A two-dimensional nano-positioner: Design, modelling and experiments

In this paper, an X-Y nano-positioner driven by the shear piezoelectric actuators (SPAs) is proposed based on the friction-inertial theory. The nano-positioner can output a two-dimensional motion at a maximum speed of 0.187 mm/s within a 5 mm×5 mm workspace. In order to solve the contradiction between the motion velocity and the motion resolution, the coarse and the fine motion modes are first proposed on the SPAs application. The coarse motion and the fine motion are realized based on the power-function-shaped signal and the combined piecewise-curve signal respectively. The performance of the nano-positioner, e.g. the resolution, the velocity and the fluctuation, are analyzed and discussed based on different driving signals. Compared with other nano-positioners, the proposed system in this paper is superior in respect of compact size, high resolution, high velocity and two switchable motion modes. Furthermore, a prototype system of the proposed nano-positioner has been developed, which is evaluated by using a capacitive sensor based measurement system. Experiment results validate the effectiveness of the proposed methodology that can be employed and extended to a variety of SPA involved systems.