Laterally actuated torsional micromirrors for large static deflection

We report on the implementation of laterally electrostatically actuated, torsionally suspended silicon-on-insulator (SOI) micromirrors with a static optical deflection angle of over 40(degree) peak-to-peak. Decoupling the actuator and mirror design allows for large actuator arrays, allowing large dc deflection angle and high resonant frequency to coexist in the same device. The micromirror structures are fully monolithic, micromachined from the front side and back side of an SOI wafer-device layer. In-plane actuation is transformed into out-ofplane motion and rotation, enabling integration of a wide variety of SOI-MEMS sensors, actuators, and micromirrors. When operated in resonance at 1321 Hz, a typical device measured up to 92(degree) peak-to-peak optical deflection at 127 Vdc with 15 Vac amplitude.