A High Q-Factor Outer-Frame-Anchor Gyroscope Operating at First Resonant Mode.

Area of Science:

• Microelectromechanical Systems (MEMS)
• Inertial Sensors
• Vibrational Mechanics

Background:

• Microelectromechanical systems (MEMS) disc gyroscopes are crucial for high-performance applications.
• Existing designs often face challenges with antivibration characteristics, especially in dynamic environments.
• Out-of-plane motions in central-anchored multi-ring structures are susceptible to external vibrations.

Purpose of the Study:

• To present a novel multi-ring MEMS disc gyroscope design with enhanced dynamic characteristics.
• To improve antivibration performance by relocating anchor points.
• To achieve superior static performance and operational stability.

Main Methods:

• Design and fabrication of a multi-ring MEMS disc gyroscope using silicon on insulator (SOI) processes.
• Wafer-level vacuum packaging for enhanced performance.
• Harmonic experiments to analyze resonant modes and interference frequencies.

Main Results:

• The new design operates effectively at the first resonant mode, offering improved static and antivibration performance.
• Anchor points positioned outside the multi-ring resonator significantly reduce susceptibility to external vibrations.
• The nearest interference mode was found at 30,311 Hz, with a substantial frequency separation of 72.8% from working modes.
• Fabricated gyroscopes achieved an asymmetry of 780 ppm and a high Q-factor of 162 k at 0.15 Pa.

Conclusions:

• The proposed multi-ring MEMS disc gyroscope design demonstrates excellent antivibration characteristics and high performance.
• The design's ability to operate at the first resonant mode, coupled with strategic anchor placement, leads to superior dynamic and static performance.
• The high Q-factor and low noise levels indicate significant mechanical sensitivity, making it suitable for demanding engineering applications.