Study Of Pull-in Phenomenon Of MEMS Devices Based On Perforated-Plate Microstructure

Micro-Electro-Mechanical System(MEMS)is a revolutionary high-tech industry,which has potential applications in military,aerospace,biomedicine and other fields,and has been attached great importance by governments and experts all over the world.As an important part of MEMS,microactuator can not only provide the power as needed but also act as operation and execution unit.It is well known that electrostatic micro-actuator is one of the micro-actuators that are most widely used.Among the electrostatic micro-actuator,the Pull-in phenomenon,including static and dynamic,is a decisive factor that limits the travel range of micro-actuator.Besides,in the micro device dimensions,the damping effect has obvious effect on Pull-in phenomenon,the smaller device size is,the greater the damping effect would be,this feature has been seriously affecting the efficiency of the micro device.Therefore,in order to reduce damping,perforated-plate is introduced to the design of electrostatic micro-actuator.And this paper will look into the phenomenon of Pull-in on the basis of perforated-plate structure.In this thesis,the static and dynamic characteristics of fixed-fixed perforated-plate electrostatic micro-actuator is analyzed with the aid of simulated software Matlab and ANSYS.According to the simulated results,the effects of Casimir force,squeeze damping effect,quality factor and other factors on the Pull-in parameters can be obtained.The research shows that: the exist of squeeze damping effect will lead to the increase of Pull-in voltage as well as decrease of displacement of Pull-in while micro device dimensions are not considered;because of the exist of Casimir force,both the Pull-in voltage and displacement will decrease and Pull-in phenomenon will exist without applying electrostatic force while the dimension of MEMS is small enough.