Investigation of single-crystal face-plated 2-2 piezocomposites for deep-sea hydrophone applications

This study presents performance predictions and selection strategies for different generations of single crystals to guide the application of single-crystal face-plated 2-2 piezocomposites in deep-water hydrophones. Accordingly, the home-built setups were developed for measuring the parameter variation of three generations of single crystals under uniaxial stress. Based on this foundation, a stress-dependent static equilibrium model for face-plated 2-2 piezocomposites was established. The stress-dependent parameters were incorporated into the model to evaluate the performance of face-plated 2-2 piezocomposite hydrophones. Furthermore, a finite element model including the stress-dependent parameters was established to verify the effectiveness and enhance the accuracy of the prediction. The results show that the receiving voltage sensitivity (RVS) of the hydrophone using PMN-PT single-crystal piezocomposites tends to be better under uniaxial stress within the range of 0.6-1.8 MPa, while for Mn:PIN-PMN-PT, the RVS decreases by no more than 6 dB until the stress reaches 4 MPa. In conclusion, the PMN-PT single crystal is advantageous for hydrophones operating under uniaxial stress below 200 m, whereas the Mn:PIN-PMN-PT single crystal is more suitable for deep-water hydrophone applications due to its stable piezoelectric performance.