Surface and defect controlled high power piezoelectric ultrasonic transducers

<sec>Researches have shown that a reasonably designed phononic crystal defect structure in high-power piezoelectric ultrasonic transducers can effectively suppress stray vibration modes. However, when the size of the transducer is large, the improvement of the displacement amplitude of the radiation surface of the transducer device by the phononic crystal defect structure is still not so ideal. How to effectively suppress harmful vibrations while ensuring the operational efficiency of transducers and enhancing the displacement amplitude of their radiating surfaces has always been a challenging problem in the field of power ultrasonics that needs to be solved urgently. Researches have found that acoustic surface structures can achieve unidirectional energy transmission, effectively reduce energy loss, and enhance the efficiency of energy transmission. Based on this, the high-power piezoelectric ultrasonic transducers with surface and defect regulation are investigated in this work.</sec><sec>By designing reasonable defects and acoustic surface structures in the transducer, strong localization effects of sound waves can be excited to achieve acoustic anomalous transmission, significantly increasing the longitudinal radiated sound power of the transducer. At the same time, a data analysis technique is used to analyze the influence of material composition and geometric parameters of acoustic surface structure and defect structure on the performance of transducers, and a performance prediction model is established for high-power piezoelectric ultrasonic transducers, ultimately achieving optimized design of transducers. In this study, a new theory and method are systematically proposed for optimizing the design of high-power piezoelectric ultrasonic transducers quantitatively. Simulation and experimental results show that the innovative design capability and intelligent level of high-power piezoelectric ultrasonic transducers can be improved, making the vibration mode of the transducer more singular in high-power application environments, and thus significantly improving the displacement amplitude and amplitude distribution uniformity of the transducer radiation surface.</sec>