Piezo-stack Driven Type Displacement Magnification Mechanism Reinforced by Bimorph Piezoelectric Members.

This paper deals with fundamental characteristic of the mechanism which consists of lever and toggle mechanisms. The mechanism is chiefly actuated by twin multilayer piezoelectric actuators. It can locate minutely and quickly for mechanical working and handling of some minute and thin objects. The lever members were made from a bimorph type piezoelectric actuator. As they were connected by elastic joints, the mechanism has no clearance and no friction. The mechanism is based on two concepts. In the first., mechanical stiffness of the members is variable and reinforced by additional electrical stiffness due to actuation of the bimorph members. Therefore the members can take smaller mechanical stiffness and inertia. The second, it can be variable input-output, characteristic of a piezo-stack actuator and correct deviated position of an output, point, by additional actuation of the bimorph members. With the experimental mechanism, the resolution is 1.57 μm.