Naval Device Applications of Relaxor Piezoelectric Single Crystals

This proposed project is for the new application of PMN-PT based piezoelectric crystals. Shear modes of PMN-PT crystals show the supreme properties: k15 poled PMN-PT crystal has a coupling coefficient greater than 0.95 and k36 poled PMN-PT crystal gives a coupling coefficient greater than 0.90. The k36 has a unique re-pole-ability and larger coercive field over 5 kV/cm (2 times higher than poled k33 mode) that more promising for high power projectors. The proposed device is designed to replace the transducer which is being used in a mine counter measure (MCM) application on an autonomous underwater vehicle (AUV). The proposed shear mode transducer will give the following advantages over the existing transducer: insensitive to the hydrostatic pressure (under water depth), compact volume, less reactive load to the system power amplifier and broaden sandwich. The proposed work will investigate these material properties to produce a compact low frequency SONAR projector capable of very high bandwidth. Anticipated work in Phase II would enable the fabrication of the shear mode transducers for military and commercial applications.