Design Approach for Reducing Cross-Axis Sensitivity in a Single-Drive Multi-Axis MEMS Gyroscope

Area of Science:

• Microelectromechanical Systems (MEMS)
• Inertial Sensors
• Sensor Design

Background:

• Cross-axis sensitivity (CAS) is a critical performance limitation in microelectromechanical systems (MEMS) gyroscopes, affecting measurement accuracy.
• Existing methods for CAS reduction often involve complex fabrication processes or limited effectiveness.

Purpose of the Study:

• To present a new design technique, the "ratio-matching method," for estimating and reducing CAS in single-drive multi-axis MEMS gyroscopes.
• To validate the proposed method through simulation and experimental verification.

Main Methods:

• Analysis of a simplified single-drive multi-axis MEMS gyroscope using COMSOL Multiphysics.
• Application of the "ratio-matching method" focusing on drive displacement amplitudes and sense frequency differences ratios.
• Validation via simulation by varying coupling spring position and sense frequency difference, and experimental verification on fabricated devices.

Main Results:

• Initial average CAS of 0.301% (x-axis: 0.482%, y-axis: 0.120%) was reduced to an average of 0.045% (x-axis: 0.018%, y-axis: 0.073%) using the ratio-matching method.
• Achieved an 85.1% reduction in average CAS.
• Demonstrated successful validation through simulations and experimental testing.

Conclusions:

• The proposed "ratio-matching method" is an effective technique for significantly reducing cross-axis sensitivity in single-drive multi-axis MEMS gyroscopes.
• This method offers a practical approach to enhance gyroscope performance and reliability.
• The findings are supported by both simulation and experimental results, confirming the methodology's robustness.