High Frequency Needle Ultrasonic Transducers Based on Lead-Free Co Doped Na0.5Bi4.5Ti4O15 Piezo-Ceramics

Chunlong Fei; Tianlong Zhao; Danfeng Wang; Yi Quan; Pengfei Lin; Di Li; Yintang Yang; Jianzheng Cheng; Chunlei Wang; Chunming Wang; Qifa Zhou

doi:10.3390/mi9060291

Micromachines (Jun 2018)

High Frequency Needle Ultrasonic Transducers Based on Lead-Free Co Doped Na0.5Bi4.5Ti4O15 Piezo-Ceramics

Chunlong Fei,
Tianlong Zhao,
Danfeng Wang,
Yi Quan,
Pengfei Lin,
Di Li,
Yintang Yang,
Jianzheng Cheng,
Chunlei Wang,
Chunming Wang,
Qifa Zhou

Affiliations

Chunlong Fei: School of Microelectronics, Xidian University, Xi’an 740071, China
Tianlong Zhao: School of Microelectronics, Xidian University, Xi’an 740071, China
Danfeng Wang: School of Microelectronics, Xidian University, Xi’an 740071, China
Yi Quan: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi’an Jiaotong University, Xi’an 740049, China
Pengfei Lin: School of Microelectronics, Xidian University, Xi’an 740071, China
Di Li: School of Microelectronics, Xidian University, Xi’an 740071, China
Yintang Yang: School of Microelectronics, Xidian University, Xi’an 740071, China
Jianzheng Cheng: School of Electronic and Electrical Engineering, Wuhan Textile University, Wuhan 430200, China
Chunlei Wang: School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
Chunming Wang: School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
Qifa Zhou: Department of Ophthalmology and Biomedical Engineeing, University of Southern California, Los Angeles, CA 90089-1111, USA

DOI: https://doi.org/10.3390/mi9060291
Journal volume & issue: Vol. 9, no. 6
p. 291

Abstract

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This paper describes the design, fabrication, and characterization of tightly focused (ƒ-number close to 1) high frequency needle-type transducers based on lead-free Na0.5Bi4.5Ti3.975Co0.025O15 (NBT-Co) piezo-ceramics. The NBT-Co ceramics, are fabricated through solid-state reactions, have a piezoelectric coefficient d33 of 32 pC/N, and an electromechanical coupling factor kt of 35.3%. The high Curie temperature (670 °C) indicates a wide working temperature range. Characterization results show a center frequency of 70.4 MHz and a −6 dB bandwidth of 52.7%. Lateral resolution of 29.8 μm was achieved by scanning a 10 μm tungsten wire target, and axial resolution of 20.8 μm was calculated from the full width at half maximum (FWHM) of the pulse length of the echo. This lead-free ultrasonic transducer has potential applications in high resolution biological imaging.

Published in Micromachines

ISSN: 2072-666X (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Mechanical engineering and machinery
Website: https://www.mdpi.com/journal/micromachines

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