Design and Analysis of a Novel 3-DOF Large Range Micropositioning Mechanism

This paper proposes a novel 3-DOF monolithic XY theta micropositing mechanism. Unlike other 3-DOF designs, this mechanism is fully compliant. The mechanism consists of two parts: the platform mechanism and the driving mechanism. The platform mechanism is a 3PPR configuration mechanism based on leaf type flexures. The displacements of this configuration are more deterministic as compared to other configurations such as 3RRR and 3PRR. The driving mechanism consists of three driving arms equally spaced at 120 degrees, and each of these arms is a single degree of freedom mechanism. A double four bar leaf linkage has been used in the driving arms to provide a translation in one degree of freedom only and to reject any other motions and rotations. The Voice Coil Motors (VCMs) has been used to drive the arms. VCMs have been embedded in the arms to have a compact 3-DOF mechanism. The mechanism offers a large workspace of +/- 1.97mmx +/- 1.706mmx +/- 34.81mrad. The forces required to drive the mechanism are well under the VCM maximum driving force.