Development of a flexure-hinged translation mechanism driven by two piezoelectric stacks

This paper describes a monolithically constructed, flexure-hinged translation mechanism suitable for mechanical scanning stages of very high precision. Two piezoelectric stacks are employed to drive the mechanism; one piezoelectric stack pushes whilst the other pulls the moving platform. This push-pull drive system is effective for raising the natural frequency of the stage. The mechanism described in this paper functions as both a guide for rectilinear motion and a mechanical amplifier to amplify a limited output displacement of the piezoelectric stack. Static and dynamic characteristics of the mechanism are considered in detail, and design equations are presented. The validity of the design equations is confirmed by experiment. A brief description of the accuracy of motion of the moving platform is included. It is demonstrated that a scan range of 60 mu m is achievable with a natural frequency as high as 1175 Hz in the scanning direction.