For safety of night walking, there are luminescent shoes flashing with walking motion. These power supplies are batteries, power generation by walking has attracted attention of reducing batteries, and power generation shoes are being developed. However, power generation shoes have yet to be practical realization. We considered using a magnetostrictive vibration generator developed in our laboratory as the power source for power generation shoes. This generator has advantages over conventional piezoelectric or movable magnet types in terms of high efficiency, high robustness and low electrical impedance. Although it was confirmed that the LED flashes by walking using the magnetostrictive vibration generator attached to the sole, there was a problem of miniaturization and high sensitivity. On the other hand, it was found that the fluctuation of the nonmagnetic gap due to the vibration is effective for increasing the sensitivity. In this report, we propose a design method of power generation device with consideration of assist effect. Next we tried and evaluated the thickness of the magnetostrictive element (Fe-Ga alloy) and frame (magnetic material) as parameters and verified the design method. From the results, we report the design guidelines for miniaturization and the small device confirmed luminescence by walking motion.

A spin-thermoelectric (STE) voltage is generated when a temperature gradient ∇T is applied to an element having a thin Pt layer coated on a magnetic substance. In this study, yttrium iron garnet (YIG) ferrimagnetic films prepared by liquid phase epitaxy (LPE) were tested as magnetic insulators. In addition, polycrystalline YIG slabs were tested to compare the STE voltages of film and slab samples. In a Pt coating and YIG film bilayer structure made by an ultrathin Pt layer of 1-4 nm thickness and an LPE film of ~10 µm thickness, a large STE voltage of 600 µV was observed at a probe distance of 5 mm with a temperature difference ∇T of 30 K. On the other hand, the STE voltage of a Pt layer and YIG slab bilayer structure was 340 µV, which is roughly half of that of the Pt/YIG-film element. The cause of the large voltage observed experimentally for the longitudinal spin Seebeck effect element incorporating an LPE YIG film was discussed mainly from the viewpoint of the Pt layer resistivity and the effects of YIG specimen surface conditions on crystallinity and the magnetization process.

We investigated the fundamental electrical characteristics of pure water using coated spherical electrodes with diamond-like carbon (DLC). When the spherical electrodes made of chromium steel, which is one of metals, were put in pure water, the resistivity of pure water decreased 23% compared to pure water alone after 120 minutes. On the other hand, when the spherical electrodes made of chromium steel coated with DLC with a thickness of 1 µm were put in pure water, the decrease in resistivity of pure water could be suppressed to 10%. Furthermore, with chromium steel spherical electrodes coated with DLC, the lightning impulse breakdown voltage of pure water was 16% higher than that with the bare chromium steel spherical electrodes.

We have been developing NLTL (Nonlinear Transmission Line) using magnetic switches that can output a pulse train with multiple pulses as a burst pulse for cancer treatment by pulsed electric field. The point for this NLTL is the performance of a core material of the magnetic switch for generating the burst pulse. Currently, 43Material is used as the core material. In this study, we considered which one of 43Material, 31Material, HF70, and FINEMET is the best. As a result, 31Material was shown to have the highest performance to use as magnetic switch for high frequency.