Design, fabrication, and evaluation of high frequency, single-element transducers incorporating different materials

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 49; no. 2; pp. 169 - 176
• Main Authors: Snook, K.A., Jian-Zhong Zhao, Alves, C.H.F., Cannata, J.M., Wo-Hsing Chen, Meyer, R.J., Ritter, T.A., Shung, K.K.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2002; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acoustics; Bandwidth; Ceramic fibers; Ceramics; Crystalline materials; Equipment Design; Exact sciences and technology; Eye - diagnostic imaging; Fabrication; Fiber composites; Frequency; Fundamental areas of phenomenology (including applications); High frequencies; Humans; Lead zirconate titanates; Mechanical factors; Microscopy - instrumentation; Noise levels; Physics; Piezoelectric materials; Piezoelectric transducers; Titanium compounds; Transducers; Transduction; acoustical devices for the generation and reproduction of sound; Ultrasonic transducers; Ultrasonography - instrumentation; Pulse echo method; Lithium niobate; Vinylidene fluoride polymer; Medical imagery; High frequency; Ultrasonic transducer; Composite material
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/58.985701

The performance of high frequency, single-element transducers depends greatly on the mechanical and electrical properties of the piezoelectric materials used. This study compares the design and performance of transducers incorporating different materials. The materials investigated include 1-3 lead zirconate titanate (PZT) fiber composite, lead titanate (PbTiO/sub 3/) ceramic, poly(vinylidene fluoride) (PVDF) film, and lithium niobate (LiNbO/sub 3/) single crystal. All transducers were constructed with a 3-mm aperture size and an f-number between 2 and 3. Backing and matching materials were selected based on design goals and fabrication limitations. A simplified coaxial cable tuning method was employed to match the transducer impedance to 50 /spl Omega/ for the PZT fiber composite and PbTiO/sub 3/ ceramic transducers. Transducers were tested for two-way loss and -6 dB bandwidth using the pulse/echo response from a flat quartz target. Two-way loss varied from 21 to 46 dB, and bandwidths measured were in the range from 47 to 118%. In vitro ultrasonic backscatter microscope (UBM) images of an excised human eye were obtained for each device and used to compare imaging performance. Both press-focusing and application of a lens proved to be useful beam focusing methods for high frequency. Under equal gain schemes, the LiNbO/sub 3/ and PbTiO/sub 3/ transducers provided better image contrast than the other materials.