SonoPanel 1-3 piezocomposite hydrophone-actuator panels

A cost-effective technology has been developed for producing 1-3 piezoelectric ceramic/polymer composites for active and passive sonar applications. SonoPanel 1-3 piezocomposite transducers consist of an array of piezoelectric ceramic rods in a compliant polymer matrix. The standard composite consists of 15 volume percent PZT-SH rods 1.1 mm diameter×6.3 mm long in a matrix of soft polyurethane. Stiff face plates are then bonded to the 1-3 composite sheet for stress amplification when used as a sensor and to enhance the surface response uniformity when used as an actuator. Many variations on this composite design have been produced. The key technology in piezocomposite manufacturing is the PZT ceramic injection molding process. Using this process, an entire array of piezoelectric ceramic rods are molded in one operation using specially designed tooling. The process eliminates the need for handling thousands of individual PZT rods during composite manufacturing. Several thousand components with excellent piezoelectric properties and part-to-part reproducibility have been manufactured. The piezocomposite fabrication process has been successfully scaled up for low volume manufacturing. More than thirty 250×250 mm SonoPanel transducers have been produced and evaluated. The transducers have been tested by the Naval Research Laboratory and others, with high receiving voltage sensitivity and transmitting voltage response as well as symmetrical beam patterns. Advanced panels for active surface control are also being developed by incorporating actuators, pressure sensors, and velocity sensors