Language：English   Publishing type：Research paper (scientific journal)  

Publisher：Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers  

We present a novel soft tentacle actuator combining magnetic actuation with pressure-controlled local stiffness modulation. By utilizing a tapered tube design, the actuator achieves controlled buckling progression under negative internal pressure, enabling precise manipulation with a single-axis magnetic field. We developed a comprehensive deformation model incorporating the effects of cross-sectional buckling and geometric tapering, which demonstrated excellent agreement with experimental results. Through numerical optimization, we determined the optimal magnetization profile that maximizes the operational workspace. The established pressure-magnetic field mapping enabled the actuator to trace arbitrary trajectories. This design approach overcomes the limitations of conventional magnetic soft actuators by achieving multi-degree-of-freedom control without requiring complex magnetic field systems, offering potential applications in minimally invasive surgery and micro-manipulation tasks.

DOI： 10.35848/1347-4065/adbc71

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Language：English   Publisher：Japan Society of Powder and Powder Metallurgy  

<p>Additive manufacturing of ceramic/metal composites combines the material's advantages with the flexibility of 3D printing, allowing the customized production of complex structures while enhancing lightweight design outcomes. Currently, this technology is widely employed in sectors such as aerospace and automotive for processing and manufacturing high-performance components. In this study, we developed a material extrusion 3D printing system for metal-ceramic hybrid structures. The system facilitates low-heat printing, and the printed samples can be easily and safely debound using an alcohol-based process, greatly simplifying the process flow and improving the processing efficiency of high-performance composites. Furthermore, as part of this research, 3D printed composites of SUS316L/ZrO₂ were developed to fabricate intricate structural workpieces.</p>

DOI： 10.2497/jjspm.15p-t1-04

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CiNii Research

Publisher：Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers  

Inspired by natural cilia, we developed magnetically actuated artificial cilia capable of controlled three-dimensional motion. The key innovation lies in concentrating hard magnetic particles at the tip of a silicon pillar, enabling asymmetric effective and recovery strokes under a constant rotational magnetic field. By magnetizing the pillar at 45° to the ground, we achieved complex three-dimensional movements that closely mimic biological ciliary motion. Our developed simulation system reproduced individual pillar trajectories in static conditions, showing consistency with experimental results in the range without snapping, a phenomenon characterized by the sudden release of twist-induced stress. Furthermore, we demonstrated metachronal wave-like motion in pillar arrays. These arrays exhibited both transport capabilities, successfully moving a 10 mg object, and locomotion functions. The combination of precise motion control, predictive modeling, and demonstrated functionality suggests promising applications in microfluidic manipulation and biomedical devices.

DOI： 10.35848/1347-4065/adacf3

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Language：Japanese   Publisher：THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES  

DOI： 10.14822/kjsass.72.12_450

CiNii Research

Publisher：IEEJ Transactions on Electrical and Electronic Engineering  

Bacterial cellulose (BC) produced by acetic acid bacteria is a promising biomaterial that exhibits exceptional mechanical strength, biocompatibility, and biodegradability. In this study, we have successfully fabricated BC composites with various materials such as alumina fibers, zirconia particles, carbon nanotubes, and magnetic particles by adding each material to the culture medium. We also demonstrate the actuation of BC-magnetic particle composites by a magnetic field. Furthermore, we have achieved the patterning of arbitrarily shaped patterns onto BC pellicles by placing templates in the culture medium. These findings suggest that BC composites have the potential to be applied in various fields such as tissue engineering and drug delivery. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

DOI： 10.1002/tee.24009

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Language：English   Publishing type：Research paper (scientific journal)  

Bacterial cellulose (BC) produced by acetic acid bacteria is a promising biomaterial that exhibits exceptional mechanical strength, biocompatibility, and biodegradability. In this study, we have successfully fabricated BC composites with various materials such as alumina fibers, zirconia particles, carbon nanotubes, and magnetic particles by adding each material to the culture medium. We also demonstrate the actuation of BC-magnetic particle composites by a magnetic field. Furthermore, we have achieved the patterning of arbitrarily shaped patterns onto BC pellicles by placing templates in the culture medium. These findings suggest that BC composites have the potential to be applied in various fields such as tissue engineering and drug delivery.

DOI： https://doi.org/10.1002/tee.24009

Repository Public URL： https://hdl.handle.net/2324/7178664

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japanese Journal of Applied Physics  

Many organisms have functional microstructured surfaces. Particularly, lotus leaves have hierarchical dual-scale micro/nanostructures on their surface and exhibit highly water repellent properties. We have developed techniques to fabricate patterns on inorganic material surfaces such as ceramics. Applying these techniques to fabricate hierarchical structures can make ceramic surfaces even more promising. In this paper, we prepared 2 kinds of mold with line-and-space patterns with pitches 50 μm and 2 μm and fabricated micro (rough patterns)/submicron (fine patterns) hierarchical structures on sintered ceramic sheets using a newly developed imprinting process with in-plain compression method. We proposed processes for the fabrication of such hierarchical structures, discussed the possibility of higher resolution of the patterns by comparison with the analytical results.

DOI： 10.35848/1347-4065/ad2d05

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Repository Public URL： https://hdl.handle.net/2324/7178642

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Progress in Additive Manufacturing  

Fused Deposition Modelling (FDM) is one of the additive manufacturing (AM) techniques that have emerged as the most feasible and prevalent approach for generating functional parts due to its ability to produce neat and intricate parts. FDM mainly utilises one of the widely used polymers, polylactic acid, also known as polylactide (PLA). It is an aliphatic polyester material and biocompatible thermoplastic, with the best design prospects due to its eco-friendly properties; when PLA degrades, it breaks down into water and carbon dioxide, neither of which are hazardous to the environment. However, PLA has its limitations of poor mechanical properties. Therefore, a filler reinforcement may enhance the characteristics of PLA and produce higher-quality FDM-printed parts. The processing parameters also play a significant role in the final result of the printed parts. This review aims to study and discover the properties of PLA and the optimum processing parameters. This review covers PLA in FDM, encompassing its mechanical properties, processing parameters, characterisation, and applications. A comprehensive description of FDM processing parameters is outlined as it plays a vital role in determining the quality of a printed product. In addition, PLA polymer is highly desirable for various field industrial applications such as in a medical, automobile, and electronic, given its excellent thermoplastic and biodegradability properties.

DOI： 10.1007/s40964-022-00356-w

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Language：English   Publisher：The Society of Photopolymer Science and Technology(SPST)  

<p>In this study, we developed a new actuator that can be driven by both magnetic and pneumatic and conducted driving experiments using the fabricated actuator. Soft actuators are widely used as a means of biomimicry. However, many existing actuators that use a single drive source have limited degrees of freedom and deformation capabilities. Recently, hybrid actuators that can be driven by multiple sources have gained attention due to their ability to produce movements that are not achievable by a single drive source. In this study, we fabricated a simple actuator that combines a cylindrical pillar made of silicone material containing magnetic particles with a hollow structure for pneumatic deformation. Three types of actuators with varying diameters and positions of the hollow structure were fabricated, and the drive of each actuator was measured. The pneumatic extensible actuator allows the actuator tip to be manipulated on a fan-shaped two-dimensional plane. The pneumatic bending actuator could manipulate the actuator tip in three dimensions. The actuator with a larger diameter hollow structure could be deformed differently in the same magnetic field by changing the stiffness of the actuator depending on the air pressure. Furthermore, by modifying the hollow structure and the external shape of the actuator, more unique movements can be achieved, and it is expected to be applied to bio-mimicry such as tentacle movement and cilia structure.</p>

DOI： 10.2494/photopolymer.36.167

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CiNii Research

Language：English   Publisher：The Society of Photopolymer Science and Technology(SPST)  

<p>This study presents the development of a balloon-type dielectric elastomer actuator (DEA) that utilizes the Maxwell stress generated by applying voltage between electrodes. DEAs have been recognized for their superior responsiveness, durability, and energy efficiency, making them a promising candidate for applications such as artificial muscles. We fabricated two types of DEA using a latex balloon as the elastic material and carbon grease as the electrode to generate inflating and squashed deformations. We conducted experiments to measure and analyze the two types of deformation while varying the size or inner pressure of the balloon and the voltage magnitude. We found that the voltage magnitude affected the magnitude of the deformation in the actuator with inflating deformation, but not in the actuator with squashed deformation. Additionally, we estimated the applied Maxwell stress in the actuator. The developed actuators were capable of producing movements that imitate the behavior of organisms, such as the pufferfish.</p>

DOI： 10.2494/photopolymer.36.191

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CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

This study presents the development of a balloon-type dielectric elastomer actuator (DEA) that utilizes the Maxwell stress generated by applying voltage between electrodes. DEAs have been recognized for their superior responsiveness, durability, and energy efficiency, making them a promising candidate for applications such as artificial muscles. We fabricated two types of DEA using a latex balloon as the elastic material and carbon grease as the electrode to generate inflating and squashed deformations. We conducted experiments to measure and analyze the two types of deformation while varying the size or inner pressure of the balloon and the voltage magnitude. We found that the voltage magnitude affected the magnitude of the deformation in the actuator with inflating deformation, but not in the actuator with squashed deformation. Additionally, we estimated the applied Maxwell stress in the actuator. The developed actuators were capable of producing movements that imitate the behavior of organisms, such as the pufferfish.

DOI： https://doi.org/10.2494/photopolymer.36.191

Repository Public URL： https://hdl.handle.net/2324/7178656

Language：English   Publishing type：Research paper (scientific journal)   Publisher：International Journal of Computer Integrated Manufacturing  

This research proposes a multi-period multiple parts mixed-integer linear programming optimization model for the trade-off analysis of spare parts supply through computer numerical control (CNC) manufacturing and additive manufacturing (AM). The multiple spare parts have different characteristics such as volume, shape size, and geometry complexity. The model focuses on minimizing lead times and thus reducing downtime costs. Scenario analyses are developed for some parameters to assess the robustness of the model. The analysis shows that the mix between AM-based spare parts and CNC-based spare parts is sensitive to changes in demand. For the given data, the findings demonstrate that AM is cost-effective with spare parts having high geometry complexity while CNC-based manufacturing is economically feasible for spare parts with low geometry complexity and large sizes. The proposed model can support decision-makers in selecting the optimal manufacturing method for multiple spare parts having different characteristics and attributes. The paper concludes with limitations and future directions.

DOI： 10.1080/0951192X.2023.2228263

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Language：English   Publishing type：Research paper (scientific journal)  

In this study, we developed a new actuator that can be driven by both magnetic and pneumatic and conducted driving experiments using the fabricated actuator. Soft actuators are widely used as a means of biomimicry. However, many existing actuators that use a single drive source have limited degrees of freedom and deformation capabilities. Recently, hybrid actuators that can be driven by multiple sources have gained attention due to their ability to produce movements that are not achievable by a single drive source. In this study, we fabricated a simple actuator that combines a cylindrical pillar made of silicone material containing magnetic particles with a hollow structure for pneumatic deformation. Three types of actuators with varying diameters and positions of the hollow structure were fabricated, and the drive of each actuator was measured. The pneumatic extensible actuator allows the actuator tip to be manipulated on a fan-shaped two-dimensional plane. The pneumatic bending actuator could manipulate the actuator tip in three dimensions. The actuator with a larger diameter hollow structure could be deformed differently in the same magnetic field by changing the stiffness of the actuator depending on the air pressure. Furthermore, by modifying the hollow structure and the external shape of the actuator, more unique movements can be achieved, and it is expected to be applied to bio-mimicry such as tentacle movement and cilia structure.

DOI： https://doi.org/10.2494/photopolymer.36.167

Repository Public URL： https://hdl.handle.net/2324/7178651

Publisher：2023 22nd International Conference on Solid-State Sensors, Actuators and Microsystems, Transducers 2023  

Bacterial cellulose (BC) produced by acetic acid bacteria is a promising biomaterial that exhibits exceptional mechanical strength, biocompatibility, and biodegradability. In this study, we have successfully fabricated BC composites with various materials such as alumina fibers, zirconia particles, carbon nanotubes, and magnetic particles by adding each material to the culture medium. We also demonstrate the actuation of BC-magnetic particle composites by a magnetic field. Furthermore, we have achieved the patterning of arbitrarily shaped patterns onto BC pellicles by placing templates in the culture medium. These findings suggest that BC composites have the potential to be applied in various fields such as tissue engineering and drug delivery.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society of Photopolymer Science and Technology(SPST)  

<p>In this paper, a simple but effective method is proposed to generate a bio-mimic wave propagating motion in a magnetic soft actuator. Two examples, a metachronal wave in artificial cilia and a crawling motion of an artificial caterpillar, are shown as demonstrations. These are kinds of wave propagating motions which are popular in natural systems and are also primitive systems of natural creatures. In the proposed system, an elastic material and a magnetic powder were used to fabricate a flexible magnetic structure. There are 2 essential features in the system; one is periodic arrangement of magnetic anisotropy, and the other is application of a rotating magnetic field. Using this method of wave generation, we realized drastic change in flow making behavior of artificial cilia and a crawling motion very similar to living caterpillars. The proposed system would be useful to enhance the field of the bio-mimic soft robotics.</p>

DOI： 10.2494/photopolymer.35.225

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society of Photopolymer Science and Technology(SPST)  

<p>Microchannels have been studied actively in recent years. Various types of materials are used for fabricating microchannels in different types of applications including polymers, and ceramics. Since glass materials have appealing properties such as hardness, transparency, thermal resistance, and chemical resistance, they are used in biomedical devices and microfluidic application. Glass microchannel fabrication methods include chemical etching, imprinting, and 3D printing. This paper proposes unprecedented methods to fabricate glass microchannels using plant roots growth and nematodes migration. The microchannels fabricated by these methods have a complex three-dimensional structure, and the smallest channels have a diameter of several tens of micrometers in the glass. Although glass is attractive material, it is challenging to sinter the green body to fully dense and transparent solid structure. Hence, experiments were also conducted to establish a fabrication technique for transparent silica glass.</p>

DOI： 10.2494/photopolymer.35.219

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.35848/1347-4065/ac5a99

Language：English   Publishing type：Research paper (international conference proceedings)  

Pillared surfaces are the products of a surface modification technique that allow the implementation of active control methods by an outer source such as magnetic fields. Pillar arrays with magnetic tips exhibit different characteristics depending on the initial positional arrangement of the pillars and/or the environmental magnetic field conditions. This study develops methods for simulation and parameter optimization by machine learning to aid the investigation of pillar behaviors in various combinations of initial positions and magnetic fields. Optimization is performed using the co-variance adaptation evolution strategy (CMA-ES). The algorithm is tested to obtain preliminary results: (1) the maximum size of the pillar pitch at a given magnetic field; (2) the initial pillar arrangement of a 3-pillar unit cell and three settings of applied magnetic field-each corresponds to a predefined contact state of a three-stage paring pattern.

DOI： 10.1109/CYBCONF51991.2021.9464138

Repository Public URL： http://hdl.handle.net/2324/4752556

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.35848/1347-4065/ac5a99

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：Japanese   Publisher：The Japan Society for Technology of Plasticity  

DOI： 10.32277/plastos.5.53_285

CiNii Research

Publishing type：Research paper (international conference proceedings)   Publisher：Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)  

This paper reports a fine magnetic patterning process for a gel sheet. Recently, tough gel materials have been developed which are known as double-network gels (DN-gels). Authors employed an extremely tough DN-gel for soft actuators by dispersing fine magnetic particles. The proposed material showed not only high strength and large elongation but also high anti-cutting strength. Authors also proposed a new process for a magnetic micro patterning process for this material using local heating by laser. The resolution was finer than reported conventional magnetic soft actuators. We performed tensile tests of the gel material and showed mechanical properties. We also tried to scan laser on a magnetic gel sheet for micro patterning of the magnetic anisotropy. Finally, we demonstrate crawling motion of a magnetic patterned gel sheet.

DOI： 10.1109/MEMS51670.2022.9699514

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.35848/1347-4065/abe698

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2494/photopolymer.34.369

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2494/photopolymer.34.375

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2494/photopolymer.34.381

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2494/photopolymer.34.411

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Repository Public URL： http://hdl.handle.net/2324/4476139

Language：English   Publishing type：Research paper (scientific journal)  

Repository Public URL： http://hdl.handle.net/2324/4476138

Language：Others   Publishing type：Research paper (scientific journal)  

Soft robotics has become an attractive research topic with the recent development of soft actuators. Herein, we propose a deformable soft actuator with large volumetric changes. The proposed elastomer contains liquid droplets; their transition from the liquid phase to the vapor phase can be controlled by heat. We chose silicone and urethane rubbers as the matrix materials; droplets of water and fluorine were dispersed homogeneously in the rubber matrix as micelles or solutes. After curing the rubber, bubbles appeared owing to microwave heating. We succeeded in generating a fine bubble structure using the proposed method, and we could reduce the leakage of the droplet material using urethane as the matrix material. Finally, we attempted to fabricate a small actuator to work in the channels. The proposed method can be useful for miniaturized soft robots.

DOI： 10.35848/1347-4065/ab85ae

Repository Public URL： http://hdl.handle.net/2324/4403546

Language：English   Publishing type：Research paper (scientific journal)  

In this study, a micro-patterning process is proposed and developed in order to obtain various functional properties on the surface of an object. Nano imprint lithography has recently been the focus of much attention, because of advantages such as high accuracy, low cost, and ease of operation. However, problems can occur during demolding when using this method, such as the destruction of high aspect patterns during the process. It is also, almost impossible to form an over-hanging pattern. In order to overcome these problems, we propose a multi-step imprinting process with an in-plane compression method. A hierarchical multi-scale pattern can be produced using multi-step imprinting, and the aspect ratio of the imprinted pattern can be increased by using the in-plane compression method. A hierarchical multi-scale pattern with a high aspect ratio was produced by combining the two methods. The effectiveness of the proposed method is demonstrated by the results of the experimentation.

DOI： 10.35848/1347-4065/ab79ef

Repository Public URL： http://hdl.handle.net/2324/4403549

Language：English   Publishing type：Research paper (scientific journal)  

Recently, many studies on bio-mimic soft robots have been reported. Among living organisms, the locomotion of soft-bodied creatures, such as snails, worms and nematodes, have been actively studied. These soft creatures locomote by deforming the muscles of the whole body into waveforms and propagating the waves of the deformation. This locomotion of soft creatures could be applicable to develop a worm-type soft robot, which can move in drain pipes and even in a human body. In this study, we developed worm-like robots that could generate wavy motion under a rotating magnetic field using silicone and magnetic rubber, and investigated their movement characteristics. In addition, based on a deformation experiment of a silicone cantilever with a single magnetic element inside made of the same material as a worm-like robot, we investigated the effect of the size of the worm robot for further miniaturization.

DOI： 10.35848/1347-4065/ab7b18

Repository Public URL： http://hdl.handle.net/2324/4403548

Language：English   Publishing type：Research paper (other academic)  

Our study aims to realize artificial cilia with metachronal wave and to apply them to a micro pump. Metachronal wave is a typical motion observed in natural cilia motion of living organisms. To clarify the characteristics of fluid transport by metachronal waves, we fabricated two modes of artificial cilia that form symplectic and antiplectic metachronal waves, and drove them in silicone oil. We used particle imaging velocimetry (PIV) to visualize the flows generated by these metachronal waves. This is the first time that these two types of metachronal waves were generated in artificial cilia.

DOI： 10.1109/MEMS46641.2020.9056137

Language：English   Publishing type：Research paper (international conference proceedings)  

I propose a simple manipulation system of micro magnetic particles in this paper. Magnetic particles to be actuated are put on a substrate which has a grid pattern of magnetic elements. We could manipulate a tiny particle precisely by 1 grid unit by macroscopic rotation of the magnet. Also, manipulation on the vertical wall was demonstrated. It is possible to apply this system also in a micro-channel.

Repository Public URL： http://hdl.handle.net/2324/4476140

Language：English   Publishing type：Research paper (international conference proceedings)  

Nano Imprint lithography (NIL) is a technique that transfers a fine mold pattern to the surface of a work material. NIL is an excellent technology in terms of high productivity, accuracy, and resolution. Recently, a technology called multilayered imprint has been developed in which NIL is applied to processing of a multilayered material. In this process, it is possible to form not only surface of a workpiece, but also an interfacial pattern between the upper layer and the lower layer simultaneously. Using this technology, processing of functionally graded materials and fabrication of complex patterns using a sacrificial layer have been studied. Control of interface shape is necessary in multilayered imprint. The interface pattern can be controlled by the deformation characteristics, initial thickness, and so forth. In this research, we compared the interfacial pattern changes of imprinted multilayered materials in milli- and microscales. For multilayered imprint using multiple materials, it is important to know the flow of the resist and its dependence on the scale. If there is similarity in the relationship produced by the scale on the imprinted samples, a process design with a number of feedbacks could be realized. It also becomes easier to treat structures in the millimeter scale for the experiment. In this study, we employed micropowder imprint (μPI) for multilayered material imprint. A compound sheet of alumina powder and polymer binder was used for imprint. Two similar experiments in different scales, micro- and millimeter scales, were carried out. Results indicate that the interfacial patterns of micro- and millimeter-scale-imprinted samples are similar.

Language：English   Publishing type：Research paper (scientific journal)  

Recently, many researches on biomimetics have been reported, in which soft motions of natural creatures have also been targeted. Among them, cilia are attracting natural soft organ, which is an effective fluidic system in the natural world. Cilium is a simple hair-like organ; however, it works in a non-simple way. For example, beating pattern of natural cilium consists of 2 types of different stroke patterns; effective stroke and recovery stroke. We focused on a cilium as our target as a simple cantilever of a soft elastic material. We have already developed artificial cilia with magnetic elastomers. In this research, we compared cantilever beams with soft-and hard-magnetic particles. In this paper, we performed 2 experiments to compare the characteristics of cantilevers with 2 types of magnetic powders. In the first experiment, we utilized neodymium magnets that could be controlled the angle in order to observe the motion of beams in the static state. The latter one, we actuated beams in rotating magnetic fields to obtain dynamic behavior of an artificial cilium. As a result, we showed some differences between soft-and hard-magnetic materials.

DOI： 10.2494/photopolymer.32.309

Language：English   Publishing type：Research paper (scientific journal)  

Biomimetics is a field of technologies based on imitating the functions and properties found in living organisms. The application of the super-water-repellent fine structure of lotus leaves to create waterproof products is a well-known example of biomimetics. The present study examined the surface structure of snail shells, which exhibit oleophobic properties oil repellency and explored the feasibility of recreating this structure on the inner surfaces of conventional biliary stents. Observations of snail shells under an electron microscope show a covering of extremely fine protrusions of around 200 nm in size. When water enters the pores between these fine protrusions, a film of water exhibiting super-nanohydrophilic structure forms on the shell. Because water and oil are immiscible, this film repels oil. We would expect stent occlusion to be less likely with a biliary stent having this structure on its inner surface. Biliary stricture caused by bile duct cancer or bile duct obstruction can lead to icterus and may, in serious cases, induce fatal hepatic failure. A surgical procedure that places indwelling biliary stents inside the biliary tract is sometimes performed to secure a passage for bile flow. However, conventional stents are prone to occlusion due to the accumulation of biliary sludge, resulting in the need for a second surgery to replace the stent. This problem is attributable to the polyethylene used to make the biliary stents; polyethylene is susceptible to the adhesion of cholesterol and fats found in the bile, eventually leading to stent occlusions. This paper reports our efforts to develop biliary stents that feature antifouling properties inspired by biomimetics to address this problem; specifically, the development of oleophobic inner stent surfaces featuring super-nanohydrophilic structures inspired by snail shell surfaces.

DOI： 10.2494/photopolymer.32.373

Language：English   Publishing type：Research paper (scientific journal)  

In this research, we propose an in-plane compression imprint method as a further development of the special micro patterning method to realize various biomimetic functional surfaces. Biomimetic is popular in the field of engineering in recent years. We focused on biomimetic functional surfaces of natural organisms. For example, micro scales on the wing of a morpho butterfly develop a bright blue color. The scales have specific dendrite-like nano-structures. We aim to mimic such functional surfaces by nano imprint lithography (NIL). NIL has high resolution and high productivity, and is known as a technology that can be applied to various materials. Conventional NIL requires mold release in the process, so it is difficult to form special shapes such as the overhang shape. To solve this problem, we propose an in-plane compression process. In our new process, work materials were imprinted on a stretched silicone film, and imprinted materials were compressed by in-plane compressive stress due to the elastic recovery of the silicone film. In this paper, we show some examples increasing the aspect ratio more than twice by the proposed process. We also show a strategy to form a complicated morpho’s surface pattern with an overhang structure having a high aspect ratio.

DOI： 10.2494/photopolymer.32.315

Language：English   Publishing type：Research paper (scientific journal)  

The authors have proposed a fabrication process of “4D printer” for magnetic soft actuators. In this paper, we applied this 4D printer to bio-mimic field and show some examples using a gel material dispersed with magnetic powder. 4D printer is a recently developed process that can print out not only a 3-dimensional structure but also print deformations of the printed structure at the same time. We employed a UV-curable gel material. The material could be used in the same manner as the conventional 3D-printing process. We applied a magnetic field to set magnetic anisotropy in the curing portion during the building step. This anisotropy is set in each portion of the structure so that the printed structures could deform under an applied magnetic field. Using this technique, we demonstrated 2 kinds of biomimetic examples; one is a worm-type soft actuator and the other is an array of artificial cilia. The first example could crawl in a narrow gap. The second one could reproduce a metachronal wave, which is a phase propagation wave found on natural small organisms. We will also show a computational method to design the deformation of the structure.

DOI： 10.1149/2.0361909jes

Language：English   Publishing type：Research paper (other academic)  

We propose a 4D-printing process for soft actuators. 4D-printing system can print out not only a 3-dimensional object but also deformations in the printed structure simultaneously. In this paper, we propose a new 4D-printing system that utilizes soft resin dispersed with magnetic particles. The printed structure could be actuated by an applied magnetic field. The key in this system is magnetic anisotropy located at each portion of a structure. We show 2 demonstrations of printed actuators, and also a computational method to design the deformations of printed structures. This 4D-printing could be a powerful tool to fabricate micro soft actuators in the MEMS field.

DOI： 10.1109/MEMSYS.2019.8870639

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

The authors proposed a fabricating process for soft actuators, named 4D printing system for magnetic gel materials. 4D printer is a recently developed process that can print out not only a 3-dimensional structure but also deformations in the printed structure at the same time. Our proposing process utilizes a gel material dispersed with magnetic particles as a starting material. We can design magnetic anisotropy in each portion of the printed object during additive manufacturing so that the printed structures could deform under an applied magnetic field. In this paper, we demonstrated 2 kinds of biomimetic examples by this printing system, a worm-type soft actuator and an array of artificial cilia. The first example could crawl in a narrow gap. The second one could reproduce a metachronal wave, which is a phase propagation wave found on natural small organisms. These demonstrations show that the proposed printing system could output variable bio-mimic soft actuators.

DOI： 10.1149/08801.0089ecst

Language：English   Publishing type：Research paper (scientific journal)  

The stable oxide layer formed through thermal oxidation (TO) process on selective laser melted 316 L stainless steel (SLMed-316 L SS) substrate surface attested to assists in refining their corrosion resistance and observed to behave relatively inert in physiological conditions. The surface characterisation and corrosion behaviour of the oxidised SLMed-316 L SS are the primary focus of this study. The formation of the oxide layer on SLMed-316 L SS was investigated at constant ambient atmosphere and 700 °C temperature for three different soaking times (150, 200 and 250 h). The surface characterisation of the oxide layer was performed using Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray Spectroscopy (EDX) and X-ray Diffraction (XRD) to correlate the thickness of oxide layer and surface morphology after the TO treatment. Whereas, the electrochemical analysis was conducted using potentiodynamic polarisation to investigate the corrosion behaviour of the oxide layer. The finding disclosed an increase in the oxide layer thickness formation at prolonged exposure in ambient atmosphere. Also, the TO at 150 h showed an improved corrosion behaviour due to the presence of Fe₂O₃ and Cr₂O₃ layers. However, the extended soaking time showed no improvement towards the corrosion behaviour.

DOI： 10.1016/j.jallcom.2018.03.233

Language：English   Publishing type：Research paper (scientific journal)  

In this paper, a direct fine patterning of ceramics at room temperature combining 2 kinds of laser microfabrication methods is proposed. The first method is called laser-induced forward transfer and the other is called laser shock imprinting. In the proposed method, a powder material is deposited by a laser shock wave; therefore, the process is applicable to a low-melting-point material, such as a polymer substrate. In the process, a carbon layer plays an important role in the ablation by laser irradiation to generate a shock wave. This shock wave gives high shock energy to the ceramic particles, and the particles would be deposited and solidified by high-speed collision with the substrate. In this study, we performed deposition experiments by changing the thickness of the carbon layer, laser energy, thickness of the alumina layer, and gap substrates. We compared the ceramic deposits after each experiment.

DOI： 10.7567/JJAP.57.06HJ06

Language：English   Publishing type：Research paper (scientific journal)  

Nanoimprint lithography (NIL) is a technique that transfers a mold pattern of nanometer order to the surface of a resist material by heating and pressing. NIL is an excellent technology in terms of high productivity, accuracy, and resolution. Recently, NIL has been applied to the processing of different multilayered materials, in which it is possible to process multiple materials simultaneously. In this processing of multilayered materials, it is possible to form an interfacial pattern between the upper layer and the lower layer simultaneously with patterning on the mold surface. This interface pattern can be controlled by the deformation characteristics, initial thickness, and so forth. In this research, we compared the interfacial pattern changes of imprinted multilayered materials in milli- and microscales. For multilayered imprint using multiple materials, it is important to know the flow of the resist and its dependence on the scale. If there is similarity in the relationship produced by the scale on the imprinted samples, a process design with a number of feedbacks could be realized. It also becomes easier to treat structures in the millimeter scale for the experiment. In this study, we employed micropowder imprint (μPI) for multilayered material imprint. A compound sheet of alumina powder and polymer binder was used for imprint. Two similar experiments in different scales, micro- and millimeter scales, were carried out. Results indicate that the interfacial patterns of micro- and millimeter-scale-imprinted samples are similar.

DOI： 10.7567/JJAP.57.06HG05

Language：English   Publishing type：Research paper (scientific journal)  

In this paper, we propose a power generation method using the deformation of a magnetic elastomer for vibration energy harvesting. The magnetic flux lines in the structure of the magnetic elastomer could be markedly changed if the properly designed structure was expanded and contracted in a static magnetic field. We set a coil on the magnetic elastomer to generate electricity by capturing this change in magnetic flux flow. We fabricated a centimeter-scale device and demonstrated that it generated 10.5mV of maximum voltage by 10 Hz vibration. We also simulated the change in the magnetic flux flow using finite element analysis, and compared the result with the experimental data. Furthermore, we evaluated the power generation of a miniaturized device.

DOI： 10.7567/JJAP.57.06HJ05

Language：English   Publishing type：Research paper (scientific journal)  

Complicated three-dimensional (3D) microchannels are expected to be applied to a lab-on-a-chip, especially an organ-on-a-chip. There are fine microchannel networks such as blood vessels in a living organ. However, it is difficult to recreate the complicated 3D microchannels of real living structures. Plant roots have a similar structure to blood vessels. They spread radially and three-dimensionally, and become thinner as they branch. In this research, we propose a method of fabricating microchannels using a live plant root as a template to mimic a blood vessel structure. We grew a plant in ceramic slurry instead of soil. The slurry consists of ceramic powder, binder and water, so it plays a similar role to soil consisting of fine particles in water. After growing the plant, the roots inside the slurry were burned and a sintered ceramic body with channel structures was obtained by heating. We used two types of slurry with different composition ratios, and compared the internal channel structures before and after sintering.

DOI： 10.7567/JJAP.57.06HJ07

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

The purpose of this study was to explicate the mechanism of transition storage modulus and loss modulus under external magnetic field. Magneto-rheological elastomer (MRE) is expected to be used as damping material and actuator controlled by an external magnetic field. However, magnetic particles' behavior inside of MRE has not been explained completely. Especially, the mechanisms of loss modulus transition under external magnetic field has not been known well. We constructed a simple model with two magnetic particles, and try to make MRE behavior clear. In this report, we show a data of the viscoelastic property of MRE which consists of magnetic particles and polydimethylsiloxane (PDMS). The obtained viscoelastic property is explained by using two magnetic particles model.

DOI： 10.1541/ieejsmas.138.48

Language：English   Publishing type：Research paper (other academic)  

Cilia are hairlike organs that are found on the surface of small organisms in water such as paramecia. The movement pattern of cilia is known as a metachronal wave, which realizes efficient fluid transport. Our study aims to mimic the metaclonal wave of cilia and apply it to micro pumps. Artificial cilia fabricated using elastic material dispersed with magnetic particle could generate a metachronal wave by applying a rotating magnetic field. The experimental results showed that the developed device was able to make flow, and the cilia with metachronal wave improved the flow rate compared with cilia with synchronous motion.

Language：English   Publishing type：Research paper (other academic)  

We fabricated silica microchannels by using a plant root as a template. A root spreads and branches three-dimensionally and has the finest parts, which are called root hair, at the root tips. The thickness of root hair is about 10 μm. We focused on this structure to apply to the μTAS field. We put a germinated plant seed so that the root grew in a compound material with silica particles. The compound with the root was heated to burn out the plant and sinter the material. In this way, we obtained the transparent sintered body with the root-shaped cavity. We also tried to control the growth of the root. We grew plants in the patterned channel filled with aqueous gel material and observed the root pattern.

Language：English   Publishing type：Research paper (other academic)  

Ceramic materials show superior properties in heat resistance, corrosion resistance, chemical resistance, strength, etc. compared to polymer materials. Thus, the ceramics are expected in many fields to be replaced from conventional polymer. However, ceramics are fragile and micro fabrication of channel is challenging. In this work, we developed the fabrication process of 3D ceramic micro channels by imprinting a laminated sheet of 2 compound sheets and a sacrificial sheet in between them. Our ceramic micro channels could be useful for highly efficient solid oxide fuel cells (SOFC), or micro electro mechanical systems (MEMS) used in harsh environments where polymer materials could not be applicable.

Language：English   Publishing type：Research paper (scientific journal)  

It has long been known that snail shells have an excellent anti-fouling function, as it is said that there are no dirty snails. The snails encountered during the baiu rainy season in Japan always have clean, shining shells. These shells are known to have convex-concave nanoscale structures on their surface (roughness on the order of approximately 200 nm) that promote the formation of a film of water on the shell surface, creating an ultra-hydrophilic nanoscale structure that repels oils and stains. Creating such an ultra-hydrophilic nanoscale structure on a polymer surface should allow us to produce an antifouling polymer sheet. Additionally, producing a tube from a polymer film with this nanoscale structure should make it possible to create a tube with high antifouling properties. The field of technologies based on imitating properties and structures observed in living organisms in nature is called biomimetics. This paper reports on the development of antifouling sheets and tubes with antifouling functions fabricated using the above technologies. The first step was creating a mold with an artificial snail shell structure using ZrO
₂
nanoparticles, whose patterns were then transferred to polymer with nanoimprint technology. These antifouling sheets and tubes are expected to see wide use for medical applications.

DOI： 10.2494/photopolymer.31.101

Language：English   Publishing type：Research paper (other academic)  

It has long been known that snail shells have an excellent anti-fouling function, as it is said that there are no dirty snails. The snails encountered during the baiu rainy season in Japan always have clean, shining shells. These shells are known to have convex-concave nanoscale structures on their surface (roughness on the order of approximately 200 nm) that promote the formation of a film of water on the shell surface, creating an ultra-hydrophilic nanoscale structure that repels oils and stains
^[1]
. Creating such an ultra-hydrophilic nanoscale structure on a polymer surface should allow us to produce an antifouling polymer sheet. Additionally, producing a tube from a polymer film with this nanoscale structure should make it possible to create a tube with high antifouling properties. The field of technologies based on imitating properties and structures observed in living organisms in nature is called biomimetics
^[2]
. This paper reports on the development of antifouling sheets and tubes with antifouling functions fabricated using the above technologies. The first step was creating a mold with an artificial snail shell structure using ZrO
₂
nanoparticles [3], whose patterns were then transferred to polymer with nanoimprint technology
^[4-5]
. These antifouling sheets and tubes are expected to see wide use for medical applications.

DOI： 10.1117/12.2319698

Language：English   Publishing type：Research paper (scientific journal)  

In this paper, we developed a new 3D-printing system for magnetic elastomer, and demonstrated to fabricate artificial cilia. Natural cilia are hair-like organ found in nature. They are effective fluidic system in the natural world that are widely observed on surfaces of microorganisms of creatures, such as Paramecium and throat surface of mammals. Recently, the motion of cilia has been analyzed and mimicked for developing soft actuator, for example, some studies on artificial cilia driven magnetically have been reported. They are small soft actuators, and there are various manufacturing methods for these actuators depending on materials and products. Among them, authors have already developed the concept of a printing system that not only forms a three-dimensional object but also prints out the deformation of the structure. This system can fabricate various shapes of soft actuators without any assembly. In this report, we utilized UV-curable urethane acrylate as a more flexible material than that used in the previous reports, and fabricated artificial cilia by the printer. We set magnetic anisotropy to each cilium and mimicked a metachronal wave, sequential action of plural cilia that causes effective flow.

DOI： 10.2494/photopolymer.31.121

Language：English   Publishing type：Research paper (scientific journal)  

Solid oxide fuel cells (SOFCs) are fuel cells made of ceramics. To increase the SOFC energy density, we developed an SOFC with a wavy electrolyte layer. As a wavy electrolyte has a larger reaction surface area than a flat electrolyte, a higher energy density could be obtained. Our proposed process is named micro-powder imprint (µPI) with a multilayer imprint process that is useful for fabricating a microscale pattern on a ceramic sheet such as an SOFC electrolyte layer. µPI is based on nanoimprint lithography; therefore, it also exhibits the same advantages of high resolution and mass productivity. The starting material for µPI is a compound sheet containing ceramic powder and binder materials consisting of thermoplastic resin. In this study, two different sheets were stacked into one sheet as a multilayer sheet for the µPI process to form a wavy compound sheet. As the initial state of the stacked sheet, including the mechanical properties of each layer, affects the final wavy shape, we changed the material composition. As a result, the SOFCs unit cell with a wavy electrolyte was fabricated. Note that the anode layer was formed at the same time. After adding the cathode layer, we succeeded in preparing a complete cell for testing power generation.

DOI： 10.7567/JJAP.56.06GL04

Repository Public URL： http://hdl.handle.net/2324/1916278

Language：English   Publishing type：Research paper (scientific journal)  

Artificial cilia actuated by an applied magnetic field have been developed. In our previous report, we demonstrated actuated cilia of a few millimeters scale, which were fabricated by cutting a magnetic elastomer sheet. The fabricated artificial cilia worked similarly to natural cilia;
however, they had a much larger structure than natural ones, and showed difficulty for use in pumping systems in micro-total analysis systems
(µTAS) fields. Thus, our goal is further miniaturization. In this study, we introduce a new process of fabricating smaller pillar structures with a
magnetic orientation in each pillar by ultraviolet (UV) laser machining. We also give different orientations to groups of pillars by the alternate laser machining of the mold and casting processes.

DOI： 10.7567/JJAP.56.06GN15

Language：English   Publishing type：Research paper (international conference proceedings)  

Metal Injection Molding (MIM) process is suitable for fabricating small parts in large quantity. In this work, relatively large and complex shaped parts were prepared thorough MIM. In order to decrease the deformation of sintered parts, powders of different sizes were mixed. The effect of powder particle distribution and powder loading on the distortion of complex shaped compacts were investigated and evaluated. Smaller deformation of the large and complex shaped parts could be realized by using mixed powder with smaller particle.

Language：English   Publishing type：Research paper (scientific journal)  

As Ni-based superalloy has poor workability, direct laser forming (DLF) would be a powerful tool for fabricating the complex shaped Ni-based superalloy parts. We focused on the microstructure of the parts produced by DLF, the crystal grains of which grow along the building direction. This anisotropic microstructure is one of the major features of the parts produced by DLF, and which may cause anisotropic mechanical properties.In this work, the optimum laser-forming conditions such as laser power, laser scan speed, and powder feeding rate were determined by evaluating the density of the produced parts. Three types of tensile test pieces and two types of fatigue test pieces were fabricated in different building direction. They had higher ultimate tensile strength than that of JIS standards in wrought materials. However, their elongation was lower than that of JIS standards, and also the dispersion of elongation was large. On the other hand, fatigue limit was a little lower than the standard value. It was confirmed that the mechanical properties of Ni-based superalloy parts produced by DLF were different by a difference in building direction.

DOI： 10.2497/jjspm.63.427

Language：English   Publishing type：Research paper (scientific journal)  

Yttria-stabilized zirconia (YSZ) has been used for an electrolyte of solid oxide fuel cells (SOFC). To enhance the efficiency of SOFC, we developed a corrugated, or wavy-shaped, YSZ sheet for the electrolyte. As the corrugated sheet has larger surface area than a flat-type sheet, higher energy density can be obtained. We have proposed micro powder imprint (μPI) with multi-layer imprint process to fabricate micro scale pattern on the both surfaces of a thin YSZ sheet. The μPI is a combined process of nano imprint lithography and powder metallurgy; the resolution is high, and the process is mass-productive. In this work, we selected a compound material containing YSZ powder and a binder consisting of thermoplastic resin as a starting material. The compound sheet was prepared by tape casting from slurry and was imprinted by a fine-patterned mold with stacked on a silicone rubber sheet. The silicone rubber was so flexible that micro patterns on the both sides of the compound sheet was obtained after imprint. In the present work, the process condition of μPI and the heat program of debinding and sintering were also considered. As a result, a wave-type sintered YSZ sheet without significant defects was successfully obtained.

DOI： 10.2497/jjspm.63.519

Language：English   Publishing type：Research paper (scientific journal)  

Micro channels made of polymers are commonly used for MEMS and μTAS (micro-total analysis system) devices. In this research, we developed a process for fabricating a ceramic sheet with micro channels. The developed process is based on powder metallurgy process. A compound material, a mixture of ceramic powder and polymer, was prepared as sheet material. We employed laser machining to machine the sacrificial layer to form micro channels inside the sheet. We also employed imprinting, which is a process of pressing with a mould while heating, to form a structure with surface patterns and micro channels curving along with it. After the imprinted sheet was debound and sintered by heating, a ceramic sheet with micro-surface patterns and micro channels was obtained. As ceramics have high heat durability and low chemical reactivity, ceramic micro channels can be used for flow sensors or chemical reaction testers operated in harsh environments, such as high temperature or mechanical parts operated with reactive chemicals. In addition, by imprinting wavy patterns, the surface area can be increased. Therefore high efficiency heat exchangers can be built. Moreover, this method can be applied on SOFCs (solid oxide fuel cell) by fabricating YSZ (yttria stabilized zirconia) micro channels.

DOI： 10.2497/jjspm.63.511

Language：English   Publishing type：Research paper (scientific journal)  

Metal Injection Molding (MIM) is an effective way to manufacture small components with low cost and high precision. However, in the case of large components, it becomes difficult to control the distortion and cracking because of the big shrinkage during debinding and sintering process. Therefore it is important to optimize the condition of each process to reduce the distortion of MIM compacts. Moreover, powder size is also one of the most important parameters. The small particle powder shows high shrinkage and high density as compared to large particle powder during sintering process. In this study, blending of both powders was conducted and the influence of powder size distribution on the distortion of complex shaped parts was evaluated. A coordinate measuring machine, which is a 3D device for measuring the physical geometrical characteristics of an object, was used to measure the distortion. Finally, through controlling the distribution of particle size, distortion of the comparatively large and complex shaped MIM compacts was successfully restrained.

DOI： 10.2497/jjspm.63.473

Language：English   Publishing type：Research paper (scientific journal)  

Superalloy has been used for aerospace application because of their excellent attributes of high strength and corrosion resistance at high temperature. Inconel 718 is one of the representative Ni-based superalloy. Generally, superalloy has poor workability, especially high tool wear by machining, so that it is not easy to produce the components of complex shaped parts at low cost. To overcome such as the problem, metal injection molding (MIM) process would be a useful technique which offers net shape production, high design flexibility, and high cost efficiency for mass production. In this study, gas-atomized fine alloy powder of Inconel 718 was prepared for MIM process, and the mechanical properties of injection molded compacts were investigated. The relative density over 99.7 %, which is much higher than density of usual MIM compacts, was obtained by supersolidious liquid-phase sintering. Furthermore, injection molded Inconel 718 showed high fatigue strength comparable to the wrought materials, because the pore size of the MIM compacts was smaller than the inclusion size of wrought materials. And it was found that the grain size was more dominant than pore size against the fatigue failure of MIM Inconel 718 with near full density.

DOI： 10.2497/jjspm.63.462

Language：English   Publishing type：Research paper (scientific journal)  

It is not easy to fabricate the complicate shaped titanium aluminide (Ti-Al) components by conventional methods such as machining or forging, and casting leads to inhomogeneous microstructures. Metal injection molding (MIM) has the potential to be a cost-efficient process and near net shape technique, especially for the complex shaped mass-produced components. In this study, Ti-Al intermetallic alloy compacts were fabricated through MIM technique. Sound compacts with over 95 % of relative density and without any warpage or defects were obtained thorough MIM process. Different microstructures of duplex, near lamellar, and full lamellar were obtained by changing the sintering temperature. Their tensile strength at room and high temperature is 85 to 90 % of that of wrought material. Tensile strength of MIM compact would be expected the same level with cast materials by optimization of sintering conditions, densification by HIP treatment and so on.

DOI： 10.2497/jjspm.63.457

Language：English   Publishing type：Research paper (scientific journal)  

Ti-6Al-4V alloy has attracted a lot of attention from the automotive and aerospace industries because of their outstanding specific strength and corrosion resistance. On the other hand, Ti-6Al-4V alloy has normally poor workability because of the low thermal conductivity and the low elastic modulus. Metal injection molding (MIM) process is expected to manufacture a complex part with near net shape and reduce the manufacturing cost. However, Ti-6Al-4V alloy compacts by MIM process had a problem of low fatigue strength compared to wrought material.In this study, we tried to add a minor amount of boron using TiB2 powder for improving the fatigue strength. Addition of boron resulted refinement of the grain size of lamellar structure, which lead to increase the high cycle fatigue strength and fatigue limit. In addition, tensile properties at high temperature was investigated.

DOI： 10.2497/jjspm.63.451

Language：English   Publishing type：Research paper (scientific journal)  

Titanium alloys show not only the excellent mechanical properties but also good biocompatibility. However, they show normally poor machinability, which become the disadvantage of high processing cost. Metal injection molding (MIM) process is one of the techniques to improve that drawback. Because MIM process can produce the three dimensional complex shaped parts at low cost. Ti-6Al-4V is a typical titanium alloy and the MIM compacts show high static strength as same as wrought materials. However, their fatigue strength is a little low level as compared to wrought materials. To improve the mechanical properties of Ti-6Al-4V alloy compacts, it is important to refine the grain size and increase the relative density. In this study, the effects of the particle size of the powders on the mechanical properties were investigated. The use of a fine powder improved the mechanical properties because of their high density. Moreover, the crystal grain growth was restrained as compared to the case of the same relative density using larger powder.

DOI： 10.2497/jjspm.63.445

Language：English   Publishing type：Research paper (scientific journal)  

In this paper, we report on a new system of three-dimensional (3D) printing for a magnetic elastomer that contains magnetic particles. Not only can we fabricate a three-dimensional structure, but we can also control the magnetically anisotropic property o

DOI： https://doi.org/10.7567/JJAP.55.06GP18

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

The objective of the work reported in this paper is to create multi-scale and hierarchical surface structures using a simple imprinting process. The hierarchical structures can be fabricated with only simple patterned molds by proposed multi-step imprinting process, instead of using a high cost hierarchical-patterned mold. In the proposed process, the starting material is a layered sheet material. The layered sheet is pressed by a mold with a finer pattern, and subsequently pressed by a mold with a rougher pattern. A pure polymer sheet is employed as the upper layer, which will be removed during heating processes as a sacrificed layer, while the lower layer is a compound material of polymer and ceramic powder. After heating process, ceramic compact is sintered and formed a full-dense patterned sheet. By the proposed multi-step imprinting process with a layered material, ceramic sheets with micro hierarchical pattern can be fabricated with low cost. In the present work, poly(vinyl alcohol) (PVA) was prepared as the upper layer, and a compound material of alumina powder and PVA as a lower layer. Molds with finer and rougher patterns were also prepared for multi-step imprinting. As a result, a hierarchical structure on a thin ceramic sheet could be fabricated.

DOI： 10.1051/mfreview/2015008

Language：English   Publishing type：Research paper (scientific journal)  

Microchannels made of polymers are commonly used for MEMS and micro-total analysis system (µTAS) devices. If a micro-channel structure can be constructed of a more stable material, the analysis of more reactant chemicals in harsher environments can be realized. In this research, we developed a process for fabricating a ceramic sheet with micro-channels. The developed process is based on powder metallurgy process. A compound material, a mixture of ceramic powder and polymer, was prepared as the sheet material. We employed laser machining to machine the sacrificial layer to form micro-channels inside the sheet. We also employed imprinting to form a structure with surface patterns and microchannels curving along with it. After the imprinted sheet was debound and sintered by heating, a ceramic sheet with micro-surface patterns and microchannels was obtained.

DOI： 10.7567/JJAP.54.06FM03

Language：Japanese   Publishing type：Research paper (scientific journal)  

Deformation Control of Large Sized MIM Parts by Changing the Powder Size Distribution

Language：English   Publishing type：Research paper (international conference proceedings)  

The objective of this paper is to create multi-scale and hierarchical surface structures using simple imprinting technique. The hierarchical structures are found in the natural world; for example, lotus leaves, which are famous for high hydrophobic surface. A multi-step imprinting process was developed in this work to fabricate such kind of bio-mimetic surface structure. The hierarchical structures can be fabricated with only simple patterned molds. Another characteristic of the proposed process is that the starting material is a layered sheet material. The layered sheet was pressed by a mold with a finer pattern, and subsequently pressed by a mold with a rougher pattern. Both fine and rough patterns were obtained on the interface between the upper and lower layers after these multi-step imprinting. A polymer sheet was employed as the upper layer, which will be removed during heating processes. After removing the upper layer, hierarchical surface structure is left on the surface. In the present work, poly(vinyl alcohol) (PVA) was prepared as a upper layer, and a compound material of alumina powder and PVA as a lower layer. The PVA can be easily removed by heating. Molds with finer and rougher patterns were also prepared for multi-step imprinting. As a result, a hierarchical structure on a thin ceramic sheet was fabricated.

Language：English   Publishing type：Research paper (international conference proceedings)  

A micro patterning process for thin ceramic sheets is proposed and developed in this paper. Thin sheets with a micro pattern have been expected to improve performance of solid oxide fuel cell. The authors focused on imprinting and powder metallurgy processes, and have developed the combined process, which has been named micro powder imprinting process. In this process, ceramic powder and polymer binder materials are mixed with pure water by milling machine. After drying out the water from the slurry, a thin compound sheet was obtained. Subsequently, the sheet was pressed using a fine patterned mold with heating to transcribe a micro pattern on the sheet. Finally, the imprinted sheet was heated for removing the polymer binder and for sintering. As further improvement of the process, a compound sheet was stacked on a pure polymer sheet during the imprint process to transcribe a micro pattern on the both sides of the sintered sample. The technique is useful for improved solid oxide fuel cell.

DOI： 10.1016/j.proeng.2014.10.169

Language：English   Publishing type：Research paper (international conference proceedings)  

In the field of the industrial use of the PM-HIP process, it is a common understanding that dimensional accuracy and shape are critical factors as well as the material yield. Thus, the precise prediction of　shrinkage during HIP treatment is becoming more important as product sizes have become larger in recent years. For this reason, computer simulation technology has been utilized by many engineers in the PM-HIP field. In this study, a quarter-sized model of an actual valve made of Stainless Steel 316L for　offshore drilling rigs or cooling water lines of a PWR (pressurized water reactor) is manufactured and　tested along with the FEM simulation of the shrinkage phenomenon. Both results are compared, especially applying stress on the dimensional accuracy using HIP. Three dimensional measurement by a laser scanning system is used for the experiment because the conventional two dimensional methods have not been necessarily satisfactory depending on the shape of the object. By the use of this measurement technique, a significant improvement in the accuracy is achieved. Details of the experimental data are　discussed.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Micro Patterning on the Sheets of Ceramic Material by a Combined Process of Laser Machining and Powder Metallurgy

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

A study is presented of an improved interfacial structure between the electrode and electrolyte of a solid oxide fuel cell. An imprint process,
which is considered as a powerful tool to transcribe nano to micropatterns on materials, was employed to imprint fine patterns onto a ceramic
sheet of electrolyte. In the presented work, a sheet of ceramic compound material was prepared, and micropatterns were imprinted on its
surface. After debinding and sintering, a dense ceramic sheet with fine micropatterns was obtained. To investigate the effect of
micropatterns on the overall performance of a fuel cell, three kinds of electrolyte sheets with different surface patterns were employed for
this technique. After applying anode and cathode layers, the three fuel cell samples were assembled to test the cell performance. The
result was that the finer pattern caused better performance in the three samples by exhibiting the highest overall voltage and power
density, and the effective factors of patterns on ion conductivity were discussed as well. Based on the investigation, some further
improved three-dimensional microstructures were proposed and fabricated by the method of micro powder imprinting (μPI).

DOI： 10.1049/mnl.2013.0310

Language：English   Publishing type：Research paper (international conference proceedings)  

This paper reports simulation of deformation during micro powder imprinting process, which is a newly developed process to form micro patterned surface on ceramic sheets. The process is proposed as a combined process of traditional hot-embossing and powder metallurgy. A compound sheet of powder material and polymer binder is pressed by a mold to be transcribed a micro-pattern on its surface. After pressing, the binder is removed by heating, and the sheet is sintered. Finally dense ceramic sheet with fine pattern can be obtained. This process can be used also for layered sheet of two different materials. By using this layered sheet, we can make a pattern not only on the surface of the upper layer but also along the interface between each layer. Of course, the same pattern with the mold’s shape can be transcribed on the surface, while, there can be found another micro pattern along the interface. These two patterns of the surface and the interface are useful to fabricate ceramic sheet with patterns on its both surfaces. For example, if a compound sheet was used as an upper layer and a pure organic sheet as a lower, the lower organic layer can act as a sacrificed layer. After debinding and sintering, only the upper layer remains, which has micro-patterns on the both sides. The shape of interface between layers can be controlled by changing properties of layers. It could be also influenced by the imprinting conditions, such as temperature and pressure. In order to design the shape of the interface, finite element analysis was employed in the present paper. Mooney-Rivlin’s deformation model was used to express deformation of materials during imprinting. In this paper, we compared the simulated results with experimental data to show effectiveness of the present simulation method.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

This paper reports a magnetic actuator using interaction between micro magnetic elements. It was already reported that the present actuator can work even if the structure was miniaturized to nano-scale. In the present work, simple fabrication process with photolithography and PDMS casting was employed to obtain beam type structures with micro array of magnetic elements on their surface. Two samples with simple grid patterns were prepared for testing. These samples had the same grid pattern but different orientation, which caused directly opposite bending deformation under the same applied magnetic field. We used magneto finite element method (FEM) to explain the behavior of the present actuators.

Language：English   Publishing type：Research paper (international conference proceedings)  

This paper reports an improved interfacial structure between electrode and electrolyte of Solid Oxide Fuel Cell (SOFC). We employed an imprint process to give fine patterns onto a ceramic electrolyte sheet. The imprint process is a powerful tool to transcribe nano- to micro-patterns on materials. In the present work, a sheet of ceramic compound material was prepared, and micro patterns were given on the sheet. After debinding and sintering, dense ceramic sheet with fine patterns were obtained. We prepared three kinds of electrolyte sheets with different surface patterns using this technique. After applying anode and cathode layers, the three fuel cell samples were assembled to test the cell performance. It was resulted that the finer pattern caused the best performance in the three samples.

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Titanium and its alloys have been widely used for medical and aerospace applications
because of their excellent attributes of high specific strength, corrosion resistance, and
biocompatibility. However, it is not easy to produce the complex shaped parts due to their poor
castability and machinability. Metal injection molding (MIM) is one of suitable processing
technique to produce the complex shaped parts in order to reduce the manufacturing cost. In this
study, complex shaped Ti-6Al-4V compacts was prepared by MIM process for airplane application.
The effects of high molecular binder content and different compact’s set-up during thermal
debinding on the distortion of complex shaped compacts were measured and evaluated. The binder
with 10 % APP (Atactic polypropylene) was found to have better shape retention for the parts.
Furthermore the results indicate that high distortion occurs at early stage of thermal debinding
process. The use of supports during thermal debinding can significantly reduce the distortion of the
final parts.

DOI： doi:10.4028/www.scientific.net/KEM.520.187

Language：English   Publishing type：Research paper (scientific journal)  

In micro electro mechanical system (MEMS) field, there have been used many kinds of actuators. Among them, the magnetic actuator has some
advantages. As magnetic micro actuators do not need electric wiring for energy supply, the structure can be simple and be downsized easily.
However, the magnetic force would be very small with downsizing, which is the main problem for conventional magnetic actuators. We propose a
new type actuator using magnetic interaction force between magnetic elements to solve this matter. This actuator can work even if it gets smaller,
because the interaction force is dominant in a microscopic region. We fabricated the actuator by a casting process with photolithography using the
SU-8 resist material. Then, the structure was fabricated by casting the mixture of poly(dimethylsiloxane) (PDMS) and a magnetic powder material.
The beam type actuator works successfully and also shows interesting behavior. We can control the behavior of this actuator by changing the
arrangement of magnetic elements on the structure. We also show theoretical evaluation of the deformation of the present actuator.

Language：English   Publishing type：Research paper (scientific journal)  

The ceramic thin sheet with micrometer scale 3D patterns may be used widely in the field of Micro Electro Mechanical Systems and we improved a new method of micro powder imprinting to fabricate the thin sheet with the powder of zirconia nanometer scale powder. The micrometer scale line and space patterns from 5 μm to 1 mm were imprinted on ceramic sheets at the binder's glassy state temperature with three kinds of mold in order to remove the mold from 400 μm ceramic sheets. In debinding and sintering steps, effects of parameters such as heating and cooling ratio, temperature of sintering on the final sample's mechanical properties such as the flatness of sheet, porosity and hardness will be investigated and discussed. Finally, we employed the 300 μm thick ceramic sheets with micro patterns fabricated by the μPI method for the electrolyte for solid oxide fuel cell.

DOI： 10.1166/asl.2012.2774

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Mezzo-Heterogeneous Microstructure and Rolling on the Rolling Contact Fatigue Strength of Sintered High Ni Alloy Steels

Language：Japanese   Publishing type：Research paper (scientific journal)  

Evaluation and Analysis of Distortion during MIM Process of Titanium Alloy Materials - 2nd Report -

Language：English   Publishing type：Research paper (scientific journal)  

Effect of MIM Processing Parameters on the Properties of 440C Stainless Steel

Language：Japanese   Publishing type：Research paper (scientific journal)  

Improvement of Surface Densification and Fatigue Strength by Tooth Root Rolling of Sintered Ferrous Alloy Gear Added Mo

Language：Japanese   Publishing type：Research paper (scientific journal)  

Fatigue Failure Properties of Injection Molded Superalloy Compacts

Language：Japanese   Publishing type：Research paper (scientific journal)  

Fabrication of Porous Structured WC-Co Alloy Compacts by Indirect Laser Forming

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1143/JJAP.50.06GK11

Language：Japanese   Publishing type：Research paper (scientific journal)  

Fabrication of Super-Elastic Ti-10V-2Fe-3Al Alloy Compacts by MIM Process

Language：Japanese   Publishing type：Research paper (scientific journal)  

Fatigue Properties of Ti Alloy Compacts by Metal Injection Molding - Part 1

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Mezzo-Heterogeneous Microstructure and Rolling on the Tooth Root Bending Fatigue Properties of Sintered Ni Alloy Steel Gears

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Development of High Precision and Strength Sintered Ferrous Alloy Gear by Rolling - 3nd Report -
Improvement of Tooth Root Bending Fatigue Strength of Sintered Ferrous Alloy Gear by Modified Tool

Language：Japanese   Publishing type：Research paper (scientific journal)  

Improvement of the Contact Fatigue Strength by Rolling of Sintered Ferrous Alloy Rolle - 2nd Report-

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Powder Type on the Polling Contact Fatigue Strength of 4600 Sintered Alloy Steels

Language：Japanese   Publishing type：Research paper (scientific journal)  

The Control Method of Porous Structure for density Gradient Materials in Direct Metal Laser Sintering (DMLS)

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Book type：Scholarly book

Responsible for pages：ISBN: 978-4-339-07278-5   Language：Japanese   Book type：Scholarly book

Event date： 2009.11

Presentation type：Oral presentation (general)  

Venue：Barcelona   Country：Spain  

Event date： 2007.1

Presentation type：Oral presentation (general)  

Venue：Salerno   Country：Italy  

Event date： 2002.1

Presentation type：Oral presentation (general)  

Venue：Yokohama   Country：Japan  

Event date： 1997.1

Country：Japan  

Event date： 2024.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Bangkok   Country：Thailand  

Event date： 2024.11

Language：English   Presentation type：Poster presentation  

Venue：Kyoto   Country：Japan  

Event date： 2024.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2024.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2024.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2024.11

Language：Japanese  

Venue：福岡市   Country：Japan  

Event date： 2024.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2024.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2024.11

Language：English   Presentation type：Poster presentation  

Venue：Kyoto   Country：Japan  

Event date： 2024.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2024.11

Language：English  

Venue：Kyoto   Country：Japan  

Event date： 2024.5

Language：English   Presentation type：Oral presentation (invited, special)  

Venue：Tokyo   Country：Japan  

Event date： 2024.5

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：名古屋   Country：Japan  

Event date： 2024.2 - 2024.3

Language：English   Presentation type：Oral presentation (general)  

Venue：Okinawa   Country：Japan  

Event date： 2023.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Other Link： https://mrm2023.jmru.org/

Event date： 2023.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Other Link： https://mrm2023.jmru.org/

Event date： 2023.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Other Link： https://mrm2023.jmru.org/

Event date： 2023.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長崎   Country：Japan  

Event date： 2023.11

Language：English  

Venue：Sapporo   Country：Japan  

Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2023.9

Language：English  

Venue：Evanston   Country：United States  

Event date： 2023.7

Language：Others   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Event date： 2023.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Makuhari   Country：Japan  

Event date： 2023.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Makuhari   Country：Japan  

Event date： 2023.6

Language：English  

Venue：Kyoto   Country：Japan  

Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Okinawa   Country：Japan  

In recent years, magnetically actuated pillars have been attracted by researchers. The structures are mainly inspired by organisms in nature, cilia. These organisms are used for many purposes, such as swimming, locomotion, pumping, and transportation. The magnetically actuated structures which mimic the natural creature can be used for various engineering applications. Microfluidic devices and micro transportation systems are typical examples. of the magnetic material is useful for these purposes since they have high mechanical property and could be actuated wirelessly. However, there are some issues to mimic the natural cilia motion; the movement pattern is simple and limited; and the size is much larger than the natural ones. In this work, we developed 2-dimensional magnetic pillar arrays composed of silicone elastomer and magnetic particles to be controlled by coils set in 2-axial directions. We also tried to fabricate micrometer size pillars using polycarbonate tracked etched membrane．

Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Okinawa   Country：Japan  

This study focuses on the development of a 3D printing system for multi-material dispensing nozzles that can fabricate multi-material products by combining ceramic and metal materials. In various structural and functional applications, zirconia components could improve performance by bonding ceramic to metal so that we employed zirconia and stainless steel for this experiment. We attempted to employ powder injection molding compounds as print materials both for the ceramic and metal powders. To facilitate handling in the desktop printing system, we mixed synthetic wax and rapeseed oil as binder material. The use of rapeseed oil allowed for lower printing temperatures and the use of alcohol for debinding prior to sintering. The goal of this work is to fabricate composite structures of stainless steel and zirconia using the developed 3D printing system.

Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Okinawa   Country：Japan  

In this work, we propose a new magnetic gel material for soft robotics. Micropatterning of magnetic properties can be printed on a gel sheet to design deforming of the sheet material. We selected a tough gel material, which are known as double-network gels (DN-gels), as a base material and dispersed a magnetic powder. The proposed material showed not only high strength and large elongation but also high anti-cutting strength. Authors also developed a new process for a magnetic micro patterning process for this material using local heating by laser. The resolution of the printed pattern was finer than reported conventional magnetic soft actuators. We performed cutting and tensile tests of the gel material and showed mechanical properties. We also tried to scan laser on a magnetic gel sheet for micro patterning of the magnetic anisotropy.

Event date： 2022.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Niigata City   Country：Japan  

Event date： 2022.10

Language：English  

Venue：Toyama City   Country：Japan  

Event date： 2022.10

Language：English  

Venue：Toyama City   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2022.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2022.5 - 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2022.1

Language：English  

Venue：Online   Country：United States  

Event date： 2022.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Tokyo and online (hybrid)   Country：Japan  

Event date： 2021.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2021.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.9

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2021.7

Language：English  

Venue：Online   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Online   Country：Japan  

Event date： 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2021.5

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2021.4

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2020.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2020.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2020.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2020.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2020.10

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2020.10

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2020.10

Language：English  

Venue：オンライン   Country：Japan  

Event date： 2020.10

Language：English  

Venue：Online   Country：Other  

In this paper, we propose a new actuation system for magnetic beads or particles. Magnetic beads were precisely actuated as a rotator, which could be used for a pumping system. The magnetic beads were set on a round base which periodically embedded magnetic beads on the surface, and were actuated by magnetic interaction force excreted by a rotating magnetic field. We show theoretical background and demonstrate actuation using a 3D-printed sample. Also, we tried to use the present system as a pumping system.

Event date： 2020.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2020.1

Language：English  

Venue：Vancouver   Country：Canada  

Event date： 2020.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Event date： 2019.11

Language：Japanese  

Venue：Hamamatsu   Country：Japan  

Event date： 2019.11

Language：Japanese  

Venue：Hamamatsu   Country：Japan  

Event date： 2019.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Hiroshima   Country：Japan  

Event date： 2019.10

Language：English  

Venue：Hiroshima   Country：Japan  

Event date： 2019.10

Language：English  

Venue：Hiroshima   Country：Japan  

Event date： 2019.10

Language：English  

Venue：Hiroshima   Country：Japan  

Event date： 2019.10

Language：English  

Venue：Hiroshima   Country：Japan  

Event date： 2019.10

Language：English  

Venue：Basel   Country：Switzerland  

Event date： 2019.10

Language：English  

Venue：Basel   Country：Switzerland  

Event date： 2019.7 - 2019.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Nano Imprint lithography (NIL) is a technique that transfers a fine mold pattern to the surface of a work material. NIL is an excellent technology in terms of high productivity, accuracy, and resolution. Recently, a technology called multilayered imprint has been developed in which NIL is applied to processing of a multilayered material. In this process, it is possible to form not only surface of a workpiece, but also an interfacial pattern between the upper layer and the lower layer simultaneously. Using this technology, processing of functionally graded materials and fabrication of complex patterns using a sacrificial layer have been studied. Control of interface shape is necessary in multilayered imprint. The interface pattern can be controlled by the deformation characteristics, initial thickness, and so forth. In this research, we compared the interfacial pattern changes of imprinted multilayered materials in milli- and microscales. For multilayered imprint using multiple materials, it is important to know the flow of the resist and its dependence on the scale. If there is similarity in the relationship produced by the scale on the imprinted samples, a process design with a number of feedbacks could be realized. It also becomes easier to treat structures in the millimeter scale for the experiment. In this study, we employed micropowder imprint (μPI) for multilayered material imprint. A compound sheet of alumina powder and polymer binder was used for imprint. Two similar experiments in different scales, micro- and millimeter scales, were carried out. Results indicate that the interfacial patterns of micro- and millimeter-scale-imprinted samples are similar.

Event date： 2019.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Makuhari   Country：Japan  

Event date： 2019.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Makuhari   Country：Japan  

Event date： 2019.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Makuhari   Country：Japan  

Event date： 2018.11

Language：English  

Venue：Kaohsiung   Country：Taiwan, Province of China  

Event date： 2018.11

Language：English  

Venue：Kaohsiung   Country：Taiwan, Province of China  

Event date： 2018.11

Language：English  

Venue：Kaohsiung   Country：Taiwan, Province of China  

Event date： 2018.10 - 2018.11

Language：Japanese  

Venue：札幌   Country：Japan  

Event date： 2018.10 - 2018.11

Language：Japanese  

Venue：札幌   Country：Japan  

Event date： 2018.10 - 2018.11

Language：Japanese  

Venue：札幌   Country：Japan  

Event date： 2018.10 - 2018.11

Language：Japanese  

Venue：札幌   Country：Japan  

Event date： 2018.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Okinawa   Country：Japan  

Event date： 2018.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Munakata   Country：Japan  

Event date： 2018.10

Language：English  

Venue：Munakata   Country：Japan  

Event date： 2018.10

Language：English  

Venue：Munakata   Country：Japan  

Event date： 2018.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Copenhagen   Country：Denmark  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Sapporo   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Event date： 2018.9

Language：English  

Venue：Fukuoka   Country：Japan  

Event date： 2018.9

Language：English  

Venue：Fukuoka   Country：Japan  

外部磁場により駆動できる柔軟構造体を造形する３Dプリンタを開発した．本発表においては特に微細構造体の造形例として人工繊毛群が協調して駆動する構造を示した．繊毛の協調運動（メタクロナール波）の人工構造による実現は世界初の成果である．

Event date： 2018.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Yonezawa   Country：Japan  

Event date： 2018.8

Language：English   Presentation type：Oral presentation (general)  

Venue：San Diego   Country：United States  

Event date： 2018.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Kitakyushu   Country：Japan  

Event date： 2018.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2018.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Makuhari   Country：Japan  

Event date： 2018.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Makuhari   Country：Japan  

Event date： 2018.5

Language：Japanese  

Venue：福岡市   Country：Japan  

Event date： 2018.5

Language：Japanese  

Venue：福岡市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2018.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2017.12

Language：Japanese  

Venue：大阪   Country：Japan  

Event date： 2017.12

Language：Japanese  

Venue：大阪   Country：Japan  

Event date： 2017.12

Language：Japanese  

Venue：大阪   Country：Japan  

Event date： 2017.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Jeju   Country：Korea, Republic of  

Event date： 2017.11

Language：English  

Venue：Jeju   Country：Korea, Republic of  

Event date： 2017.11

Language：English  

Venue：Jeju   Country：Korea, Republic of  

Event date： 2017.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Jeju   Country：Korea, Republic of  

Event date： 2017.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Jeju   Country：Korea, Republic of  

Event date： 2017.11

Language：English  

Venue：Jeju   Country：Korea, Republic of  

Event date： 2017.10 - 2017.11

Language：Japanese  

Venue：広島   Country：Japan  

本研究では，3次元構造のセラミックマイクロ流路を作製する新しい方法を提案する．本研究では，マイクロ流路の上面に波状の構造などの表面パターンを形成することにより，流路上面の表面積拡大と流路長さの延長を行う．セラミックスマイクロ流路は，樹脂に比べて耐熱性，耐食性，耐薬品性，強度などに優れているため，従来の樹脂製流路では使用できない，高温または過酷な環境で使用することができ，高効率の熱交換器，固体酸化物燃料電池の電解質，燃料改質器などのような製品への適用が可能である．
セラミックマイクロ流路の作製のために，本研究ではμPI（Micro Powder Imprint）法とレーザ加工を組み合わせた加工プロセスを開発した（1）．図1にマイクロ流路形成プロセスの概要を示す．まず，ホットエンボス用コンパウンドシートとして，セラミック粉末と樹脂を混合する．続いて，レーザ加工により微細な流路パターンに形成された犠牲層を2枚のコンパウンドシートで挟み込み，インプリント処理を行う．その際，犠牲層はコンパウンドシートの表面に沿って変形する．最後に，脱脂・焼成工程において，樹脂および犠牲層を分解し，セラミックのみからなる微細な流路を得た．
研究の結果，コンパウンドシートと犠牲層は異なる成形特性を有していた．これは，流路の形状が，材料のインプリント条件または成形性に影響されることを意味する．本研究では，コンパウンドシートの材料比やプレス温度を変えることにより，流路の成形性を制御した．図2に（a）40℃および（b）100℃でインプリントされた試料の断面画像を示し，加圧温度と流路の振幅の関係を図3に示す．これらの結果から，温度の影響を把握し，流路の形状制御を行った．
図4は，焼結後のアルミナマイクロ流路のX-CTスキャンによる（a）断面および（b）外観画像である．マイクロ流路の高さは約20μmであり，幅は約40μmであった，X-CT画像からはアルミナマイクロ流路内のクラックなどの欠陥は見られない．図5は，水中での空気を用いた流動試験中のマイクロ流路の出口の写真画像である．流路の入口から送られてきた空気が出口から出ており，微小流路の表面から空気の漏れがないことが確認された．
波型モールドによるインプリント加工と，レーザ加工の複合により，マイクロ流路の作製に成功した．作製したマイクロ流路は高効率の熱交換機や，様々な環境下での，MEMS用としての使用が期待できる．

Event date： 2017.10 - 2017.11

Language：Japanese  

Venue：広島   Country：Japan  

真核細胞には繊毛と呼ばれる髪の毛のような小器官が存在する．このような繊毛は，ゾウリムシの体表や哺乳類の呼吸器において，送液や異物の搬送システムとして効果的に機能している．本研究の目的は，磁性粒子を分散した弾性ゴム材料を使用し，天然の繊毛を模倣した優れたマイクロデバイスを開発することである．
天然の繊毛の運動では，繊毛が直線的な形状で変形する有効打，曲線的な形状で変形する回復打の2つの異なるストロークを繰り返している．この非対称運動により，低レイノルズ数領域で流れを作り出している．著者らは磁性粒子を分散させたPDMS製の人工繊毛を回転磁場下で駆動させることでこの振る舞いを模倣できることをすでに報告している(1)．図１に，人工繊毛の動きの例を示すが，この例では，人工繊毛は垂直な２次元平面内で運動を行っている．しかしながら，近年，詳細な繊毛の観察により自然界の繊毛が３次元的な運動を行っていることが分かってきた．有効打では繊毛は真っ直ぐな構造になり，回復打では表面に沿うような運動を行っている(2)．また，計算機による最適解析では結果として同様の運動が得られている(3)．
このような３次元的な動きを行うため，磁場印加時に図２のような実験のセットアップを用意した．軸方向に垂直に磁化された永久磁石を用意し回転させる．磁石の真下にある点Aは既報において人工繊毛を設置した位置である．この位置では垂直平面内を回転する磁場が得られる．今回の報告では，右横と右斜め前方の点Bおよび点Cに人工繊毛を設置した．図３に磁石を回転させたときの磁束の変化を示す．この単純なシステムを使用して，回転軸を傾斜させた回転磁場を容易に印加することができる．
人工繊毛の作製には，シリコーンゴム材料（Ecoflex00-30，Smooth-on）およびカルボニル鉄粉末（径：4.36 μm）を使用した．樹脂材料と磁性粒子を混合し，型に充填し，硬化させピラー状に成形した．柱の高さは3 mm，厚さは150 μmとした．繊毛のスナップショットの一例を図4に示し，繊毛の先端の軌跡を図5に示す．B点およびC点の両方において３次元的な運動が観察された．点Bと点Cでは挙動が異なり，点Cでの動きは，報告されている天然の繊毛の動き(2)と似た挙動が得られた．今後，この人工繊毛を用いPIVによる流れ場解析を行う予定である．

Event date： 2017.10 - 2017.11

Language：Japanese  

Venue：広島   Country：Japan  

弾性基板上に，より硬質の薄膜層が存在する場合，この基板を面内方向に圧縮すると表面上にしわ構造が生成する．この自己組織的なパターン周期は上下層の機械的な特性と薄膜層の厚さにより変化することが理論的に示されている(1)．表層の硬質層には金属蒸着膜等の均質な素材を用いた例が多く報告されているが，本研究では微細な粒子を分散させた層を用いる．図1に示すように表層部に粒子を含む層が存在する場合，この部分はコンポジットとなり弾性率も変化する．そのため，変形時にしわが生成する．粒子の密度は容易に変更できるため，物性の制御も容易である．また，本研究では粒子として磁性粒子を用い，磁場印加による粒子鎖構造を生成し機械的異方性を粒子層に付与した．
実験にはPDMS（Poly-dimethyl-siloxane; Sylgard184）とカルボニル鉄粉（平均粒径4.36 μm）を用いた．粉末が1 mass%になるように混合・分散し，プラスチック容器に注いだ後，遠心分離機により粒子を沈降させ，容器底部に粒子層を生成した．この際，容器内に材料を装填する深さを変えることで，最終的な粒子層の厚さを変化させたサンプルを得た．その後，水平方向に磁場を印加し粒子鎖構造を生成し，PDMSを硬化した．得られたサンプルに対し所定の一軸ひずみを面内に加えた際，表層部にしわが観察された．
図2に圧縮ひずみを与えた際の粒子層厚さとしわ周期との関係を示す．また，図3に，しわが生成するまでに与えたひずみ（臨界ひずみ: εc）を示す．ここでは圧縮方向を粒子鎖構造に対して平行，垂直の2種類のデータを示している．均質材料では，周期は薄膜厚さに比例するが，ここでは非線形の関係が見られた．粒子の沈降時に厚さ方向になんらかの分布が生成していることが予想される．また，しわの周期は粒子鎖の向きにはほとんど影響していないことがわかる．一方，図3に示したしわの生成する限界ひずみ量では，特に層が薄い場合に大きな差が見られる．
次に粒子鎖構造の異方性（粒子鎖の向き）をパターニングした例を示す．紫外線硬化型PDMS（KER-4690，信越化学）を用い，マスクを用いたパターニング結果を図4に示す．また，このサンプルを圧縮した様子を図5に示す．与えたひずみ方向と粒子鎖構造が平行な領域にのみしわが生成しており，局所的なしわの生成が制御できることが示された．

Event date： 2017.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：久留米   Country：Japan  

Event date： 2017.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：久留米   Country：Japan  

Event date： 2017.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Event date： 2017.4

Language：English   Presentation type：Oral presentation (general)  

Venue：Nara   Country：Japan  

Solid oxide fuel cells (SOFC) are fuel cells made of ceramics. SOFC have the highest efficiency among various kinds of fuel cells. They are mainly used for relatively large scale power source such as power plants. SOFC is expected to be a new main generator; however, energy density is not high and downsizing is also required to be more popular. To enhance the energy density of SOFC, we developed a SOFC with wave-electrolyte layer. As a wavy electrolyte has larger reacting area than a flat-electrolyte, higher energy density could be obtained. We propose a new method to form a wavy electrolyte layer in this work. The aim of our study is to develop a processing method of the thin and wavy YSZ electrolyte for SOFC. Our proposed process is named micro powder imprint (µPI) with multi-layer imprint process that is useful to fabricate micro scale pattern on a ceramic sheet such as an electrolyte layer of SOFC. The µPI is inspired by nano imprint lithography (NIL). NIL is a process to transcribe a nano-pattern on a resin film using a mold, and has been proposed by S. Y. Chou. The process can produce a fine pattern on the surface in high resolution, and is mass-productive. NIL is a process for polymer as a work material, while µPI is a process for inorganic materials. The starting material for µPI is a compound sheet containing material ceramic powder and binder consisting of thermoplastic resin. Fine pattern can be transcribed on a compound sheet by pressing with a mold as similarly with NIL. After imprinting, the resin in the compound is decomposed by heating, and inorganic powder is bonded together during the following sintering step. Authors already have reported fabrication of electrolyte sheet which has micro pattern on one side of the sheet by µPI In this study, we propose a method to form not only an electrolyte sheet but also an anode layers at a one time. Two different sheets were stacked into one sheet as a multi-layer sheet for the µPI process to form a wave-type compound sheet. We could control interface pattern between electrolyte and anode layers by changing mechanical property of each starting compound material. Next the formed layered sheet was sintered subsequently. Generally, it is not easy to sinter two kinds of materials at same time, because different shrinkage rate causes distortion. In this work, we tried several conditions to obtain sound sintered samples. As a result, the SOFC unit cell with wavy-electrolyte was fabricated without any cracking and bending. It is noted that the anode layer was formed at the same time. After adding the cathode layer, we succeeded to prepare a complete cell for testing power generating. The area of interfaces between anode and electrolyte was increased to over 120 % from flat electrolyte. This means a reaction surface area increased and higher efficiency would be expected. By using unit cells with wavy-electrolyte developed by our study, improvement of power generation efficiency of SOFC by simple processing can be expected．

Event date： 2016.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2016.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2016.11

Language：English  

Venue：Kyoto   Country：Japan  

Event date： 2016.11

Language：English  

Venue：Kyoto   Country：Japan  

Event date： 2016.10

Language：Japanese  

Venue：平戸市   Country：Japan  

Event date： 2016.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：刈谷市   Country：Japan  

Event date： 2016.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Hamburg   Country：Germany  

Metal Injection Molding (MIM) process is suitable for fabricating small parts in large quantity. In this work, relatively large and complex shaped parts were prepared thorough MIM. In order to decrease the deformation of sintered parts, powders of different sizes were mixed. The effect of powder particle distribution and powder loading on the distortion of complex shaped compacts were investigated and evaluated. As smaller the particle size of mixed powder, tap density of powder were decreased. However, sintered density and shrinkage were increased. Although high powder loading increased the viscosity during the injection molding, decreased the shrinkage of sintered compact. From these results, smaller deformation of the large and complex shaped parts could be realized by using mixed powder with smaller particle and higher powder loading.

Event date： 2016.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Daejeon   Country：Korea, Republic of  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2016.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌市   Country：Japan  

Event date： 2016.7

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2016.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Event date： 2015.11

Language：English  

Venue：Toyama   Country：Japan  

Event date： 2015.11

Language：English  

Venue：Toyama   Country：Japan  

Event date： 2015.11

Language：English  

Venue：Kyoto   Country：Japan  

Event date： 2015.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Microchannels composed of polymers are commonly used in devices such as MEMS and μTAS (micro total analysis system). In this research, the polymers have been replaced by ceramics, which can endure a much harsher environment. The ceramic micro channels can be used in mechanical parts operated in extreme heat and in the presence of highly reactant chemicals.
In this work, the microchannels were fabricated by a combined process, which consists of micro powder imprinting and laser beam machining. A sheet composed of ceramic particles and polymers was prepared. A sacrificial layer, which was laser beam machined into the shape of the microchannels, was placed in between two ceramic compound sheets. A mould was placed on the upper surface then the imprinting process was carried out. By using a deep mould and replacing the sacrificial layer with a material that has larger elongation strength, the microchannels can be shaped into wavy channels which are along the imprinted wavy surface. After heating, the polymers decompose and the ceramic compact was sintered; ceramic micro channels with surface patterns are obtained.
As our microchannel forming process enables surface patterning and fabrication of out-of-plane micro channels, the surface area is increased, which enables applications as high efficiency heat exchangers. Moreover, by using yttria stabilized zirconia as structure material, which is used as electron exchanging membranes in solid oxide fuel cells, application on high efficiency fuel cells can be achieved.

Event date： 2015.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Yttria-stabilized zirconia (YSZ) has been used for an electrolyte of solid oxide fuel cells (SOFC). To enhance the efficiency of SOFC, we developed a corrugated, or wavy-shaped, YSZ sheet for the electrolyte. As the corrugated sheet has larger surface area than a flat-type sheet, higher energy density can be obtained. We have proposed micro powder imprint (µPI) with multi-layer imprint process to fabricate micro scale pattern on both surfaces of a thin YSZ sheet. The µPI is a combined process of nano imprint lithography and powder metallurgy; the resolution is high, and the process is mass-productive. We can use various inorganic materials as powder materials. In this work, we selected a compound material containing YSZ powder and a binder consisting of thermoplastic resin as a starting material. The compound sheet was prepared by tape casting from slurry. Next, the compound sheet was stacked on a silicone rubber sheet and was imprinted by a fine-patterned mold. The silicone rubber was so flexible that micropatterns on the both sides of the compound sheet was obtained after imprinting. For the further improvement of the manufacturing method for a wave-type YSZ electrolyte, higher mold precision, and the process parameters such as temperature and pressure control, are important factors. In the present work, we used laser machining for mold manufacturing, and the process condition of µPI and the heat program of debinding and sintering were also optimized. As a result, a wave-type sintered YSZ sheet without significant defects was successfully obtained.

Event date： 2015.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2015.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2015.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2015.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2015.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Event date： 2015.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2015.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2015.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2015.5

Language：English   Presentation type：Oral presentation (general)  

Venue：San Diego   Country：United States  

Ti-6Al-4V alloy is paid the attention from the automotive and aerospace industries because of its outstanding specific strength and corrosion resistance. On the other hand, Ti-6Al-4V alloy has normally poor workability. Therefore, Metal Injection Molding (MIM) process is hoped to be one of the technique to reduce the manufacturing cost. Recently many researches for Ti-6Al-4V compacts by MIM process were reported, however, there are a few reports about fatigue fracture properties. According to our previous study, they presented a problem of low fatigue strength compared to wrought material. In this study, to improve the fatigue strength of Ti-6Al-4V compacts by MIM process, a little amount of boron was added by using TiB2 powder. Boron showed the effect of refining the grain size of lamellar structure of Ti-6Al-4V compacts, which lead to increase the fatigue strength.

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪市   Country：Japan  

Event date： 2014.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：鹿児島   Country：Japan  

Event date： 2014.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Taipei   Country：Taiwan, Province of China  

Event date： 2014.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Event date： 2014.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Event date： 2014.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Event date： 2014.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Event date： 2014.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Event date： 2014.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Event date： 2014.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Nagoya   Country：Japan  

A micro patterning process for thin ceramic sheets is proposed and developed in this paper. Thin sheets with a micro pattern have been expected to improve performance of solid oxide fuel cell (SOFC). The authors focused on imprinting and powder metallurgy processes, and have developed the combined process, which has been named micro powder imprinting (μPI) process. In this process, ceramic powder and polymer binder materials are mixed with pure water by milling machine. After drying out the water from the slurry, a thin compound sheet was obtained. Subsequently, the sheet was pressed using a fine patterned mold with heating to transcribe a micro pattern on the sheet. Finally, the imprinted sheet was heated for removing the polymer binder and for sintering. As further improvement of the process, a compound sheet was stacked on a pure polymer sheet during the imprint process to transcribe a micro pattern on the both sides of the sintered sample. The technique is useful for improved SOFC.

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Effect of Form Rolling on the Improvement of Tooth Root Bending Fatigue Strength for Sintered SCM415 Gears

Event date： 2014.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Stockholm   Country：Sweden  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田   Country：Japan  

Event date： 2014.5

Language：English   Presentation type：Oral presentation (general)  

Venue：Florida   Country：United States  

In this study, a numerical 3D modeling using FEM for typically heterogeneous Microstructure for super high strengthened low Fe-Ni alloy steel, which was obtained by metal injection molding (MIM) process, is investigated. The designing of geometry models and material properties are introduced according to the experimental data. Moreover, the predicted stress-strain curve and distribution of each model are discussed.

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2013.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2013.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Sapporo   Country：Japan  

Event date： 2013.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Sapporo   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：兵庫県   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡山   Country：Japan  

Fe-Cr soft magnetic materials have been used for solenoid valves and electronic fuel injector because of their high corrosion resistance and excellent magnetic properties in AC magnetic field. Conventionally, Fe-Cr soft magnetic parts have been produced by machining. The authors applied Metal Injection Molding (MIM) process to fabricate Fe-Cr compacts. MIM process is one of near net shape forming techniques of metal powders, which can produce complicated parts with low processing cost. The objective of this study is to investigate the effect of Cr contents on the magnetic properties of Fe-Cr compacts fabricated by MIM process. The magnetic properties were measured in DC and AC magnetic fields. Three types of MIM compacts were fabricated, which contain 5, 11 and 17 %Cr. These compacts were sintered at 1250-1350 °C for 3 hours in H2 and they showed nearly full density. As a result, magnetic flux density and coercivity of MIM compacts are comparable to that of Fe-13Cr-2Si material (K-M31) which is a conventional material. Moreover, Cr contents improve the initial permeability and relative loss factor in AC field.

Event date： 2013.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Barcelona   Country：Spain  

This paper reports simulation of deformation during micro powder imprinting process, which is a newly developed process to form micro patterned surface on ceramic sheets. The process is proposed as a combined process of traditional hot-embossing and powder metallurgy. A compound sheet of powder material and polymer binder is pressed by a mold to be transcribed a micro-pattern on its surface. After pressing, the binder is removed by heating, and the sheet is sintered. Finally dense ceramic sheet with fine pattern can be obtained. This process can be used also for layered sheet of two different materials. By using this layered sheet, we can make a pattern not only on the surface of the upper layer but also along the interface between each layer. Of course, the same pattern with the mold’s shape can be transcribed on the surface, while, there can be found another micro pattern along the interface. These two patterns of the surface and the interface are useful to fabricate ceramic sheet with patterns on its both surfaces. For example, if a compound sheet was used as an upper layer and a pure organic sheet as a lower, the lower organic layer can act as a sacrificed layer. After debinding and sintering, only the upper layer remains, which has micro-patterns on the both sides.
The shape of interface between layers can be controlled by changing properties of layers. It could be also influenced by the imprinting conditions, such as temperature and pressure. In order to design the shape of the interface, finite element analysis was employed in the present paper. Mooney-Rivlin’s deformation model was used to express deformation of materials during imprinting. In this paper, we compared the simulated results with experimental data to show effectiveness of the present simulation method.

Event date： 2013.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Chicago   Country：United States  

The microstructure and mechanical properties of high performance sintered Fe-Ni alloy steels by using metal injection molding (MIM) process were investigated. The mixed elemental materials, iron and wateratomized Ni powders, were utilized in this study. The microstructure of the compacts have been consistently structured heterogeneously by molding and sintering the mixed elemental powders as same as our previous reports. In this study, the microstructural aspects of the compact were changed by the characteristics of Ni powder, such as particle size, shape, and distribution, which play important roles in the deformation behavior. Eventually, tempered compacts added 6 mass% fine Ni powder showed ultrahigh strength of more than 2 GPa (290 ksi) and elongation of higher than 8 %. In order to understand how the microstructure results these high mechanical properties, we developed 2D finite element modeling based on the spatial distribution obtained experimentally. The simulated results of the models were compared to experimentally obtained behavior, and showed good agreements.

Event date： 2013.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2013.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2013.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2013.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2013.3

Presentation type：Oral presentation (general)  

Venue：九州産業大学   Country：Japan  

Event date： 2013.3

Presentation type：Oral presentation (general)  

Venue：九州産業大学   Country：Japan  

Event date： 2013.3

Presentation type：Oral presentation (general)  

Venue：San Antonio   Country：United States  

Superalloys have been used for aerospace application because of their excellent attributes of high strength, corrosion and oxidation resistance at high temperature. The Inconel 718 and Rene 95 are representative Ni based superalloys. However, it is not easy to produce the complicated parts at low cost due to their poor workability. Moreover, segregation occurred in casting. Metal Injection Molding (MIM) process, one of near net shape forming of powders, has been applied to fabricate the both superalloy compacts. By optimizing MIM process parameters, near full density was obtained. Tensile strength of the heat-treated MIM compacts shows excellent values that are higher strength than that of wrought materials. Strength and fatigue properties at high temperature will be discussed in detail.

Event date： 2012.11

Presentation type：Oral presentation (general)  

Venue：立命館大学琵琶湖草津キャンパス   Country：Japan  

Event date： 2012.11

Presentation type：Oral presentation (general)  

Venue：立命館大学琵琶湖草津キャンパス   Country：Japan  

Event date： 2012.11

Presentation type：Oral presentation (general)  

Venue：立命館大学琵琶湖草津キャンパス   Country：Japan  

Event date： 2012.11

Presentation type：Oral presentation (general)  

Venue：北九州市   Country：Japan  

Event date： 2012.11

Presentation type：Oral presentation (general)  

Venue：北九州市   Country：Japan  

Event date： 2012.11

Presentation type：Oral presentation (general)  

Venue：北九州市   Country：Japan  

Event date： 2012.11

Presentation type：Oral presentation (general)  

Venue：北九州市   Country：Japan  

Event date： 2012.10

Presentation type：Oral presentation (general)  

Venue：Yokohama   Country：Japan