Analysis of the electromechanical responses of sandwich circular nano-plate based on flexoelectric nano-ultrasonic transducer

Flexoelectric nano-ultrasonic transducer is an important development direction of ultra-high frequency ultrasonic transducers. The key to its development lies in addressing the electromechanical coupling dynamics of a flexoelectric nano-element, that is, sandwich circular nano-plate. In this paper, a novel dynamic theoretical model of sandwich circular nano-plate is developed based on the transversely isotropic flexoelectricity couple stress and Kirchhoff plate theories. Based on the novel model, this study demonstrates the influence of flexoelectricity effect and size effect on its electromechanical responses of the core component in the nano-ultrasonic transducer. Simultaneously, using finite element software, the paper presents the first six mode shapes of the structure and reveals the mode shape most conducive to the energy conversion of the transducer. The main objective of this study is to provide a theoretical foundation for the development of nano-ultrasonic transducers based on flexoelectric materials. The novel model can also be applied in various energy conversion devices, including flexoelectric actuator and flexoelectric energy harvesters.