Efficient Driving of Piezoelectric Transducers Using a Biaxial Driving Technique

• Published in: PloS one Vol. 10; no. 9; p. e0139178
• Main Authors: Pichardo, Samuel, Silva, Rafael R C, Rubel, Oleg, Curiel, Laura
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 29.09.2015; Public Library of Science (PLoS)
• Subjects: Acoustics; Biomedical engineering; Biomedical materials; Ceramics; Coercivity; Composite materials; Condensed matter; Condensed matter physics; Efficiency; Electric fields; Electric Impedance; Electric power; Electric Stimulation; Electrical engineering; Electricity; Electrodes; Energy; Equipment Design; Experiments; Ferroelectric materials; Ferroelectricity; Ferroelectrics; High-Intensity Focused Ultrasound Ablation - instrumentation; Lead; Magnetic properties; Materials science; Methods; Piezoelectric ceramics; Piezoelectric materials; Piezoelectric transducers; Piezoelectricity; Power efficiency; Power supply; Propagation modes; Properties; Radiation; Resonance; Titanium; Transducers; Ultrasonic imaging; Ultrasonics - instrumentation; Ultrasound; Ultrasound imaging; Zirconium; Canada; Thunder Bay Ontario Canada
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0139178

Efficient driving of piezoelectric materials is desirable when operating transducers for biomedical applications such as high intensity focused ultrasound (HIFU) or ultrasound imaging. More efficient operation reduces the electric power required to produce the desired bioeffect or contrast. Our preliminary work [Cole et al. Journal of Physics: Condensed Matter. 2014;26(13):135901.] suggested that driving transducers by applying orthogonal electric fields can significantly reduce the coercivity that opposes ferroelectric switching. We present here the experimental validation of this biaxial driving technique using piezoelectric ceramics typically used in HIFU. A set of narrow-band transducers was fabricated with two sets of electrodes placed in an orthogonal configuration (following the propagation and the lateral mode). The geometry of the ceramic was chosen to have a resonance frequency similar for the propagation and the lateral mode. The average (± s.d.) resonance frequency of the samples was 465.1 (± 1.5) kHz. Experiments were conducted in which each pair of electrodes was driven independently and measurements of effective acoustic power were obtained using the radiation force method. The efficiency (acoustic/electric power) of the biaxial driving method was compared to the results obtained when driving the ceramic using electrodes placed only in the pole direction. Our results indicate that the biaxial method increases efficiency from 50% to 125% relative to the using a single electric field.