title: Fabrication and performance of high-frequency composite transducers with triangular-pillar geometry.
abstract: A single-element, 40-MHz, 3-mm diameter transducer was fabricated with a geometric focus at 9 mm. The transducer was based on a piezo-composite substrate with triangular-shaped composite pillars. The 2-way bandwidth of 50% and impedance magnitude were in agreement with that predicted using finite-element modeling. A one-way radiation pattern was collected using a needle hydrophone. The one-way -3 dB beamwidth at the geometric focus was measured to be 120 microm and the -3 dB depth of field was 2.5 mm. This is in good agreement with the theoretical predictions of 112.5 microm and 2.4 mm. The triangular-pillar composite transducer was then compared with a transducer with square composite pillars with similar volume fraction of active ceramic. A 9.5 dB reduction in the amplitude of the secondary resonance was found for the triangular-pillar composite as well as a 30% gain in the 2-way pulse bandwidth. A 256-element 30-MHz linear array was fabricated as a preliminary investigation into the use of the triangular pillar as the substrate in a high-frequency linear array transducer. In vivo images were generated with both the single-element and linear-array transducers.
authors.affiliation: Dalhousie University, Halifax, NS, Canada.
authors.forename: Jeremy A
authors.initials: JA
authors.lastname: Brown
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Chérin
authors.forename: Jianhua
authors.initials: J
authors.lastname: Yin
authors.forename: F Stuart
authors.initials: FS
authors.lastname: Foster
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation*