Wu Shuang, Yan Wenhui, Wang Xiaoxu, Xiao Qingxiong, Wang Zhenshan, Sun Jiaxin, Yu Xinlong, Yang Yaoxian, Zhu Qixuan, Yang Guantai, Yao Zhongyang, Li Pengfei, Jiang Chao, Huang Wei, Lu Qianbo
Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, Xi'an, China.
School of Automation, Northwestern Polytechnical University, 127 West Youyi Road, Beilin District, Xi'an, China.
Nat Commun. 2025 Feb 20;16(1):1786. doi: 10.1038/s41467-025-57176-z.
Gravimeter measures gravitational acceleration, which is valuable for geophysical applications such as hazard forecasting and prospecting. Gravimeters have historically been large and expensive instruments. Micro-Electro-Mechanical-System gravimeters feature small size and low cost through scaling and integration, which may allow large-scale deployment. However, current Micro-Electro-Mechanical-System gravimeters face challenges in achieving ultra-high sensitivity under fabrication tolerance and limited size. Here, we demonstrate a μGal-level Micro-Opto-Electro-Mechanical-System gravimeter by combining a freeform anti-spring design and an optical readout. A multi-stage algorithmic design approach is proposed to achieve high acceleration sensitivity without making high-aspect ratio springs. An optical grating-based readout is integrated, offering pm-level displacement sensitivity. Measurements reveal that the chip-scale sensing unit achieves a resonant frequency of 1.71 Hz and acceleration-displacement sensitivity of over 95 μm/Gal with an etching aspect ratio of smaller than 400:30. The benchmark with a commercial gravimeter PET demonstrates a self-noise of 1.1 μGal Hz at 0.5 Hz, sub-1 μGal Hz at 0.45 Hz, and a drift rate down to 153 μGal/day. The high performance and small size of the Micro-Opto-Electro-Mechanical-System gravimeter suggest potential applications in industrial, defense, and geophysics.
重力仪测量重力加速度，这对于诸如灾害预测和勘探等地球物理应用非常有价值。从历史上看，重力仪一直是大型且昂贵的仪器。微机电系统重力仪通过缩放和集成具有小尺寸和低成本的特点，这可能允许大规模部署。然而，当前的微机电系统重力仪在制造公差和有限尺寸下实现超高灵敏度方面面临挑战。在此，我们通过结合自由形式的抗弹簧设计和光学读出，展示了一种微伽级的微光机电系统重力仪。提出了一种多级算法设计方法，以在不制造高纵横比弹簧的情况下实现高加速度灵敏度。集成了基于光栅的光学读出，提供皮米级的位移灵敏度。测量结果表明，芯片级传感单元实现了1.71 Hz的共振频率和超过95μm/Gal的加速度-位移灵敏度，蚀刻纵横比小于400:30。与商业重力仪PET的基准测试表明，在0.5 Hz时自噪声为1.1μGal Hz，在0.45 Hz时低于1μGal Hz，漂移率低至153μGal/天。微光机电系统重力仪的高性能和小尺寸表明其在工业、国防和地球物理学中的潜在应用。
