Characterization of resonant behavior and sensitivity using micromachined PZT cantilever

Abstract

Micromachined piezoelectric cantilevers have been fabricated using PZT (52/58) films. Electromechanical characteristics of micromachined PZT cantilever were measured by laser vibrometer system as a function of cantilever length for the cantilever with two different supported layer thickness respectively. The 1(st) version unimorph cantilever consists of a 0.6 (square)-thick PZT layer on 1.5 (square)-thick SiN x elastic supported layer. In order to increase Q-factor in air and liquid, from calculated spring constant as a function of variable supporting layer thickness, 2(nd) version cantilever was designed to have a 0.8 (square)-thick PZT layer on 4.5 (square)-thick SiNx/Si elastic supported layer. The gravimetric sensitivities of cantilever in air were characterized by Au deposition on the backside of cantilever. The gravimetric sensitivity of 100x200 (square)-dimension cantilever was 300 cm(2)/g and the mass of 5 ng was detectable.