High-resolution MEMS inertial sensor combining large-displacement buckling behaviour with integrated capacitive...

Area of Science:

• * Physics
• * Electrical Engineering
• * Mechanical Engineering

Background:

• * Commercially available gravimeters and seismometers offer limited resolution and are often expensive and bulky.
• * Existing technologies struggle to meet the demand for high-resolution, miniaturized acceleration measurement devices.

Purpose of the Study:

• * To design and demonstrate a novel bulk micromachined MEMS device for measuring Earth's acceleration.
• * To achieve a resolution of 17.02 $\mu$g by maximizing mechanical and capacitive sensitivity.
• * To develop a cost-effective and compact alternative to traditional gravimeters.

Main Methods:

• * Design of a MEMS device exploiting non-linear buckling behavior for enhanced mechanical sensitivity.
• * Integration of a capacitive comb transducer and a high-resolution impedance readout Application-Specific Integrated Circuit (ASIC).
• * Maximization of displacement-to-capacitance sensitivity using trench isolation and large-displacement principles.

Main Results:

• * Demonstrated tunable resonance frequency from 8.7 Hz to 18.7 Hz based on process parameters and device tilt.
• * Achieved a high capacitive transducer sensitivity of 2.55 aF/nm.
• * Theoretically calculated system resolution of 17.02 $\mu$g.

Conclusions:

• * The developed MEMS device offers a significant advancement in high-resolution acceleration measurement.
• * Its small size and integrated electronics enable diverse applications, including Internet of Things (IoT) data collection.
• * The device presents a promising, low-cost solution for precise gravimetric measurements.