Research and Experimental Verification of a Flextensional Disk Transducer Based on Relaxor Ferroelectric Single Crystals

In this article, the electroacoustic properties of the flextensional disk transducer based on relaxor ferroelectric single crystals are studied. First, the transducer structure, consisting of relaxor ferroelectric single crystals, metal plates, and air cavity, and an operating principle are introduced. Then, we investigate, by finite element modeling, the influence of different air cavity sizes on the transducer behavior. Furthermore, we optimize the size of the air cavity and analyze the performance of flextensional disk transducers based on relaxor ferroelectric single crystals and piezoelectric ceramics, such as the resonant frequency and transmitting voltage response (TVR). Finally, transducers of the same size are manufactured using the two kinds of materials, and the experimental measurements are carried out in an anechoic water tank. The measured maximum TVR of the single-crystal transducer is 141.04 dB at 22.2 kHz. Compared with the piezoelectric ceramic transducer, the maximum TVR of the single-crystal transducer is increased by 12.51 dB, and the corresponding resonant frequency is reduced by 4.8 kHz, which extends the working frequency.