Fabrication of PZT-based Piezoelectric Ultrasonic Transducers
Open Access
- Author:
- Gigliotti, James Vincent
- Area of Honors:
- Materials Science and Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Dr. Susan E Trolier Mckinstry, Thesis Supervisor
Dr. Robert Allen Kimel, Thesis Honors Advisor - Keywords:
- PZT
Thin films
Ultrasonic transducers
MEMS - Abstract:
- Lead zirconate titanate (PZT) piezoelectric ceramics are at the heart of most medical imaging transducers. There is considerable interest in being able to miniaturize such ultrasound systems to enable higher resolution imaging. Recently, PZT has been incorporated into piezoelectric micromachined ultrasonic transducers (pMUTs) for evaluation of its usefulness in high frequency medical ultrasound imaging and sonotweezing applications. The fabrication limitations, design parameters, and output performance were explored in order to improve the sensing and imaging performance of PZT based pMUTs and to guide future development of the technology. A spectrum of geometries was fabricated to test and analyze the acoustical performance for imaging and sonotweezing and to explore the modes and limitations of operation. Transducers of similar design were shown to be functional with a resonance frequency of 55 MHz, 90% two-direction bandwidth, and pulse-echo response. With improvements in fabrication procedures and reduced parasitic capacitance, pMUTS with a tunable resonance frequency from 1-100 MHz have been fabricated into large 1-D and 2-D arrays to be integrated into low voltage electronics. Finite element simulations were conducted to guide future development of pMUT devices. Using the CFS++ finite element software package, good correlation between simulated and experimental results was demonstrated. The simulations suggest that pMUT devices can be modeled using the equations for a clamped uniform plate under tension.