Miao Tongqiao, Xiao Dingbang, Li Qingsong, Hou Zhanqiang, Wu Xuezhong
College of Mechatronics Engineering and Automation, National University of DefenseTechnology, Changsha 410073, China.
Sensors (Basel). 2017 Oct 2;17(10):2264. doi: 10.3390/s17102264.
This paper reports the design and simulation of a 4 mm² double differential torsional MEMS accelerometer based on a double-beam configuration. Based on the structure of conventional torsional accelerometers, normally composed of one pair of proof masses and one torsional beam, this work explores the double differential configuration: a torsional accelerometer with two pairs of unbalanced proof masses rotating in reverse. Also, the torsional beam is designed as a double-beam structure, which is a symmetrical structure formed by two torsional beams separated by a certain distance. The device area of the novel accelerometer is more than 50 times smaller than that of a traditional double differential torsional MEMS accelerometer. The FEM simulation results demonstrate that the smaller device does not sacrifice other specifications, such as mechanical sensitivity, nonlinearity and temperature robustness. The mechanical sensitivity and nonlinearity of a ±15 g measuring range is 59.4 fF/g and 0.88%, respectively. Compared with traditional single-beam silicon structures, the novel structure can achieve lower maximum principle stress in critical regions and reduce the possibility of failure when high-g acceleration loading is applied along all three axes. The mechanical noise equivalent acceleration is about 0.13 mg / Hz in the theoretical calculations and the offset temperature coefficient is 0.25 mg/ ℃ in the full temperature range of - 40 ℃ to 60 ℃ .
本文报道了一种基于双梁结构的4mm²双差分扭转式MEMS加速度计的设计与仿真。基于传统扭转式加速度计的结构（通常由一对检测质量块和一根扭梁组成），本研究探索了双差分结构：一种具有两对不平衡检测质量块反向旋转的扭转式加速度计。此外，扭梁被设计为双梁结构，即由两根相隔一定距离的扭梁形成的对称结构。新型加速度计的器件面积比传统双差分扭转式MEMS加速度计小50倍以上。有限元模拟结果表明，较小的器件并未牺牲其他性能指标，如机械灵敏度、非线性和温度鲁棒性。±15g测量范围的机械灵敏度和非线性分别为59.4fF/g和0.88%。与传统单梁硅结构相比，新型结构在关键区域可实现更低的最大主应力，并降低沿所有三个轴施加高g加速度载荷时的失效可能性。理论计算中的机械噪声等效加速度约为0.13mg/Hz，在-40℃至60℃的全温度范围内，失调温度系数为0.25mg/℃。
