Bian Wei, Zhao Xiaoguang, Lu Wenshuai, Yang Yijun, Zhang Junjie, You Rui, Xing Fei
Qiyuan Lab, Beijing, 100190, China.
Microsyst Nanoeng. 2025 Jul 15;11(1):144. doi: 10.1038/s41378-025-00971-x.
This paper addresses a critical challenge in the design of MEMS actuators: the rejection of out-of-plane motion, specifically along the Z-axis, which can severely impact the precision and performance of these micro-actuation systems. In many MEMS applications, unwanted out-of-plane displacement can lead to reduced accuracy in tasks such as optical steering, micro-manipulation, and scanning applications. In response to these limitations, this paper proposes a novel design technique that effectively rejects Z-axis motion by transforming the motion of the micro stage along the Z-axis into equivalent displacements between pairs of points on cantilevers. These point pairs are founded exhibiting variable common-mode and differential-mode motion characteristics, depending on whether the stage is undergoing in-plane (X/Y) or out-of-plane (Z) displacements. By connecting these point pairs with rods, differential motion between the points in the pairs is suppressed, reducing unwanted out-of-plane motion significantly. We provide a detailed analysis of this design methodology and present a practical application in the form of an electromagnetic large displacement MEMS actuator. This actuator undergoes a complete design-simulation-manufacturing-testing cycle, where the effectiveness of the Z-axis motion rejection structure is systematically evaluated, and compared against traditional designs. Experimental results reveal a significant improvement in performance, with static and dynamic travel ranges reaching ±60 μm and ±400 μm, respectively. Moreover, the Z-axis stiffness was enhanced by 68.5%, which is more than five times the improvement observed in the X/Y axes' stiffness. These results highlight the potential of the proposed method to provide a robust solution for out-of-plane motion suppression in MEMS actuators, offering improved performance without compromising other critical parameters such as displacement and actuation speed.
本文探讨了MEMS致动器设计中的一个关键挑战：抑制平面外运动，特别是沿Z轴的运动，这可能会严重影响这些微驱动系统的精度和性能。在许多MEMS应用中，不需要的平面外位移会导致诸如光学转向、微操纵和扫描应用等任务的精度降低。针对这些限制，本文提出了一种新颖的设计技术，通过将微平台沿Z轴的运动转换为悬臂梁上各点对之间的等效位移，有效地抑制Z轴运动。根据平台是在平面内（X/Y）还是平面外（Z）位移，发现这些点对具有可变的共模和差模运动特性。通过用杆连接这些点对，抑制了点对中各点之间的差动，显著减少了不需要的平面外运动。我们对这种设计方法进行了详细分析，并以电磁大位移MEMS致动器的形式给出了一个实际应用。该致动器经历了一个完整的设计-模拟-制造-测试周期，在这个周期中，系统地评估了Z轴运动抑制结构的有效性，并与传统设计进行了比较。实验结果表明性能有了显著提高，静态和动态行程范围分别达到±60μm和±400μm。此外，Z轴刚度提高了68.5%，这是X/Y轴刚度提高幅度的五倍多。这些结果突出了所提出方法在抑制MEMS致动器平面外运动方面提供强大解决方案的潜力，在不影响位移和驱动速度等其他关键参数的情况下提高了性能。
