Piezoelectric elements are compact, lightweight, large force generation, and possible ultra precise positioning of nm order resolution, so, they suit to miniatuation and ultra precision of actuator. For millimeter travel range, inch worm type of actuator was designed and manufactured using piezoelectric elements, and the characteristics of the system was tested. The piezoelectric elements can not be position exactly due to hysterisis by open loop control, and it was resolved by closed loop control using strain gages. So the system can be get sub-micro resolution in unit step motion.
