Dynamic pull-in of parallel-plate and torsional electrostatic MEMS actuators

An analysis of the dynamic characteristics of pull-in for parallel-plate and torsional electrostatic actuators is presented. Traditionally, the analysis for pull-in has been done using quasi-static assumptions. However, it was recently shown experimentally that a step input can cause a decrease in the voltage required for pull-in to occur. We propose an energy-based solution for the step voltage required for pull-in that predicts the experimentally observed decrease in the pull-in voltage. We then use similar energy techniques to explore pull-in due to an actuation signal that is modulated depending on the sign of the velocity of the plate (i.e., modulated at the instantaneous mechanical resonant frequency). For this type of actuation signal, significant reductions in the pull-in voltage can theoretically be achieved without changing the stiffness of the structure. This analysis is significant to both parallel-plate and torsional electrostatic microelectromechanical systems (MEMS) switching structures where a reduced operating voltage without sacrificing stiffness is desired, as well as electrostatic MEMS oscillators where pull-in due to dynamic effects needs to be avoided

[1]  C. Nguyen,et al.  High-Q HF microelectromechanical filters , 2000, IEEE Journal of Solid-State Circuits.

[2]  M. Younis,et al.  A Study of the Nonlinear Response of a Resonant Microbeam to an Electric Actuation , 2003 .

[3]  G. A. Feather,et al.  The digital micromirror device for projection display , 1995, Proceedings IEEE International Conference on Wafer Scale Integration (ICWSI).

[4]  K. Sarabandi,et al.  Electromechanical considerations in developing low-voltage RF MEMS switches , 2003 .

[5]  P. Pinsky,et al.  Nonlinear dynamic modeling of micromachined microwave switches , 1997, 1997 IEEE MTT-S International Microwave Symposium Digest.

[6]  T. Veijola,et al.  Model for gas film damping in a silicon accelerometer , 1997, Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97).

[7]  S. Senturia.  Microsystem Design , 2000 .

[8]  O. Solgaard,et al.  Deformable grating optical modulator. , 1992, Optics letters.

[9]  Gregory Nolan Nielson,et al.  Micro-opto-mechanical switching and tuning for integrated optical systems , 2004 .

[10]  H. Tilmans,et al.  Electrostatically driven vacuum-encapsulated polysilicon resonators part II. theory and performance , 1994 .

[11]  Robert Sattler,et al.  Modeling of an electrostatic torsional actuator: demonstrated with an RF MEMS switch , 2002 .

[12]  Gabriel M. Rebeiz.  RF MEMS: Theory, Design and Technology , 2003 .

[13]  Michiel Steyaert,et al.  An Oscillator Circuit For Electrostatically Driven Silicon-based One-port Resonators , 1995, Proceedings of the International Solid-State Sensors and Actuators Conference - TRANSDUCERS '95.

[14]  Gabriel M. Rebeiz,et al.  Nonlinear electro-mechanical modeling of MEMS switches , 2001, 2001 IEEE MTT-S International Microwave Sympsoium Digest (Cat. No.01CH37157).

[15]  J. Thompson,et al.  Nonlinear Dynamics and Chaos , 2002 .

[16]  J. B. Starr.  Squeeze-film damping in solid-state accelerometers , 1990, IEEE 4th Technical Digest on Solid-State Sensor and Actuator Workshop.

[17]  David A. B. Miller,et al.  Parallel-plate MEMS mirror design for large on-resonance displacement , 2000, 2000 IEEE/LEOS International Conference on Optical MEMS (Cat. No.00EX399).

[18]  S. Senturia,et al.  Speed-energy optimization of electrostatic actuators based on pull-in , 1999 .

[19]  C. Nguyen,et al.  Frequency-selective MEMS for miniaturized low-power communication devices , 1999 .