Abstract
This study develops directional piezoelectric sensors for planar source location. A directional piezoelectric element for the low-frequency Lamb A_0 mode was designed and its performance was evaluated. To decrease the size of the sensor element, we prepare a piezoelectric film transducer element of 10-μm-thick Pb_<1.1>(Zr_<0.53>Ti_<0.47>)O_3 film deposited on 2-inch Pt/Ti/SiO_2/Si substrates using a chemical solution deposition (CSD) process. Pt top electrode and PZT layer were etched by reactive ion etching (RIE) process with Ar/CHF_3 mixture gas, and the rectangular (5mm×0.5mm) shape PZT film transducers were fabricated. The sensor element was bonded on a 1-mm-thick aluminum plate. The transmitting/receiving properties of the PZT transducers were measured. When the film transducer was driven at lateral oscillation mode, about 250kHz Lamb wave propagated on the aluminum plate.
