Study of strain sensor using FeSiB magnetostrictive thin film

We examined the strain sensor using the inverse magnetostriction effect to obtain high sensitivity. Since the sensor is composed of a conductive layer sandwiched between two magnetostrictive films, the impedance of the sensor is low compared with the former works. Therefore, sensitivity of the sensor can be significantly improved due to the increase of the impedance change ratio. The sensor using molybdenum as the conductive layer exhibited higher sensitivity with a large impedance change ratio caused by the anisotropy induced to the width direction of the magnetostrictive films. In this study, for the sensor sample whose size is 0.5 mm in width and 2 μm in thickness, we could obtain the highest sensitivity of 18 000.