High output micromotor using amorphous nanowires and thin film magnets

点击翻译按钮获取中文摘要

In general, out-put power of conventional electro-magnetic motors is proportional to volume of used magnetic materials. When the motor is miniaturized to the size down to a few mm square, its out-put power is around 10muN-m. To get larger out-put power, a new driving technique is needed to develope. In the present research program, an attempt was made to develope a high output acutuater by using magnetic nanowires and thin film magnets.(1) Magnetic nanowires with high aspect ratioSo far the magnetic nanowire has been fabricated by anodization technique for application to perpendicular recording media. But its length is limited less than a few microns, since acelectrodeposition has been used. In the present investigation, effort was made to apply dc eletrodeposition for fabrication of the nanowire with high aspect ratio more than a few thausands. By making holes in the insulating layr, so called barrier layr, and subsequent application of dc electrodeposition, we fabricated successfuly the nanowire 90 mum long. Its aspect ratio is more than 2000. The fabricated wire is flexible enough to be applied to actuater.(2) Thin film magnetsThin film magnet with high energy product was developed. To restrain the grain growth, layred structue with Nd-Dy-Fe-B and Fe thin film was fabricated by sputtering. It was found that addition of Dy element increases coercivety and cutts off the exchange interaction between both layrs. By this way, high coercivity was obtained with the layred thick film magnet.(3) ActuaterA new principle for micro-actuater was demonstrated using the magnetic nanowires and thin film magnet. The nanowires on the anodized Al substrate was biased in the transverse direction by the thin film magnet and magnetization of the wires was reversed by the longitudinal ac field. By this way, the nanowires can be vibrated in the transeverse direction.