A Novel Frequency Modulation Based System Using Bi-Layer Thin Film Displacement Sensors

摘要

A novel method has been used for accurately measuring low voltage signals (～10{sup}(-4)V) associated with inductance changes of bi-layer thin film sensors under bending stress, without the use of sophisticated hardware. Bi-layer thin films form the building blocks for a new generation of multifunctional sensors. They consist of a magnetic layer deposited on a non magnetic layer that is used to enhance the changes in the relative permeability of the magnetic material, caused by tensile or compressive stresses. Bi-layer sensors are cost effective and easy to operate and they have been developed to detect various parameters such as displacement, temperature, stress etc [1]. Previous methods for detecting and analyzing sensor signals required the use of costly measurement systems such as Laser Scanning Doppler Vibrometer [2].