Sensitive stress sensor using amorphous magnetostrictive wires on both ends fixed double beam and diaphragm

New sensitive stress sensors having a both ends fixed double beam and a diaphragm on which a pair of 20 /spl mu/m diameter CoSiB amorphous wires are adhered as the stress-impedance (SI) element connecting with a CMOS IC multivibrator circuit. The SI characteristics are quantitatively analyzed using a magnetization rotation model and measured BH hysteresis loops. Detection of a blood vessel pulsation is also carried out.