THICK-FILM RESONANT PIEZO-LAYERS AS NEW GRAVIMETRIC SENSORS

Resonant piezo-layers (RPLs) manufactured in thick-film technology are proposed as highly sensitive gravimetric sensors. RPLs rely on a PZT- based screen printable paste which is used for the fabrication of plan ar elements on alumina substrates behaving as thickness-made resonator s. When operated at resonance, these elements are sensitive to a mass load applied on their free moving face, working as resonant microbalan ces with a frequency output, reaching a mass sensitivity of 114 kHz mg (-1). This paper describes the paste preparation, background theory, f requency-tracking oscillator and the characterization of the sensors a nd anticipates their application in sensing arrays for chemical measur ements.