A 2D MEMS Crosstalk-Free Electromagnetic Micromirror for LiDAR Application

Light Detection and Ranging (LiDAR) devices are critical for constructing three-dimensional scenes around vehicles, making them essential for automatic and intelligent driving systems. Micro-Electro-Mechanical Systems (MEMS) electromagnetic micromirrors have significantly developed MEMS-based LiDAR due to their inherent advantages. However, the traditional electromagnetic micromirrors, typically actuated by a single coil, experience crosstalk between the slow and fast axes. In this study, we introduce a dual-axis electromagnetic micromirror designed to eliminate this crosstalk. Unlike conventional micromirrors, our model features two distinct driving coils placed over the balance gimbal and reflecting mirror to control the slow and fast axes independently. This micromirror, with a 7.2 mm-diameter circular mirror, is manufactured using silicon on insulation (SOI) technology and incorporates a low-residual-stress packaging design. Our tests show that the scanning images from the fast axis of the proposed micromirror exhibit no crosstalk, achieving a significant improvement over traditional designs. Performance evaluation through geometric optical testing revealed that the slow axis resonates at 132 Hz and achieves a deflection angle of 36.3(degrees) with a quality factor of 26.9, while the fast axis resonates at 712 Hz, reaching 35.2(degrees) with a quality factor of 53.5. Additionally, the angle sensor performance was assessed, showing outputs that are highly proportional to the optical angles, recorded at 13.04 mV/deg and 9.80 mV/deg for the slow and fast axes, respectively.