In recent years, hydroacoustic transducers made of PZT/epoxy composites have been extensively employed in underwater detection, communication, and recognition for their high energy conversion efficiency. Despite the ease with which these transducers can be formed into complex shapes, their lack of mechanical flexibility limits their versatility across various sizes of underwater vehicles. This study introduces a novel flexible piezoelectric composite hydroacoustic transducer (FPCHT) based on a 1-3 PZT-5A/silicone rubber composite and an island–bridge flexible electrode, which can break the limitations of existing hydroacoustic transducers that do not have flexibility. The finite element method is used to optimize the structural parameters of high-performance 1-3 FPC. A large-sized (187 mm × 47 mm × 5.12 mm) FPC is fabricated using an improved cutting–filling method and packaged into the FPCHT. Compared with the planar rigid PZT/epoxy composite hydroacoustic transducer (RPCHT) of the same size, the TVR (186.5 db) of the FPCHT has increased by about 7 dB, indicating that it has better acoustic radiation performance and electroacoustic conversion efficiency. Furthermore, its electroacoustic performance exhibits excellent stability under different bending states. Therefore, the FPCHT with high electroacoustic performance is an ideal substitute for the existing RPCHT and promotes the development of hydroacoustic transducers towards flexibility and portability.

The bandwidth of composite transducer was successfully expanded via matching layer design. Firstly, the admittance equation of transducer was deduced through combining the equivalent model of 1–3 piezoelectric composite with the electromechanical equivalent circuit of piezoelectric crystal thickness vibration. Then, the relations between bandwidth and the parameters of matching layer were summarized by the conductance curves. Finally, a composite transducer with matching layer was designed and fabricated. Experimental results show that the bandwidth reaches to 56 kHz and the mechanical quality factor Q drops to 1.8. The results are in agreement with the theoretical calculation.

This paper presents an arc broadband piezoelectric composite vibrator and its transducer array. The arc broadband piezoelectric composite vibrator was fabricated by 1-3 piezoelectric composite with matching layer and was prepared by the curved forming process. The vibration characteristics of a new vibrator were simulated via finite element analysis (FEA) and investigated by experiment. First, the acoustic impedance and thickness of the optimized matching layer were determined by theoretical analysis. Second, the arc piezoelectric vibrator was modeled and simulated in air conditions by the FEA method, and the variation law of resonant frequency was analyzed. Finally, the fabrication process of the arc broadband piezoelectric composite vibrator and its transducer array was studied, and the experimental sample was fabricated and measured. The bandwidth of the arc broadband transducer array was found to be up to 56.5 kHz. Results show that the experimental results were in accordance with the simulation results and have good directivity to realize the purpose of bandwidth and beam expansion.

A new class of piezoelectric composite spherical cap transducer that produces a wide beam and bandwidth was developed for underwater acoustics. A finite element analysis (FEA) simulation was used to design the transducer. Electroacoustic response measurements in water were made on a transducer to evaluate the performance characteristics and then compared with the FEA results. The measured results show the transducer can provide a 112° beamwidth and a usable frequency band from 215 kHz to 355 kHz. The maximum transmitting voltage response (TVR) of the transducer is 161.7 dB re 1µPa/V@1m at 255 kHz.