受賞国：日本国

受賞国：日本国

受賞国：日本国

受賞国：日本国

受賞国：日本国

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Fuji Technology Press Ltd.  

Fast atom beam (FAB) source is used for surface activated bonding. This process is attracting attention as an essential process for next-generation semiconductor manufacturing. Traditional wafer direct bonding processes require annealing or cannot be directly bonded at room temperature. Therefore, there are restrictions on the materials that can be bonded and the combinations of materials that can be bonded. However, surface activated bonding has made it possible to directly bond dissimilar materials at room temperature. This technology is expected to be applied to the manufacturing of various MEMS and three-dimensional stacking of semiconductors. This bonding process involves bom-barding the wafer surface with fast argon atom beam in a vacuum chamber. Irradiation removes oxide layer and contaminants, exposing dangling bonds. By press-ing the wafers together, the dangling bonds are bonded together, and a strong bond is achieved. The device that generates this fast argon atom beam is FAB source. This device has been of the type that generates a saddle field electric field. However, this FAB source had a nar-row beam irradiation area and was unable to support the recent increase in wafer diameter. Therefore, it was necessary to perform irradiation using multiple FAB sources. At production sites, there is a need to develop new FAB sources that can irradiate large areas. In this study, we developed FAB source in which the beam is generated by parallel plate electrodes. We performed a comparison with the saddle field type FAB source and found that the performance was inferior in initial experiments. Next, we improved the design to oper-ate at higher voltages and increased the aperture area. Through these improvements, we have achieved performance superior to the saddle field type FAB source.

DOI： 10.20965/ijat.2024.p0513

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

We investigated the temperature dependence of agglomeration systems consisting of interacting single-domain magnetic nanoparticles (MNPs). In our study, we utilized electron spin resonance (ESR) experiments to measure how temperature-induced change in agglomerate state affects the peak-to-peak width of ESR spectra (Hpp) and validated these observations through simulations. Micromagnetic simulations were conducted by combining the classical magnetic dipolar Metropolis Monte Carlo method with the semi-classical macro-spin Landau-Lifshitz-Gilbert finite element method, and the results were compared with experimental findings. Our research elucidates the behavior of thermally-induced disruption of MNP agglomerates. We discovered that the temperature at which MNPs are completely dispersed might correspond to one at which the temperature dependence of Hpp disappears.

DOI： 10.1016/j.aej.2024.03.101

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japanese Journal of Applied Physics  

Although high-aspect-ratio iron-oxide nanoparticles (IONPs) are known to have higher heating efficiency than spherical and cubic IONPs and focused in cancer treatment areas, their synthesis methods require high temperatures, vacuum, reduction conditions, and substantial time. In this study, we proposed and established a facile manufacturing method for one-dimensional assemblies of IONPs, expected to increase heating efficiency similar to high-aspect-ratio IONPs. We investigated how the fabrication conditions affect the length of the assemblies and found that the average length of the one-dimensional assemblies increased with the extension of magnetic-field-application time. This result demonstrates that the length could be controlled by adjusting the duration of the magnetic field application.

DOI： 10.35848/1347-4065/ad26bd

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担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

We suggested improving the conversion efficiency of dye-sensitized solar cells (DSSCs) by the micro-nano periodic textures to control the diffusion angle of the incident light for certain absorbed wavelengths of the used dye. A periodic texture (Prd-Tx) was designed to enhance the light path of the wavelength of DSSCs’ dye absorption with a wide process window by optical simulation (pitch: 1400 nm, pillar diameter: 460-560 nm, pillar height: more than 500 nm). The Prd-Tx was fabricated by photolithography processes and nanoimprinting (pitch: 1400 nm, pillar diameter: 500 nm, pillar height: 1000 nm). The Prd-Tx increased the DSSCs’ conversion efficiency (η of 3.13%), surpassing our previous best result (refabricated W-Tx, η of 3.08%). It was considered that the ohmic loss was suppressed owing to the Prd-Tx enhanced electrical conductivity at the interface between the transparent electrode, F-doped tin oxide (FTO), and TiO2

DOI： 10.35848/1347-4065/ad2417

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担当区分：責任著者   記述言語：日本語   掲載種別：論文集(書籍)内論文   出版者・発行元：公益社団法人 精密工学会  

<p>本研究では，微細テクスチャの回折効果を利用してDSSCsの変換効率を向上させることを目指した．光学シミュレーションからDSSCs使用色素に適した回折テクスチャ形状を設計し，ナノインプリント等の微細加工を用いて作製した．回折テクスチャを適用したDSSCsは変換効率を向上させたが，これは回折テクスチャ上に成膜された透明電極FTOの広い表面積により，FTO/TiO₂界面の導電性が向上したことに起因すると考えられた．</p>

DOI： 10.11522/pscjspe.2024s.0_713

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Sensors  

Microelectromechanical systems (MEMS)-based capacitive pressure sensors are conventionally fabricated from diaphragms made of Si, which has a high elastic modulus that limits the control of internal stress and constrains size reduction and low-pressure measurements. Ru-based thin-film metallic glass (TFMG) exhibits a low elastic modulus, and the internal stress can be controlled by heat treatment, so it may be a suitable diaphragm material for facilitating size reduction of the sensor without performance degradation. In this study, a Ru-based TFMG was used to realize a flattened diaphragm, and structural relaxation was achieved through annealing at 310 °C for 1 h in a vacuum. The diaphragm easily deformed, even under low differential pressure, when reduced in size. A diaphragm with a diameter of 1.7 mm was then applied to successfully fabricate a capacitive pressure sensor with a sensor size of 2.4 mm2. The sensor exhibited a linearity of ±3.70% full scale and a sensitivity of 0.09 fF/Pa in the differential pressure range of 0–500 Pa.

DOI： 10.3390/s23239557

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PubMed

その他リンク： https://www.mdpi.com/1424-8220/23/23/9557

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Microelectronic Engineering  

The lift-off process is a microfabrication technique that has the capability of forming thin film structures. However, several issues, such as structural shape and burr formation, arise when applying this method to the formation of thick film structures. Thick film structures formed through the lift-off process exhibit a mountainous cross-sectional shape and non-uniform film thickness due to variations in the width of the structure. These challenges make it difficult to apply the method to MEMS. While the reverse lift-off process addresses some of the structural shape problems, its initial development using metal molds makes it challenging to directly apply to MEMS without modification. Therefore, this paper proposes an adaptation to the Si process and presents a method to reduce burrs. The microfabrication characteristics are evaluated by comparing the cross-sectional shapes of thick metallic glass structures formed through both the lift-off and reverse lift-off processes. The structures formed through the reverse lift-off process exhibit a rectangular cross-sectional shape, and the film thickness remains consistent regardless of the structure's width. However, burrs persist on the backside edge of the structure, which hinders its application to MEMS. This paper confirms that pre-etching the underlying Si substrate into an inverse tapered shape effectively reduces burrs. As an illustration of the improved reverse lift-off process applied to MEMS, MEMS mirror structures are fabricated, and their resonance frequency closely aligns with the design value.

DOI： 10.1016/j.mee.2023.112081

Scopus

その他リンク： https://www.sciencedirect.com/science/article/pii/S0167931723001466

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 電気学会  

DOI： 10.1541/ieejsmas.143.236

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CiNii Research

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Microelectronic Engineering  

Non-destructive testing methods based on magnetic Barkhausen noise (MBN) are expected to be applied to thin films. Recently, MBN analysis using machine learning has been performed on bulk materials and used as an in-situ stress and material evaluation method. However, for thin films, it is difficult to measure due to the weak MBN signal intensity, and few examples of its use as a stress and material evaluation method have been reported. This study acquired and analyzed MBN of Fe–Co polycrystalline thin films under bending stress. After pre-processing the acquired MBNs, two representative machine learning algorithms were used to learn the relationship between MBN and stress. By quantitatively comparing the prediction accuracy of each machine learning method, the characteristics of the MBN-based stress evaluation method were discussed from two perspectives: the need for domain knowledge and its applicability to unknown data. This study provides insight into machine learning-assisted MBN analysis as a stress evaluation method for thin films. The extension of MBN-based stress evaluation methods to thin films could be applied to the non-destructive stress evaluation of micro- and nanostructures, where stress state is critical, and could improve process development efficiency.

DOI： 10.1016/j.mee.2023.112057

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その他リンク： https://www.sciencedirect.com/science/article/abs/pii/S0167931723001223

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.3390/nanomanufacturing3030020

その他リンク： https://www.mdpi.com/2673-687X/3/3/20

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Magnetics Letters  

We present a novel manufacturing technique for generating unidirectional pores in ultraviolet (UV)-curable resins using self-assembled magnetic nanoparticles (MNPs) with chain-like structures. The method utilizes two templation mechanisms for pore formation: the UV-masking effect of the MNP chains and the physical presence of MNP chains themselves. Fe3O4 nanoparticles and PAK-01 were used as the template and UV-curable resin, respectively. Unidirectional pores formed only when resin/MNP mixtures were cured under a strong externally applied magnetic field. Water absorption tests indicated that some of the unidirectional pores were through-hole-type pores. The pores were cylindrical with an ellipsoidal cross-section. When the UV irradiation angle theta) was 30 degrees, the long and short diameters of the pores were approximately 9 and 8 mu m, respectively, before MNP removal, and 12 and 8 mu m, respectively, after removal. After MNP removal, the ellipticity of the pores in the samples increased from 1.5 to 2.4 with the increase in theta because of the increased UV-masking effect of the MNP chains.

DOI： 10.1109/LMAG.2023.3268851

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担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemag.126.1253_38

CiNii Research

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：The Japan Society of Mechanical Engineers  

<p>As the application areas of MEMS (microelectromechanical systems) expand, more advanced functions and performance are being demanded from MEMS. To meet these demands, materials with various functionalities such as mechanical strength and shape memory, which are difficult to achieve with Si-based materials alone, are being used in MEMS. When applying new materials to MEMS, it is essential to establish micromachining techniques and control internal stresses in the same way as for Si-based thin films. In this research, a method for measuring the internal stress of thin film structures formed by microfabrication technology was developed. The thin film structure sample to be measured is in the form of a beam with fixed ends. The uniaxial strain due to internal stress is measured using a micro spring, and the internal stress is calculated. A process for fabricating a device that realizes the novel measurement method was devised and the device was fabricated. The microfabrication technique used was a reverse lift-off process, which can form thin film structures with rectangular cross-sections and uniform film thickness. Thin film metallic glass, an amorphous alloy with higher strength and lower Young's modulus than Si-based materials, was used as the new material to be measured. Using the developed measurement method, the internal stress change of the thin film was measured as a function of annealing temperature. As a result, it was confirmed that the internal stress of the thin film changed from the compressive direction to the tensile direction with increasing annealing temperature. The internal stress values measured by the novel method were compared with those measured by Stoney's equation, and the two measurement methods were close, demonstrating the usefulness of the new measurement method.</p>

DOI： 10.1299/mej.23-00074

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2023.j133p-02

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2023.j133p-06

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2023.j133p-04

CiNii Research

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

DOI： 10.35848/1347-4065/ac6a97

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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：Japanese Journal of Applied Physics  

In this paper, the effect of structural relaxation at temperatures below crystallization on internal stress of Ni-Nb-Zr thin film amorphous alloy (including thin film metallic glass: TFMG) diaphragms was investigated. We fabiricated the Ni-Nb-Zr diaphragm samples with four compositions. Before fabrication of diaphragm structure by etching, Ni-Nb-Zr thin films on Si substrate were annealed at a temperature below crystallization (473, 523, and 573 K) for structural relaxation. By performing bulge tests on annealed Ni-Nb-Zr diaphragms, we were able to determine their mechanical properties. As the result, Young’s modulus of all samples increased slightly with increasing annealing temperature because of the decrease of the free volumes during structural relaxation. Based on the results of internal stress, structural relaxation of all samples occurred below 473 K. Moreover, the effects of annealing temperature on internal stress differed by compositions. They were thought to be caused by the rate of structural relaxation.

DOI： 10.35848/1347-4065/ac5d12

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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：IEEE Transactions on Magnetics  

Stress-driven magnetic Barkhausen noise (MBN) can be potentially used to develop a high-sensitivity dynamic force sensor. MBN is a compositional pulse due to the domain wall movement in ferromagnetic material induced by the external field. In this study, we provide an in-depth understanding of the responsiveness of MBN to external stress using ferromagnetic materials with a high magnetostriction constant ( $\lambda $ ). We demonstrate stress-driven MBN from strong textured Fe29Co71 alloy wires ( $\lambda _{\mathrm {s}} =117$ ppm)/epoxy resin composite via uniaxial compression testing by changing the stress rate level from 0.55 to 28 GPa/s under a static bias magnetic field of 55 mT. The relationship between the stress rate of the external force and root-mean-square (rms) value of MBN output voltages showed high sensitivity, i.e., $V_{\mathrm {rms}}= 0.00441 (d\sigma /dt)$ , and acceptable linearity that could be used to quantitatively evaluate the dynamic force. This stress-driven MBN generation mechanism could be based on the domain wall movement induced by the inverse magnetostrictive effect of FeCo alloys. We believe that this study will aid in the research focusing on the dynamic magnetostrictive mechanism and development of novel applications for high-sensitivity force sensors that have no batteries.

DOI： 10.1109/TMAG.2021.3126898

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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：Journal of Medical Devices, Transactions of the ASME  

Catheter surgery is a minimally invasive treatment in which visual information is limited to a two-dimensional image generated by an X-ray camera. This results in the possibility that stress applied by the catheter onto a blood vessel wall damages the vessel. Doctors must therefore be skillful at catheter surgery. We proposed a catheter surgery simulator that visualizes the stress applied to the blood vessel wall using photoelasticity. The manufacture of this simulator requires creating blood vessel mimics that reproduce the physical properties of blood vessel tissue using photoelasticity. This study investigated the mechanical and photoelastic properties of gel materials and selected a gel composition suitable for making blood vessel mimics. The mechanical properties of polyvinyl alcohol (PVA) hydrogel changed in the range 70–335 kPa by changing the composition ratio, and double network (DN) gel changed in the range 0.13–1.06 MPa by changing the composition ratio. These gels could be adjusted by changing the material composition to provide Young’s moduli similar to that of blood vessels. The photoelastic properties of PVA hydrogel changed in the range 1.38–2.76 109/Pa by changing the composition ratio, and DN gel changed in the range 0.012–0.029 109/Pa by changing the composition ratio.

DOI： 10.1115/1.4051516

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記述言語：日本語   出版者・発行元：一般社団法人 電気学会  

In this paper, we report on the fabrication and evaluation of actuator for reaction force variable passive-type tactile display using high formable Ti-Ni-Cu shape memory alloy. This actuator is driven by the superelastic effect and superior in force expression, responsiveness, and miniaturization compared to conventional tactile displays using shape memory alloys. This actuator was fabricated in a convex shape by utilizing a viscous flow of Ti-Ni-Cu metallic glass. After crystallization, the metallic glass was changed to the shape memory alloy. In this manner, we successfully acquired the desired convex cross structure with a height of 123 μm at the center of cross. Additionally, while pushing 100 μm, we successfully varied the reaction force ranged from 40 to 80 mN, necessary to deform the skin and electrical resistance linearly by controlling the temperature. From these results, we showed that the actuator of this study can be used as tactile display that can express desired hardness and softness by temperature control. We also showed the possibility that the temperature of each actuator can be controlled individually by electrical heating using the linear relationship between temperature and electrical resistance.

DOI： 10.1541/ieejsmas.141.304

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CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Non-Crystalline Solids  

Fe-based nanocrystalline FeSiBPCuC alloys (NANOMET®) with a combination of high magnetic flux density, high permeability, and low iron loss have attracted much attention for use in magnetic core devices such as small power supplies, motors, and transformers. However, further improvement of the corrosion resistance is still required because surface oxidation during the water atomization process inevitably deteriorates the magnetic properties of these alloys. Here, we use a combinatorial magnetron sputtering system to fabricate new (FeSiBPCuC)100−x−yNix(Nb,Mo)y (0 ≤ x ≤ 10, 0 ≤ y ≤ 2 at%) amorphous thin films with enhanced corrosion resistance. We found that the co-presence of Ni (2–4 at%) and Mo (1–2 at%) in the FeSiBPCuC amorphous thin films promoted a further improvement of the corrosion resistance. The magnetic coercivity of (FeSiBPCuC)95.5Ni4.0Nb0.5 and (FeSiBPCuC)97.0Ni2.0Mo1.0 thin films was deteriorated compared with that of a FeSiBPCuC ribbon.

DOI： 10.1016/j.jnoncrysol.2021.120808

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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：Japanese Journal of Applied Physics  

Ar plasma in a fast atom beam (FAB) source with magnetic fields, which was previously developed [Precis. Eng. 62, 106 (2020)] to achieve high-performance surface activated bonding, was analyzed by particle-in-cell-Monte Carlo collision simulation and experimental measurements. Simulation in the proposed FAB source with magnetic fields shows that higher electron density accumulation occurs near the irradiation port by E × B drift, and the potential gradient near the irradiation port steepens, which results in an increase in Ar+ flux to the irradiation port. The variation in the plasma distribution due to the effect of the magnetic field contributes to an increase in the amount of Ar-FAB irradiation, which reduces erosion of the carbon electrodes and suppresses the formation of carbon agglomerates. These simulation results were verified experimentally with Langmuir probe measurements and FAB irradiation experiments with oxide layer removal. The analysis results explain why high performance is achieved with the proposed FAB source.

DOI： 10.35848/1347-4065/abe683

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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：21st International Conference on Solid-State Sensors, Actuators and Microsystems, TRANSDUCERS 2021  

In this paper, we report the fabrication and evaluation of an actuator for reaction force variable passive-type tactile displays using a highly formable Ti-Ni-Cu shape-memory alloy. The actuator relies on the superelastic effect of SMAs and can influence the applied reaction force. We successfully fabricated the desired convex cross structure with a height of 123 m, varied the reaction force between 40 and 80 mN at a depth of 100 m, and controlled the electrical resistance linearly with temperature.

DOI： 10.1109/TRANSDUCERS50396.2021.9495608

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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：2021 7th International Workshop on Low Temperature Bonding for 3D Integration, LTB-3D 2021  

We clarify a mechanism for longer lifetime of the fast atom beam (FAB) source for surface activated bonding proposed in our previous study. The new FAB source achieves highly efficient FAB irradiation and suppression of generation of fine carbon (C) particles. In this study, the distribution of sputtering and deposition on the inner wall of the C electrodes have been evaluated by measuring the thickness of the electrodes before and after long-time use. In the new source, the C erosion area due to sputtering is localized near the irradiation port and the sputtered C is deposited on other electrode surface, whereas in the conventional one, the erosion occurs on all surfaces of C electrodes. The reduction of electrode erosion due to sputtering contributes significantly to the extension of the lifetime of the new FAB source.

DOI： 10.1109/LTB-3D53950.2021.9598414

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2021.j221-07

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2021.k041-01

CiNii Research

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

© 2019 Elsevier Inc. Surface-activated bonding (SAB), also called room-temperature bonding, is used in three-dimensional integration technology for semiconductor devices. An Ar fast atom beam (FAB) is used for SAB. However, conventional FAB guns must be replaced after hundreds of minutes of irradiation because carbon abrasion powders are generated by Ar ions sputtering in the gun. Therefore, this study develops a novel FAB gun with improved lifetime. The proposed FAB gun applies magnetic fields to guide Ar ions to reduce sputtering in the gun and improve irradiation efficiency. The proposed FAB gun indicates the possibility of improving gun lifetime.

DOI： 10.1016/j.precisioneng.2019.11.006

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出版者・発行元：JSME 2020 Conference on Leading Edge Manufacturing/Materials and Processing, LEMP 2020  

The present paper proposes novel microvalves remotely controlled without electrical wiring on each valve. The proposed microvalves are controlled utilizing heat from magnetic nanoparticles in an alternating magnetic field. A procedure for fabrication of the microvalves was established. the fabricated microvalves operated on a hotplate.

DOI： 10.1115/LEMP2020-8529

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemp.2020.28.267

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2020.j22204

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2020.j24111

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemp.2020.28.156

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2020.j13105

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2020.j22207

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemp.2020.28.266

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2020.j22210

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemp.2020.28.158

CiNii Research

出版者・発行元：MHS 2019 - 30th 2019 International Symposium on Micro-NanoMechatronics and Human Science  

In this paper, we fabricated optical textured glass substrates by a polydimethylsiloxane (PDMS) nanoimprint lithography (NIL) on the front glass to enhance conversion efficiency of dye-sensitized solar cells (DSSCs). Two types of nano-texture (N-Tx) and micro-nano-double texture (D-Tx) were prepared. Finally, we fabricated DSSCs with textured glass. The used dye was red N719. The cell size was 6 mm square. As the results, the conversion efficiency of DSSCs with textured glasses increased by 26% for N-Tx and 19% for D-Tx compared to DSSC with flat glass.

DOI： 10.1109/MHS48134.2019.9249295

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出版者・発行元：MHS 2019 - 30th 2019 International Symposium on Micro-NanoMechatronics and Human Science  

In recent years, minimally invasive treatment aimed at reducing the physical and mental burden of patients as well as treating diseases has attracted attention. Catheter surgery is one of the minimally invasive treatments. This surgical technique can reduce invasion compared to incision and replacement with artificial vessels. Furthermore, it is known to be superior in terms of safety. On the other hand, in catheter surgery, visual information is limited to only a two-dimensional image by an X-ray camera. Therefore, there is a problem that stress is applied to the blood vessel wall and it is damaged, so doctors are required the skill of catheter surgery. This study is proposed a catheter surgery simulator that visualizes the stress applied to the blood vessel wall in realtime using photoelasticity. The blood vessel model used for the surgery simulator focused on PVA hydrogel. Previous experiments by our group have shown that PVA hydrogel can be applied to a surgical simulator. This study has developed an image processing program to measure stress in real-time. It has verified that the application to a surgery simulator is possible by this image processing program.

DOI： 10.1109/MHS48134.2019.9249277

Scopus

出版者・発行元：MHS 2019 - 30th 2019 International Symposium on Micro-NanoMechatronics and Human Science  

Dynamic force sensors play a key role in emerging smart technologies that can measure various types of human motions. Magnetostrictive force sensors are the most promising, lightweight, and reliable sensing technologies; however, an in-depth understanding of the sensing mechanism is still lacking. In this study, we focus on magnetic Barkhausen noise (MBN), which is generated by the inverse magnetostriction effect upon impact loading. Further, the stress-induced MBN characteristics of Fe-Co alloy/epoxy composites were investigated using a cyclic compression test. By measuring and analyzing MBN signals in magnetostrictive/epoxy resin composites, it was revealed that the root mean square value of MBN increased linearly with the increase in the stress rate. Additionally, we observed that the MBN outbreaks were affected by the magnetostriction constant. The proposed MBN force sensor system is expected to achieve high sensitivity, wide measurement range, and downsizing.

DOI： 10.1109/MHS48134.2019.9249081

Scopus

出版者・発行元：MHS 2019 - 30th 2019 International Symposium on Micro-NanoMechatronics and Human Science  

Most microvalves need electrical wiring on each one, and the need prevents further integration and miniaturization of microfluidic systems. Hence, we propose novel microvalves remotely controlled without the wiring on each valve. The proposed microvalves are driven by heat from magnetic nanoparticles in an alternating magnetic field. The nano-scale magnetic particles, which possess superparamagnetic behavior, generate heat in the alternating magnetic field. There is a theoretical formula for the heat generation. However, few reports are available on comparing experimental values of the heat generation with theoretical values. In this study, the experimental heating power was compared with the theoretical values, and the possibility of the proposed microvalves was verified.

DOI： 10.1109/MHS48134.2019.9249321

Scopus

記述言語：英語   出版者・発行元：Advanced Optical Technologies  

© 2019 THOSS Media &amp; De Gruyter, Berlin/Boston. We proposed a fabrication of nanoimprinted textures on a front glass/transparent conductive oxide interface for dye-sensitized solar cells (DSSCs). These textures were fabricated through polydimethylsiloxane (PDMS) nanoimprint lithography on organosilsesquioxane solution. The texture structures were estimated via optical simulation. Master molds were anodic aluminum oxide templates with nano-texture (N-Tx) and micro-nano double texture (D-Tx). Meanwhile, replicate molds used a hard PDMS. Fluorine-doped tin oxide and titanium dioxide were deposited on textured glass substrates to generate electrodes for DSSCs. Unlike the DSSCs without texture, textured DSSCs realized 11.4% (N-Tx) and 10% (D-Tx) improvement in conversion efficiency.

DOI： 10.1515/aot-2019-0010

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記述言語：日本語   出版者・発行元：公益社団法人 精密工学会  

<p>本研究では，サンプルとして，ガラス基板上に長さ4 mm，幅1 mm，厚さ500 nmの薄膜金属ガラスPd₇₇Cu₇Si₁₆ at.%を10 mm間隔に成膜し，試作した温度傾斜加熱装置により，543 K以下，471 K以上の異なる温度で同時加熱試験を行った．この時の各温度での大気中における結晶化度の時間変化を，放射率変化としてサーモグラフィで捉えることに成功し，XRDにより結晶化度を測定した．</p>

DOI： 10.11522/pscjspe.2019a.0_5

CiNii Research

記述言語：日本語   出版者・発行元：公益社団法人 精密工学会  

<p>表面活性化接合は半導体分野における三次元積層技術として利用されている．しかし，表面活性化接合に用いられる高速原子ビームガンは，短時間の使用で内部が磨耗してしまう．そこで，高速原子ビームの高効率な照射により，接合回数に対する相対的な長寿命化を目指す新規高速原子ビームガンの開発を行った．また，新規高速原子ビームガンを用いて，その照射特性を評価し，更なる高性能化を目指した設計指針の確立を目指した．</p>

DOI： 10.11522/pscjspe.2019a.0_687

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 電気学会  

Nonspherical monodisperse polydimethylsiloxane (PDMS) microparticles were fabricated by lithography and ultraviolet ozone (UVO) treatment for self-assembly of periodic structures. PDMS solution was poured into photoresist molds on glass substrates, whereupon it was cured at 80°C. After irradiating ultraviolet to the surface of the PDMS, remaining thin PDMS films on the molds were eliminated using ultrasonic waves. Attenuated-total-reflection Fourier-transform infrared spectra indicated that the surface of the UVO treated PDMS was changed to glass SiO2-like materials, resulting that the remaining thin PDMS films could be ultrasonically removed by fracture. The PDMS microparticles were separated from the substrates using ultrasonic waves, and microparticles of a desired shaped were formed. A suspension was prepared by mixing the PDMS microparticles in deionized water, and a droplet of the suspension was placed on a hydrophobic template substrate. The PDMS microparticles self-assembled on the substrate along the template walls, leading to PDMS microparticles being closely packed. Such PDMS microfabrication would be useful for microdevices.

DOI： 10.1541/ieejsmas.139.132

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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：Journal of Microelectromechanical Systems  

© 1992-2012 IEEE. Based on our prior combinatorial analysis aimed at materials discovery, Cu82Cr18 and Cu80Cr20 were selected in chemical dealloying experiments as candidates for incorporation in sensors for the first time. The Cu82Cr18 film was Cu-dealloyed, altering its composition to Cu25Cr75 after 7 min of dealloying. The dealloyed Cu82Cr18 film exhibited a Cr-based nanoporous structure with 20-40-nm-diameter pores, indicating that Cu was sufficiently dealloyed. In contrast, the Cu80Cr20 film could not be sufficiently Cu-dealloyed, which was consistent with the results of the combinatorial analysis; the original composition was changed to Cu46Cr54 after 7 min, and the pores were not visible. Sensors A and B were fabricated via chemical dealloying of Cu82Cr18 and Cu80Cr20, respectively, and they were evaluated with respect to a reference sensor in both air and oil. The measured hysteresis in the air was 7.4% full scale (FS) for sensor A, which was below the acceptable limit of 10.0% FS, whereas that for sensor B was 13.3% FS. Moreover, the 90% response time in oil was 8 min for sensor A and 10 min for sensor B, as compared to 12 min for the reference sensor; thus, the response time of sensor A was below the acceptable limit of 10 min. [2018-0242]

DOI： 10.1109/JMEMS.2019.2895164

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記述言語：英語  

DOI： 10.1128/MRA.01441-18

PubMed

記述言語：英語   出版者・発行元：2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems and Eurosensors XXXIII, TRANSDUCERS 2019 and EUROSENSORS XXXIII  

© 2019 IEEE. We report on the fabrication and evaluation of tactile pins for passive-type tactile displays using high formable Ti-Ni-Cu shape memory alloy. These pins were fabricated by utilizing a viscous flow of Ti-Ni-Cu metallic glass. After crystallization, the material transformed to a shape memory alloy and was driven by the superelastic effect. In this manner, we successfully acquired the desired three-dimensional structure and measured a reaction force of 20 mN or larger, necessary to deform the skin. Additionally, we successfully varied the reaction force by controlling the temperature and demonstrated the potential application of these tactile pins.

DOI： 10.1109/transducers.2019.8808618

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemp.2019.27.207

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemp.2019.27.p01

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemp.2019.27.p04

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2019.j22208p

CiNii Research

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

Direct laser-writing techniques have attracted attention for their use in two- and three-dimensional printing technologies. In this article, we report on a micropatterning process that uses femtosecond laser reductive sintering of mixed CuO/NiO nanoparticles. The writing speed, laser fluence, and incident total energy were varied to investigate the influence of heat accumulation on the micropatterns formed by these materials. Heat accumulation and the thermal history of the laser irradiation process significantly affected the material composition and the thermoelectric properties of the fabricated micropatterns. Short laser irradiation durations and high laser fluences decrease the amount of metal oxide in the micropatterns. Selective fabrication of p-type and n-type thermoelectric micropatterns was demonstrated to be possible with control of the reduction and reoxidization reactions through the control of writing speed and total irradiation energy.

DOI： 10.3390/mi9060264

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出版者・発行元：Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)  

In this study, novel transparent nanoporous films exhibiting insulating properties were fabricated by a new chemical dealloying method of Cu-Cr with no requirement of high-temperature annealing. Furthermore, for the first time to the best of our knowledge, the fabricated nanoporous film was successfully applied as a nanoporous electrode film filter of a moisture-in-oil sensor: The fabricated moisture-in-oil sensor exhibited outstanding sensitivity and a low hysteresis of 7.4% FS in air, which was less than the desired value of 10.0% FS. Furthermore, the sensor exhibited a favorable 90% response time in oil, which was 8 min and well less than the desired value of 10 min.

DOI： 10.1109/MEMSYS.2018.8346753

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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：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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記述言語：英語  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1557/adv.2018.198

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記述言語：英語  

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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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DOI： 10.1088/1742-6596/1052/1/012032

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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：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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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.46.5_257

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmetokai.2018.67.208

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmetokai.2018.67.225

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2018.j1110203

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmetokai.2018.67.701

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2018.s0410103

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2018.j2220204

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemp.2018.26.901

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2018.j2220202

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmetokai.2018.67.224

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmetokai.2018.67.223

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2018.j2220305

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmetokai.2018.67.703

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2018.j2220201

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmetokai.2018.67.702

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmetokai.2018.67.219

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmetokai.2018.67.216

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmetokai.2018.67.221

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2018.j2220304

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2018.j2220303

CiNii Research

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

We designed and fabricated thin-film thermoelectric generators (TEGs) with ball lenses, which separated visible light and near-infrared (NIR) solar light using a chromatic aberration. The transmitted visible light was used as daylight and the NIR light was used for thermoelectric generation. Solar light was estimated to be separated into the visible light and NIR light by a ray tracing method. 92.7% of the visible light was used as daylight and 9.9% of the NIR light was used for thermoelectric generation. Then, the temperature difference of the pn junctions of the TEG surface was 0.71 K, determined by heat conduction analysis using a finite element method. The thin-film TEGs were fabricated using lithography and deposition processes. When the solar light (A.M. 1.5) was irradiated to the TEGs, the open-circuit voltage and maximum power were 4.5V/m2 and 51μW/m2, respectively. These TEGs are expected to be used as an energy supply for Internet of Things sensors.

DOI： 10.7567/JJAP.56.06GN06

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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：Japanese Journal of Applied Physics  

Ni-based composite micropatterns were fabricated by the femtosecond laser reductive sintering of NiO/Cr mixed nanoparticles. A NiO/Cr mixed nanoparticle solution including ethylene glycol and polyvinylpyrrolidone was irradiated with focused femtosecond laser pulses. The X-ray diffraction spectra of the fabricated micropatterns indicated that NiO nanoparticles were well reduced under atmospheric conditions in the laser scanning speed range of 5-15mm/s. In contrast, micropatterns including NiO were formed at a laser scanning speed of 1mm/s, indicating that the reduced Ni was reoxidized by overheating. These results were supported by those of energy-dispersive X-ray spectrometry analysis and the electrical resistivity of the micropatterns. The compositions such as Ni, NiO, Cr2O3, and Ni-Cr in the fabricated micropatterns depended on laser scanning speed. The selective fabrication of a ferromagnetic free microgear from the substrate and an axis fixed on the substrate was demonstrated by controlling the laser scanning speed. The fabrication process for Ni-based composite microstructures is useful for the fabrication of ferromagnetic microdevices.

DOI： 10.7567/JJAP.56.06GN08

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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：Journal of Micromechanics and Microengineering  

We have demonstrated the fabrication of two types of thermal flow sensors with Cu-rich and Cu2O-rich microheaters using femtosecond laser-induced reduction of CuO nanoparticles. The microheaters in the shape of microbridge structures were formed to thermally isolate from the substrates by four layer-by-layer laminations of two-dimensional micropatterns. First, we evaluated the patterning properties such as dispensing coating conditions and degree of reduction for the selective fabrication of three-dimensional Cu-rich and Cu2O-rich microstructures. Then, a hot-film flow sensor with a Cu-rich microheater and a calorimetric flow sensor with a Cu2O-rich microheater were fabricated using their respective appropriate laser irradiation conditions. The hot-film sensor with the Cu-rich microbridge single heater enabled us to measure the flow rate in a wide range of 0-450 cc min-1. Although a large temperature dependence of the Cu2O-rich microbridge heaters caused a large error for the hot-film flow sensors with single heaters, they showed higher heat-resistance and generated heat with a lower drive power. The temperature coefficient of resistance of the Cu2O-rich microstructures had a semiconductor-like large absolute value and was less than -4.6 × 10-8 °C-1. The higher temperature sensitivity of the Cu2O-rich microstructures was useful for thermal detection. Based on these advantages, a calorimetric flow sensor composed of the Cu2O-rich microbridge single heater and two Cu2O-rich thermal detectors was proposed and fabricated. The calorimetric flow sensor was driven by a circuit for measuring the temperature difference. The Cu2O-rich flow sensor could detect bi-directional flow with a small output error.

DOI： 10.1088/1361-6439/aa6820

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Three-dimensional Cu microstructures were formed using a combined process of dispensing coating and femtosecond laser-induced reduction of CuO nanoparticles. Layer-by-layer lamination of two-dimensional Cu micropatterns was performed by alternately coating with a CuO nanoparticle solution and using direct laser writing, followed by the removal of nonirradiated CuO nanoparticles. The resistance of the 3D microstructures decreased as the number of layers increased, indicating that each layer was electrically connected to the others. We also demonstrated the fabrication of a microbridge heater composed of electrode pads and a microbridge, and found that its heating characteristics are suitable for use in microsensors, such as thermal-type flow sensors.

DOI： 1882-0786/10/1/017201

出版者・発行元：2016 International Symposium on Micro-NanoMechatronics and Human Science, MHS 2016  

In this study, we proposed and demonstrated combinatorial evaluation substrates, which were fabricated by micro electro mechanical systems (MEMS) process, for brine electrolysis. Proposed evaluation substrate has 9 electrode catalyst samples on the glass substrate. Ir-Ru/Ti and Ir-Ru-Ti/Ti electrode catalyst samples were prepared by a combinatorial co-sputtering system. We evaluated the maximum current density of polarization curves and the durability during brine electrolysis. In the case of binary Ir-Ru/Ti evaluation substrate (composition of Ru ranged from 35.1 to 58.8 at.%.), the maximum current density increased with increasing Ru-content. From these results, we confirmed the usability of proposed combinatorial evaluation substrate for the brine electrolysis. Finally, we evaluated the electrochemical characteristics of 9 Ir-Ru-Ti/Ti samples. Their electrochemical characteristics depend on alloy composition.

DOI： 10.1109/MHS.2016.7824159

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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：Applied Physics Express  

Three-dimensional Cu microstructures were formed using a combined process of dispensing coating and femtosecond laser-induced reduction of CuO nanoparticles. Layer-by-layer lamination of two-dimensional Cu micropatterns was performed by alternately coating with a CuO nanoparticle solution and using direct laser writing, followed by the removal of nonirradiated CuO nanoparticles. The resistance of the 3D microstructures decreased as the number of layers increased, indicating that each layer was electrically connected to the others. We also demonstrated the fabrication of a microbridge heater composed of electrode pads and a microbridge, and found that its heating characteristics are suitable for use in microsensors, such as thermal-type flow sensors.

DOI： 10.7567/APEX.10.017201

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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：一般社団法人 電気学会  

A moisture-in-oil sensor, with a sandwich structure of Cr nanoporous thin film/polyimide film/Au electrode, was fabricated using a lithographic process, sputter deposition, and chemical dealloying. One of the Cr nanoporous thin films used as a molecular filter was made using oblique incidence film formation and sputter deposition at 2.5 Pa of argon and a 60 degree attaching angle. The fabricated Cr nanoporous thin film consisted of 30-50 nm pore sizes as a result of a "shadowing effect". A moisture-in-oil sensor made with this Cr nanoporous thin film showed favorable responsiveness in oil, with a response time of about 7 minutes, well within the desired maximum value of 10 minutes. To further improve the responsiveness of the sensor, another Cr nanoporous thin film was prepared using a chemical dealloying process, which facilitates control of the pore sizes. This process consists of co-sputtering Cu and Cr, annealing for 1 h at 573 K and dealloying for 15 h in 32.5% HNO3. The thin film pore sizes depend on the initial Cu-Cr compositions, which were researched using a combinatorial technique at various fabrication conditions. We investigated a wide compositional range between 32 and 22 at.% Cr. It was found that between 28 and 22 at.% Cr, chemical dealloying results in low residual Cu, less than 10 at.%. The pore sizes obtained were < 20 nm for 32 at.% Cr, 20-40 nm for 28 at.% Cr, 40- 60 nm for 25 at.% Cr and > 60 nm for 22 at.% Cr. The initial composition ratio of 28 at.% Cr was used to fabricate a Cr nanoporous electrode film filter for a moisture sensor. Unfortunately, the final residual Cu composition ratio was 17 at.%, which is more than the desired maximum of 10 at.%, because the thin film had a uniform composition. The changes in the electrostatic capacity of the moisture sensor as a function of relative humidity (50%RH-90%RH) in air were studied, and the sensor output followed changes in the relative humidity.

DOI： 10.1541/ieejsmas.137.15

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

Cu-based micro-temperature sensors were directly fabricated on poly(dimethylsiloxane) (PDMS) blood vessel models in EVE using a combined process of spray coating and femtosecond laser reduction of CuO nanoparticles. CuO nanoparticle solution coated on a PDMS blood vessel model are thermally reduced and sintered by focused femtosecond laser pulses in atmosphere to write the sensors. After removing the non-irradiated CuO nanoparticles, Cu-based microtemperature sensors are formed. The sensors are thermistor-type ones whose temperature dependences of the resistance are used for measuring temperature inside the blood vessel model. This fabrication technique is useful for direct-writing of Cu-based microsensors and actuators on arbitrary nonplanar substrates.

DOI： 10.1117/12.2265050

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

Copper (Cu)-based micropatterns were fabricated on polymer substrates using femtosecond laser reduction of copper (II) oxide (CuO) nanoparticles. CuO nanoparticle solution, which consisted of CuO nanoparticles, ethylene glycol as a reductant agent, and polyvinylpyrrolidone as a dispersant, was spin-coated on poly(dimethylsiloxane) (PDMS) substrates and was irradiated by focused femtosecond laser pulses to fabricate Cu-based micropatterns. When the laser pulses were raster-scanned onto the solution, CuO nanoparticles were reduced and sintered. Cu-rich and copper (I)-oxide (Cu2O)-rich micropatterns were formed at laser scanning speeds of 15 mm/s and 0.5 mm/s, respectively, and at a pulse energy of 0.54 nJ. Cu-rich electrically conductive micropatterns were obtained without significant damages on the substrates. On the other hand, Cu2O-rich micropatterns exhibited no electrical conductivity, indicating that microcracks were generated on the micropatterns by thermal expansion and shrinking of the substrates. We demonstrated a direct-writing of Cu-rich micro-temperature sensors on PDMS substrates using the foregoing laser irradiation condition. The resistance of the fabricated sensors increased with increasing temperature, which is consistent with that of Cu. This direct-writing technique is useful for fabricating Cu-polymer composite microstructures.

DOI： 10.1117/12.2261398

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemnm.2017.8.pn-17

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.j2220203

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemnm.2017.8.pn-70

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.j2220103

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.j2220102

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.j0470302

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.j2220202

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.j2220201

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.j2220101

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.j0470305

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemnm.2017.8.pn-16

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.s0460101

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.j2220105

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2017.j2220104

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：富士技術出版株式会社  

We investigated the effect of different solvents on the Cu micropatterns formed via femtosecond laser reduction patterning. Solvents such as ethylene glycol, 2-propanol, and glycerol were mixedwith CuO nanoparticles and polyvinylpyrrolidone. The degree of reduction and the resistivity of the fabricated micropatterns depended on the solvent. Glycerol was the most effective reducing agent. This solution was used to fabricate Cu/Cu2O composite micro-temperature sensors. Cu-rich electrodes and Cu2O-rich sensors were selectively formed by controlling the laser scanning speed at 5 mm/s and 0.5 mm/s, respectively, when the pulse energy was 0.53 nJ. The temperature sensor exhibited a negative temperature coefficient of the resistance, which was consistent with the value for Cu2O.

DOI： 10.20965/ijat.2016.p0934

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記述言語：英語  

DOI： 10.4172/2321-6212.1000155

記述言語：英語   出版者・発行元：IOP publishing  

Micro-temperature sensors, which composed of a Cu<inf>2</inf>O-rich sensing part and two Cu-rich electrodes, were directly fabricated by femtosecond laser reduction patterning of CuO nanoparticles. Patterning of the microstructures was performed by laser scanning with pitches of 5, 10, and 15 µm. Cu<inf>2</inf>O-rich micropatterns were formed at the laser scan speed of 1 mm/s, the pitch of 5 µm, and the pulse energy of 0.54 nJ. Cu-rich micropatterns that had high generation selectivity of Cu against Cu<inf>2</inf>O were fabricated at the laser scan speed of 15 mm/s, the pitch of 5 µm, and the pulse energy of 0.45 nJ. Electrical resistivities of the Cu<inf>2</inf>O- and Cu-rich micropatterns were approximately 10 Ω m and 9 µΩ m, respectively. The temperature coefficient of the resistance of the micro-temperature sensor fabricated under these laser irradiation conditions was −5.5 × 10⁻³/°C. This resistance property with a negative value was consistent with that of semiconductor Cu<inf>2</inf>O.

DOI： 10.7567/JJAP.55.06GP05

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記述言語：英語   出版者・発行元：IOP publishing  

We fabricated antireflection structures (ARSs) on the hot side of a thermoelectric generator (TEG) to absorb near-infrared (NIR) solar light with low reflective energy loss. First, the ARSs, composed of a CuO thin-film coated hemisphere array were designed using rigorous coupled wave analysis. Reflective loss was reduced to 6.7% at a grating period of 200 nm, as determined by simulation. Then, the ARSs were fabricated on a glass substrate using self-arranged submicron SiO<inf>2</inf>spheres, following the coating of a CuO thin film. Finally, the effect of the ARSs on NIR solar light generation was investigated by evaluating the generation properties of the TEG with the ARSs on the hot side. In comparison with the TEG with the CuO flat thin film on the hot side, the ARSs increased the temperature difference between the hot and cold sides by approximately 1.4 times. The CuO-based ARSs absorbed NIR solar light effectively.

DOI： 10.7567/JJAP.55.06GP07

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 1347-4065/55/6S1/06GP07

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Micro-temperature sensors, which composed of a Cu2O-rich sensing part and two Cu-rich electrodes, were directly fabricated by femtosecond
laser reduction patterning of CuO nanoparticles. Patterning of the microstructures was performed by laser scanning with pitches of 5, 10, and
15 µm. Cu2O-rich micropatterns were formed at the laser scan speed of 1 mm/s, the pitch of 5 µm, and the pulse energy of 0.54 nJ. Cu-rich
micropatterns that had high generation selectivity of Cu against Cu2O were fabricated at the laser scan speed of 15 mm/s, the pitch of 5 µm, and
the pulse energy of 0.45 nJ. Electrical resistivities of the Cu2O- and Cu-rich micropatterns were approximately 10 Ω m and 9 µΩ m, respectively. The
temperature coefficient of the resistance of the micro-temperature sensor fabricated under these laser irradiation conditions was %5.5 ' 10%3/°C.
This resistance property with a negative value was consistent with that of semiconductor Cu2O. © 2016 The Japan Society of Applied Physics

DOI： 1347-4065/55/6S1/06GP05

記述言語：日本語  

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：2015 International Symposium on Micro-NanoMechatronics and Human Science, MHS 2015  

In this study, we proposed to search for new electrode catalyst for the electrolysis of brine using a combinatorial method. The evaluation substrate consisting of 72 catalyst samples and 9 Pt reference electrodes was designed and fabricated by micro electro mechanical system (MEMS) techniques. The thin film electrode catalyst library on the evaluation substrate was prepared by a combinatorial multi target sputtering system. To evaluation the characteristics of catalyst samples, the polarization curves (current density/potential curves) of catalyst samples were measured by the potential sweep method. Surface poisoning and elution of catalysis samples were observed by an optical microscopy. Finally, we confirmed that the proposed combinatorial method was useful to search for new electrode catalytic materials.

DOI： 10.1109/MHS.2015.7438321

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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：2015 International Symposium on Micro-NanoMechatronics and Human Science, MHS 2015  

A thin-film thermoelectric generator (TEG) with ball lenses which enable the visible light to pass through was designed and fabricated. When diameters of the ball lens and the pinhole were 6 mm and 200 μm, respectively, 76% of the visible light and 36% of the infrared light were transmissive to the TEG under the condition that the ball lens position from the device substrate was 0 μm. Thin-film TEGs were fabricated using lithography and thermoelectric thin film deposition processes. The thin film thermoelectric elements were formed on the glass substrate without removal by inserting the Cr buffer layers between the thermoelectric thin films and the substrate. The width of the elements were up to 10 μm greater than that of the designed one. The difference between the fabricated and the designed one was less than 10%, which is negligible value for the internal resistance of the TEGs.

DOI： 10.1109/MHS.2015.7438318

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記述言語：英語   出版者・発行元：Institute of Physics  

Cu-based micro-temperature detectors were fabricated using femtosecond laser reduction of CuO nanoparticles. Cu-based microstructures were directly created by laser scanning on a CuO nanoparticle solution film. Cu-rich and Cu<inf>2</inf>O-rich microstructures were selectively formed to electrically connect two Cu thin-film electrodes for use in temperature detectors. Cu-rich and Cu<inf>2</inf>O-rich micro-temperature detectors were fabricated at scanning speeds of 500 and 1000 µm/s, respectively, at a pulse energy of 1.2 nJ. The temperature coefficient of resistance values of the Cu-rich and Cu<inf>2</inf>O-rich microstructures were positive and negative, respectively; these temperature behaviors are typical of metal and semiconductor materials, respectively.

DOI： 10.7567/APEX.9.036701

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担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemag.119.1170_300

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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）  

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2016.j2240101

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2016.j2240203

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2016.j2240103

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2016.j2230101

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2016.j2240204

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2016.j2240105

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2016.j2240201

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2016.j2240102

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：富士技術出版株式会社  

In this paper, we investigate the characteristics of Ti-Ni-Zr thin film metallic glasses (TFMGs)/shape memory alloys (SMAs) for microelectromechanical systems (MEMS) applications with three-dimensional structures. The amorphous Ti-Ni-Zr thin films having a Ni content of more than 50 at.% and Zr content of more than 11 at.% undergo glass transitions and are TFMGs. The Ti39Ni50Zr11 TFMG has the lowest glass transition temperature Tg of 703 K and a wide supercooled liquid region ΔT of 57 K. Moreover, it has high thermal stability at Tg. However, the apparent viscosity of the Ti39Ni50Zr11 is higher than those of other Ti-Ni-Zr TFMGs. Moreover, the Ti-Ni-Zr TFMG exhibits higher viscosity than conventional TFMGs because the alloy composition of Ti-Ni-Zr TFMGs/SMAs is far from the eutectic point.

DOI： 10.20965/ijat.2015.p0662

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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：富士技術出版株式会社  

In technologies involving micro electromechanical systems, lift-off processes combined with sputter deposition are general patterning methods for the formation of amorphous alloy thick film structures. However, the thicknesses of structures fabricated in this manner are not uniform because sputtered particles are blocked by the sidewalls of the lift-off layer. In this paper, a reverse lift-off process is proposed as a new patterning method for fabricating amorphous alloy thick film structures of uniform thickness. In the reverse lift-off process, a template of the desired structure is formed on top of the chosen substrate. The thick film structure is then formed by sputter deposition on the top surface of the template. In contrast to a conventional liftoff process, here the thickness of the structure is uniform because there is nothing to hinder the sputtered particles. To demonstrate this process, we successfully fabricated a Cu-Zr-Ti metallic glass thick film structure with a uniform film thickness and a rectangular cross section across different target structure widths and thicknesses. This demonstrates that the reverse lift-off process is more suitable than conventional liftoff processes for the fabrication of metallic glass thick film structures.

DOI： 10.20965/ijat.2015.p0646

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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：Japanese Journal of Applied Physics  

Cu-based microstructures were directly patterned using femtosecond laser-induced CuO nanoparticle reduction. CuO nanoparticle-based solution, consisting CuO nanoparticles, ethylene glycol, and polyvinylpyrrolidone, was spin-coated on glass substrates. Microstructures were formed by irradiating focused femtosecond laser pulses. Cu and Cu2O peak intensities were observed in the X-ray diffraction (XRD) spectra of the microstructures. Compared to single scan, the Cu peak intensities increased by double scan. This result suggests that double scan is effective for increasing the amount of Cu from CuO nanoparticle solution. Cu- and Cu2O-rich microstructures were formed selectively by controlling laser irradiation conditions. The resistivity of the Cu-rich microstructures was estimated by 528 μΩm which was 104 times and 10 times larger than the values of Cu and Cu2O, respectively. This large resistivity could be applied for microheaters.

DOI： 10.7567/JJAP.54.06FP07

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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）  

DOI： 10.1299/jsmemipe.2015._MoB-2-2-1

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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：Microelectronic Engineering  

In micro-electro-mechanical systems (MEMS) technology, one of the conventional patterning methods used for metallic thin films is the lift-off process using a photoresist material. However, there is concern regarding the photoresist material generating gas due to the long-term annealing or the high power used in sputter deposition. Thin-film amorphous alloys, such as thin-film metallic glass (TFMG), when used in the device, become crystallized by such heating and outgassing during sputtering. Unlike photoresist material, a metal mask does not generate gas during sputtering. However, a metal mask is subject to deformation by the stress in the sputtered film on the mask. The pattern shape of the TFMG structure can thus collapse due to this mask deformation. Its cross-sectional shape then deviates significantly from a rectangle. We propose a novel lift-off process using a double metal mask for reducing changes in the cross-sectional shape, and maintaining the amorphous nature of the TFMG structure. The characteristic of the double metal mask lift-off process is duplication of the metal mask for restraint of the lower metal mask deformation. Since nearly all of the sputtered material is deposited on the upper metal mask, the material is only minimally deposited onto the lower metal mask. In this work, the double metal mask lift-off process was compared with the conventional lift-off process, and important points for using the double metal mask lift-off process were elucidated. Using the double metal mask lift-off process, a very thick amorphous TFMG structure could be obtained, as compared to the conventional lift-off process. To maintain the rectangular cross-sectional shape of the structure, it was found to be necessary to decrease the height of the double metal mask, as compared to the conventional lift-off process, in anticipation of upper metal mask deformation.

DOI： 10.1016/j.mee.2015.02.041

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出版者・発行元：2014 International Symposium on Micro-NanoMechatronics and Human Science, MHS 2014  

Combinatorial New-Facing Targets Sputtering (combi-NFTS) is one of the co-sputtering method applied to the combinatorial method. Combi-NFTS could easily control the composition range by changing the distance from substrate to targets. Furthermore composition gradient is relatively linear comparing to other thin film deposition method. In this paper, the influence of the distance between target and target gives for the composition distribution is investigated. As a result, it was elucidated that composition distribution and gradient increase as the TT distance increase. This is caused by the peak position of amount of deposited sputtering atom on the substrate change by the TT distance.

DOI： 10.1109/MHS.2014.7006100

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担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemag.118.1161_468_2

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemnm.2015.7._28pm3-f-7

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemnm.2015.7._29pm1-b-4

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記述言語：英語   出版者・発行元：一般社団法人 日本機械学会  

Magnetostrictive materials of the Fe-Ni-Cr ternary system for sensitivity enhancement of force sensors were searched by using a combinatorial method. Magnetostrictive materials for force sensors require large magnetostriction, high relative permeability, and high resistivity. This research is an attempt to find composition ranges that satisfy the following requirements: magnetostriction greater than 20×10 ^-6, relative permeability greater than 4,000, and resistivity over 90 μΩ cm. A novel combinatorial deposition method, known as Combinatorial New Facing Targets Sputtering (Combi-NFTS) method was applied to fabricate libraries of samples with various compositions. Samples for measurement of the relative permeability and resistivity were synthesized with a composition distribution by using Combi-NFTS onto a 108 mm×76 mm glass substrate. After deposition of thin film, each sample is divided into 10 mm×10 mm. The relative permeability and resistivity were measured by using a vibrating sample magnetometer and the four probe method, respectively. Bilayer cantilever samples for evaluation of magnetostriction were fabricated onto a 6 mm×20 mm×0.1 mm Si substrate, whereby deflection of the samples changes when a magnetic field is applied. The laser lever method was used to measure the cantilever deflection. The results indicate that the composition range with an Fe content of 26-36.5 at.%, a Ni content of 61-66 at.%, and a Cr content of 7.5-9.5 at.% satisfy the requirement criteria.

DOI： 10.1299/mej.14-00462

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2015._s0440103-

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2015._s0440102-

CiNii Research

記述言語：英語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemipe.2015._mob-2-1-1

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2015._j2220305-

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2015._j2220302-

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2015._j2220201-

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2015._j2220105-

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2015._j2220102-

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2015._j2220101-

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DOI： 10.1016/j.actaastro.2014.10.020

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出版者・発行元：Electronics and Communications in Japan  

Combinatorial search is one of the useful methods that could search for optimal composition of alloy materials or novel alloy materials. Combinatorial sputtering provides sample group (library) having different compositions in a limited place. Then, the properties of the samples can be scanned in an efficient way. In this research, magnetostrictive material with high magnetostriction, relative permeability, and resistivity was studied. Desired value of magnetostriction is more than 20 × 10-6, relative permeability is more than 4000, and resistivity is more than 100 μΩ·cm. As a result, composition that Cr content is less than 14 at.% fill the desired value of relative permeability, and more than 10 at.% fill the desired value of resistivity. There is possibility to fill the desired value of magnetostriction. © 2014 Wiley Periodicals, Inc.

DOI： 10.1002/ecj.11681

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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：Applied Physics Express  

We have demonstrated a patterning process for the fabrication of thermoelectric thick-film modules by a thermally assisted sputtering method (TASM) and a lift-off technique. Given the experimental requirements of TASM, poly(dimethylsiloxane) (PDMS) was used as the heat-resistant masks in the lift-off technique. After the film deposition, the PDMS lift-off mask was removed from the substrate. This process enables the fabrication of 30-μm-thick and 300-μm-wide Sb2Te3 and Bi 2Te3 thick-film patterns. The increase in film thickness increased the power generated by the module, which was consistent with the theoretical value. © 2014 The Japan Society of Applied Physics.

DOI： 10.7567/APEX.7.057101

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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：Microelectronic Engineering  

Mold materials for glass lenses with microstructures, such as gratings, require not only excellent mechanical properties, high thermal stability and oxidation resistance, but also sufficient machinability by Single-Point Diamond Turning (SPDT). Our research on Ni-Nb-Zr alloys has shown that one amorphous alloy composition (Ni35Nb40Zr25 at.%) met almost all the requirements for glass lens mold materials. Unfortunately, when fabricating gratings on the mold, the immense wear on the bit, which may be caused by the high hardness of the alloy (more than 10 GPa by the nano-indentation method), made it impossible to cut precise gratings. Consequently, the addition of a fourth element was considered to decrease the hardness. After several experiments, the addition of Ti was found to decrease the hardness. At first, Ti was added to substitute 10% Zr, to give Ni 35Nb40Zr15Ti10 at.%. Although this alloy had a lower hardness (9.5 GPa) than Ni35Nb40Zr 25 at.%, it still cannot be micro-cut by SPDT. It was then decided to substitute Ti for Ni-Nb instead of Zr. Three samples: Ni30Nb 35Zr25Ti10 at.%, Ni28Nb 32Zr25Ti15 at.% and Ni25Nb 30Zr25Ti20 at.%, were fabricated for evaluation. Finally, the Ni28Nb32Zr25Ti 15 at.% and Ni25Nb30Zr25Ti 20 at.% were found to have a low enough hardness to allow for precision machining. © 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.mee.2013.11.008

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出版者・発行元：2014 International Symposium on Micro-NanoMechatronics and Human Science, MHS 2014  

Copper oxide anti-reflection structures were designed by rigorous coupled wave analysis for thin-film thermoelectric solar generator. We proposed thin-film thermoelectric generator with the anti-reflection structure on the hot side of pn junction. When infrared solar light from 800 to 1200 nm wavelength is irradiated to the thermoelectric generator, the anti-reflection structure on the hot side generates the temperature gradient between the hot side and cold side of pn junction. When the cross-sectional geometry of the anti-reflection structures was hemisphere which was geometrically approximated pyramid one, the reflectance from 800 to 1200 nm wavelength was reduced than flat and binary ones. The reflectance of solar light was obtained by considering the solar light spectra and its polarization. By assuming that the average of TM and TE polarized light was the reflectance of solar light, the reflectance was reduced to be 9.6% when the period of the anti-reflection structure was 700 nm. Taking into account of the reflectance of Cu on cold side 99%, this large reflectance difference is expected to generate a large temperature gradient between hot side and cold side.

DOI： 10.1109/MHS.2014.7006118

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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）  

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2014._s0440101-

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2014._j2220203-

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2014._j2220202-

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2014._j2220102-

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2014._f041003-1

CiNii Research

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）  

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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：IEEJ Transactions on Electrical and Electronic Engineering  

This paper suggests a poly(vinylidene fluoride) (PVDF) piezoelectric diaphragm actuator used in a novel fatigue test method for thin metal films. A thin-film metal specimen is stamped on top of the actuator using a stamping epoxy. As the actuator vibrates, the stress in the specimen increases until it fails under fatigue. A finite element model of the actuator is built, and its vibration amplitude is confirmed to be in a good agreement with experiment. Then, a model of the specimen is added to this model to simulate the vibration of the specimen for fatigue test. Stress analysis of the specimen at a driving voltage of 200 V0-p confirms that this actuator can increase the stress in the specimen to near 1 GPa, which is high enough for the fatigue test of metals such as titanium. In the experiment, a thin-film titanium specimen is stamped on top of the actuator which is then vibrated. The stress in the fatigue gauge on thin-film specimen increased until the specimen failed under fatigue. This shows that the proposed PVDF actuator is suitable for the fatigue test of thin-film metals such as titanium. © 2012 Institute of Electrical Engineers of Japan.

DOI： 10.1002/tee.21840

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 電気学会  

Combinatorial search is one of the useful methods that could search for optimal composition of alloy materials or novel alloy materials. Combinatorial sputtering provides sample group (library) having different compositions in a limited place. Then, the properties of the samples can be scanned in an efficient way. In this research, it was studied that magnetostrictive material with high magnetostriction, relative permeability and resistivity. Desired value of magnetostriction is more than 20×10-6, relative permeability is more than 4000, and resistivity is more than 100 µΩ·cm. As a result, composition that Cr content is less than 14 at.% fill the desired value of relative permeability, and more than 10 at.% fill the desired value of resistivity. There is possibility to fill the desired value of magnetostriction.

DOI： 10.1541/ieejsmas.133.342

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 電気学会  

Thin film shape memory alloys (SMAs) are promising materials for micro-machines because of their high-output power, large strain, and actuation without high voltage. To search for compositions of suitable thin film SMAs for each application, combinatorial technique is useful tool, however the technique requires high-throughput characterization method for thermal property which is an important property of thin film SMAs such as two way martensitic transformation temperature and thermal hysteresis. In this paper, novel high-throughput characterization method for such properties using thermography is proposed and demonstrated. Compositionally integrated thin film SMA samples (TiNiPd) with only 1mm2 of each area are characterized at once. The difference of martensitic and reverse martensitic transformation temperature against those temperatures measured by a conventional method, differential scanning calorimetry, is about 5K.

DOI： 10.1541/ieejsmas.133.348

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担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）   出版者・発行元：一般社団法人 電気学会  

DOI： 10.1541/ieejsmas.133.nl6_2

CiNii Research

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemag.116.1137_534_2

CiNii Research

記述言語：英語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemp.2013.21._632-1_

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2013._f113004-1

CiNii Research

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2013._j212036-1

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2013._j212021-1

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2013._j212017-1

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2013._j212012-1

CiNii Research

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemag.116.1130_11

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出版者・発行元：Materials Research Society Symposium Proceedings  

Combinatorial sputtering is one of the useful methods that can be used to search for optimal composition of alloy materials or for new alloy materials. To search materials more efficiently, it is required that compositions and their distribution on samples can be easily controlled for the evaluation of their properties. Moreover, it is desirable that compositions change linearly to search for novel materials systematically. In conventional combinatorial sputtering method, it is difficult to fabricate samples having linear compositions distribution without moving hard masks or rotating substrate. In this paper, a novel combinatorial sputtering method with New Facing Targets Sputtering (Combi-NFTS) of material search is introduced. In this method, several sputtering targets are placed in opposite direction, and substrates are placed in vertical direction of these targets. From this structure, thin film with binary/ternary composition distribution could be synthesized onto one single substrate. Moreover, it can fabricate samples having relatively linear composition distribution without moving hard masks or rotating substrate. As an example, Cu, Zr and Ti pure targets were used to confirm the performance of Combi-NFTS. Binary system of Cu-Zr and ternary system of Cu-Zr-Ti thin films were fabricated by using Combi-NFTS. After deposition, compositions of the films were characterized by the energy dispersive X-ray spectroscopy. As a result of Cu-Zr binary system, the composition of the thin film was changed as the power of targets was changed. Moreover, composition distribution was expanded as the distance from substrate to targets was decreased. In the Cu-Zr-Ti ternary system, it was obtained similar trend for composition distribution. Moreover, the composition changed two dimensional by changing the substrate position. These results indicate that combi-NFTS can easily control the composition and composition distribution of thin films by changing the power of targets or the distance from substrate to targets which make combi-NFTS very suitable for combinatorial materials search. © 2012 Materials Research Society.

DOI： 10.1557/opl.2012.1403

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記述言語：英語   出版者・発行元：Materials Science and Engineering: A  

We conducted a search for Ti-Ni-Zr thin film metallic glasses (TFMGs) exhibiting a shape memory effect after crystallization. We investigated the possibility of (Ti, Zr)(100-x)-Nix thin film amorphous alloys exhibiting a glass transition. All prepared samples were classified into three groups such as Ti-rich (x<50), equiatomic (50<x<51) and Ni-rich (x>51) samples. Equiatomic Ti-Ni-Zr thin film amorphous alloys with Zr content ranging from 11 to 17at.% showed a glass transition, and thus were concluded to be TFMGs. Several Ni-rich samples exhibit glass transition and were also TFMGs. On the other hand, Ti-rich samples did not exhibit a glass transition irrespective of the Zr content. Moreover, we investigated the shape memory behavior of crystallized TiNiZr TFMGs. Ti39Ni50Zr11 TFMGs annealed at 973K for 3.6ks exhibited a martensitic transformation from the B2 to the B19' phase upon cooling and heating. The martensitic phase start temperature and reverse martensitic phase start temperature were 296 and 352K, respectively. In addition, this alloy showed good shape memory behavior, achieving recovery strain of 2.5% and a critical stress for slip of 500MPa. © 2012 Elsevier B.V.

DOI： 10.1016/j.msea.2012.01.075

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記述言語：英語   出版者・発行元：IEICE Electronics Express  

Novel high-frequency bending fatigue test method for sputtered metallic thin films using PVDF microactuator is proposed. Thin film titanium specimen as an example and a PVDF piezoelectric microactuator are fabricated. The specimen is stamped on this actuator and the actuator is vibrated at its resonance frequency until the specimen fails by fatigue. The stress in the specimen is calculated from vibration amplitude. By using the proposed method, the stress-fatigue life cycle (S-N) curve of the thin film titanium is obtained over 50 times faster than conventional method. © IEICE 2012.

DOI： 10.1587/elex.9.403

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1299/jmmp.4.1742

記述言語：英語  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.4028

記述言語：英語  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.4028

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.4028

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1088/0964-1726/19/4/045008

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2472

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1299

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1143

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DOI： 10.1143

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DOI： 10.1143

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016

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DOI： 10.1016

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DOI： 10.1016

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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DOI： 10.1016

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DOI： 10.1016

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DOI： 10.1541

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DOI： 10.1143

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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DOI： 10.4172/2321-6212.1000155

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出版者・発行元：European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 19th International Conference and Exhibition, EUSPEN 2019  

© 2019 European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 19th International Conference and Exhibition, EUSPEN 2019. All rights reserved. Argon fast atom beam (FAB) gun is used as a neutral atom beam irradiation source for surface activated bonding (SAB). Since SAB does not require any heat treatments, stress due to difference in thermal expansion coefficients does not occur, and the bonding between not only the same material but also different materials is realizable. However, the conventional FAB gun can be used for only short time because carbon abrasion powders are generated from the worn part of the inside walls of the gun due to argon ion sputtering. We developed the novel FAB gun applied magnetic fields and new position of the anodes in the gun to control the motion of the argon ions and reduce the sputtering. The design concept is that the magnetic fields guide both argon ions and electrons to the irradiation port of the gun and the argon atoms for the irradiation increased. In this study, we investigated the influence of the positions of the magnetic fields and the anodes on the plasma generation, the argon irradiation and the sputtering. With the novel FAB gun, the stable plasma is generated in the vicinity of the irradiation port, and the maximum irradiation amount is 3 times in comparison with the conventional design. Less sputtering of the inside walls of the gun was observed after the irradiation for more than thousands of minutes, while the sputtering with the conventional gun is more observed at the same condition.

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：MHS 2018 - 2018 29th International Symposium on Micro-NanoMechatronics and Human Science