D33 mode based piezoelectric micromachined ultrasonic transducers

Abstract

Piezoelectric Micromachined Ultrasonic Transducer (PMUT) is an acoustic transducer used in application of medical diagnostic, medical imaging and underwater imaging. The design concept of conventional PMUT is based on sandwich piezoelectric between two electrodes. This is based on d31 mode polarization PMUT and the sensitivity is depend on thickness of piezoelectric and flexural deformation of membrane. The d33 mode polarization design concept is normally applied in energy harvester. This concept will increased the energy. This paper will present D33 mode based Piezoelectric Micromachined Ultrasonic Transducers to increase the sensitivity. Polyimide (PI) is used as membrane and substrate and dielectric help to increase the sensitivity. Pulse-Echo method is an experimental method to characterize the receiving sensitivity. The simulation on PMUT design to see the peak displacement of PMUT and it will be represented as resonance frequency occurred in collecting receiving signal. The PMUT device has more receiving sensitivity compared to conventional hydrophone and it is shows in result. The receiving sensitivity achieved by PMUT is −64.44 dB re 1V/uPa. The fractional bandwidth for PMUT is 28%. The operational bandwidth is needed to be improve for future design.