Abstract
High frequency ultrasound (HFUS) transducers are in demand for medical diagnoses requiring high spatial resolution. Compared with bulk piezoceramics, conventional crystals, and piezopolymers, piezoceramic-polymer composites have highly desirable properties such as improved piezoelectric coupling and acoustic matching to tissue. However, for 30 MHz operation, a typical 1-3 piezocomposite is approximately only 50 µm thick, requiring ceramic pillar widths of around 15 µm or less. Fabrication is thus challenging with dice-and-fill technology. This may be overcome using micromoulding of ceramic paste produced by viscous polymer processing (VPP). This brings a need for material characterisation to support the new approach but conventional techniques cannot be used due to the small structures involved. This paper therefore reports characterisation using electrical impedance spectroscopy followed by data fitting to a theoretical model based on the 1-D piezoelectric wave equation and homogenized piezocomposite model of Smith and Auld. Results are presented from multiple VPP and HFUS piezocomposites spanning a development program of several years. The piezocomposites investigated showed effective piezoelectric properties in the following ranges: c: 1.76 - 6.77 (x 10 Nm, e: 2.04 - 8.50 (Cm), e S: 70.6 - 460, d: 7.82 - 12.7 (x 10 mV), h: 2.01 - 2.09 (x 10 Vm) and k: 0.45-0.51. These data confirm that the VPP fabrication method has good potential for HFUS piezocomposites.
Original language | English |
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Title of host publication | Ultrasonics Symposium, 2008 |
Subtitle of host publication | IUS 2008 |
Publisher | IEEE |
Pages | 58-61 |
Number of pages | 4 |
ISBN (Electronic) | 978-1-4244-2480-1 |
ISBN (Print) | 978-1-4244-2428-3 |
DOIs | |
Publication status | Published - 2008 |
Event | 2008 IEEE International Ultrasonics Symposium (IUS) - Beijing, China Duration: 2 Nov 2008 → 5 Nov 2008 http://ewh.ieee.org/conf/ius_2008/ |
Conference
Conference | 2008 IEEE International Ultrasonics Symposium (IUS) |
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Abbreviated title | 2008 IEEE IUS |
Country/Territory | China |
City | Beijing |
Period | 2/11/08 → 5/11/08 |
Internet address |