Piezoelectric device generates a required displacement with low voltage. The electrical energy can be converted to mechanical energy at 60% of the conversion efficiency rate. For example, a piezoelectric device of 10mm × 10mm cross section size produces 3,500N(357kgf). However, as the displacement to be generated ranges from a few μm up to 40μm, the application fields should be limited due to the very small displacement. In order to overcome the disadvantage, Mechano Transformer Corporation has developed the displacement enlargement mechanism by using an unique lever principle. The enlarged displacement achieves one hundred times of the piezoelectric device itself. The displacement enlargement mechanism is a kind of a passive structure and no additional energy is required. As the mechanism is similar principle to a transformer which is used in electric circuits, it was called mechanical transformer but has been abbreviated to MechaTransR later on and registered as a trademark in Japan. MechaTransR was originally named only for the displacement enlargement mechanism but currently it is used as the actuator with a piezoelectric device.