Piezoelectric Micro Ultrasonic Transducer (Pmut) With Fluidic Backing Layer As A Sensing Mechanism For Short Distance Underwater Microphone Application

• Main Author: Ahmad, Khairul Azman
• Format: Thesis
• Language: English
• Published: 2022
• Subjects: TK7800-8360 Electronics
• Online Access: http://eprints.usm.my/59547/1/24%20Pages%20from%20KHAIRUL%20AZMAN%20BIN%20AHMAD.pdf; http://eprints.usm.my/59547/
• Institution: Universiti Sains Malaysia

Piezoelectric micro ultrasonic transducer (PMUT) is vital for underwater microphone (hydrophone) applications. Hydrophone is generally used for listening or receiving any acoustic signal in underwater. Several studies have documented that PMUT served as underwater hydrophone with low receiving sensitivity and narrow operation bandwidth. The received acoustic signals with low receiving sensitivity are not accurate due to interference by unwanted signal. Acoustic transducers with narrow bandwidth were effected low resolution for underwater acoustic imaging. Narrow bandwidth transducers were captured for certain frequency only and it were difficult to catch acoustic signal at a long range frequency. In imaging, it is important the transducers can receive the signal for a long range of frequencies. The objectives of this study to increase the low receiving sensitivity transducer in the range of 300 kHz to 800 kHz and widen the narrow frequency bandwidth underwater ultrasonic transducer. Subsequently objectives are a PMUT designed using d33 mode piezoelectric structure, flexural membrane and fluidic backing layer.