Modeling of finger-like functionally graded microstructure piezoelectric actuator

The mechanical behavior of a cylindrical, finger-like shaped, piezoelectric actuator with Functionally Graded Microstructure (FGM) was modeled by our analytical model and FEM. Different layers or lamina of different piezoelectric volume fraction in a polymer matrix were stacked to create FGM. Although the bimorph plate exhibit reasonably high out-of-plane displacement, induced stress field remains very high limiting its long life use. FGM piezoelectric plates have been developed to increase the out-of-plane displacement while reducing the stresses where the electro-elastic properties are graded through the plate thickness. Finger-like shape piezo actuators are developed where the properties are graded in the radial direction. FGM piezoelectric type actuator showed promising results in that the deflections to any direction can be obtained by manipulating the magnitude and direction of the applied electric field. Analytical modeling in computing the deflection of the finger-like actuator and stress field induced in each lamina was developed and compared to FEM modeling. The theory of cylindrical FGM is based on lamination theory in which the coordinate system is changed from the rectangular to cylindrical one and from infinite to finite plate.