Design and analysis of a novel flexure-based 3-DOF mechanism

This paper focuses on the design and analysis of a novel flexure-based mechanism which is capable of performing planar motion with three degrees of freedom (3-DOF). This mechanism utilizes three piezoelectric actuators to achieve desired displacements in X, Y and θ, where the lever based amplification is used to enhance the displacement of the mechanism. The design focuses on achieving kinematics with X-direction motions decoupled from those in the Y and θ directions. The proposed design is small and compact in size (about 142 mm by 110 mm). Pseudo rigid body modeling (PRBM), kinematic analysis, computational analysis and an experimental study of the mechanism are conducted to investigate the performance of the mechanism. In the PRBM, the associated spring effects in the flexure joints are considered to characterize the reachable workspace of the mechanism. A computational study is performed to examine the stress distribution at all critical points, maximum reach, natural frequencies and the corresponding mode shapes. A prototype of the mechanism has been fabricated and an experimental facility established. The computational and experimental studies demonstrate that the topology of the mechanism adequately minimizes cross axis coupling effects.