Theoretical characterization of square piezoelectric micro ultrasonic transducer for underwater applications

There are numerous advantages of employing MEMS based transducer within underwater applications. This work utilized MEMS based acoustic transducer for underwater applications. Two common types of micro ultrasonic transducer are capacitive (cMUT) and piezoelectric (pMUT). In this study, square pMUT will be characterized using finite element method (FEM). The model consist of ZnO film as a piezo active layer and nickel aluminum bronze (CuAl
₁₀
Ni
₅
Fe
₄
) as the electrodes, adhered on the silicon on insulator (SOI) wafer. Structural parameters namely diaphragm width and thickness were manipulated for resonance frequency tuning. Then, the model undergone piezoelectric and modal analyses to obtain the relationship between applied voltage and generated pressure and vise versa. Next, device sensitivity was estimated. After characterization, model design has been finalized to carry fundamental frequency of 50 kHz. It was also estimated that device transmitting voltage response is 139 dB re 1 μPa/V on the surface of the transducer while its receiving response was estimated at -69 dB re 1 V/μPa. Developed model should be fabricated in order to validate the findings and this will be included in our future works.