Design and modeling of a piezo-driven three-dimensional bridge-type amplification mechanism with input/output guiding constraint

Owing to the limited stroke of piezo stacks, compliant amplification mechanisms are widely employed to magnify the displacement of piezoelectric actuators for emerging applications in precision engineering. In this study, a three-dimensional (3D) bridge-type amplification mechanism composed of two serially connected bridge-type amplifiers with a novel constraint form has been developed. The parallel guiding beams mounted at the input and output ends significantly increase the lateral stiffness and minimize parasitic displacements for higher accuracy. Furthermore, a new theoretical model is established to predict the magnification behavior of the 3D amplifier that takes into account the displacement loss caused by the coupling of the two bridge-type amplifiers. The accuracy of this model and the mechanical performance of the developed amplifier are verified by conducting finite element simulations and experimental studies on the manufactured prototypes.