Ferroelectric materials display an extensive range of functional properties, for example piezoelectricity, pyroelectricity, high non-linear optical activity, switchable polarization, and non-linear dielectric behavior. Ferroelectric materials in iber form are suitable for incorporation into smart ceramic–polymer composites. The main advantage to the use of fibers instead of monolithic ferroelectric ceramics is the attained improvement in the design flexibility of the composites. Such composites are also called smart, intelligent, or adaptive composites. The concept of adaptive composite materials with integrated fibers for sensing and actuation is still an essential spur that drives the development of piezoelectric ceramic fibers. Nowadays a wide range of smart composites like piezoelectric, magnetostrictive, electrostrictive, magnetorheological, electrorheological, shape-memory, and thermoelectric materials are under investigation for a number of applications. Piezoelectric fiber composites (i.e. 1-3 composites) and active fiber composites (AFCs) are attractive for transducers, structural health sensors, and mechanical energy harvesters. A very good overview about the theoretical organization of smart composites is given by Newnham et al. Nowadays such composites are also published as smart hybrid materials. In these hybrid materials the active fibrous inorganic material is embedded in a passive polymeric matrix. [...]