Device fabrication and performance of electrostrictive P(VDF-TrFE) based actuators and transducers

Taking advantage of the high electrostrictive strain and high elastic energy density of a newly developed electrostrictive P(VDF-TrFE) polymer, a flextensional transducer was designed and its performance was investigated. The flextensional transducer consists of a multilayer stack made of electrostrictive P(VDF-TrFE) polymer films and two flextensional elements which are fixed at their two ends to the multilayer stack, to perform the displacement amplification. Because of the large strain level achievable in the electrostrictive polymer and the displacement amplification of the flextensional elements, the device of a few mm thick and lateral dimension of 1 inch × 1 inch can generate a displacement output of more than 1 mm along the thickness. The unique flextensional configuration and the high elastic energy density of the active polymer also enable the device to offer high load capability. As an underwater transducer, the device can be operated at frequencies below 2 kHz while still exhibit relatively high transmitting voltage response (TVR), very high source level (SL), and low mechanical quality factor (Q_m).