A vibrating beam MEMS accelerometer for gravity and seismic measurements

Area of Science:

• Geophysics
• Sensor Technology
• Materials Science

Background:

• Traditional accelerometers face limitations in long-term stability for high-precision geophysical measurements.
• Micro-Electro-Mechanical Systems (MEMS) offer miniaturization and potential for enhanced performance.

Purpose of the Study:

• To introduce and characterize a novel differential vibrating beam MEMS accelerometer.
• To evaluate its suitability for demanding applications like gravimetry and seismology.

Main Methods:

• Development of a differential vibrating beam MEMS accelerometer.
• Performance evaluation using Allan deviation, noise floor analysis, and dynamic range testing.
• In-situ monitoring of Earth tides and teleseismic events.

Main Results:

• Achieved an output Allan deviation of 9 μGal at 1000s integration time.
• Demonstrated a noise floor of 100 μGal/√Hz across a ±1g dynamic range.
• Successfully tracked Earth tides and recorded seismic ground motion over several months.

Conclusions:

• Vibrating beam MEMS accelerometers exhibit excellent long-term stability and resolution.
• This technology has significant potential for precision geophysical measurements.
• Wider implications exist for other resonant-output MEMS devices in precision sensing.