A flexure-based 4-DOF coaxial alignment system: Design and application

This paper presents the design of a novel 4-DOF (x-y-θ_x-θ_y) flexure-based system used for coaxial alignment. The movable head (a rigid rod) of the system is suspended with two monolithic flexural mechanisms constructed with leaf flexures. To achieve the required x-y-θ_x-θ_y motion, the leaf-type flexures are specially arranged in such a configuration that is compliant in the specified axes but stiff in other axes. The leaf flexures are initially designed based on the linear models of the flexible beam deflection and then improved through FEA simulations. A system prototype was built with the flexural mechanisms. It demonstrates superior motion performances in the x and y axes as well as the angular axes. The prototype has been successfully applied in the coaxial alignment of the capillary machining.