. To enhance the collection efficiency, we added gold nanoparticles to the vesicle solution. The addition of gold nanoparticles into the solution reduced the collection time to one-tenth of that without it, and this was attributed to thermal mixing promoted by the heat generated by the absorption from the gold nanoparticles in the solution, as well as to an enhancement of light scattering induced by the gold nanoparticles. The optical collection of vesicles coupled with gold nanoparticles shows a promise for the collection of trace amounts of extracellular vesicles in biological fluids.

    DOI: 10.1021/acsomega.8b00033

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  • Selective electroless plating of 3D-printed plastic structures for three-dimensional microwave metamaterials 査読

    Atsushi Ishikawa, Taiki Kato, Nobuyuki Takeyasu, Kazuhiro Fujimori, Kenji Tsuruta

    APPLIED PHYSICS LETTERS111 ( 18 )   2017年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    A technique of selective electroless plating onto PLA-ABS (Polylactic Acid-Acrylonitrile Butadiene Styrene) composite structures fabricated by three-dimensional (3D) printing is demonstrated to construct 3D microwave metamaterials. The reducing activity of the PLA surface is selectively enhanced by the chemical modification involving Sn2+ in a simple wet process, thereby forming a highly conductive Ag-plated membrane only onto the PLA surface. The fabricated metamaterial composed of Ag-plated PLA and non-plated ABS parts is characterized experimentally and numerically to demonstrate the important bi-anisotropic microwave responses arising from the 3D nature of metallodielectric structures. Our approach based on a simple wet chemical process allows for the creation of highly complex 3D metal-insulator structures, thus paving the way toward the sophisticated microwave applications of the 3D printing technology. Published by AIP Publishing.

    DOI: 10.1063/1.4986203

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  • Blocking Hot Electron Emission by SiO2 Coating Plasmonic Nanostructures 査読

    Nobuyuki Takeyasu, Kenzo Yamaguchi, Ryusuke Kagawa, Takashi Kaneta, Felix Benz, Masamitsu Fujii, Jeremy J. Baumberg

    JOURNAL OF PHYSICAL CHEMISTRY C121 ( 34 ) 18795 - 18799   2017年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    Noble metallic nanostructures provide a platform for high-sensitivity spectroscopic sensing with significantly enhanced electromagnetic fields due to surface plasmon polaritons. However, target molecules can be transformed into other molecules under irradiation with an excitation laser during the surface-enhanced measurement, which thus disturbs detection of unknown samples. In this paper, we perform Raman measurements of p-aminothiophenol on gold nanosurfaces with and without deposition of SiO2 thin films at the surface. The Raman signals, are enhanced on both substrates, but the deposition of the glass thin film clearly prevents the chemical transformation. This indicates that hot electrons are effective for Chemical transformation and that thin glass films are sufficient to prevent this while still benefiting from surface plasmons.

    DOI: 10.1021/acs.jpcc.7b02345

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  • Temperature-induced Coalescence of Droplets Manipulated by Optical Trapping in an Oil-in-Water Emulsion 査読

    Manami Mitsunobu, Sakurako Kobayashi, Nobuyuki Takeyasu, Takashi Kaneta

    ANALYTICAL SCIENCES33 ( 6 ) 709 - 713   2017年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN SOC ANALYTICAL CHEMISTRY  

    Coalescence of oil droplets in an oil-in-water (O/W) emulsion was achieved with heating and optical trapping. Three types of O/W emulsions were prepared by adding a mixture of butanol and n-decane to an aqueous solution containing a cationic surfactant (cetyltrimethylammonium bromide, CTAB), an anionic surfactant (sodium dodecyl sulfate, SDS), or a neutral hydrophilic polymer (polyethylene glycol, PEG) as an emulsifier. Two oil droplets in the emulsions were randomly trapped in a square capillary tube by two laser beams in order to induce coalescence. Coalescence of the droplets could not be achieved at room temperature (25 degrees C) regardless of the type of emulsifier. Conversely, the droplets prepared with PEG coalesced at a temperature higher than 30 degrees C, although the droplets with ionic surfactants CTAB and SDS did not coalesce even at the elevated temperature due to their electrostatic repulsion. The size of the resultant coalesced droplet was consistent with that calculated from the size of the two droplets of oil, which indicated successful coalescence of the two droplets. We also found that the time required for the coalescence could be correlated with the temperature using an Arrhenius plot.

    DOI: 10.2116/analsci.33.709

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  • Invited Article: Plasmonic growth of patterned metamaterials with fractal geometry 査読

    Takeyasu Nobuyuki, Taguchi Natsuo, Nishimura Naoki, Cheng Bo Han, Kawata Satoshi

    APL PHOTONICS1 ( 5 )   2016年8月

  • Oil-in-water emulsion as fabrication platform for uniform plasmon-controlled two-dimensional metallic nanoparticle array 査読

    Ryusuke Kagawa, Nobuyuki Takeyasu, Takashi Kaneta, Yoshito Takemoto

    APPLIED PHYSICS EXPRESS9 ( 7 )   2016年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IOP PUBLISHING LTD  

    Gold/silver nanoparticles were trapped at the oil/water interface of oil droplets dispersed in water. The metallic nanoparticles were self-assembled into a uniform two-dimensional large array structure through the aggregation and coalescence of the nanoparticle-covered oil droplets. The plasmon resonance of the array structure was tunable and a surface-enhanced Raman scattering measurement was performed with the silver nanoparticle array. The enhancement factor was similar to 10(5) and enhanced Raman signals were observed over the whole array (greater than or similar to cm(2)) with high reproducibility, which is an advantage of a self-assembly method using a liquid/liquid interface. (C) 2016 The Japan Society of Applied Physics

    DOI: 10.7567/APEX.9.075003

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  • Laser Power Threshold of Chemical Transformation on Highly Uniform Plasmonic and Catalytic Nanosurface 査読

    Nobuyuki Takeyasu, Ryusuke Kagawa, Kohei Sakata, Takashi Kaneta

    JOURNAL OF PHYSICAL CHEMISTRY C120 ( 22 ) 12163 - 12169   2016年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    Noble metallic nanosurface exhibits both plasmonic and catalytic functions. Surface-enhanced Raman scattering of para-aminothiophenol (p-ATP) was measured on a highly uniform two-dimensional silver nanoparticle array at different intensities of an excitation laser (532 nm) ranging from 4 to 4000 W/mm(2). It was observed that p-ATP was chemically transformed to 4,4'-dimercaptoazobenzene (DMAB) with the laser intensities of >= 40 W/mm(2) during the Raman measurement. At 4 W/mm(2), the Raman peaks of DMAB disappeared, which indicates that the laser intensity was insufficient for the chemical transformation although it was sufficient for the Raman measurement. The highly uniform silver nanoparticle array allowed quantitative analysis on the Raman peak intensity. The threshold of the chemical transformation from p-ATP to DMAB was estimated to be similar to 48.8 W/mm(2) on the silver nanoparticle array whose enhancement factor is similar to 10(4).

    DOI: 10.1021/acs.jpcc.6b01756

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  • Speciation of arsenic in a thermoacidophilic iron-oxidizing archaeon, Acidianus brierleyi, and its culture medium by inductively coupled plasma-optical emission spectroscopy combined with flow injection pretreatment using an anion-exchange mini-column. 査読 国際誌

    Naoki Higashidani, Takashi Kaneta, Nobuyuki Takeyasu, Shoji Motomizu, Naoko Okibe, Keiko Sasaki

    Talanta122   240 - 5   2014年5月

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    記述言語:英語  

    The thermoacidophilic iron-oxidizing archaeon Acidianus brierleyi is a microorganism that could be useful in the removal of inorganic As from wastewater, because it simultaneously oxidizes As(III) and Fe(II) to As(V) and Fe(III) in an acidic culture medium, resulting in the immobilization of As(V) as FeAsO₄. To investigate the oxidation mechanism, speciation of the As species in both the cells and its culture media is an important issue. Here we describe the successive determination of As(III), As(V), and total As in A. brierleyi and its culture medium via a facile method based on inductively coupled plasma-optical emission spectroscopy (ICP-OES) with a flow injection pretreatment system using a mini-column packed with an anion-exchange resin. The flow-injection pretreatment system consisted of a syringe pump, a selection valve, and a switching valve, which were controlled by a personal computer. Sample solutions with the pH adjusted to 5 were flowed into the mini-column to retain the anionic As(V), whereas As(III) was introduced into ICP-OES with no adsorption on the mini-column due to its electrically neutral form. An acidic solution (1 M HNO₃) was then flowed into the mini-column to elute As(V) followed by ICP-OES measurement. The same sample was also subjected to ICP-OES without being passed through the mini-column in order to determine the total amounts of As(III) and As(V). The method was verified by comparing the results of the total As with the sum of As(III) and As(V). The calibration curves showed good linearity with limits of detection of 158, 86, and 211 ppb for As(III), As(V), and total As, respectively. The method was successfully applicable to the determination of the As species contained in the pellets of A. brierleyi and their culture media. The results suggested that the oxidation of As(III) was influenced by the presence of Fe(II) in the culture medium, i.e., Fe(II) enhanced the oxidation of As(III) in A. brierleyi. In addition, we found that no soluble As species was contained in the cell pellets and more than 60% of the As(III) in the culture medium was oxidized by A. brierleyi after a 6-day incubation.

    DOI: 10.1016/j.talanta.2014.01.057

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  • Determination of association constants between 5 '-guanosine monophosphate gel and aromatic compounds by capillary electrophoresis 査読

    Kaori Yamaguchi, Nobuyuki Takeyasu, Takashi Kaneta

    JOURNAL OF CHROMATOGRAPHY A1288   149 - 154   2013年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    Hydro gel formed by 5'-guanosine monophosphate (GMP) in the presence of a potassium ion is expected to exhibit interesting selectivity in capillary electrophoretic separations. Here, we estimated the conditional association constants between the hydro gel (G-gel) and aromatic compounds by capillary electrophoresis in order to investigate the separation selectivity that is induced by the G-gel. Several aromatic compounds were separated in a solution containing GMP and potassium ion at different concentrations. The association constants were calculated by correlating the electrophoretic mobilities of the analytes obtained experimentally using a concentration of G-gel. During semi-quantitative estimation, naphthalene derivatives had larger association constants (K-ass = 10.3-16.8) compared with those of benzene derivatives (K-ass = 3.91-5.31), which means that the binding sites of G-gel match better to a naphthalene ring than to a benzene ring. A hydrophobic interaction was also found when the association constants for alkyl resorcinol were compared with those of different hydrocarbon chains. The association constants of nucleobases and tryptophan ranged from 6.05 to 12.6, which approximated the intermediate values between benzene and naphthalene derivatives. Consequently, the selective interaction between G-gel and aromatic compounds was classified as one of three types: (1) an intercalation into stacked planar GMP tetramers; (2) a hydrophobic interaction with a long alkyl chain; or, (3) a small contribution of steric hindrance and/or hydrogen bonding with functional groups such as amino and hydroxyl groups. (C) 2013 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.chroma.2013.02.090

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  • C-2v symmetrical two-photon polymerization initiators with anthracene core: synthesis, optical and initiating properties 査読

    Jin-Feng Xing, Mei-Ling Zheng, Wei-Qiang Chen, Xian-Zi Dong, Nobuyuki Takeyasu, Takuo Tanaka, Zhen-Sheng Zhao, Xuan-Ming Duan, Satoshi Kawata

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS14 ( 45 ) 15785 - 15792   2012年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ROYAL SOC CHEMISTRY  

    A series of C-2v symmetrical two-photon absorption compounds with anthracene core, 2,7-bis[2-(4-substituted phenyl)-vinyl]-9,10-dipentyloxyanthracenes designated as I, II and III (the substituted groups at the 4-position of phenyl of I, II and III were dimethylamino, methyl and cyano, respectively) were designed and synthesized as initiators in two-photon induced polymerization (TPIP). The anthracene ring was modified by linking vinylphenyl groups to the 2,7-position to extend conjugation system length and two pentyloxy groups to the 9,10-position to serve as electronic donors. Two-photon absorption cross section of I was around 300 GM, which was much larger than the 10 GM of II and 29 GM of III at 800 nm. I of 0.18% molar ratio in resin composed of methacrylic acid and dipentaerythritol hexaacrylate exhibited a dramatically low threshold of 0.64 mW compared with commercial photoinitiator benzil at a scanning speed 10 mu m s(-1). Moreover, the threshold of photoinitiator I was only increased to 2.53 mW at a scanning speed of 1000 mu m s(-1). The dependency of threshold on the concentration and exposure time was in accordance with theoretical calculation. Finally, a reasonable mechanism of the two-photon initiating process was proposed. This study provides good prospects for developing low threshold photoinitiator in TPIP.

    DOI: 10.1039/c2cp42512b

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  • Morphology and size dependence of silver microstructures in fatty salts-assisted multiphoton photoreduction microfabrication 査読

    Yao-Yu Cao, Xian-Zi Dong, Nobuyuki Takeyasu, Takuo Tanaka, Zhen-Sheng Zhao, Xuan-Ming Duan, Satoshi Kawata

    APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING96 ( 2 ) 453 - 458   2009年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    The morphology and size dependence of silver microstructures in a novel microfabrication process, fatty salts-assisted multiphoton photoreduction (MPR), were investigated by using the fatty salts with different carbon chain lengths (C (n) : n=4,5,7,9) under varied powers and irradiation times of a femtosecond near-infrared laser with the wavelength of 800 nm. Not only the feature size of the silver structures was reduced but also the surface smoothness was improved by increasing the chain length of the fatty salts. The highest resolution of a silver line was obtained to be 285 nm, which exceeded the diffraction limit. The fatty salts-assisted MPR microfabrication approach would provide an efficient protocol for fabricating metallic micro/nanostructures with fine morphology and size and could play an important role in the fabrication of the metallic micro/nanostructures for applications in photonics and electronics as well as in sensors.

    DOI: 10.1007/s00339-009-5270-7

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  • 3D Metallic Nanostructure Fabrication by Surfactant-Assisted Multiphoton-Induced Reduction 査読

    Yao-Yu Cao, Nobuyuki Takeyasu, Takuo Tanaka, Xuan-Ming Duan, Satoshi Kawata

    SMALL5 ( 10 ) 1144 - 1148   2009年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-V C H VERLAG GMBH  

    DOI: 10.1002/smll.200801179

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  • Two-photon Fabrication of Three-dimensional Metamaterials 査読

    Satoshi Kawata, Takuo Tanaka, Nobuyuki Takeyasu

    2009 CONFERENCE ON LASERS AND ELECTRO-OPTICS AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (CLEO/QELS 2009), VOLS 1-5   2170 - 2171   2009年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    Two-photon-induced metal ion reduction technique is developed for fabricating 3D metallic micro/nano structures. The fabrication of continuous and electrically conductive silver structures with a minimum width of 100nm are demonstrated. Moreover, the realization of self-supporting 3D silver microstructures is demonstrated. This technique will become a promising tool for realizing three-dimensional plasmonic metamaterials.

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  • Fabrication of 3D metal/polymer microstructures by site-selective metal coating 査読

    N. Takeyasu, T. Tanaka, S. Kawata

    APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING90 ( 2 ) 205 - 209   2008年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Three-dimensional silver/polymer conjugated microstructures were fabricated by site-selective metal deposition on photopolymer structures in the sub-micrometer scale. Photopolymerizable resins with and without an amide group were independently prepared, and a three-dimensional polymer structure was fabricated with those resins by means of the two-photon-induced photopolymerization technique to confine the photopolymerization to a sub-micrometer volume. Silver was selectively deposited on the surface of the amide-containing polymer parts by electroless plating. This method can provide 3D arbitrary silver/polymer composite microstructures with sub-micrometer resolution.

    DOI: 10.1007/s00339-007-4298-9

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  • Improving spatial resolution of two-photon microfabrication by using photoinitiator with high initiating efficiency 査読

    Jin-Feng Xing, Xian-Zi Dong, Wei-Qiang Chen, Xuan-Ming Duan, Nobuyuki Takeyasu, Takuo Tanaka, Satoshi Kawata

    APPLIED PHYSICS LETTERS90 ( 13 )   2007年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    The lateral spatial resolution (LSR) in two-photon induced polymerization was improved to 80 nm by using an anthracene derivative (9,10-bis-pentyloxy-2,7-bis[2-(4-dimethylamino-phenyl)-vinyl]anthracene (BPDPA)) as a highly sensitive and efficient photoinitiator. Photocurable resin containing 0.18 mol % BPDPA exhibited a low polymerization threshold of 0.64 mW at 800 nm. Theoretical calculations showed that the LSR can be increased by reducing the laser power, indicating that the LSR could be improved using more sensitive initiators in the future. (c) 2007 American Institute of Physics.

    DOI: 10.1063/1.2717532

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  • Design of high efficiency for two-photon polymerization initiator: combination of radical stabilization and large two-photon cross-section achieved by N-benzyl 3,6-bis(phenylethynyl)carbazole derivatives 査読

    Jin-Feng Xing, Wei-Qiang Chen, Jie Gu, Xian-Zi Dong, Nobuyuki Takeyasu, Takuo Tanaka, Xuan-Ming Duan, Satoshi Kawata

    JOURNAL OF MATERIALS CHEMISTRY17 ( 14 ) 1433 - 1438   2007年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ROYAL SOC CHEMISTRY  

    Novel A-pi-D-pi-A V-shaped 3,6-bis(phenylethynyl)carbazole based chromophores were designed and synthesized as two-photon polymerization (TPP) initiators combining a large two-photon absorption cross-section with facilitated radical formation. 9-Benzyl-3,6-bis(4-nitrophenylethynyl) carbazole (4d) shows a strong two-photon absorption around 800 nm and exhibits very high two-photon polymerization initiating sensitivity with a threshold power of 0.8 mW at the concentration of 0.18 mol%, which is much lower than the threshold power of 6.37 mW found for benzil. The corresponding threshold of laser exposure intensity for TPP is 3.06 x 10(7) mJ cm(-2). The lowest loading of 4d is up to 0.012 mol% with a threshold power of 3.2 mW.

    DOI: 10.1039/b616792f

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  • Three-dimensional metal microfabrication technique by using two-photon reduction 査読

    Nobuyuki Takeyasu, Takuo Tanaka, Satoshi Kawata

    2007 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS, VOLS 1-4   1073 - 1074   2007年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    We propose micro-fabrication technique that enables us to obtain arbitrary 3D micro/nano metallic structures by scanning the laser beam spot in three dimensions. The spatial resolution and the electrical conductivity of the fabricated structures are discussed.

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  • PMSE 349-Effects of PEG600 and Tween80 on performances and gelation kinetics of PPEK hollow fiber membranes 査読

    Nobuyuki Takeyasu, Florian Formanek, Takuo Tanaka, Atsushi Ishikawa, Satoshi Kawata

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY232   491 - 491   2006年9月

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    記述言語:英語   出版者・発行元:AMER CHEMICAL SOC  

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  • Selective electroless plating to fabricate complex three-dimensional metallic micro/nanostructures 査読

    F Formanek, N Takeyasu, T Tanaka, K Chiyoda, A Ishikawa, S Kawata

    APPLIED PHYSICS LETTERS88 ( 8 )   2006年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    We report on selective metal deposition over complex polymer structures formed by two-photon induced photopolymerization technique. Periodic three-dimensional micro/nanostructures are fabricated by means of a microlens array to produce multiple spots from a single-beam femtosecond laser. An electroless plating method is used to deposit a thin silver film onto the sample surface. The glass slide surface supporting the structures is chemically modified to avoid silver coating of the substrate. Our technique enables to produce complex metallic structures with arbitrary shapes under ambient conditions. (c) 2006 American Institute of Physics.

    DOI: 10.1063/1.2178261

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  • Three-dimensional fabrication of metallic nanostructures over large areas by two-photon polymerization 査読

    F Formanek, N Takeyasu, T Tanaka, K Chiyoda, A Ishikawa, S Kawata

    OPTICS EXPRESS14 ( 2 ) 800 - 809   2006年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:OPTICAL SOC AMER  

    An experimental protocol for the realization of three-dimensional periodic metallic micro/nanostructures over large areas is presented. Simultaneous fabrication of hundreds of three-dimensional complex polymer structures is achieved using a two-photon photopolymerization (TPP) technique combined with a microlens array. Metallization of the structures is performed through the deposition of thin and highly conductive films by electroless plating. A chemical modification of the photopolymerizable resin and the production of a hydrophobic coating on the glass surface supporting the structures are realized. This process prevents metal deposition on the substrate and restricts adhesion on polymer. Our technique can produce periodic and/or isolated metallic structures with arbitrary shape, created by more than 700 individual objects written in parallel.

    DOI: 10.1364/OPEX.14.000800

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  • Site-selective metal deposition on 3D micro/nanostructures fabricated by two-photon polymerization 査読

    N. Takeyasu, F. Formanek, K. Chiyoda, T. Tanaka, A. Ishikawa, S. Kawata

    PLASMONICS: NANOIMAGING, NANOFABRICATION, AND THEIR APPLICATIONS II6324   2006年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING  

    Recently, fabrication of metal micro-pattern has attracted a great attention. For such purpose, site-selective activation is crucial for metal deposition on a substrate, and it can be achieved through lithography, chemical vapor deposition and micro-contact printing. Here, we propose to control the activation point three-dimensionally (3D) through two-photon absorption (TPA) polymerization method, which leads to 3D site-selective deposition. Two types of photopolymer were prepared for deposition control of metal through electroless plating method. One was a commercially available resin, which is typically inactive to metal deposition. Another was a modified resin containing suitable functional groups for metal adhesion. We created a 3D polymer structure consisting of those two components by localizing each resin through TPA method. The fabricated structures were immersed in an electroless plating solution of silver. The partially silver coated sample was observed by a scanning electron microscope after washing and desiccation. Metal microstructure supported with polymer can be realized by 3D site-selective metal deposition. Therefore, it is a useful technique for 3D aligned metallic microstructures without any contacts each other.

    DOI: 10.1117/12.681511

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  • Three-dimensional fabrication of metallic micro/nanostructures by two-photon polymerization for Metamaterials 査読

    Florian Formanek, Nobuyuki Takeyasu, Takuo Tanaka, Kenta Chiyoda, Atsushi Ishikawa, Satoshi Kawata

    PLASMONICS: NANOIMAGING, NANOFABRICATION, AND THEIR APPLICATIONS II6324   2006年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING  

    We report on selective metal deposition over complex polymer structures formed by two-photon induced photopolymerization (TPP) technique. Periodic three-dimensional (3D) polymer micro/nanostructures are fabricated by means of a microlens array to produce multiple spots from a single-beam femtosecond laser amplified by a regenerative amplifier. The photopolymerizable resin and the glass substrate are chemically modified, and a pre-treatment with SnCl2 is applied before realizing a uniform silver coating by electroless plating. This preparation enables a selective deposition of small silver particles only on the polymer surface all over the sample and to avoid metal deposition on the substrate. Electrical measurements show the structures to be highly conductive with typical resistivities p similar to 10(-7) Omega m, only a few times larger than the value for bulk silver. By taking advantage of the high accuracy and arbitrary shape modeling of TPP fabrication, we can realize complex periodic and/or metallic micro-nanostructures which were so far out of reach. Thus, a straightforward application could be the realization of metamaterials. The processing efficiency of our technique is demonstrated with the fabrication of several large samples, created by more than 700 objects written in parallel and metallized with silver.

    DOI: 10.1117/12.681430

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  • Multiple-spot parallel processing for laser micronanofabrication 査読

    J Kato, N Takeyasu, Y Adachi, HB Sun, S Kawata

    APPLIED PHYSICS LETTERS86 ( 4 )   2005年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    A tightly focused femtosecond laser has been established as a unique tool for micronanostructure fabrication due to its intrinsic three-dimensional processing. In this letter, we utilize a microlens array to produce multiple spots for parallel fabrication, giving rise to a revolutionary augmentation for our previously developed single-beam two-photon photopolymerization technology [S. Kawata, H.-B. Sun, T. Tanaka, and K. Takada, Nature (London) 412, 697 (2001)]. Two- and three-dimensional multiple structures, such as microletter set and self-standing microspring array, are demonstrated as examples of mass production. More than 200 spot simultaneous fabrication has been realized by optimizing the exposure condition for the photopolymerizable resin, i.e., a two-order increase of yield efficiency. Potential applications of this technique are discussed. (C) 2005 American Institute of Physics.

    DOI: 10.1063/1.1855404

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  • Metal deposition deep into microstructure by electroless plating 査読

    N Takeyasu, T Tanaka, S Kawata

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS44 ( 33-36 ) L1134 - L1137   2005年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:INST PURE APPLIED PHYSICS  

    It is generally difficult to deposit metal on an occluded part of a structure or inside a long tubular structure. In this paper, we report an electroless plating method that is useful for metal deposition onto internal obscured regions of a complex structure, and we show that the technique can deposit metal over a wide area. We demonstrate gold deposition inside a capillary tube and a complex concave structure of micrometer scale consisting of polystyrene microbeads sandwiched between glass plates.

    DOI: 10.1143/JJAP.44.L1134

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  • Effect of laser pulsewidth on the generation of multi-color laser emission by stimulated Raman scattering and four-wave Raman mixing in a KGd(WO4)(2) crystal 査読

    M Matsuse, T Deguchi, H Ohtsuka, N Takeyasu, Y Hirakawa, T Imasaka

    OPTICS COMMUNICATIONS223 ( 4-6 ) 411 - 416   2003年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    Picosecond and femtosecond lasers having different pulsewidths were employed for the generation of multi-color laser emission via stimulated Raman scattering and four-wave Raman mixing using a KGd(WO4)(2) crystal. Seven emission lines, consisting of high-order Stokes and anti-Stokes emissions, were observed at a laser pulsewidth of 20 ps and a pulse energy of 70 muJ. (C) 2003 Elsevier B.V. All rights reserved.

    DOI: 10.1016/S0030-4018(03)01675-4

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  • A hybrid laser system consisting of a frequency-doubled, narrow-line-width, distributed-feedback dye laser oscillator and a high saturation-fluence Ce : LiCaAlF6 crystal amplifier 査読

    DQ Hoa, ND Hung, J Moroe, N Takeyasu, T Imasaka

    APPLIED PHYSICS LETTERS82 ( 20 ) 3391 - 3393   2003年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    A tunable narrow-band picosecond dye laser emitting in the ultraviolet region was amplified using a Ce:LiCaAlF6 crystal pumped by the fourth-harmonic emission of a Nd:Y3Al5O12 laser. The single-pass gain obtained exceeded 2 in the spectral range of 288 to 297 nm. (C) 2003 American Institute of Physics.

    DOI: 10.1063/1.1576294

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  • Direct generation of a tunable nearly transform-limited picosecond pulse in the ultraviolet region using a distributed-feedback dye laser 査読

    DQ Hoa, N Takeyasu, T Imasaka, ND Hung

    REVIEW OF SCIENTIFIC INSTRUMENTS74 ( 1 ) 28 - 31   2003年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    A new design and the characteristics of operating a distributed-feedback dye laser (DFDL) pumped by the fourth-harmonic emission of a Q-switched Nd:YAG laser are described. An ultraviolet nearly transform-limited picosecond pulse was generated by means of two right-angle prisms in the pumping geometry, and the laser wavelength was continuously tunable from 318 to 369 nm using two dye solutions (BM-terphenyl and BMQ). The application of this DFDL to the lifetime measurement of a fluorescent dye is also presented. (C) 2003 American Institute of Physics.

    DOI: 10.1063/1.1529298

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  • Elemental analysis of stainless steel using hard X-ray emission arising from a high-density plasma produced by an intense femtosecond KrF laser pulse 査読

    N Takeyasu, Y Hirakawa, T Imasaka

    APPLIED SPECTROSCOPY56 ( 9 ) 1161 - 1164   2002年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SOC APPLIED SPECTROSCOPY  

    Characteristic hard X-rays emitted from a laser-produced plasma induced by focusing a femtosecond KrF laser pulse are employed for elemental analysis. The emission spectrum of the hard X-ray arising from a stainless steel sample is measured by means of a single-photon-counting X-ray detector equipped with a multichannel analyzer. The elemental analysis is carried out from the photon energy of the Kalpha. line observed in the X-ray emission spectrum, and a calibration curve is constructed for Fe using stainless steel samples prepared at different concentrations (SUS-301, 310, and 316). A continuum band was overlapped on the sharp Kalpha lines in the Xray spectrum, which made the assignment of the weak characteristic Kalpha lines arising from minor elements difficult. In order to suppress this undesirable emission, a prepulse technique was employed. The continuum emission was shifted toward lower energies, and, as a result, the characteristic Kalpha lines were more clearly observable. The potential advantages of the present approach are also discussed in this study.

    DOI: 10.1366/000370202760295395

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  • Measurement of the first-excited-singlet-state lifetime of chlorobenzenes by a pump-probe method using a narrow-band tunable picosecond laser 査読

    T Deguchi, N Takeyasu, T Imasaka

    APPLIED SPECTROSCOPY56 ( 9 ) 1241 - 1243   2002年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SOC APPLIED SPECTROSCOPY  

    DOI: 10.1366/000370202760295511

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  • New quenching scheme for the generation of a nearly transform-limited picosecond pulse in a distributed feedback dye laser 査読

    T Deguchi, N Takeyasu, T Imasaka

    REVIEW OF SCIENTIFIC INSTRUMENTS73 ( 5 ) 2203 - 2204   2002年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    We report on the generation of a background-free nearly transform-limited picosecond pulse using a simple quenching scheme in a distributed feedback dye laser. The pulsewidth and spectral linewidth were 65 ps and 10 pm, respectively. The product of these values is 0.650, which is close to the transform limit of 0.441 for a Gaussian pulse. (C) 2002 American Institute of Physics.

    DOI: 10.1063/1.1470242

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  • A tunable picosecond dye laser for use in dioxin analysis 査読

    N Takeyasu, T Deguchi, M Tsutsumikawa, J Matsumoto, T Imasaka

    ANALYTICAL SCIENCES18 ( 3 ) 243 - 246   2002年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN SOC ANALYTICAL CHEMISTRY  

    A distributed-feedback dye laser with a quenching cavity was designed and constructed for generating a tunable picosecond pulse with a narrow spectral linewidth. This nearly transform-limited pulse was succeedingly amplified by a triple-pass off-axis amplifier. The pulse duration and the spectral linewidth were 60 ps and 9.4 pm, respectively. The amplified pulse was frequency-doubled by second-harmonic generation, producing a 0.5-mJ pulse with no background emission. The potential advantage of this laser in the analysis of dioxin based on supersonic jet/resonance-enhanced multiphoton ionization/mass spectrometry is discussed.

    DOI: 10.2116/analsci.18.243

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  • Elemental analysis using hard x-ray emission from a laser-produced plasma, induced by a femtosecond laser pulse 査読

    N Takeyasu, Y Hirakawa, T Imasaka

    REVIEW OF SCIENTIFIC INSTRUMENTS72 ( 10 ) 3940 - 3942   2001年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    A new approach for elemental analysis, which is based on the measurement of the hard x ray emitted from a laser-produced plasma is reported here. Since the K-shell emission is characteristic of the element in a sample, Cu, Zn, Fe, Co, and Ni were readily confirmed to be present in brass and kovar alloys by measuring the x-ray emission spectrum over an energy range from 2 to 30 keV. (C) 2001 American Institute of Physics.

    DOI: 10.1063/1.1405790

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  • Emission spectrum of hard x-rays, generated from iron, copper, and molybdenum targets by subpicosecond KrF laser pulses 査読

    N Takeyasu, Y Hirakawa, T Imasaka

    APPLIED PHYSICS LETTERS78 ( 9 ) 1195 - 1197   2001年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    K-shell emission spectra of iron, copper, and molybdenum in the range of 1.5-20 keV using a 500 fs KrF excimer laser have been observed and are reported herein. (C) 2001 American Institute of Physics.

    DOI: 10.1063/1.1342777

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  • A volume pinhole for mode-filtering of the femtosecond laser for use in the generation of high-order vibrational and rotational emissions by four-wave Raman mixing 査読

    Y Hirakawa, K Ogata, N Takeyasu, T Imasaka

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS39 ( 9A ) 5115 - 5117   2000年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:INTS PURE APPLIED PHYSICS  

    The beam quality of a femtosecond dye/KrF excimer laser was improved using a pinhole, prepared from an acrylic plate. The pinhole acts as a volume light absorber that discriminates high-order transverse modes of the laser beam. A breakdown at the surface of the pinhole, which degrades the quality of the transmitted beam, can be avoided using this spatial filter. This approach was useful in minimizing self-phase modulation, which exhausts the limited laser energy and reduces the Raman output. A conversion efficiency of some vibrational and rotational emissions was improved, even though the laser pulse energy was substantially reduced by mode filtering.

    DOI: 10.1143/JJAP.39.5115

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  • Novel route for the production of X-ray masks from a range of organometallic films. 査読

    MR Davidson, GJ Berry, JA Cairns, AG Fitzgerald, B Lawrenson, J Thomson, ICE Turcu, W Shaikh, N Spencer, RM Allott, N Takeyasu

    MICROELECTRONIC ENGINEERING42   279 - 282   1998年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    The majority of commercial photomasks and X-ray masks produced at present are manufactured by a multistep process which involves the use of etching. This route imposes a limitation on the resolution that can be achieved. We describe here a new approach which utilises a recently synthesised range of organometallic compounds designed to undergo direct conversion to metal under the influence of electron beam irradiation. This opens up the prospect of a novel route for the production of both X-ray masks and EUV masks in essentially a single processing step. The attainable resolution is better than 300nm, since the process involves the direct deposition of metal atoms under the influence of a focused electron beam.
    The method is very versatile in that a whole range of metals and metal alloys can be deposited, e.g. gold, platinum and palladium and their corresponding alloys. We describe here the production of a gold X-ray mask, which was used in conjunction with a compact laser plasma source.

    DOI: 10.1016/S0167-9317(98)00064-1

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  • Multiplication of spectral lines generated by two-color stimulated Raman effect 査読

    N Takeyasu, CH Lin, T Imasaka

    OPTICAL REVIEW3 ( 6B ) 549 - 551   1996年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:OPTICAL SOC JAPAN  

    A dye laser emitting at four different frequencies separated by 293.5 (=587/2) cm(-1) is made by inserting an etalon in the resonator cavity of the laser. This laser beam is focused into molecular hydrogen (rotational Raman shift frequency, 587 cm(-1)) to generate a multicolor laser beam consisting of more than 10 rotational lines in the vicinity of the fundamental lines by four-wave Raman mixing. Such rotational lines also occur in the vicinity of the vibrational Raman lines. Thus more than 25 emission lines appear simultaneously. This approach is useful to multiply the line density, i.e., the emission lines within a specified wavelength region.

    DOI: 10.1007/BF02932065

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MISC

  • ラマン分光とマッピング/イメージング

    武安 伸幸

    JSMI Report13 ( 2 ) 3 - 9   2020年5月

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    記述言語:日本語   出版者・発行元:日本分子イメージング学会  

    ラマン分光法は、試料にレーザー光を照射して生じるラマン散乱光を解析することにより、試料中に存在する化学結合や分子種を同定することができる。本手法は、蛍光標識のような前処理が不要であり、非破壊で試料の化学情報を取得できる優れた手法である。また、光学顕微鏡と組み合わせることにより、ミクロンスケールでの観察が可能である。しかしながら、蛍光と比べてラマン散乱光は非常に弱いため、希薄な試料の測定が困難とされてきた。そこで本稿では、貴金属ナノ構造に形成される表面プラズモンを利用した表面増強ラマン散乱を紹介する。レーザー焦点を試料中でスキャンすると、試料中の化学的情報を示すラマンマッピング/イメージングを行える。ラマンマッピング/イメージングにおける照明方法の工夫やタグの利用、ラマン信号の増強について述べる。(著者抄録)

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  • 次世代分子イメージング技術の進展と生命科学/医療分野への新展開 ラマン分光法と生体分子イメージング応用

    武安 伸幸

    JSMI Report12 ( 2 ) 63 - 63   2019年5月

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    記述言語:日本語   出版者・発行元:日本分子イメージング学会  

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  • 役に立つホットエレクトロン

    武安 伸幸

    応用物理88 ( 10 ) 659 - 662   2019年

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    記述言語:日本語   出版者・発行元:公益社団法人 応用物理学会  

    <p>近年,周囲の電子と比較して高いエネルギーをもつ"ホットエレクトロン"が注目されている.計測においては好まれないホットエレクトロンだが,新奇な光化学反応や光電子変換の高効率化に向けた研究が行われている.光で電子を高いエネルギー状態に励起するためには,バンドギャップを超える十分に短波長の光を注入する必要があるが,局在表面プラズモン共鳴を用いると,ホットエレクトロンを発生させることができる.ここでは,エネルギー生成への応用に関して,ホットエレクトロンの生成方法から,金属で生成したホットエレクトロンが界面を介して半導体や吸着分子へ移動するプロセス,および誘起される化学反応について概説する.</p>

    DOI: 10.11470/oubutsu.88.10_659

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  • メタマテリアルとナノ加工技術

    武安 伸幸

    高分子61 ( 7 ) 464 - 466   2012年7月

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    記述言語:日本語  

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  • サイト選択金属コーティング法とその3次元機能デバイスへの応用

    武安 伸幸, 田中 拓男, 河田 聡

    レーザー研究36 ( 0 ) 174 - 175   2008年

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    記述言語:日本語   出版者・発行元:一般社団法人 レーザー学会  

    DOI: 10.2184/lsj.36.174

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  • 海外における大学院生の活動

    今坂 藤太郎, 松本 純一, 武安 伸幸, 内村 智博, 大塚 博之

    ぶんせき322   550 - 552   2001年10月

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    記述言語:日本語   出版者・発行元:日本分析化学会  

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共同研究・競争的資金等の研究

  • 機能性フッ素ポリマーのフェムト秒レーザー加工基盤と3次元構築した細胞の顕微観察法

    研究課題/領域番号:17H02794  2017年04月 - 2020年03月

    日本学術振興会  科学研究費助成事業 基盤研究(B)  基盤研究(B)

    花田 修賢, 山田 勝也, 澤田 英夫, 武安 伸幸

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    配分額:17680000円 ( 直接経費:13600000円 、 間接経費:4080000円 )

    本年度は、波面制御したフェムト秒レーザーおよび汎用ナノ秒レーザーを用いたCYTOP製ナノファイバー加工の基本特性について調査を行い、細胞集塊の培養応用を目的として、堆積したナノファイバーの濡れ性評価を行った。その結果、波面制御したフェムト秒レーザーをCYTOP基板上に集光照射することで作製したナノファイバーは、汎用ナノ秒レーザーや単一フェムト秒レーザー照射に比べ高分解能であることを確認した。また、ファイバーをCYTOP基板上に堆積した際の濡れ性評価については、実験条件を最適化し、ファイバー堆積することで、その表面が超撥水になることを確認した。これらの結果については、学会発表にて成果を報告している。
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    CYTOPをベースとした新規材料開発については、表面プラズモンを利用したCYTOPの化学変化を試みた。溶剤に溶けたCYTOP溶液を、銀ナノ粒子2次元アレイ上に滴下し、波長532 nmのレーザーを照射し、表面増強ラマンスペクトルを計測した。その結果、CYTOPの通常ラマンスペクトルとは異なるラマンスペクトルが得られた。この結果から、表面プラズモンを利用することで、CYTOPが化学変化を起こすことが分かった。本成果については、学会発表にて報告を行っている。
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    更に、本研究を行う過程で、CYTOPを含めた熱硬化性材料の新しいレーザー加工方法についても検討を行っており、その加工技術の確立を行うと共に本研究課題への応用を試みている。本成果についても、学会発表にて、その成果を報告している。

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  • プラズモニックダイマーの高選択的作製と表面増強ラマン計測への応用

    研究課題/領域番号:15K04609  2015年04月 - 2018年03月

    日本学術振興会  科学研究費助成事業 基盤研究(C)  基盤研究(C)

    武安 伸幸, 田中 拓男

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    配分額:4940000円 ( 直接経費:3800000円 、 間接経費:1140000円 )

    ラングミュアーブロジェット膜を利用して金ナノ粒子の親水性表面の一点を疎水修飾し、疎水部同士の疎水結合を利用することによって、自己組織的に金ナノ粒子2量体(プラズモニックダイマー)を作製した。原子間力顕微鏡で観察したところ、単量体、3量体、それ以上の凝集体も同時に形成されており、プラズモニックダイマーの割合は約13%であった。作製したプラズモニックダイマーの散乱スペクトルは、その長軸と短軸で異なるプラズモン共鳴を示した。

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  • 脂質支持膜への細胞融合法の開発と膜タンパク質計測への応用

    研究課題/領域番号:26288067  2014年04月 - 2017年03月

    日本学術振興会  科学研究費助成事業 基盤研究(B)  基盤研究(B)

    金田 隆, 笹木 圭子, 武安 伸幸, 東谷 直樹, 金地 啓介, 小林 桜子, 牧 朋美, 尾川 冬馬, 苅田 真吾, 光延 愛美, 島田 雄飛, 原田 愛梨, 工藤 すみれ, 礒山 美華, 久保井 麻衣, 藤井 達也, 三木 笙子

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    配分額:16640000円 ( 直接経費:12800000円 、 間接経費:3840000円 )

    本研究は、細胞膜に局在する膜タンパク質を計測するための新しいサンプリング法として、基板上に作製した脂質二分子膜に生体細胞を融合させる技術を確立し、その手法を活用した細胞膜の膜タンパク質分離、並びに計測方法を開発することを目的とした。基板上に細胞膜を展開し、それを観測するための全反射蛍光観察システムを作製し、それを用いた脂質固定化膜形成の観察、平面化した細胞膜の観察を行い、細胞膜に局在する膜タンパク質の計測法開発を行った。

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  • DNAの自己組織化能を用いた可視光領域で磁性を有する新規メタマテリアルの創生

    研究課題/領域番号:22651045  2010年 - 2011年

    日本学術振興会  科学研究費助成事業 挑戦的萌芽研究  挑戦的萌芽研究

    武安 伸幸, 田中 拓男, 座古 保

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    配分額:3470000円 ( 直接経費:3200000円 、 間接経費:270000円 )

    DNA/金ナノ粒子接合体同士をリング状に連結する手法により, 3量体リング構造を大量に作製できた.本構造の光の磁場成分に対する応答を調べるために, 3量体リング構造をガラス基板表面に分散・固定し,偏光および入射角度を変えながら透過スペクトル測定を行った.観測されたピークは各金ナノ粒子のプラズモン共鳴,リング状に配置した金ナノ粒子のプラズモンのナノギャップを介した相互作用に由来するものと判断した.

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  • プラズモニック液晶材料の開発

    研究課題/領域番号:21550175  2009年 - 2011年

    日本学術振興会  科学研究費助成事業 基盤研究(C)  基盤研究(C)

    城田 幸一郎, 渡邉 眞次, 武安 伸幸

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    配分額:4810000円 ( 直接経費:3700000円 、 間接経費:1110000円 )

    金属ナノ粒子に液晶性を持たせたプラズモニック材料の開発を行った。研究は、(1)ランダムレーザーへの応用を目指したカラミチック液晶-金ナノ粒子複合体と、(2)自己組織化による3次元構造を目指したカラムナー液晶-金ナノ粒子複合体に大別できる。(1)では、色素ドープ液晶に複合体を添加すれば、ランダムレーザー発振の閾値を低減できることを明らかにした。(2)では、作製した複合体が、カラムナー相を示し、立方晶構造を自発的に形成させることを示した。

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  • 2光子吸収微細造形を用いる三次元空間に配列された金属微細構造の作製

    研究課題/領域番号:18710107  2006年 - 2007年

    日本学術振興会  科学研究費助成事業 若手研究(B)  若手研究(B)

    武安 伸幸

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    配分額:3400000円 ( 直接経費:3400000円 )

    光硬化性樹脂にフェムト秒レーザーを集光すると光強度の高い焦点でのみ2光子吸収が起こり,硬化スポットが得られる.その焦点を3次元走査するとナノ/ミクロンスケールで任意形状の3次元ポリマー構造体を作製できる.3次元ポリマー構造体に無電解めっき法により金属をコーティングすると3次元金属構造体が得られる.無電解めっき法による金属コーティングは下地の化学的性質に大きく依存し,一般に無電解めっき法でポリマーへ金属をコートするためにはスズやパラジウムなどで前処理を行う必要がある.昨年度,めっき前処理が不要な金属の付着し易い樹脂として市販の光硬化性樹脂にメタアクリルアミドを混ぜた改質樹脂を開発した.また,それを従来樹脂と併用することによって選択的に改質樹脂のみが金属でコートされることを確認した.本年度は,照射レーザー条件を最適化し,本手法により3次元金属/ポリマーハイブリッド微細構造を作製した.造形用光源には波長796nm,パルス幅140fs,平均出力1.4W,繰返し1kHzのチタンサファイアレーザー(再生増幅器)を用いた.アッテネータを用いて造形に適当な出力としたレーザーをマイクロレンズアレイを用いてマルチスポットを創製し,対物レンズにより光硬化性樹脂中へ集光した.従来樹脂および改質樹脂を用いて3次元ポリマー構造を作製し,洗浄後,硝酸銀水溶液中に数時間浸した。サンプルを洗浄し,アンモニア性硝酸銀水溶液中に浸し,還元剤としてグルコース水溶液を加えた.洗浄・乾燥後,走査型電子顕微鏡により観察した.その結果,改質樹脂部分のみが銀でコーティングされた3次元銀/ポリマー構造体を確認できた.その最小金属線幅は約300nmであった.以上から,本手法によりサブミクロンの分解能で3次元金属/ポリマーハイブリッド構造を作製できることが示せた.

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  • 3次元フォトニック構造を利用した液晶レーザーの開発

    研究課題/領域番号:17360014  2005年 - 2006年

    日本学術振興会  科学研究費助成事業 基盤研究(B)  基盤研究(B)

    城田 幸一郎, 深野 天, 武安 伸幸

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    配分額:9100000円 ( 直接経費:9100000円 )

    本研究は、液晶相が自発的に形成する3次元フォトニック構造を活用し、そのバンドギャップ内にフォトンを閉じこめることにより、低閾値で発振する液晶レーザーを開発することを目的とした。そのために3次元立方構造を有する青色相を研究対象とした。
    1.青色相(BP)のモノドメイン化
    温度制御下でBPを保ちながら、顕微分光スペクトルならびにコッセル線図の測定を行い、BPの各結晶面からの反射を確認した。次に、基板配向処理、冷却速度、印加電場の各結晶面に与える影響を調べ、単一の結晶面を成長させる方法を検討した。この結果、BPI相において、セルのほぼ全面を(110)面に揃えた試料を作製することができた。
    2.BPモノドメインからのレーザー発振
    BPに蛍光色素をドープした後、単一の結晶面を成長させたセルを作製した。これを波長530nmのレーザー光により励起したところ、バンド端でのレーザー発振を起こすことが確認できた。BP相での発振閾値は1次元のキラルネマチック(CN)相に比べ、約半分にまで低減できた。
    3.モノドメイン化した高分子安定化青色相(PSBP)の作製
    液晶に液晶性モノマーと長鎖アクリルモノマー、および光重合開始剤を添加した混合物を用い、BPIの(110)面を基板面と平行に揃えた後に紫外線を照射すると、ほぼモノドメイン化したPSBPを得ることができた。本来の青色相の温度域は数℃であるが、安定化により室温を含む50℃以上に拡大した。
    4.PSBPモノドメインからのレーザー発振
    色素ドープPSBPのモノドメインセルを波長520nmのレーザー光で励起したところ、バンド端でレーザー発振を得た。発振閾値は、通常の青色相と同じく、CN相の半分程度まで低減できた。モノドメイン化したPSBPは、温度制御が不要であり、レーザー以外の様々な光デバイスに利用可能である。

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  • オンデマンドに直接細胞内で組み立て・計測・破棄する微小球生体センサー

    研究課題/領域番号:17650146  2005年 - 2006年

    日本学術振興会  科学研究費助成事業 萌芽研究  萌芽研究

    田中 拓男, 武安 信幸

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    配分額:3400000円 ( 直接経費:3400000円 )

    本研究の目的は、生体細胞の計測を行うにあたり,直接細胞内でセンサープローブを製作して生体活動に伴う発現物質等を検出し,検出後はプローブが自己消滅するといったオンデマンド光計測法を開発することである。そしてこの目的を実現する手法として,蛍光色素がドープされた生分解性紫外線樹脂を2光子重合で硬化させてマイクロレーザーキャビティー作成し,これをプローブとして使用することを考案した。本年度は、2光子重合により硬化させた樹脂の中にさらに金ナノ微粒子をドープし,この金微粒子に末端をチオール修飾したDNAを結合させた.次にこの樹脂をDNAを混合した水溶液に浸すことで,金微粒子に結像させたDNAと相補的な配列を持つDNAを結合させて2重螺旋構造をつくった.そしてDNAの2重螺旋構造のみに選択的に結像する蛍光色素をドープしてその蛍光発光を観測することで,作成したDNAを付加したマイクロキャビティーが,生体分子を選択的に認識して結合することを確認した.さらにマイクロキャビティの結合状態を蛍光色素の蛍光発光強度の変化,もしくは蛍光スペクトルの変化として観測できることを確認した.また,この樹脂で周期的な構造を作製しその蛍光発光スペクトルを測定したところ,共振波長に対応するスペクトルにおいて,蛍光強度が増強されることを確認した.2光子重合加工手法そのものについても,樹脂に配合する重合開始剤やモノマーとの配合比等を最適化することで,加工分解能を約100nm程度にまで高めることに成功した.特に重合開始剤については,樹脂の重合プロセスをレート方程式で記述して数値計算し,その結果をもとに光利用効率高いが高くかつ空間分解能も高い樹脂構造を実現するのに必要な色素を設計・合成した.

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  • レーザー生成プラズマからの硬X線の発生に関する研究

    研究課題/領域番号:99J03081  1999年 - 2000年

    日本学術振興会  科学研究費助成事業 特別研究員奨励費  特別研究員奨励費

    武安 伸幸

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    配分額:1800000円 ( 直接経費:1800000円 )

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担当授業科目

  • レーザー化学特論 (2020年度) 前期  - 木3,木4

  • 一般化学 (2020年度) 1・2学期  - 金1,金2

  • 一般化学2 (2020年度) 第2学期  - 金1,金2

  • 一般化学2 (2020年度) 第2学期  - 金1,金2

  • 分析化学演習 (2020年度) 前期

  • 分析化学演習 (2020年度) 通年  - その他

  • 分析化学3 (2020年度) 第1学期  - 月3,月4

  • 分析化学4 (2020年度) 第2学期  - 月3,月4

  • 分析化学II (2020年度) 1・2学期  - 月3,月4

  • 基礎化学実験 (2020年度) 1・2学期  - 火5,火6,火7,火8

  • 基礎化学実験1 (2020年度) 第1学期  - 火5,火6,火7,火8

  • 基礎化学実験2 (2020年度) 第2学期  - 火5,火6,火7,火8

  • 生体分析化学 (2020年度) 後期  - その他

  • 自然科学特論 (2020年度) 第2学期  - 水7,水8

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