Magnetostrictive LC Circuit Sensors

Abstract

Magnetostrictive thin films in electric resonant LC circuits are attractive as novel strain sensors. In order to achieve high resonance frequencies exchange coupled nanometer multilayers were used. LC circuits incorporating Fe 50 Co 50 /Co 80 B 20 multilayers exhibited a gauge factor ((Áf =f Þ=Á") of the order of 1000. This LC circuit sensor enables wireless interrogation, which is demonstrated in a torque measurement.

Evaluation of Coil-Induction, Foil-Capacity and Growth in Pot Plant Batteries

“…Equations for magnetism and e.g. rotations are given in [6,9], and may be modified to describe larger scale induction on a drum membrane. A model could be that of piezo-electric response to acoustic displacement.…”

“…Applied in this case, it can reduce the LC-oscillator to an exponential capacitor-solution added by a term proportional to L. Other experimental modeling shows how the velocity c given by the electric constants, can be measured with an LC-circuit, [8]. The characterisation of a shift in a LC-circuit sensor is addressed in [9] and measurement of strain and torque with inverse magnetostriction are derived.…”