Magnetoelastic bilayer concept for skin curvature sensor

Abstract

The present paper describes the magnetoelastic bilayer concept as a basis for skin curvature sensor. Bending the single magnetoelastic layer yields local regions of compressive and tensile stresses. The corresponding magnetic permeability changes compensate each other. The introduced bilayer consists of a magnetoelastic layer that is in contact with a nonmagnetic counter layer. Bending the bilayer causes the magnetoelastic layer to experience in its whole volume either tensile or compressive stress, depending on the direction of bending. The resulting large changes of magnetic permeability can be measured using a coil. The type of the used nonmagnetic layer and the fixation procedure of the layers influence strongly the sensitivity of the curvature sensor. The sensor’s effectiveness is demonstrated for assessment of cardiorespiratory parameters on the neck.