Abstract: A broad bandwidth electro-mechanical transducer is shaped into a wedge of varying thickness, with a plurality of PZT elements or sheets embedded in an inactive polymer. The transducer is driven at frequencies corresponding to resonance of the thickness dimensions. The piezoelectric elements with different thicknesses are decoupled mechanically from one another using an inactive polymer of low Q so as to prevent interference.

Abstract: Composites of lead zirconate titanate (PZT) and inactive polymers with 3-1 and 3-2 patterns and a method of fabrication thereof are described. Fabrication is accomplished by drilling holes in sintered PZT blocks and filling the holes with epoxy or some other inactive polymer. The influence of hole size and volume fraction PZT on the hydrostatic properties of the composite is evaluated. By decoupling the piezoelectric coefficients d.sub.33 and d.sub.31 in the composite, the hydrostatic coefficients are greatly enhanced.

Abstract: A composite of PZT (Lead Zirconate Titanate) and a compliant polymer matrix aving 3-1 connectivity (i.e., in a diphasic material, one of the two phases is continuously self-connected in all three mutually perpendicular directions and the second phase is self-connected only along one of the three mutually perpendicular directions) and fabrication method thereof is described. An array of parallel PZT rod elements is embedded in a mechanically compliant polymer matrix with their axes along the direction of the poling electric field. Such a composite has a high value of g.sub.h, d.sub.h and g.sub.33 with very little sacrifice in the value of d.sub.33.

Abstract: A flexible, low-density piezoelectric transducer utilizing a PZT-polymer posite that is formed with the two phases three-dimensionally interpenetrant. The ceramic PZT microstructure, which is produced by a replication process that in one embodiment reproduces the structure of a coral species, is filled with silicone rubber and thereafter its transverse connectivity is broken by a light shearing deformation to give it flexibility.

Abstract: Ferroelectric crystals and ceramics prepared with tailored domain patterns hich are selected to enhance or suppress certain modes of vibration which may include those normally unattainable such as, for example, second harmonics.

Abstract: Lead germanate, Pb.sub.5 Ge.sub.3 O.sub.11, or lead germanate/silicate in which up to 2/3 on a molar basis of the germanium has been substituted with silicon, can be formed from a glassy state to a ferroelectric state by a simple annealing process. The lead germanate or lead germanate/silicate is heated to a temperature sufficient to anneal it into a crystalline phase, then cooled below the ferroelectric transition temperature for the composition while an electric field is applied.