研究者詳細 - 秦　誠一

論文 - 秦　誠一

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Selective fabrication of p-type and n-type thermoelectric micropatterns by the reduction of CuO/NiO mixed nanoparticles using femtosecond laser pulses 査読有り

Mizoshiri, M; Hata, S

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING 124 巻 ( 1 ) 2018年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Applied Physics A: Materials Science and Processing

p-type and n-type thermoelectric micropatterns were selectively fabricated via the reduction and reoxidation of CuO/NiO mixed nanoparticles using femtosecond laser pulses. The micropatterns were formed by raster scanning focused femtosecond laser pulses on a solution film containing CuO and NiO nanoparticles, ethylene glycol, and polyvinylpyrrolidone, followed by the removal of the non-irradiated nanoparticles. Cu–Ni was generated by reductive sintering of the CuO/NiO mixed nanoparticles at laser scanning speeds ranging from 5 to 20 mm/s and a laser fluence of 0.055 J/cm2. In contrast, intense peaks corresponding to Cu2O and NiO were observed in the X-ray diffraction spectrum of the micropattern formed at a scanning speed of 1 mm/s, indicating that Cu2O and NiO were generated via the reoxidation of the reduced metals. The Seebeck coefficients of the micropatterns formed at a fluence of 0.055 J/cm2 and scanning speeds of 5–20 mm/s were between − 32 and − 16 µV/K, whereas that of the micropattern formed at a fluence of 0.055 J/cm2 and scanning speed of 1 mm/s was ~ 250 µV/K. These results suggest that the Seebeck coefficient depends on the generated n-type Cu–Ni and p-type Cu2O and NiO phases. A thermoelectric couple was fabricated by selectively fabricating p-type and n-type thermoelectric elements. The thermoelectric couple exhibited a thermoelectric voltage of 0.25 mV/K when a temperature gradient was applied between its hot and cold sides. The generated voltage was nearly consistent with the estimated voltage based on the Seebeck coefficient. The developed process for selective fabrication is expected to be useful for the direct writing of thermoelectric-type sensors.

DOI： 10.1007/s00339-017-1489-x

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FABRICATION OF A NOVEL NANOPOROUS FILM BY CHEMICAL DEALLOYING OF CU-CR AND ITS APPLICATION FOR A SENSOR 査読有り

Yoshii, Y; Sakurai, J; Mizoshiri, M; Hata, S

2018 IEEE MICRO ELECTRO MECHANICAL SYSTEMS (MEMS) 頁： 1104 - 1107 2018年

Fabrication of Novel Nanoporous Films in Moisture in-Oil Sensors via Chemical Dealloying of Cu-Cr using Combinatorial Search of Cu Cr Alloy Compositions 査読有り

Yoshii Yusuke, Sakurai Junpei, Mizoshiri Mizue, Hata Seiichi

MRS ADVANCES 3 巻 ( 4 ) 頁： 225-232 2018年

FABRICATION OF FLEXIBLE THE OELECTRIC GENE A TORS WITH A LENS ARRAY FOR NEAR-INFRARED SOLAR LIGHT HARVESTING 査読有り

Shimizu, Y; Mizoshiri, M; Mikami, M; Ito, Y; Sakurai, J; Hata, S

2018 IEEE MICRO ELECTRO MECHANICAL SYSTEMS (MEMS) 頁： 604 - 607 2018年

Basic research on micro processing characteristics of reverse lift-off process

Nakagawa, Y; Yamada, K; Mizoshiri, M; Oka, C; Sakurai, J; Hata, S

2018 INTERNATIONAL SYMPOSIUM ON MICRO-NANOMECHATRONICS AND HUMAN SCIENCE (MHS) 2018年

Direct writing of three-dimensional Cu-based sensors using femtosecond laser reduction of CuO nanoparticles 査読有り

Mizoshiri, M; Hata, S

LASER-BASED MICRO- AND NANOPROCESSING XII 10520 巻 2018年

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：Proceedings of SPIE - The International Society for Optical Engineering

2D and 3D metal microstructures are directly written using femtosecond laser reductive sintering of metal oxide nanoparticles. CuO nanoparticle solutions including CuO nanoparticles, a reductant agent, and a dispersant, were coated on glass substrates. Then, focused femtosecond laser pulses were irradiated onto the solution film to write the microstructures in air. Finally, non-irradiated CuO nanoparticles were removed. Cu-rich and Cu2O-rich microstructures were selectively fabricated by controlling the laser irradiation conditions. We demonstrated direct-writing of 2D and 3D Cu-based microstructures using femtosecond laser-induced reduction of CuO NPs. Using respective appropriate femtosecond laser conditions, 3D Cu-rich microstructures were obtained by a combined process of the dispensing coating and laser irradiation. The Cu-rich hot-film flow sensor which had microbridge structure, were successfully produced. This direct-writing technique is useful for fabricating various sensors on arbitral shaped substrates in air.

DOI： 10.1117/12.2290166

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Femtosecond laser direct writing of Cu-based fine patterns using Cu<sub>2</sub>O nanospheres

Kondo, Y; Mizoshiri, M; Sakurai, J; Hata, S

LASER-BASED MICRO- AND NANOPROCESSING XII 10520 巻 2018年

記述言語：英語出版者・発行元：Proceedings of SPIE - The International Society for Optical Engineering

© Copyright SPIE. Cu-based fine patterns were directly fabricated using femtosecond laser reduction of Cu2O nanospheres (NSs) via nonlinear optical absorption. Cu2O NS solution films, containing Cu2O NSs, polyvinylpyrrolidone (PVP), and 2-propanol, were prepared by spin-coating of the Cu2O NS solution on glass substrates or Cu-coated glass substrates. Finer line patterns were formed by scanning the focused femtosecond laser pulses. The absorption of the Cu2O NS solution film at wavelength of the femtosecond laser pulses, 780 nm, was low, whereas the intense absorption at wavelength of 390 nm was observed. Finer patterns were obtained on the Cu-coated glass substrates than on the glass substrates. The minimum line width of 0.6 μm was obtained on the Cu-sputtered film, which was smaller than the focal spot diameter of 1.3 μm. The heat accumulation is lower on the Cu-sputtered films due to their high thermal conductivity, resulting that the line width with the sub diffraction limit was achieved. The electrical conductivity of the patterns on the glass substrates was evaluated to be 4.1×106S/m at scanning speed of 200 μm/s and pulse energy of 0.312 nJ, which is close to that of bulk copper.

DOI： 10.1117/12.2287686

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Fabrication of Miniaturized Capacitive Pressure Sensor using Thin Film Metallic Glass

Uejima, S; Oka, C; Hata, S; Sakurai, J

2018 INTERNATIONAL SYMPOSIUM ON MICRO-NANOMECHATRONICS AND HUMAN SCIENCE (MHS) 2018年

FABRICATION OF COPPER/COPPER-NICKEL THIN-FILM THERMOELECTRIC GENERATORS WITH ENERGY STORAGE DEVICES

Shimizu Y., Mizoshiri M., Mikami M., Sakurai J., Hata S.

17TH INTERNATIONAL CONFERENCE ON MICRO AND NANOTECHNOLOGY FOR POWER GENERATION AND ENERGY CONVERSION APPLICATIONS (POWERMEMS 2017) 1052 巻 2018年