Squeeze Film Damping Effect of the Micro Airflow in a MEMS Sealed Chamber

The squeeze film damping effect between the air gap and the PZT actuator in a sealed chamber is analyzed.Both the gas damping effect and the Rayleigh-Ritz energy method are utilized to investigate the coupled effect between the micro airflow and its actuator.The air pressure distribution of the micro airflow is determined by solving the nondimensionalized and linerized isothermal compressible Reynolds' equation and combined with the sealed pressure boundary condition.The coupled model of piezoelectric-silicon film-micro airflow is derived according to the Rayleigh-Ritz energy method.By comparing the undetermined coefficient λ of the displacement function without micro airflow and the undetermined coefficient λ' with micro airflow,the air damping factor is extracted.The influencing of micro airflow squeeze film damping on PZT actuator can be exhibited by such air damping factor.All the investigation provide theoretical foundation and control strategy for microfluid actuating.