Design, Fabrication, Characterization, and System Integration of a 1-D PMUT Array for Medical Ultrasound Imaging
Alessandro Stuart Savoia, Marco Casavola, Enrico Boni, Marco Ferrera, Carlo Prelini, Piero Tortoli, Domenico Giusti, Fabio Quaglia
Abstract
Micromachined Ultrasonic Transducer (CMUT and PMUT) technologies are playing a fundamental role in the development of novel applications such as ultra-portable medical imaging systems. This paper presents the design, fabrication, characterization, and system integration of a 1-D PMUT array for low-frequency diagnostic imaging applications. The PMUT array was fabricated using a sol-gel PZT thin film-based MEMS technology from STMicroelectronics. The 1-D array was integrated into an ultrasound probe and acoustic characterization and imaging tests were carried out using the ULA-OP 256 open scanner. The two-way frequency response of the PMUT had a center frequency of 2.5 MHz and a -6dB fractional bandwidth of 81%, and peak transmit and receive sensitivities assessed at the transducer surface of 31 kPa/V and 3.2 mV/kPa, respectively. In vitro and in vivo scans of a tissue-mimicking phantom and of a carotid artery, respectively, were successfully carried out demonstrating the potentiality of this PMUT technology for medical imaging applications.