Fig. 6: AlN-Based MEMS Micromirrors with 2-DOF.

a Schematic showing strain-relief springs with color-coded sensing and actuation components, and simulated displacement profiles of the micromirror under single-axis resonant excitation obtained using COMSOL¹⁰⁷. b Layout of the AlN-based micromirror structure, where L-shaped beams link the actuators to the mirror plate. Each actuator incorporates dual sensor elements positioned at its outer ends. LDV scans illustrate dynamic response under both torsional and piston-mode actuation¹⁰⁸. c Finite element simulation of a 2-DOF resonantly actuated MEMS micromirror¹¹⁰. d Finite element simulation results illustrating the displacement profiles of the MEMS micromirror under two orthogonal torsional resonance modes¹⁰⁹. e Actuator-side photograph of the fabricated MEMS micromirror, showing piezoelectric elements and their electrodes as bright regions on the suspension springs. Simulated tilting modes demonstrate two orthogonal resonant directions, whose superposition enables rotational wobble scanning¹¹¹