Magnetostrictive bilayer sensors [multifunction sensors]

This paper concerns a new generation of bilayer materials with controlled magnetic behaviour as a basic element for multi-functional sensor families. The bilayer consists of a magnetostrictive layer and a non-magnetic counter-layer which are connected to each other by gluing, meltspinning, soldering, sputtering or electroplating techniques. The mean permeability of the bilayer is strongly affected by bending or temperature changes, respectively. Thus it can be applied as a basic element for sensors of curvature, force, acceleration or temperature. Additionally, it is robust and can be activated at low-forces. It is nearly free of wear, compact, light-weighted and cheap. The behaviour of the sensor system is shown with emphasis on the mechanical and magnetostrictive character of the amorphous layer and of the additional layers.