Bi-Axial Piezoelectric MEMS Micromirror with Arched Actuator Utilizing D32 Effect for Both Raster and Lissajous Scanning

This study presents a novel piezoelectrically driven bi-axial MEMS micromirror design capable of achieving both uniform raster scanning and high fill-factor Lissajous scanning within a compact 5×5mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> die size. The proposed design includes three main merits: (1) Outer arched actuator: providing adequate stiffness while utilizing the d32 effect for enhanced out-of-plane displacement; (2) Virtual anchor: transmitting excitation from outer actuator to the mirror while effectively decoupling the actuation of outer-linner axes. (3) Inner gimbal actuator: concentrating energy for mirror rotation, enabling large scanning angle for fast-axis motion and effective decoupling during bi-axial actuation. Measurements indicate the proposed micromirror can achieve 173°×93° for Lissajous scanning under resonant operation and 14°×93° for raster scanning under quasi-static operation without vacuum packaging.