OPERATIONAL PRINCIPLE, FABRICATION AND DISPLACEMENT CHARACTERISTICS OF A FUNCTIONALLY GRADIENT PIEZOELECTRIC CERAMIC ACTUATOR

In this paper, the theoretical relationship between the bending displacement at the free end of a functionally gradient material (FGM) actuator and the FGM coefficient of the sandwich has been derived from the structure of an FGM actuator. FGM actuators based on PNN-PZT piezoelectric ceramics have been developed by the powder mould stacking press method and their displacement characteristics have also been measured. The results show that the bending displacement at the free end of a 20 mm x 8 mm x 0.7 mm FGM actuator is about 20 mu m when a voltage of 1000 V is applied. The morphology and the compositional distribution across the profile of the FGM actuator are examined by using SEM and EDS, respectively.