A Damped Decoupled XY Nanopositioning Stage Embedding Graded Local Resonators

Lightly damping linear dynamic characteristics of a flexure-based stage mainly limit control bandwidth when its piezo-actuating hysteresis is well compensated. In this article, a novel damped decoupled XY nanopositioning stage embedding graded local resonators (GLRs) is developed and optimized based on the maximization of motion range and first-order natural frequency. The modal damping strengthening mechanism of local resonant metastructures is analyzed based on the built dynamic model. The GLRs embedded in the working platform has different dynamic parameters, which are optimized based on $H_2$ norm. The motion decoupling is guaranteed by the designed hybrid flexure-guided mechanism while strengthening the Z-direction supporting stiffness. The static/ scanning-frequency dynamic experiment and trajectory tracking control with a propotional-integral-derivative (PID) controller is implemented. The experimental results indicate that maximum motion crosstalk is 0.69%, and validate the effectiveness of improving the linear dynamics of the stage and expanding control bandwidth.

I. Introduction

With the extensive applications of piezo-driven flexure-based compliant mechanisms or nanopositioning stages in a field of precision engineering, such as micromanipulation and imaging using atomic force microscope (AFM) [1], precision positioning [2], precision alignment [3], [4], high-speed piercing in cell microinjection [5], and nanomanufacturing [6], etc., their dynamic positioning or dynamic control performances have been attracting the attention of many researchers except their static performances.