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Extending the Validity of Squeeze Film Damping Models with Lower Aspect Ratios
Xiang Xu1, Weidong Fang1, Jian Bai1
1State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, China.
Sensors (Basel, Switzerland)
|February 15, 2022
Summary
This study quantifies the finite size effect on squeeze film air damping in MEMS devices. New formulas accurately predict damping, improving MEMS design by considering pressure changes across the film.
Area of Science:
- Mechanical Engineering
- Materials Science
- Physics
Background:
- Squeeze film air damping significantly influences Microelectromechanical Systems (MEMS) device dynamics.
- Traditional models based on the Reynolds equation deviate from reality, particularly at low aspect ratios.
- The neglect of pressure changes across the film is a known cause of this deviation, but quantitative studies are lacking.
Purpose of the Study:
- To investigate the finite size effect on squeeze film air damping in MEMS.
- To develop a modified theoretical expression for low aspect ratio conditions.
- To provide accurate, quick-calculating formulas for MEMS damping design.
Main Methods:
- Numerical simulations were employed to study the finite size effect.
- A modified expression for squeeze film air damping was developed.
- New formulas were derived based on simulation results.
Main Results:
- The developed formulas accurately reproduce squeeze film air damping with finite size effects.
- Maximum errors were less than 1% (no border effect) and 10.185% (compact model).
- High consistency between formulas and simulations validates the consideration of the finite size effect.
Conclusions:
- The finite size effect on squeeze film air damping is accurately accounted for.
- The new formulas offer a precise design guide for MEMS devices.
- This research addresses a critical gap in understanding damping behavior in MEMS.
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