Abstract:

A ceramic injection molding process is used to custom manufacture piezoelectric composites for both sensors and actuators with operational frequencies from 100 Hz and 10 MHz. These piezoelectric composites can be specifically tailored to couple acoustic energy into and from a wide variety of mediums including air, water, biological tissue, polymers, composites, and metals. Both 1-3 and 2-2 piezoelectric composites have been made with different lead zirconate-titanate (PZT) formulations, element dimensions, PZT volume fractions, and polymeric matrices. Piezoelectric composite transducers are easily conformed to various substructures, shaded to adjust beam patterns, and sectioned into arrays for imaging. Examples include face-plated SonoPanels (and stiff matrix 1-3 piezoelectric composites for underwater actuation, sensing, and imaging. SmartPanels, capable of both sensing and actuating, have been recently introduced for active surface control. These devices integrate 1-3 piezoelectric composite actuators and pressure sensors and net-shape molded PZT velocity sensors in a large-area, low-profile panel. Multiple net-shape molded accelerometer elements have been designed, fabricated, and tested. Both single and double layer 100x100-mm SmartPanels have been characterized for sensor sensitivities, actuator authority, surface displacement uniformity, and sensor-actuator coupling. Also, recent developments of injection molded PZT bender arrays for low-frequency air acoustic transducers will be presented. [Work supported by ONR and DARPA.]