Commercially available gravimeters and seismometers can be used for measuring Earth’s acceleration at resolution levels in the order of \({\mathrm{ng}}/\sqrt {\mathrm{Hz}}\) (where g represents earth’s gravity) but they are typically high-cost and bulky. In this work the design of a bulk micromachined MEMS device exploiting non-linear buckling behaviour is described, aiming for \({\mathrm{ng}}/\sqrt {\mathrm{Hz}}\) resolution by maximising mechanical and capacitive sensitivity. High mechanical sensitivity is obtained through low structural stiffness. Near-zero stiffness is achieved through geometric design and large deformation into a region where the mechanism is statically balanced or neutrally stable. Moreover, the device has an integrated capacitive comb transducer and makes use of a high-resolution impedance readout ASIC. The sensitivity from displacement to a change in capacitance was maximised within the design and process boundaries given, by making use of a trench isolation technique and exploiting the large-displacement behaviour of the device. The measurement results demonstrate that the resonance frequency can be tuned from 8.7 Hz–18.7 Hz, depending on the process parameters and the tilt of the device. In this system, which combines an integrated capacitive transducer with a sensitivity of 2.55 aF/nm and an impedance readout chip, the theoretically achievable system resolution equals 17.02 \({\mathrm{ng}}/\sqrt {\mathrm{Hz}}\). The small size of the device and the use of integrated readout electronics allow for a wide range of practical applications for data collection aimed at the internet of things.

市售的重力仪和地震仪可用于以\({\mathrm{ng}}/\sqrt {\mathrm{Hz}}\)（其中 g 代表地球重力）的顺序在分辨率级别测量地球加速度，但它们是通常成本高且体积大。在这项工作中，描述了利用非线性屈曲行为的体微机械 MEMS 器件的设计，目标是\({\mathrm{ng}}/\sqrt {\mathrm{Hz}}\)通过最大限度地提高机械和电容灵敏度。通过低结构刚度获得高机械灵敏度。近零刚度是通过几何设计和大变形进入机构静态平衡或中性稳定的区域来实现的。此外，该设备具有集成电容梳状换能器并使用高分辨率阻抗读出 ASIC。通过使用沟槽隔离技术并利用器件的大位移行为，在给定的设计和工艺边界内，从位移到电容变化的灵敏度最大化。测量结果表明，谐振频率可以在 8.7 Hz-18.7 Hz 之间进行调整，具体取决于工艺参数和设备的倾斜度。在这个系统中，\({\mathrm{ng}}/\sqrt {\mathrm{Hz}}\)。该设备的小尺寸和集成读出电子设备的使用允许针对物联网的数据收集的广泛实际应用。