Selection criteria of piezoelectric materials for double-parabolic-reflectors ultrasonic transducers (DPLUS) for high-power ultrasound

Abstract

To suit double parabolic reflectors wave-guided ultrasonic transducer (DPLUS) for high-power ultrasound applications, we investigated the selection criteria of piezoelectric materials for DPLUS. Four piezoelectric materials were prepared: two lead–zirconate–titanate (PZT) types and two lead-free types. For non-resonant excitation of the DPLUS waveguide, the piezoelectric constant e and the thickness of piezoelectric materials are two important evaluation indexes. PZT 5H was found as the best candidate. For resonant excitation of the DPLUS waveguide, two situations should be distinguished. For low-frequency modes excitation, the discussed modes matching issue is essential. For high-frequency modes excitation, high-power properties of the piezoelectric material are important for improving the vibration output of DPLUS; LFP 0202 was found as the best candidate. Low-frequency modes can achieve 8 m s−1 of maximum peak vibration velocity, but high-frequency modes were smaller than 2 m s−1. Results are important to design the DPLUS for various high-power ultrasound applications.

Low-Loss Ultrasound Transmission Through Waveguide From Double Parabolic Reflectors (DPLUS) for Thermal Ablation

“…We had studied DPLUS with ~40 mm long thin waveguide (made of duralumin A2017) in order for understanding the working principle and exploring the excitable vibration amplitude in the thin waveguide [15][16][17]. Results showed that ~7 m/s of vibration velocity amplitude could be realized in the thin waveguide and acoustic pressure in water of over 7 MPa (spatial peak temporal average intensity of ~1.6 kW cm $ ⁄ ) between 1 to 2 MHz could be estimated under the resonant excitation of the thin waveguide [15], thus indicating the highpower performance of DPLUS.…”