  A compact large-range six-degrees-of-freedom (six-DOF) parallel positioning
system with high resolution, high resonant frequency, and high repeatability
was proposed. It mainly consists of three identical kinematic sections. Each
kinematic section consists of two identical displacement amplification and
guiding mechanisms, which are finally connected to a limb. Each limb was
designed with a universal joint at each end and connected to a moving stage. A
computational model of the positioner was built in the ANSYS software package,
hence, the input stiffness, output compliance, range, and modal analysis of the
system were found. Furthermore, a monolithic prototype made of Acrylonitrile
Butadiene Styrene (ABS) was successfully manufactured by the 3D-printing
process. It was actuated and sensed by piezoelectric actuators (PEAs) and
capacitive displacement sensors, respectively. Finally, the performances of
this proposed positioner were experimentally investigated. The positioning
resolution was achieved as 10.5nm {\times} 10.5nm {\times} 15nm {\times}
1.8{\mu}rad {\times} 1.3{\mu}rad {\times} 0.5{\mu}rad. The experimental results
validate the behavior and capabilities of the proposed positioning system, and
also verify the nanometer-scale spatial positioning accuracy within the overall
stroke range. Practical applications of the proposed system can be expanded to
pick-and-place manipulation, vibration-canceling in
microsurgery/micro-assembly, and collaborative manipulators systems.
