Optimal design and experiment of a high-bandwidth two-degree-of-freedom parallel nanopositioning stage

A high-bandwidth, two-degree-of-freedom nanopositioning stage based on the optimization of a flexible beam is proposed with the aim of improving the low-bandwidth performance, relative low-travel range, and poor coupling performance of the scanning positioning stage of Atomic Force Microscopy. Design optimization, simulation verification, and experimental analysis of the proposed stage are conducted as part of this process. Firstly, a parallel compliant moving stage composed of a doubly clamped beam and parallel hybrid beam is presented, while Castigliano's second theorem and Lagrange's equation are applied to establish the mathematical model of its stiffness and natural frequency. Then, the maximum natural frequency and optimal size of the stage are obtained using optimization theory, while the optimization result reliability is verified using finite element method software. Finally, an experimental system is built and experiments are conducted on the developed stage. The experimental results indicate that the travel range of the proposed stage is 12.950 μm×13.517 μm, with a coupling error of less than 1.77%. The natural frequencies in the X and Y directions are 12.21 kHz and 13.50 kHz, respectively. In open loop, triangular waves with frequencies less than 1 kHz can be tracked well, effectively addressing the problems of slow response, small stroke, and poor coupling performance of the traditional scanning nanopositioning stage. © 2019, Science Press. All right reserved.