A Novel Mechanical Frequency Tuning Method Based on Mass-Stiffness Decoupling for MEMS Gyroscopes

Area of Science:

• Micro-Electro-Mechanical Systems (MEMS)
• Resonator technology
• Inertial navigation

Background:

• MEMS gyroscopes are crucial for inertial navigation, operating in n=2 mode.
• Mode matching is essential for high-precision gyroscope detection, improving sensitivity, resolution, and signal-to-noise ratio.
• Initial frequency split during manufacturing necessitates tuning methods like electrostatic or mechanical trimming.

Purpose of the Study:

• To report a novel ring MEMS resonator design.
• To introduce a new mechanical frequency tuning method.
• To demonstrate effective frequency split reduction for enhanced gyroscope performance.

Main Methods:

• Designed a novel ring MEMS resonator with 16 uniformly distributed raised mass blocks.
• Achieved mass-stiffness decoupling through structural design, verified by simulation.
• Utilized an online tuning platform with a femtosecond laser for mechanical frequency tuning.

Main Results:

• The novel resonator design enables mass-stiffness decoupling.
• Frequency split was reduced from 23.3 Hz to 0.4 Hz using the femtosecond laser tuning method.
• Demonstrated a linear relationship between removed mass and frequency split reduction.

Conclusions:

• The novel ring MEMS resonator and mechanical tuning method effectively address frequency split issues.
• Mass-stiffness decoupling is a viable strategy for resonator design.
• The findings offer significant implications for MEMS gyroscope development and other transducers.