Structural Design and Optimization of a Resonant Micro-Accelerometer Based on Electrostatic Stiffness by an Improved...

Area of Science:

• MEMS (Micro-Electro-Mechanical Systems)
• Sensor Technology
• Nanotechnology

Background:

• Micro-accelerometers are crucial for inertial sensing.
• Existing designs face challenges with processing errors and common-mode noise.
• Need for improved accuracy and signal decoupling in resonant accelerometers.

Purpose of the Study:

• To design and optimize an in-plane resonant micro-accelerometer utilizing electrostatic stiffness.
• To enhance performance by minimizing processing errors and common-mode effects.
• To validate the structural design and optimization algorithm through experimental results.

Main Methods:

• A one-piece proof mass structure with two symmetrically distributed double-folded beam resonators was designed.
• A differential structure was implemented to mitigate common-mode errors.
• An improved differential evolution algorithm was developed for optimizing the accelerometer's scale factor.
• Fabrication was performed using deep dry silicon-on-glass (DDSOG) technology.

Main Results:

• The fabricated accelerometer demonstrated unloaded resonant frequencies between 24 and 26 kHz.
• The packaged accelerometer achieved a scale factor ranging from 54 to 59 Hz/g.
• The average error between the optimized and actual scale factor was 7.03%.

Conclusions:

• The developed electrostatic stiffness resonant micro-accelerometer design is rational and effective.
• The improved differential evolution algorithm successfully optimized the scale factor with reduced complexity.
• The DDSOG fabrication technology is suitable for producing such micro-accelerometers.