This paper presents a multi-electrode and pre-deformed bilayer spring structure electrostatic attractive microelectromechanical systems (MEMS) actuator; it has large stroke at relatively low actuation voltage. Generally, electrostatic-attractive-force-based actuators have small stroke due to the instability resulted from the electrostatic 'pull-in' phenomenon. However, in many applications, the electrostatic micro-actuator with large stroke at low voltage is more preferred. By introducing a multi-electrode and a pre-deformed bilayer spring structure, an electrostatic attractive MEMS actuator with large stroke at very low actuation voltage has been successfully demonstrated in this paper. The actuator contains a central plate with a size of 300 mu m x 300 mu m x 1.5 mu m and it is supported by four L-shaped bilayer springs which are pre-deformed due to residual stresses. Each bilayer spring is simultaneously attracted by three adjacent fixed electrodes, and the factors affecting the electrostatic attractive force are analyzed by a finite element analysis method. The prototype of the actuator is fabricated by poly-multi-user-MEMS-process (PolyMUMP) and the static performance is tested using a white light interferometer. The measured stroke of the actuator reaches 2 mu m at 13 V dc, and it shows a good agreement with the simulation.
1.Guilin Univ Elect Technol, Coll Elect Engn & Automatizat, Guilin 541004, Peoples R China 2.Zhejiang Normal Univ, Inst Informat Opt, Jinhua 321004, Peoples R China 3.Chinese Acad Sci, Inst Opt & Elect, State Key Lab Opt Technol Microfabricat, Chengdu 610209, Peoples R China
Hu, Fangrong,Li, Zhi,Qian, Yixian,et al. A multi-electrode and pre-deformed bilayer spring structure electrostatic attractive MEMS actuator with large stroke at low actuation voltage[J]. JOURNAL OF MICROMECHANICS AND MICROENGINEERING,2012,22(9).