2-D scanning mirror using plastically deformed angular vertical comb drive actuator

We have demonstrated microfabricated, monolithic two degrees of freedom (2-D) electrostatic torsional mirrors using a 3-mask process on SOI wafer with a single plastic deformation step. The mirror operated independently in two orthogonal directions as controlled by two sets of self-aligned angular vertical combs. The measured dynamic performance showed resonant frequencies of 10.56 kHz and 1.54 kHz with optical scanning angles up to 27 degrees and 20 degrees in the two orthogonal axes respectively, under driving voltages of 20V(dc) Plus 15V(pp). A reliability test of 90-day continuous mirror operation that corresponds to peak resonance of 80- and 12.1-billion cycles on the two orthogonal axes showed negligible performance variations.