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Piezoelectric-driven flexure-based multi-DOF motion stages have been widely employed for nano-positioning applications, in which motion-decoupled stages have been extensively investigated in order to facilitate their motion control efforts. Asymmetric motion-decoupled stage designs are simple in configurations and structures, but would cause parasitic shifts of the moving platform. Fully-symmetric motion-decoupled stage designs can minimize parasitic shifts, but would result in complicated configurations and structures. To tackle such difficulties, a new flexure-based motion-decoupled XYZ stage with a quasi-symmetric 3-Prismatic-Prismatic-Prismatic (3-PPP) configuration is proposed in this work. By adding short flexure-based auxiliary supports to the moving platform, a compact quasi-symmetric stage design is achieved, and the parasitic shifts of the moving platform are significantly reduced. To study the kinetostatic performance of the demonstrated embodiment, an analytic stiffness model is formulated and validated by the FEA method. To achieve minimal parasitic shifts, a stiffness matching approach is proposed for the design optimization of structural parameters. A research prototype of the quasi-symmetric stage is fabricated for experimental validation. Experimental results show that the stage achieves workspace of 43.6 μm × 40.3 μm × 63.2 μm, motion resolution of 25 nm, and parasitic shifts of less than 0.94 %, which indicates that the proposed quasi-symmetric design method is effective to reduce the parasitic shifts of the flexure-based nano-positioning stages. • Compact XYZ stage design with a quasi-symmetric structure and two auxiliary supports. • High accuracy and small parasitic shifts realized by stiffness matching approach. • High stiffness, payload capacity and control bandwidth with PCA direct-driving scheme. [ABSTRACT FROM AUTHOR]

There is an increasing demand to achieve manipulating operations in nanometric precision and a macro-range (over a millimeter) simultaneously. In principle, it is possible to satisfy both requirements in a compact size taking advantages of flexure-based mechanisms, whereas limitations such as the parasitic rotation, cross-axis coupling, saturation may adversely affect the motion quality in nanometric level practically. Here, we propose a novel design methodology to actively prevent parasitic rotation of XY compliant mechanisms. Further, by means of design synthesis and real-time motion control, the prototype of manipulator is fabricated, which enables large motion range (±3 mm) along each actuation axis. Experimental results demonstrate a travel range of 2 mm × 2 mm with high linearity, small cross-axis coupling (< 0.4%), and low parasitic rotation (< 6.9 μ rad over 0.5 mm × 0.5 mm motion range). Moreover, the high natural frequency (~ 60 Hz) of the manipulator facilitates it to achieve high-precision motion with tracking error < 80 nm (20 Hz sinusoids). The experimental results of the proposed nano-manipulator outperform most of the existing ones. [Display omitted] • A large range compliant XY nano-manipulator of active parasitic rotation rejection. • By design of axial force passing through stiffness center, the manipulator does not have parasitic rotation in principle. • High natural frequency facilitates mm stroke and nanometric tracking error as well as micro-radian parasitic rotation. [ABSTRACT FROM AUTHOR]