Naval Device Applications of Relaxor Piezoelectric Single Crystals

This SBIR phase-2.5 program is proposed to advance the state-of-the-art d36 shear mode projector which is the first known d36 underwater projector in the history of acoustic transduction devices. Phase II effort has shown significant advancements toward the d36 shear mode projectors in bandwidth and source level, especially its compact size. Ternary PIN-PMN-PT single crystals have been integrated into the device, which improved temperature stability and allows high, unbiased, driving fields. In order to bring it to a usable stage, we propose to develop a robust, high power, and broad bandwidth d36 shear mode projector array (12 elements). To achieve the goal, the following tasks are proposed: (1) Improving transducer fabrication methods, further optimizing device design, and testing and evaluation of these transducers at the array level; (2) Device optimization will look at improving electromechanical coupling and reducing stress in the crystal elements; (3) Fabrication improvements will include the use of crystal stacks to ease assembly, reduce the drive voltage requirements, and improve mechanical strength; and (4) Array level testing will look at frequency response, power and duty cycle characteristics, mutual impedance effects, and performance as a function of depth and temperature. The array predictions show improvements of 15 to 20 dB over other technologies operating in a similar band. We propose a budget of $ $ 897,078 to carry out the proposed works in a period of 12 months. A subcontract to the Applied Research Laboratory at Penn State University is for the design, optimization and validation of the prototype d36 shear mode crystal transducers. By the end of the contract period, we will evaluate the design and techniques developed and prepare for the commercialization of the shear mode crystal transducer.