Abstract: A parallel micro-manipulator adopts flexible joints and their flexible deformation realizes micro-movement of the end-effector, in which statics and stiffness are main problems. Considering the deformation force or moment of the flexible joints sufficiently, statics problem of a 6-PSS parallel micro-manipulator is studied, a relationship model between PZT actuator force and load effected on the end-effector is builted, and driving stiffness matrix is defined. As the particularity of a micro-manipulator, its stiffness is defined and rigidity matrix is educed. It presents a theory basis for structure stiffness design, flexible joints stiffness synthesis and dynamics analysis of micro-manipulators.

Key words: Parallel micro-manipulator, PZT actuator, Statics, Stiffness