HOLLOW PIEZOELECTRIC COMPOSITES

Current research activity in piezoelectric sensors and actuators is mo ving toward better resolution and higher power densities. Higher resol ution and smaller sizes are needed in applications such as biomedical ultrasound, probes for invasive procedures, flow noise control, nondes tructive testing, and automotive instrumentation. Piezoelectric transd ucers with enclosed hollow space offer several special advantages incl uding low acoustic impedance, reduced mass, sensitivity to weak hydros tatic waves, and enlarged displacements through flextensional and rota tional motions. This paper describes recent advances in the processing and properties of five types of hollow piezoelectric composites with the connectivity patterns 0(0)-3, 1(0)-3, 2-0-2, 3-1(0) and 2(0)-2-2(0 ). Piezocomposites with hollow space included within the structure cle arly demonstrate the advantages of functional composites in the field of smart systems.