Anodic aluminum oxide-epoxy composite acoustic matching layers for ultrasonic transducer application

H J Fang; Y Chen; C M Wong; W B Qiu; H L W Chan; J Y Dai; Q Li; Q F Yan

doi:10.1016/j.ultras.2016.04.003

Anodic aluminum oxide-epoxy composite acoustic matching layers for ultrasonic transducer application

Ultrasonics. 2016 Aug:70:29-33. doi: 10.1016/j.ultras.2016.04.003. Epub 2016 Apr 4.

Authors

H J Fang¹, Y Chen², C M Wong³, W B Qiu⁴, H L W Chan⁵, J Y Dai⁶, Q Li⁷, Q F Yan⁷

Affiliations

¹ Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China; Department of Chemistry, Tsinghua University, Beijing, PR China.
² Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China; The Hong Kong Polytechnic University, Shenzhen Research Institute, PR China.
³ Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China; Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
⁴ Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
⁵ Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
⁶ Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China; The Hong Kong Polytechnic University, Shenzhen Research Institute, PR China. Electronic address: jiyan.dai@polyu.edu.hk.
⁷ Department of Chemistry, Tsinghua University, Beijing, PR China.

PMID: 27125558
DOI: 10.1016/j.ultras.2016.04.003

Abstract

The goal of this work is to demonstrate the application of anodic aluminum oxide (AAO) template as matching layer of ultrasonic transducer. Quarter-wavelength acoustic matching layer is known as a vital component in medical ultrasonic transducers to compensate the acoustic impedance mismatch between piezoelectric element and human body. The AAO matching layer is made of anodic aluminum oxide template filled with epoxy resin, i.e. AAO-epoxy 1-3 composite. Using this composite as the first matching layer, a ∼12MHz ultrasonic transducer based on soft lead zirconate titanate piezoelectric ceramic is fabricated, and pulse-echo measurements show that the transducer exhibits very good performance with broad bandwidth of 68% (-6dB) and two-way insertion loss of -22.7dB. Wire phantom ultrasonic image is also used to evaluate the transducer's performance, and the results confirm the process feasibility and merit of AAO-epoxy composite as a new matching material for ultrasonic transducer application. This matching scheme provides a solution to address the problems existing in the conventional 0-3 composite matching layer and suggests another useful application of AAO template.

Keywords: AAO–epoxy 1–3 composites; Matching layer; Ultrasonic transducer.

Publication types

Research Support, Non-U.S. Gov't