The Application of High Energy Density Transducer Materials to Smart Systems

Recent NUWC research efforts in the field of high power sonar transducers designed to produce high acoustic outputs over significant bandwidths while being of minimal size and weight have been aided by advances in the continuing development of several new high energy density transducer drive materials. Both Terfenol-D, a rare earth magnetostrictive material, and lead magnesium niobate, a relaxor ferroelectric, have demonstrated a tenfold increase in field-limited energy density over a typical very hard lead zirconate titanate (i.e., Clevite PZT-8) piezoelectric ceramic. The Center's focus is to double the demonstrated performance of each material and to address such issues as hysteresis reduction in the magnetostrictive material and coupling coefficient improvements in the electrostrictive materials. Poly (vinylidene fluoride-trifluoroethylene) can also be considered a high energy density material because of its excellent energy density and its broad bandwidth possibilities. The application of these material technologies, either separately or as hybrid composites, to smart material design will be detailed.