Ultra Precise Positioning of a Stage Driven by Pneumatic Bellows

摘要

Ultra precise positioning techniques that support nanotechnologies led by the semiconductor industry mainly require precision of nanometer order. Cur rently, it is piezoelectric elements that are most often used for positioning control of this order. Piezoelectric elements, however, are deficient in strokes and dura bility. In this research, we propose to use for ultra pre cise positioning control pneumatic bellows instead of piezoelectric elements, because the durability of pneu matic bellows is well proven. Specifically, we manufac ture an elastic-hinge-guided, fine-motion stage which is driven by pneumatic bellows. In addition, we have developed a mathematical model for this fine-motion stage as well as its dynamic characteristics. We re view feedback control to achieve ultra precise posi tioning, using the developed stage and mathematical model. As a result, we have succeeded in developing a fine-motion stage with longer strokes than ones driven by piezoelectric elements, though it is inferior in re sponse. Positioning accuracy of the pneumatic-bellow driven stage is ±5 [nm], which is tantamount to that achieved by piezoelectric elements.