Actuators with large strokes and fine resolution have many applications, such as precise positioning, high resolution lithographing, sub-micro machining and fine manipulation of cells in biomedical fields. In this paper, a compact design of an elliptic-shaped actuator using 16 flexural hinges is presented. The device used two piezo stacks in long axis to generate amplified displacement in short axis. Overall displacement of more than 1 mm was obtained from a piezo-stack displacement of 40 μm. A feedback loop was designed to control the motion using a linear variable differential transformer (LVDT). The design achieved a fine resolution of ～20 nm. One unique feature of the design is its thermal stability. Its invar frame minimizes the change of the short axis length when temperature varies. The actuator was applied to drive an optical tunable filter. Wide tuning range and excellent wavelength tuning repeatability of+- 15 pm were achieved with the LVDT feedback loop.
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