DOUBLE-LAYER ACTUATOR

This paper examines the potential for dual-layer actuators to achieve radiation efficiencies independent of the backing structure. It presents a simple center-of-mass representation for the device, and uses it to describe the kinematics of the dual layer actuator system with the purpose of identifying broad guidelines regarding thickness and frequency range issues. This approach has the advantage of providing a direct physical view of the device operation. In this context, it is shown that these devices work by electrically moving the center of mass of the transducer in opposition to the motion of the adjoining fluid. While such devices are shown to be generally less efficient than the simple parallel-driven double-layer transducer, over much of their operating range the loss in efficiency is found to be only a few decibels.