Directivity Analysis of Piezoelectric Micromachined Ultrasonic Transducer Array

Abstract

A piezoelectric micromachined ultrasonic transducer (pMUT) is proposed. The (Pt/Ti)/Polyimide/PZT/Si3N4/SiO2/Si/SiO2/Si3N4 multimorph structure is designed and fabricated with micromachined process, resonance frequency of which is supposed to locate near 53.6 kHz. To improve the directivity pattern and increase radiation acoustic power, transducer array is adopted. A numerical simulation model was presented to study the influences of design parameters of plane combination array transducer. Interspacing between elements and number of elements are optimized. Subsequently, to verify the optimization results, experiment platform is established, directivity pattern of transducer array is obtained and compared with simulation results, which validated the optimization. The results provide the basis for structural design and fabrication of pMUT, a reliable reference for optimization of transducer array, and a method to test the directivity pattern