Date of Award

10-30-2020

Publication Type

Master Thesis

Degree Name

M.A.Sc.

Department

Electrical and Computer Engineering

First Advisor

Arezoo Emadi

Keywords

Acoustic output pressure, COMSOL, MEMS, PMUT, Resonant Frequency, Ultrasonic Transducer

Rights

info:eu-repo/semantics/openAccess

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Abstract

According to the Canadian Cancer Society, 2020, “1 in 8 women will be affected by breast cancer and 1 in 33 will die from it.” There has been a decline in breast cancer causalities due to the early detection using advanced imaging technologies. This signifies the importance of early detection of breast cancer that increases the survival rate and treatment options for the patients. One of the platforms which are aiding the early detection is Microelectromechanical Systems (MEMS)-base imaging system. In this thesis, a Piezoelectric Micromachined Ultrasonic Transducer (PMUT) is proposed to work at lower frequency ranges for higher penetration aiding imaging applications while operating at a lower voltage. In this work, a comprehensive study based on the Multi-User MEMS Process (MUMPs) has been conducted to investigate the effect of critical design parameters on output performance. Three sets of PMUTs are fabricated based on the investigated parameters. The resonant frequency and acoustic output pressure of these fabricated devices are evaluated and compared based on their respective areas of the piezo layer using COMSOL Multiphysics. The resonant frequency of the fabricated PMUT ranges from 0.5 MHz to 2 MHz. Keysight Impedance Analyzer E4990A has been utilized for the electrical characterization of the fabricated PMUT devices to determine their respective resonant frequencies and validate the COMSOL simulation results. It is shown that the fabricated individual circular PMUT achieves a high acoustic output pressure of 39 kPa at 1.3 MHz and the rectangular PMUT provides 4.7 kPa of acoustic pressure at 1.4 MHz. The results indicate that the proposed PMUT design can deliver acoustic pressure at a lower frequency

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