Design Optimization And Character Research Of Piezoelectric Micromachined Ultrasonic Transducer For Directional Loudspeaker Based On FEA

In this paper, a design optimization of piezoelectric micromachined ultrasonic transducer for its exciting sensitivity is provided. A micromachined transducer is modeled as a clamped-clamped membrane and a membrane with four edges clamped respectively, with the piezoelectric film to excite the beam or membrane vibrating.Firstly three different design variations of the piezoelectric layer structures for two type model are explored for the optimization. To perform the analysis and the subsequent optimization, the finite element models of the design options are created using ANSYS. The exciting sensitivity is taken as the optimization objective. Specifically, when the exciting voltage is fixed, the transducer structure is optimized to maximize the vibrating magnitude of the beam. The size of the piezoelectric layer is selected as the design parameters to optimize the exciting sensitivity of the transducer. The optimization results of the transducer based on clamped-clamped membrane and membrane are compared; the design method to improve the exciting sensitivity of the transducer is provided. The optimal design and the sensitivity analysis are performed, and the corresponding structural parameters of the piezoelectric film layer for optimal design are identified. Then, based on above optimization, the FEA method in ANSYS of piezoelectric-mechanical-acoustic couplings and its sound radiation is researched and the frequency response for the optimal structure is obtained. Finally, taking the practical application of transducer array into account, the transducer array directivity is simulated using MATLAB. The array directivity of linear array and rectangular array is compared to verify the feasibility of linear array and find the optimal array configuration with high directivity.