Influence of Electrostatic Force Nonlinearity on the Sensitivity Performance of a Tapered Beam Micro-Gyroscope Based...

Area of Science:

• MEMS (Micro-Electro-Mechanical Systems)
• Nonlinear Dynamics
• Sensor Technology

Background:

• Electrostatic force nonlinearity is a significant challenge in MEMS systems, affecting sensor sensitivity and stability.
• The Frequency Modulation (FM) method offers a robust solution for environmental fluctuation stability in micro-gyroscopes.
• Understanding the interplay between nonlinearity and system performance is crucial for advanced MEMS design.

Purpose of the Study:

• To investigate the impact of electrostatic force nonlinearity on the sensitivity of a Frequency Modulation (FM) micro-gyroscope.
• To analyze how design parameters like shape factor and DC voltage influence micro-gyroscope performance.
• To explore methods for mitigating nonlinearity and enhancing the dynamic detection range.

Main Methods:

• Derivation of motion equations for a tapered cantilever beam micro-gyroscope using Hamilton's principle.
• Application of the Differential Quadrature Method (DQM) for static and dynamic characteristic analysis.
• Utilizing the Invariant Manifold Method (IMM) to determine nonlinear frequencies and analyze sensitivity.

Main Results:

• Nonlinearity, influenced by shape factors and DC voltage, breaks micro-gyroscope symmetry, reducing sensitivity.
• Sensitivity exhibits a nonlinear trend with rotation speed, decreasing as DC voltage (and nonlinearity) increases.
• Negative shape factors effectively restrain nonlinearity, leading to a larger dynamic detection range.

Conclusions:

• Electrostatic force nonlinearity significantly degrades FM micro-gyroscope sensitivity.
• Optimizing shape factors, particularly negative ones, and managing DC voltage are critical for enhancing performance.
• The study provides insights into designing more robust and sensitive MEMS gyroscopes.