Tuning the quality factor of bulk micromachined structures using the squeeze film damping

Author(s):  
Ching-Chi Cheng ◽  
Weileun Fang
2010 ◽  
Vol 17 (6) ◽  
pp. 759-770 ◽  
Author(s):  
Wen-Ming Zhang ◽  
Guang Meng ◽  
Ke-Xiang Wei

In this paper, nonlinear dynamics and chaos of electrostatically actuated MEMS resonators under two-frequency parametric and external excitations are investigated analytically and numerically. A nonlinear mass-spring-damping model is used to accounting for squeeze film damping and the parallel plate electrostatic force. The micro-structure is excited by a dc bias electrostatic force and a harmonic force with a frequency tuned closely to their fundamental natural frequencies (combination oscillation). The quality factor is calculated for the microcantilever beam of the resonator considering squeeze film damping. The effect of nonlinear squeeze film damping on the frequency response, quality factor, resonant frequency and nonlinear dynamic characteristics of the dynamic system are provided with numerical simulations using the bifurcation diagram, Poicare maps, largest Lyapunov exponent and phase portrait. The results show that the dynamic system goes through a complex nonlinear vibration as the system parameters change. It is indicated that the effect of nonlinear squeeze film damping should be considered due to its decreasing the quality factor and changing the nonlinear phenomena of the MEMS resonators.


2021 ◽  
Vol 491 ◽  
pp. 115720
Author(s):  
Zheng Wei ◽  
Jing Liu ◽  
Xiaoting Zheng ◽  
Yan Sun ◽  
Ruihua Wei

Author(s):  
Weidong Yang ◽  
Menglong Liu ◽  
Linwei Ying ◽  
Xi Wang

This paper demonstrated the coupled surface effects of thermal Casimir force and squeeze film damping (SFD) on size-dependent electromechanical stability and bifurcation of torsion micromirror actuator. The governing equations of micromirror system are derived, and the pull-in voltage and critical tilting angle are obtained. Also, the twisting deformation of torsion nanobeam can be tuned by functionally graded carbon nanotubes reinforced composites (FG-CNTRC). A finite element analysis (FEA) model is established on the COMSOL Multiphysics platform, and the simulation of the effect of thermal Casimir force on pull-in instability is utilized to verify the present analytical model. The results indicate that the numerical results well agree with the theoretical results in this work and experimental data in the literature. Further, the influences of volume fraction and geometrical distribution of CNTs, thermal Casimir force, nonlocal parameter, and squeeze film damping on electrically actuated instability and free-standing behavior are detailedly discussed. Besides, the evolution of equilibrium states of micromirror system is investigated, and bifurcation diagrams and phase portraits including the periodic, homoclinic, and heteroclinic orbits are described as well. The results demonstrated that the amplitude of the tilting angle for FGX-CNTRC type micromirror attenuates slower than for FGO-CNTRC type, and the increment of CNTs volume ratio slows down the attenuation due to the stiffening effect. When considering squeeze film damping, the stable center point evolves into one focus point with homoclinic orbits, and the dynamic system maintains two unstable saddle points with the heteroclinic orbits due to the effect of thermal Casimir force.


2009 ◽  
Vol 76-78 ◽  
pp. 252-257
Author(s):  
Tian Biao Yu ◽  
Ya Dong Gong ◽  
Wan Shan Wang

In order to improve quality of deep hole machining, a new method of deep hole honing based on squeeze film damping technology is put forward. For analysis effect on damper parameters on honing quality, motion differential equation of honing spindle with a squeeze film damper (SFD) is established according to D' Alembert principle and according simulations are studied. Spindle of deep hole honing with a SFD is designed based on the result of simulations and experiments are carried on. Experimental result shows that SFD with reasonable design parameters has excellent damping function to honing spindle, and it can make the vibration of honing spindle reduced 20%~30% and the quality of deep hole machining improved 10%~20%.


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