Large-Angle Scanning and Enhanced Robustness Piezoelectric Biaxial MEMS Mirrors Based on Double Circular-Arc Design

MEMS mirrors are widely applied in LiDAR, but often face the risk of fracture when undergoing large deformations. This paper presents a double circular-arc beam design with a compact structure and enhanced robustness. The mirror achieves an ultra-large optical scanning angle of $81.3^{\circ}\times 71.8^{\circ}$, featuring a large optical aperture of 5 mm and a resonance frequency exceeding 1.2 kHz. The MEMS mirror has withstood the vehicle-level 1500 g shock for automotive LiDAR application. In addition to the double-circular-arc beam design, the ultra-large scanning angle and high reliability of the MEMS mirror are also achieved through the improved non-Bosch process, which enables smooth sidewall profiles.