A Resonant Piezoelectric MEMS Mirror with 180-Degree Optical Scan Angle Under Atmosphere Pressure

This study designs and realizes the world’s first resonant piezoelectric MEMS scanning mirror of a 180degree optical scan angle (±45-degree mechanical scan angle) without vacuum in published works. Which is close to the maximum of the human viewing angle. In Fig. 1, this design has three merits: (1) U-shape actuator (Fig. 1a): to generate a non-uniform distributed inertia force on the mirror plate (1.5mm in diameter) and further cause it rotate about the serpentine spring, (2) serpentine springs slightly off-set (distance "e") from the gravity center of mirror (Fig. 1a): to provide a moment arm to rotate the mirror, (3) serpentine spring (Fig. 1b): special shape design to lower the stress during large-angle scanning through the combination of bending and torsion on spring. Measurements demonstrate the scanner has an optical scan angle of 180-degree at the resonant frequency of 1.5kHz (no vacuum required) with driving voltage of 13V.