Design of a dual-stage, three-axis hybrid parallel-serial-kinematic nanopositioner with mechanically mitigated cross-coupling

摘要

This article describes the design and characterization of a new dual-stage, three-axis hybrid parallel-serial-kinematic nanopositioner; this platform incorporates a novel non-orthogonal mechanical amplifying mechanism for the long-range low-speed stage to mitigate parasitic motion in the lateral scanning directions. A five-bar linkage model is proposed to model the cross-coupling effects of the long-range parallel-kinematic flexure mechanisms. This model is used to design the long-range scanner with reduced parasitic motion compared to a traditional perpendicular geometry design. A short-range, three-axis shear piezoactuator is mounted on the long-range parallel-kinematic lateral scanner to create a dual-stage, high-speed, three-axis scanner. Finite element analysis (FEA) is used to optimize the dynamic performance for high mechanical resonance. Experimental results demonstrate a full range of approximately 15 μm in the x- and y-directions and short-range displacements of 1 μm in three directions from the shear piezo stack. The first mechanical resonance of the long-range lateral scanner is measured at 1,450 Hz and 11 kHz for the short-range actuator in the x- and y-directions, and over 40 kHz in the z-direction. Measured parasitic motion for the long-range scanner is only -34 dB for the x-axis and -46 dB for the y-axis, a 62.5% reduction compared to the perpendicular mechanism design.