25 MHz ultrasonic transducers with lead- free piezoceramic, 1-3 PZT fiber-epoxy composite, and PVDF polymer active elements
Autor: | A. Winder, Nader Marandian Hagh, Ahmad Safari, B. Jadidian |
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Rok vydání: | 2009 |
Předmět: |
Titanium
Materials science Chemical Phenomena Acoustics and Ultrasonics Transducers Composite number Acoustics Epoxy Piezoelectricity Transducer Lead visual_art Electric Impedance PMUT visual_art.visual_art_medium Insertion loss Polyvinyls Ultrasonic sensor Zirconium Ceramic Electrical and Electronic Engineering Composite material Instrumentation Algorithms Ultrasonography |
Zdroj: | IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control. 56:368-378 |
ISSN: | 1525-8955 0885-3010 |
Popis: | This paper presents the fabrication and characterization of single-element ultrasonic transducers whose active elements are made of lead-free piezoceramic, 1-3 PZT/polymer composite and PVDF film. The lead free piezoelectric KNNLT- LS(K(0.44)Na(0.52)Li(0.04))(Nb(0.84)Ta(0.10)S(0.06)b)O(3) powders and ceramics were prepared under controlled humidity and oxygen flow rate during sintering. Due to its moderate longitudinal piezoelectric charge coefficient (175 pC/N) and k(t) of 0.50, the KNN-LT-LS composition may be a good candidate for high frequency transducer applications. PZT fibers with 25 microm diameter formed by the viscose suspension spinning process were incorporated into epoxy to fabricate 1-3 composites with the averaged k(t) = 0.64 and d(33) = 400 pC/N. Using KNN-LS-LT ceramic, 1-3 PZT fiber composite, and PVDF film, 3 different unfocused single element transducers with center frequencies of 25 MHz were fabricated. The acoustic characterization of the transducers demonstrated that wideband and low insertion loss could be obtained employing KNN-LS-LT ceramic. The -6 dB bandwidth and insertion loss were 70% and -21 dB, respectively. In comparison, the insertion loss of the ceramic transducer was much smaller than those made with 1-3 composite and PVDF film. This was attributed to closer electrical impedance match to 50 ohm and higher thickness coupling coefficient of the ceramic transducer. |
Databáze: | OpenAIRE |
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