Analysis and Testing of A Novel 2-DOF Nanopositioner

This paper presents analysis and testing of a novel 2-DOF nanopositioner driven by piezoelectric-actuators. In order to achieve long travel range, the nanopositioner employs amplification mechanisms to overcome the small displacement of the stack-type piezoelectric element. A modified level displacement amplifier is proposed in the present paper, which has a mutually perpendicular structure for the input displacement and output displacement. To achieve a better decoupling performance for the motions in two axes, a fully symmetric configuration is introduced for the parallelogram flexures. According to the analysis results, the mechanical parameters are optimized to achieve a relatively large stroke for the nanopositioner. The prototype testing results show that the first natural frequency of the proposed stage is around 330 Hz, with the amplification ratio of the displacement in each axes about 5.3. The nanopositioner achieves an overall workshapce of 65 x 67 mu m while the cross coupling between the two axes is minimized to the level of less than 2%. Ultra high precision positioning and tracking capabilities are also demonstrated with some preliminary dosed loop control tests.