Fabrication, characterization and optimization of posfet (PVF2-silicon) piezoelectric transducers for low frequency 100 Hz to 500 KHz underwater acoustic applications

PVF2 is a new organic polymer piezoelectric material. Its unique features include an acoustic impedance closely matched to liquid environments, linearity to a broad range of input signals, wide bandwidth and mechanical strength and flexibility. In comparison with commonly used ceramic piezoelectric materials, PVF2 has a lower electromechanical coupling coefficient, a lower dielectric constant and higher dielectric losses at frequencies greater than or equal to 500 KHz. Because of these different material properties, system applications of PVF2 require different trade-offs than the ceramic materials. This report describes an investigation, both theoretical and experimental, of the potential applications of PVF2 in low frequency (100 Hz-500 KHz) underwater sound applications. Both reception and transmission of sound are considered and the experimental performance of several types of PVF2 and integrated silicon/PVF2 transducers are described.