Piezoelectric actuator has been used in different applications because of its compact structure compared to magnetic actuators. This paper reports the influence of piezoelectric actuators geometry on the plate vibrating amplitude. Through a Finite Element Method (FEM) approach, we find out the piezoelectric actuator surface area greatly affects the vibrating amplitude. Increasing the piezoelectric actuator surface can raise the plate displacement up to hundred micrometers. Besides, the piezoelectric actuator shape and orientation can be adjusted to increase the plate displacement for a fixed area. Finally, experiments on two prototypes with two piezoelectric actuators presenting different geometries are carried out to validate that the plate with greater piezoelectric actuator has bigger displacement than that with smaller piezoelectric actuator. The experimental and simulated plate displacements have a difference of around 25%.