Abstract: A method of manufacturing a piezoelectric transducer including piezoelectric fibers in a polymer matrix is described. The piezoelectric fibers or fiber segments are jacketed with a liquid polymer substance in such a way that a distribution of longitudinal axes of the fibers or fiber segments about a preferential direction occurs. The fibers are compacted among each other and the polymer substance is cured. The resulting composite structure is subsequently so processed that areas of the fibers or fiber segments are exposed along the preferential direction. Then electrical contacts are applied on at least one part of the exposed areas. The method permits the very simple and low-cost manufacture of electro-mechanical transducers made of piezoelectric fibers.

Abstract: The present invention relates to an electromechanical converter, a method of manufacturing same, as well as to a composite system including the electromechanical converter. The inventive electromechanical converter consists of at least one elongate fiber (1) made of a piezoelectric material. At least two electrodes (2) are provided at mutually spaced locations on the fiber (1) for subjecting the fiber to an electrical field. The electrodes (2) are in direct contact with the fiber (1) and enclose the fiber (1) partly or completely. The direct contact between the electrode and the fiber permits the optimum introduction of the electrical field into the fiber such that lower electrical potentials on the electrodes are sufficient for polarising the fiber. Another advantage resides in the aspect that the electrode is in direct contact with the fiber not only at one point but over part of the periphery of the fiber. This results in a further enhancement of the introduction of the electrical field.

Abstract: A ferroelectric ceramic material, for the storage of information in electrostatic printing processes, which ferroelectric ceramic material has a coercive force of less than 200 V/mm. The ferroelectric ceramic material consists of a ceramic perovskitic mixed crystal, which contains one or more components from each of Groups 1 and 2, whereby Group 1 contains the components PbTiO.sub.3, BaTiO.sub.3, Pb(Fe.sub.1/2 Nb.sub.1/2)O.sub.3 and Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 and Group 2 contains the components Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3, Pb(Ni.sub.1/3 Nb.sub.2/3)O.sub.3, Pb(Fe.sub.2/3 W.sub.1/3)O.sub.3 and Pb(Mn.sub.1/2 Nb.sub.1/2)O.sub.3. The proportions of the components from the two groups in the mixed crystal are determined according to the following equation: ##EQU1## where X.sub.i is the mole fraction of the i-component, T.sub.ci is the Curie point of the i-component and T.sub.cM is the Curie point of the mixture between 50.degree. C. and 100.degree. C.