In-air and underwater performance and finite element analysis of a flextensional device having electrostrictive poly(vinylidene fluoride-trifluoroethylene) polymers as the active driving element.

A flextensional transducer, in which the electrostrictive poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer was used as the active driving element, was fabricated and characterized. The results show that transducers of several millimeters thick can produce an axial displacement of more than 1 mm in air along the thickness direction, and a transmitting voltage response of 123 dB re 1 microPa/V at 1 m in water at frequencies of several kilohertz. A finite element code (ANSYS, Inc., Canonsburg, PA) was used to model the in-air and underwater responses of the flextensional transducer over a broad frequency range. The calculated resonance frequencies and transmitting voltage response spectra show good agreement with the experimental data. In addition, the performance of both the in-air actuator and underwater transducer was analyzed for different design parameters of the flextensional structure. These results show that the performance of the flextensional transducer could be tailored readily by adjusting the parameters of the flextensional metal shell.