Innovative Undersea Sensors Using Relaxor Piezoelectric Single Crystals

The frequency spectrum of interest for hydrophones used in Naval tactical systems, ocean surveillance systems, or for environmental monitoring is continuing to expand, due to increased interest in passively detecting third-world submarines, biologics, etc. as well as increased interest in multistatic active sonars. LewTech is proposing that our Phase II effort will be based on the on the Phase I hydrophone development using relaxor single-crystal piezoelectric materials rather than the traditionally-used polycrystalline lead-zirconate-titanate (PZT) piezoceramic materials. This type of hydrophone can be designed to increase the sensitivity and bandwidth and reduce the self-noise, due to the improved electromechanical coupling factors, dielectric constant, and the loss tangent. The overall objective is to establish an improved design for the fat line towed array, using single-crystal ceramics, and demonstrate improvements in sensitivity, self-noise, and bandwidth capabilities over the conventional PZT configuration. Phase II will fabricate prototype single crystal hydrophones and perform in-water testing and compare the results to as counterpart PZT hydrophone. LewTech has formed a strong team with a major Navy system manufacturer, UnderSea Sensor Systems, Inc. (USSI), a wholly-owned company of Ultra Electronics, to support the design and development of a practical, cost effective sensor(s) utilizing relaxor single-crystal ceramics.