Magnetic-acoustic-resonator sensors (MARS): A new sensing methodology

A new type of acoustic shear wave sensor fabricated from inexpensive glass and metal plates, in which the acoustic plate is remotely excited and detected with a radio frequency signal and a strong magnetic field, is described. This new acoustic plate resonance requires neither piezoelectric materials nor wire contacts, and is referred to as a magnetic-acoustic-resonator sensor or MARS device. This paper reports the concept of the MARS device and describes how shear wave resonances in aluminium and aluminium-glass composites are detected and verified. The effect of mass loading an aluminised glass plate demonstrates that MARS has Sauerbrey-like characteristics similar to the Quartz Crystal Microbalance (QCM). Prospects for liquid phase measurements are also indicated. © 1999 Elsevier Science S.A. All rights reserved