Ghazinouri Behrad, He Siyuan
Mechatronics and MEMS Research Laboratory, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada.
Micromachines (Basel). 2023 Oct 19;14(10):1954. doi: 10.3390/mi14101954.
This paper introduced a novel approach to enhance the vertical scanning angle of a large aperture 2D electromagnetic micromirror through the utilization of a cascaded torsional beam design. The primary objective was to increase the vertical scanning angle without compromising the robustness, which was achieved by optimizing the trade-off between the rotation angle and the first mode of resonant frequency. The cascaded design provides flexibility to either increase the outer frame's rotation angle without sacrificing torsional stiffness or enhance the torsion beam's stiffness while maintaining the same rotation angle, thus elevating the first-mode resonant frequency and overall robustness. The effectiveness of the cascaded design was demonstrated through a comparative study with a non-cascaded 2D micromirror possessing the same aperture size, torque, and mass moment of inertia. Theoretical analysis and finite-element simulation are employed to determine critical parameters such as the stiffness ratio between the cascaded torsion beams, and to predict improvements in the scanning angle and primary resonant frequency brought by the cascaded design. Prototypes of both cascaded and non-cascaded designs are fabricated using a flexible printed circuit board combined with Computer numerical control (CNC) machining of a Ti-alloy thin film, confirming the superior performance of the cascaded 2D micromirror. The cascaded design achieved vertical scanning angles up to 26% higher than the traditional design when both were actuated at close resonance frequencies. Additionally, the micromirror was successfully integrated into a 3D LiDAR system. The light detection and ranging (LiDAR) system was modelled in Zemax OpticStudio to find the optimized design and assembly positions.
本文介绍了一种新颖的方法，通过采用级联扭转梁设计来增大大孔径二维电磁微镜的垂直扫描角度。主要目标是在不影响鲁棒性的情况下增加垂直扫描角度，这是通过优化旋转角度与第一共振频率模式之间的权衡来实现的。级联设计提供了灵活性，既可以在不牺牲扭转刚度的情况下增加外框的旋转角度，也可以在保持相同旋转角度的同时增强扭梁的刚度，从而提高第一模式共振频率和整体鲁棒性。通过与具有相同孔径尺寸、扭矩和转动惯量的非级联二维微镜进行对比研究，证明了级联设计的有效性。采用理论分析和有限元模拟来确定关键参数，如级联扭梁之间的刚度比，并预测级联设计带来的扫描角度和主共振频率的提升。级联和非级联设计的原型均采用柔性印刷电路板结合钛合金薄膜的计算机数控（CNC）加工制造，证实了级联二维微镜的卓越性能。当两者在接近共振频率下驱动时，级联设计实现的垂直扫描角度比传统设计高出26%。此外，该微镜成功集成到了三维激光雷达系统中。在Zemax OpticStudio中对光探测和测距（LiDAR）系统进行建模，以找到优化的设计和组装位置。
