A5102853919- Physics of Superconductivity and Magnetism
- Superconducting Materials and Applications
- Mechanical and Optical Resonators
- Force Microscopy Techniques and Applications
- Magnetic Field Sensors Techniques
- Advanced Sensor and Energy Harvesting Materials
- HVDC Systems and Fault Protection
- Analytical Chemistry and Sensors
- Electronic and Structural Properties of Oxides
- Microfluidic and Capillary Electrophoresis Applications
- ZnO doping and properties
- Frequency Control in Power Systems
- Copper Interconnects and Reliability
- Tactile and Sensory Interactions
- Magnetic properties of thin films
- Heat Transfer Mechanisms
- Nanofabrication and Lithography Techniques
- Magnetic Properties and Applications
- Magneto-Optical Properties and Applications
- Electric Motor Design and Analysis
- Advanced MEMS and NEMS Technologies
- Engineering Applied Research
- Fluid Dynamics and Turbulent Flows
- 3D Printing in Biomedical Research
- Additive Manufacturing and 3D Printing Technologies
Okayama University
2007-2024
Sogang University
2013-2021
Okayama University of Science
2009-2014
Korea Aerospace University
2010-2011
Massachusetts Institute of Technology
2010
Seoul National University
2003
International Superconductivity Technology Center
2000-2001
Waseda University
1996
Biliary strictures are characterized by the narrowing of bile duct lumen, usually caused surgical biliary injury, cancer, inflammation, and scarring from gallstones. Endoscopic stent placement is a well-established method for management strictures. However, maintaining optimal mechanical properties stents designing surfaces that can prevent stent-induced tissue hyperplasia biofilm formation challenges in fabrication biodegradable (BBSs) customized treatment. This study proposes novel...
In recent years, the applications of high-field REBa2CuOy (REBCO) coils have remarkably progressed towards NMR MRIs, accelerators, and other such devices. a REBCO coil, magnetic field due to screening current is generated in direction opposite by transport current, thus reducing field, deteriorating homogeneity, affecting time stability field. Recently, additional force stress (referred as screening-current-induced stress) has become topic concern. The results non-uniform distributions tape....
Abstract Since the invention of atomic force microscope (AFM) three decades ago, there have been numerous advances in its measurement capabilities. Curiously, throughout these developments, fundamental nature force-sensing probe—the key actuating element—has remained largely unchanged. It is produced by long-established microfabrication etching strategies and typically composed silicon-based materials. Here, we report a new class photopolymerizable hydrogel nano-probes that are bottom-up...
This letter reports ultra-stretchable strain gauges based on a liquid metal (eutectic gallium-indium) and platinum-catalyzed silicone elastomer (EcoFlex). A custom printing setup was constructed operated in the pressure controlled mode to offer high quality by eliminating undulation typically encountered flow rate control via syringe pump. Printed liquid-metal were thoroughly tested under cyclic uniaxial stretching twisting. We achieved stretchability of ~700%, which can cover any from human...
Fluidic resonators with integrated microchannels (hollow resonators) are attractive for mass, density, and volume measurements of single micro/nanoparticles cells, yet their widespread use is limited by the complexity fabrication. Here we report a simple cost-effective approach fabricating hollow microtube resonators. A prestructured silicon wafer annealed at high temperature under controlled atmosphere to form self-assembled buried cavities. The interiors these cavities oxidized produce...
In the case of motors and generators, benefits using high-temperature superconducting (HTS) coils could be represented by reduction 50% in both losses sizes compared to conventional machines same rating. However, it is hard establish quench detection protection devices for HTS applied rotors generators. Therefore, stability lower than quiescent NMR, MRI, so on. important improve self-protection ability coils. We have been developing a novel method, which removes insulation turn-turn winding...
This paper presents a sensitivity-enhanced wireless passive LC pressure sensor for monitoring bladder pressure, which can be minimally invasive implanted in the or integrated to commercial urinary catheter and avoid battery lifetime problem. The proposed design theoretical model are useful increase sensitivity of typical air-sealed capacitive sensor, particularly having flexible diaphragm. test results an vitro evaluation prototype show 6385 ppm/kPa (a responsivity 1.215 MHz/kPa) before...
This paper proposes a new method of achieving electrical stability and controllability high-temperature superconductor (HTS) coil. The proposed applied material with metal-insulator transition (MIT) property to the turn-to-turn resistance an HTS As result, remained at insulator level in normal state, thus removing delay during charging discharging. During transient dropped metal level, current bypass occurs similar that noinsulation coil, preventing coil from burning out. validity MIT...
This paper presents experimental and analytical results of trapped field characteristics a stack square YBCO thin film plates for compact NMR magnets. Each plate, 40 mm × 0.08 mm, has 25-mm diameter hole at its center. A total 500 stacked were used to build 40-mm long magnet. Its field, in bath liquid nitrogen, was measured spatial distribution temporal stability. Comparison is presented: the effects on unsaturated nickel substrate non-uniform current plate are discussed.
Although gallium-based liquid metals are attracting growing interest thanks to its potential applications in deformable, flexible electronic devices, challenges fabrication associated with the high surface tension and oxide skin remain be overcome. We report a novel technique for metal circuits using dewetting. An excessively thin film spontaneously shrinks on substrate reduce free energy. In case of microgrooves, microgroove wall additional viscous resistance delay shrinkage grooves, which...
The detailed distribution of heat transfer coefficients in a rotating dimpled rectangular channel (aspect ratio =6 and 12) was measured by the transient liquid crystal technique. speed fixed at 500 rpm tested Reynolds number based on hydraulic diameter varied from 19,000 to 44,000. Four different dimple configurations were investigate effects relative depth, center distance, height coefficient. A stationary case two directions so that fabricated surface became trailing or leading surface....
This letter reports sensitivity-improved capacitive pressure sensors fabricated using liquid alloy and highly compliant silicon elastomer. Multilayer elastomer layers prepared by replica moulding were stacked bonded to form three isolated disk-shaped cavities whose diameters are 3 or 5 mm. Top bottom (both 200-μm tall) filled with eutectic gallium-indium realize parallel electrodes. The cavity in the middle (1-mm was left empty make it compressed applied pressure. overall diameter height of...
Recently, the superconducting devices using cryogenic and technologies were widespread in field of electric powers. The quench protection is one important issues for safety operating devices, because excessive joule heating brings about damage to magnets when occurs. However, if HTS coil starts transit normally by an initial quench, it will be recovered into state or runaway thermally. These behaviors mainly determined magnitude a disturbance, size, structure winding wire cooling condition....
This paper describes a technique for building smart insulation (SI) 2G high temperature superconductor (HTS) coils and investigates their electrical characteristics. The SI method utilizes the metal-insulated transition properties of V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> . material acts as an insulator when is lower than certain value. Above this temperature, becomes...
When a magnet generating highly homogeneous magnetic field is designed, shimming required. The usually performed so that the only in axis direction compensated by iron pieces and/or coils. compensation commonly achieved eliminating coefficients of spherical harmonics expansion generated main magnet. Some papers showed z-direction for passive shimming. However, recently some magnets generate tilted from z-axis, such as magic-angle-spinning nuclear resonance/MRI. It is, therefore, necessary to...
We present a facile method for the preparation of polyethyleneglycol diacrylate (PEG-DA) hydrogels with plasmonic gold (Au) nanospheres incorporated various biological and chemical sensing applications. Plasmonic Au were prepared ex situ using standard citrate reduction an average diameter 3.5 nm deviation 0.5 nm, evaluated their surface functionalization process intended uniform dispersion in polymer matrices. UV–Visible spectroscopy reveals existence properties pristine nanospheres,...
This report discusses the first demonstration of electrophoresis assisted time-of-flow mass spectrometry using 'U' shaped hollow nanomechanical resonators (HNR). Capillary was coupled with HNR based detection to overcome low ionic conductivity channels embedded in preventing direct in-situ electrophoretic separation. The flow analytes through achieved by balancing hydrodynamic pressure override electromotive force and inhibit motion towards anode for capillary electrophoresis. resonance...
Hydrogels, intrinsically sensitive materials to water molecules (i.e. moisture), have been mostly employed as a humidity sensing layer on top of elastic mechanical structures such microcantilevers [1] where the hydrogel is relatively thin compared underlying structure. Until now, there has no report attempting make sensor based thick microstructures with coating that are preferred for increasing curvature upon stress-induced bending and frequency shift volumetric mass uptake. Here, we...
This paper presents our analysis of the output characteristics a high-temperature superconductor (HTS) coil depending on turn-to-turn contact resistance. Important design factors were investigated by taking into account resistance based results. Analyses performed five self-fabricated models with different resistances. To consider only resistance, we used first-generation HTS BSCCO wire simpler architecture and mechanical properties than second-generation wire. From this study, it was...
This letter reports optical-lever detection with spray-coated liquid metal reflectors for transparent hydrogel atomic force microscope (AFM) cantilevers. Eutectic gallium-indium (EGaIn) filled in an air brush was locally sprayed over poly(ethylene) glycol-diacrylate (PEG-DA) AFM cantilevers a shadow mask. Oxygen plasma treatment bare prior to the EGaIn spray shown improve wetting characteristics between and PEG-DA, thus enabled relatively thin coating of ~800 nm within ~100 ms. PEG-DA coated...
In this study, a method for controlling the magnetomotive force using current bypass of no-insulation magnets was developed, and characteristics 1G high-temperature superconductivity (HTS) were elucidated through experiments. The experiments performed magnet designed with bismuth strontium calcium copper oxide HTS wires. Film-type heaters used to control MMF. analysis experimental results carried out in conjunction an finite elements method.