Cascade-Actuation Uncoupled-Motion XYZ-Microstage with Monolithic Integration of In-Plane Comb-Drive XY-Microstage and Out-of-Plane Al/SiO₂ Bimorph Thermoelectric Actuators

This study reports a monolithic-wafer-based XYZ-micro stage with large strokes and uncoupled motions by integrating in-plane comb-drive XY-microstage with out-of-plane Al/SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> bimorph thermoelectric actuators for the first time. The in-plane comb-drive XY-microstage, consisting of frame-in-frame configuration, can provide low-crosstalk movements in the X- and Y-directions. The out-of-plane Al/SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> bimorph actuators, independently supporting the comb-drive XY-microstage, can provide large stroke in the Z direction. The soft mechanical Si-springs are introduced for realizing the electrical interconnections between the comb-drive XY-microstage and the outer pads. This three-dimensional cascade-actuation mechanism among X-, Y-, and Z-axes actuation units can thoroughly facilitate the actuation characteristics to achieve large strokes and uncoupled motions in three directions. Finally, the fabricated monolithic-wafer-based XYZ-microstage can provide large displacements of 92.31 μm, 78.3 μm, and 2.0 μm in the X-, Y-, and Z-directions, respectively.