Modeling and prototype experiment of a monolithic 3-PUU parallel micromanipulator with nano-scale accuracy

This paper presents the design and experimental investigation of a piezo-driven monolithic compliant 3-PUU (1 prismatic joint (P-joint) and 2 universal joints (U-joints)) XYZ micro/nano manipulator with a high bandwidth frequency and a large workspace. The manipulator is manufactured using a 3D-printing technique, thus a monolithic structure is guaranteed. This feature allows the manipulator to work smoothly with high resolution, accuracy, and repeatability, and simultaneously, it avoids all the deficiencies of non-monolithic designs such as backlash, wear, and friction. Analytical and computational studies are conducted to investigate and confirm the performances of the manipulator. Additionally, an experimental study is performed to verify the analytical and computational results. The workspace is calculated using the three methods, and their relative errors along each axis are shown to validate the accuracy of the results. The tracking performances of the manipulator are validated in a feedback control strategy. Moreover, the proposed manipulator demonstrates the motion resolution of 23 nm, 24 nm, and 18 nm along X, Y, and Z axes, respectively. Finally, the experimental frequency test supports the computational results and confirms the manipulator's high bandwidth frequency.