A novel compliant XY micro-positioning stage using bridge-type displacement amplifier embedded with Scott-Russell mechanism

This paper presents a new bridge-type compliant displacement amplifier embedded with Scott-Russell mechanism. Based on this design, a novel compliant XY micro-positioning stage is also designed, analyzed and tested to illustrate the advantages of the proposed amplifier. The main feature of the new amplifier is to employ Scott-Russell mechanism to replace one arm of the compound bridge-type mechanism, aiming to improve its lateral stiffness and the natural frequency in the working direction. The compliant XY micro-positioning stage is driven by two novel bridge-type amplifiers with orthogonal distribution. Double parallelogram guide mechanisms are added at the output ends of the bridge-type mechanisms to further lower the parasitic movements of the XY stage. Then, an analytical model based on the stiffness matrix transfer method is established for the static and dynamic characteristics of stage, which are also verified by performing finite element analysis. Finally, an experimental prototype is manufactured and its static and dynamic performances are tested. The test results demonstrate that the stage can realize a workspace of 181.0 μm × 179.5 μm with motion resolution of 20 nm and a maximum coupling error of 1.07%. The natural frequencies of XY stage along the working direction are 178 Hz and 248 Hz respectively when the PZTs are not installed or installed. Additionally, the trajectory tracking performance of the stage is also preliminarily evaluated. All of the results obtained from the analytical model, finite element analysis and experimental tests verify the effectiveness of the novel bridge-type displacement amplifier and the compliant XY micro-positioning stage.