Piezoelectric transducer

Abstract

Various piezoelectric transducers are provided. In one form, a polymer film or thin ceramic piezoelectric transducer is formed of various piezoelectric (active) and dielectric (inactive) layers in which the piezoelectric effect may be attenuated locally at any given point on the surface of the transducer, by use of printed circuit patterns, preferably made by photolithography. This provides a practical realization of a distributed piezoelectric transducer with a bi-dimensional polarization profile that varies smoothly over the surface of the piezoelectric structure. Flexibility of the fabrication procedure provides a way to optimize the design of a distributed piezoelectric transducer for applications such as active vibration control. In another form, a segmented piezoelectric transducer includes a set of active elements such as piezofilms, electronics and flexible printed circuits and connected with external electronic circuitry. The segmented piezoelectric transducer uses a modulation scheme to combine the individual sensor outputs. Modal coordinates may be extracted from a test structure on which the segmented piezoelectric transducer is attached. As well, it is possible to use a distributed piezoelectric transducer to actuate a structure by using a time-varying polarization profile.

Dependencies are inferred from the claim text.