受賞区分：国内学会・会議・シンポジウム等の賞 

受賞区分：国内学会・会議・シンポジウム等の賞  受賞国：日本国

受賞国：日本国

受賞区分：国内学会・会議・シンポジウム等の賞  受賞国：日本国

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：International Journal of Multiphase Flow  

This paper presents a thermo-fluid dynamic analysis in a micro-textured evaporator for loop heat pipes (LHPs) that has a super wetting surface with ethanol on the basis of an experiment and modeling. In the experiment, three kinds of stainless steel plates with various morphologies of heat transfer surfaces were tested: a normal flat plate, a sandblasted plate, and a micro-groove plate. The measured contact angles between the surfaces and ethanol were 8.2° ± 1.3°, 0°, and 0°, respectively. Evaluation of the heat transfer performance and liquid-vapor interface behavior was conducted using microscale infrared and visible observations. As a result, it was revealed that the sandblasted plate and the micro-groove plate showed 7 times and 20 times higher heat transfer coefficient under high heat flux conditions respectively, compared with the normal flat plate. Different liquid-vapor interface behaviors were found between the plate types. In the modeling, the heat transfer coefficient was predicted for each case. It was found that nucleate boiling heat transfer induced by rough surface increased the heat transfer performance in the case of the sandblasted plate. In addition, it was revealed that the thin film evaporation at the long triple-phase contact line significantly enhanced heat transfer performance in the case of the micro-groove plate. The findings indicate a new promising approach to enhance the heat transfer coefficient of LHP evaporators.

DOI： 10.1016/j.ijmultiphaseflow.2021.103623

Web of Science

Scopus

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：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

Web of Science

Scopus

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：Journal of Coatings Technology and Research  

The water wettability of porous stainless steel specimens was enhanced via a nanoscaled silica coating for application to passive two-phase heat transfer devices. A combination of porous stainless steel and water has attracted attention in the area of the heat transfer devices. However, the water wettability of stainless steel is poor, limiting the performance of the devices. In the present study, the silica coating of the specimens was conducted via a reaction of tetraethyl orthosilicate (TEOS) after pretreatment using NaOH aq. or HCl aq. Energy-dispersive X-ray spectrometry revealed that the amount of silica deposited on the surface was dependent on the pretreatment conditions and the composition of the silica-coating solutions. Measurement of porous properties indicated that the silica coating did not affect pore diameter and gas permeability since the coating was in nanoscale. Microscale contact angles were directly evaluated using an environmental SEM. The specimens showed excellent water wettability when they were covered with numerous tiny silica bumps. When the specimen was pretreated with 2 M NaOH aq. and coated in weak alkaline TEOS solution, the contact angle of the porous stainless steel decreased from 87° to 54° after silica coating. The excellent water wettability originated from the relatively smooth surface and a sufficient coverage ratio, which resulted from the moderate strength of chemical etching of the NaOH aq. and the mild silica-coating condition in the weak alkaline solution.

DOI： 10.1007/s11998-020-00417-1

Web of Science

Scopus

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：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

Web of Science

Scopus

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/jsmemecj.2021.j221-07

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/LTB-3D53950.2021.9598414

Web of Science

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  

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

Web of Science

Scopus

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：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

Scopus

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/jsmemp.2020.28.267

CiNii Research

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/jsmemp.2020.28.158

CiNii Research

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  

<p>Most microvalves need electrical wiring on each one, and the need will disturb further integration and miniaturization of microfluidic systems soon. The present study proposes new remotely controlled microvalves without the electrical wiring on each valve. The microvalves consist of thermo-responsive gels and magnetic nanoparticles, and they run with heat dissipation from the magnetic nanoparticles in an alternating magnetic field. The microvalves open via shrinking of the thermo-responsive gels through the heat dissipation. In this paper, the microvalves were fabricated using Fe₃O₄ nanoparticles and patternable thermo-responsive gels mainly made from poly(<i>N</i>-isopropyl acrylamide) (PNIPA). The gels incorporating the magnetic nanoparticles were installed in Poly(dimethylsiloxane) (PDMS) microchannels. The microchannels were fabricated using a mold made of SU-8. The fabricated microvalve could perfectly block the flow of water under conditions without any external magnetic fields. When the closing microvalve was exposed to an alternating magnetic field (2 MHz, 50 Oe), the microvalve was opened and the water flow was observed. When the alternating magnetic field was stopped, the microvalve was closed again and the water flow was stopped. The proposed microvalves were successfully fabricated, and the microvalves could be operated by the alternating magnetic field as expected.</p>

DOI： 10.1299/jsmemecj.2020.j22204

CiNii Research

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  

<p>In recent years, minimally invasive treatment has attracted attention, and catheter surgery is one of them. On the other hand, 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. In order to improve the skill of catheter surgery, the authors have proposed a surgical simulator that realizes real-time visualization of stress by the photoelasticity. Photoelasticity is a property in which an isotropic elastic body such as glass or acrylic that receives an external force causes birefringence. It is often used as an experimental method to analyze the stress distribution of materials. In this study, it is proposed a measurement system for surgical simulator that can measure three-dimensional stress. The shape of the blood vessel model applicable to the proposed measurement system is determined and introduce a stress correction that guarantees constant accuracy. Finally, it is showed that the stress can be visualized in real time.</p>

DOI： 10.1299/jsmemecj.2020.j24111

CiNii Research

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  

<p>This study creates a blood vessel model for a catheter surgery simulator. In previous study was succeeded in producing a blood vessel model applicable to a surgical simulator using PVA hydrogel. On the other hand, the problem with the blood vessel model is that the reproducibility of the mechanical properties of blood vessels, which is important for the actual catheter operation sensation, is low. Therefore, in this study, creates a blood vessel model with a two-layer structure that reproduces the mechanical properties of the blood vessel wall and adipose tissue. In the proposed blood vessel model, it is shown that the mechanical properties can be reproduced by changing the compounding ratio of powdered PVA and the mass ratio of water and DMSO as a solvent. Furthermore, this study proposes a method for producing a two-layer structure and show that it is possible to produce a blood vessel model with a two-layer structure.</p>

DOI： 10.1299/jsmemp.2020.28.156

CiNii Research

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  

<p>The novel fast atom beam source (FAB) for surface-activated bonding (SAB) method was proposed in order to improve the lifetime of FAB sources. The proposed FAB source achieved the higher efficiency of Ar-FAB irradiation and less wear on the electrodes. This previously study indicated that the applied magnetic fields made the Ar ions converge on the irradiation port, increasing Ar irradiation efficiency. However, it was not measured and not clearly why the proposed FAB source achieved higher performance. In this study, we aim to reveal the factor of achievement high performance and to propose the new structure of the FAB source with much higher performance by plasma analysis. Electrostatic probe studies and the simulation for Ar plasma in the proposed source show that the electron and Ar⁺ density increase near the irradiation port. Moreover, increasing Ar⁺ flux only to the wall with irradiation port indicates improving Ar-FAB irradiation efficiency and suppressing Ar+ sputtering and carbon agglomerates on inside wall of the source.</p>

DOI： 10.1299/jsmemecj.2020.j13105

CiNii Research

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  

<p>In this paper, we fabricated three types of 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). Three types of master molds for micro-texture (M-Tx), nano-texture (N-Tx), and micro-nano-double texture (D-Tx) were prepared by an aluminum anodic oxidation. 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 7.5% for M-Tx (<i>η</i> of 2.74%), 18% for N-Tx (<i>η</i> of 3.01%) and 26% for D-Tx (<i>η</i> of 3.22%) compared to DSSC with flat glass (<i>η</i> of 2.55%).</p>

DOI： 10.1299/jsmemecj.2020.j22207

CiNii Research

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/jsmemp.2020.28.266

CiNii Research

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  

<p>We reported on the fabrication of tactile pins for reaction force variable passive type tactile displays using Ti-Ni-Cu high formable shape memory alloys. These devices take advantage of the temperature controllability of the resilience of the superelasticity effect and present hardness and softness tactile sensation. After the tactile pins being formed into three-dimensional shape by viscous flow of metallic glasses, they became shape memory alloys by annealing for crystallization. The height of tactile pin formed by conventional method was about 110 μm. However, when tactile pin was pushed by the finger, it was insufficient deformation for the stable superelasticity effect to appear. Therefore, we attempted to increase the height of tactile pin by the improving deformation method using rapidly temperature raising during forming for decreasing viscosity of metallic glasses. As a result, we successfully increased the height of tactile pin to 237 μm.</p>

DOI： 10.1299/jsmemecj.2020.j22210

CiNii Research

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：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

Scopus

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：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

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：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：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Advanced Optical Technologies  

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

Web of Science

Scopus

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：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   掲載種別：研究論文（学術雑誌）   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：日本語   掲載種別：研究論文（学術雑誌）   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  

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

Scopus

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  

<p>MEMS mirror device is a device that reflects and scans a laser by the torsion of the beam structure. By miniaturization of the device, the reduction of the deflection angle of the mirror becomes to be an issue. In this research, we fabricated a MEMS mirror structure using film metallic glass formed by sputtering as a new material for the beam structure. In order to avoid the deterioration of the cross-sectional shape of the structure caused by the film thickening, a reverse lift-off method was used in the fabrication process. It is the method that forms film on a desired pattern and remove the others to obtain the flat and uniform thickness structure. Several conditions of the anneal was tested and the structure annealed at 200 ℃ shows less deflection than others. The fabricated structure was driven by external excitation, and it was confirmed that the resonance frequency was almost as designed.</p>

DOI： 10.1299/jsmemecj.2019.j22208p

CiNii Research

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  

<p>Microvalves are used in microfluidic systems such as micro reactors, and micro-total analysis systems (μ-TAS). Most microvalves need electrical wiring on each one, and the need prevents further integration and miniaturization of the microfluidic systems. Hence, we suggest new 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 proposed microvalves consist of thermo-responsive gels and the magnetic nanoparticles with a diameter of 20 nm or less. The nano-scale magnetic particles with superparamagnetic behavior generate heat in an alternating magnetic field. The aim of this study is to verify possibility of the new microvalves. First, Fe₃O₄ magnetic nanoparticles were synthesized and characterized with an X-ray diffractometer, a transmission electron microscope, and a magnetic property measurement system. Then, the heat generation of the synthesized magnetic nanoparticles was measured in an alternating magnetic field. From the measurement, the possibility of the proposed microvalves was verified calculating how long it require to shrink the thermo-responsive gels by heat generated from the magnetic nanoparticles.</p>

DOI： 10.1299/jsmemecj.2019.j22207p

CiNii Research

Web of Science

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  

<p>In this study, we propose a combinatorial evaluation method for evaluating the corrosion resistance of the Ti-Ni-based high formable shape memory alloys (HFSMAs) based on anodic polarization tests. The proposed evaluation substrates compose nine samples which have different compositions. These samples are deposited on a glass substrate by carousel sputtering system and microelectromechanical processes. Further, we performed anodic polarization tests on the Ti–Ni–Zr and Ti–Ni–Cu HFSMAs samples. The polarization curves are obtained by sweeping the potential and the current density at the passive state (<i>i</i>_ps) of each composition tested is compared. In case of the Ti–Ni–Zr alloy, <i>i</i>_ps varied depending on the Zr content. When the Zr content ranged from 10 to 15 at.%, their <i>i</i>_ps were comparable with that of Ti₄₈Ni₅₂ used in medical devices. On the other hand, in case of the Ti-Ni-Cu alloy, their <i>i</i>_ps were similar to that of Ti₄₈Ni₅₂ regardless of Cu content. We obtained Ti–Ni–Zr and Ti–Ni–Cu HFSMAs having a corrosion resistance equivalent to that of Ti₄₈Ni₅₂. Furthermore, we conducted XPS analysis to investigate the passive film of HFSMAs. The thin surface film of Ti-Ni-Zr alloys were composed of TiO₂ and ZrO₂, while that of Ti-Ni-Cu alloys were composed of only TiO₂. We have concluded that the formation of TiO₂ enriched protective thin surface film might have been responsible for the high corrosion resistance.</p>

DOI： 10.1299/jsmemp.2019.27.207

CiNii Research

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  

<p>In recent years, minimally invasive treatment has attracted attention, and catheter surgery is one of them. 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. In order to improve the surgeon's surgical technique, the authors have proposed a surgical simulator that realizes real-time visualization of stress by the photoelastic method. In this study, we propose a measurement system using a photoelastic method that can visualize stress in three dimensions and examine the blood vessel model shape applicable to the proposed measurement system.</p>

DOI： 10.1299/jsmemp.2019.27.p01

CiNii Research

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  

<p>In this paper, we fabricated two types of 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 master molds for nano-texture (N-Tx) and micro-nano-double texture (D-Tx) were prepared by an aluminum anodic oxidation. Both N-Tx and D-Tx showed higher total transmittance and lower reflectance than bare glass. 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 (<i>η</i> of 3.67%) and 19% for D-Tx (<i>η</i> of 3.47%) compared to DSSC with flat glass (<i>η</i> of 2.91%).</p>

DOI： 10.1299/jsmemp.2019.27.p04

CiNii Research

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：European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 19th International Conference and Exhibition, EUSPEN 2019  

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.

Scopus

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：MHS 2018 - 2018 29th International Symposium on Micro-NanoMechatronics and Human Science  

In micro electromechanical systems(MEMS) technology, lift-off processes are general patterning methods for the formation of amorphous alloy thick film structures. However, thicknesses of structures fabricated in this method are not uniform and cross-sectional shapes are not flat because sputtered particles are blocked by the sidewalls of the lift-off layer. In order to solve this problem, a reverse lift-off process is proposed as a new patterning method [1]. In the reverse lift-off process, the desired structure is formed on the top of the convex pattern such as the substrate. In contrast to the lift-off process, the thickness of the structure is uniform and the cross-sectional shape is rectangular because sputtered particles are not blocked by the sidewalls. In this research, thick film structures were fabricated in reverse lift-off processes from the width of the convex pattern on the order of micrometers. And the film thickness and the cross-sectional shape of the fabricated structure are measured, and the micro processing characteristics of the reverse lift-off process, which had not yet been elucidated, were investigated. This demonstrates the usefulness of fabricating the thick film micro structures in the reverse lift-off process.

DOI： 10.1109/MHS.2018.8886962

Scopus

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：MHS 2018 - 2018 29th International Symposium on Micro-NanoMechatronics and Human Science  

In this paper, we proposed the process of the diaphragm for miniaturizing MEMS capacitive pressure sensor and controlling its sensitivity. We fabricated micro diaphragm using a Ru65Zr30Al5(at.%) thin film metallic glass (TFMG). The as-sputtered TFMG on Si substrate were annealed at 315-440°C for 5 minutes in vacuum. After annealing, micro diaphragms were fabricated by an etching Si substrate using a reactive ion etching system. Although the diaphragm without annealing had dome structure, the diaphragm annealed above 340°C formed a flat structure. The deflection of the diaphragm against applied pressure depended on the annealing temperature and decreased at higher temperatures. The pressure sensor was modeled using this diaphragms. The pressure measurement range and sensitivity were 250 Pa and 6.4×10-3 pF/Pa, respectively, for annealed at 340°C, and 1800 Pa, and 8.1 × 10-4 pF/Pa, respectively for annealed at 440°C.

DOI： 10.1109/MHS.2018.8887020

Scopus

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/jsmetokai.2018.67.519

CiNii Research

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  

<p>Further miniaturization of the diaphragm for capacitive pressure sensor requires thinner structures to deform micro diaphragm sufficiently by small differential pressure. Since stiffness of thinner structures decrease, the influence of internal stress introduced during processing cannot be ignored. In this paper, we proposed methods of controlling the internal stress for micro diaphragm using thin film metallic glasses (TFMGs). We fabricated micro diaphragms using Ru67Zr25Al8 [at.%] TFMGs. The TFMGs were fabricated by a r.f. sputtering system, and then as sputtered TFMGs had compressive internal stress. Subsequently, the as-sputtered TFMGs on Si substrate were annealed at 315-440°C for 5 minutes in vacuum. After annealing, micro diaphragms were fabricated by etching Si substrate using a reactive ion etching system. Although annealing temperatures were lower than glass transition temperature, initial internal stress was relaxed partially by the structural relaxation of the TFMGs during annealing process. While the tensile thermal stress was induced during cooling process at the interface between the substrate and TFMG. Although micro diaphragm was not induced thermal stress at interface between the substrate and TFMG, the tensile stress applied to diaphragm in the radial direction at the edge. When annealing temperatures were between 320°C and 340°C, the internal stress changed from compressive to tensile. A flat diaphragm was obtained when annealed at 330°C or higher. The pressure sensor modeled by diaphragm annealed at 340°C and the virtual electrode plate showed a linearity of 6.48 [%F.S.]. By proposed method, we succeeded the flat diaphragm and showed the method of tension control of the diaphragm.</p>

DOI： 10.1299/jsmemecj.2018.j2220304

CiNii Research

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  

<p>A diaphragm structure is a fundamental structure in a micro machine such as MEMS. Conventionally, Si has used as a diaphragm material. However, in recent years, in order to make the diaphragm structure more sophisticated and miniaturized, high sensitivity difficult to realize by using Si is required. Therefore, in this study, we aim to create a highly precise diaphragm structure by using the thin film metallic glass which is an amorphous alloy shown glass transition as a new material which meets these demands. Pd₇₇Cu₆Si₁₇ (at. %) and Ru₆₅Zr₃₀Al₅ (at. %) are used for thin film metallic glass. The thin film metallic glasses are deposited on the Si substrates by sputtering. Internal stress of each film is controlled by adjusting Ar pressure during sputtering and annealing after sputtering. The internal stress of the Pd₇₇Cu₆Si₁₇ (at. %) thin film is always tensile stress and it is minimum at an Ar pressure of 0.5 Pa, and its value is 23.6 MPa. Under this condition, we can create a highly precise diaphragm. On the contrary, the internal stress of Ru₆₅Zr₃₀Al₅ (at. %) thin film is always compressive stress in the range of sputtering Ar pressure. So, we try to relax the internal stress of Ru₆₅Zr₃₀Al₅ (at. %) thin film by annealing. In the proper annealing conditions, a diaphragm having the same flatness level as Pd₇₇Cu₆Si₁₇ (at. %) is realized.</p>

DOI： 10.1299/jsmemecj.2018.j2220303

CiNii Research

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/jsmemp.2018.26.901

CiNii Research

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：Surface Topography: Metrology and Properties  

Control of thermally induced liquid-vapor interface behavior at the contact surface of porous media is crucial for development of two-phase heat transfer devices such as loop heat pipes. The behavior experiences three modes with increase of heat flux, and the middle mode possesses the highest heat transfer performance. In this paper, the effect of improving wettability of the porous media is demonstrated experimentally and numerically for the first time, in particular with regard to the effect on a domain of the middle mode. Ethanol wettability of a porous stainless steel was improved via a facile method, which was a simple acid treatment. As a result, the domain of the middle mode was extended as a consequence of the wettability improvement. The mode transfers from the middle to the last one when the pressure drop in the liquid supply exceeds the capillary pressure of liquid bridges formed between the heating plate and the porous medium. Hence, the extension of the domain suggested that the capillary pressure was increased by the wettability improvement. This was verified via numerical calculation. The calculated capillary pressure was increased by 7% after improving wettability, which resulted in the extension of the domain of the middle mode.

DOI： 10.1088/2051-672X/aa9499

Web of Science

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1111/myc.12554

PubMed

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）  

開催年月日： 2021年10月

記述言語：英語   会議種別：口頭発表（一般）  

開催年月日： 2021年10月

記述言語：日本語   会議種別：ポスター発表  

開催年月日： 2021年10月

記述言語：英語   会議種別：口頭発表（一般）  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年8月 - 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年8月 - 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2021年6月

記述言語：英語   会議種別：ポスター発表  

開催年月日： 2021年6月

記述言語：英語   会議種別：ポスター発表  

開催年月日： 2021年6月

記述言語：英語   会議種別：ポスター発表  

開催年月日： 2021年6月

記述言語：英語   会議種別：ポスター発表  

開催年月日： 2019年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2019年12月

記述言語：英語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年12月

記述言語：英語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年11月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2019年11月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年11月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年11月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年11月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年11月

記述言語：英語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年10月 - 2019年11月

記述言語：英語   会議種別：口頭発表（一般）  

国名：アメリカ合衆国  

開催年月日： 2019年9月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年9月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年9月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年9月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2019年9月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2019年8月

記述言語：英語   会議種別：ポスター発表  

国名：中華人民共和国  

開催年月日： 2019年6月

記述言語：英語   会議種別：ポスター発表  

国名：ドイツ連邦共和国  

DOI： 10.1109/TRANSDUCERS.2019.8808618

Scopus

開催年月日： 2019年6月

記述言語：英語   会議種別：ポスター発表  

国名：スペイン  

Scopus

開催年月日： 2019年3月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

国名：日本国  

開催年月日： 2019年1月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年1月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年1月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年1月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年1月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2019年1月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2018年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2018年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：タイ王国  

開催年月日： 2018年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2018年12月

記述言語：英語   会議種別：口頭発表（一般）  

国名：タイ王国  

開催年月日： 2018年11月

記述言語：英語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2018年10月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2018年10月

記述言語：英語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2018年10月

記述言語：英語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2018年9月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

国名：日本国  

開催年月日： 2018年9月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2018年6月

記述言語：英語   会議種別：口頭発表（一般）  

国名：イタリア共和国  

開催年月日： 2018年6月

記述言語：英語   会議種別：ポスター発表  

国名：台湾  

開催年月日： 2018年6月

記述言語：英語   会議種別：ポスター発表  

国名：台湾  

開催年月日： 2018年5月

記述言語：英語   会議種別：口頭発表（招待・特別）  

国名：台湾  

Scopus

Scopus

Scopus

実験テーマ名：解析力学による回転体の力学

実験テーマ名：解析力学による回転体の力学