This paper presents our recent developments as well as emerging techniques introduced in literature for decreasing the operation voltage of electrostatic comb drive micro-mirror. Methods for decreasing the operation voltage at large rotation angle and high scan frequency for application in the laser scanning display are focused to discuss in this paper. | Vietnam Journal of Mechanics, VAST, Vol. 34, No. 4 (2012), pp. 237 – 245 LOW VOLTAGE OPERATION ELECTROSTATIC COMB DRIVE MICRO-MIRROR FOR LASER SCANNING DISPLAY Hoang Manh Chu1 , Hung Vu Ngoc1 , Kazuhiro Hane2 1 Hanoi University of Science and Technology, Vietnam 2 Tohoku University, Japan Abstract. Electrostatic comb drive micro-mirror has limitation of high operation voltage, which has limited its practice use. Recent developments in decreasing operation voltage are promising for mobile micro-mirror. Especially, the operation voltage is decreased substantially by removing the air friction of comb-drive micro-mirror at a high resonant frequency when the mirror is operated at low pressure. Removing simultaneously the air friction and anchor loss, electrostatic comb-drive micro-mirror operating at a few voltages at a high resonant frequency becomes possible. This paper presents our recent developments as well as emerging techniques introduced in literature for decreasing the operation voltage of electrostatic comb drive micro-mirror. Methods for decreasing the operation voltage at large rotation angle and high scan frequency for application in the laser scanning display are focused to discuss in this paper. Keyword: Micro-mirror, vertical electrostatic comb drive, air damping, Q factor. 1. INTRODUCTION Micro-mirror is known as a most successfully developed MEMS device for promising applications in laser medical imaging, optical communication and micro-display. Compared to actuation mechanisms such as magnetic and piezoelectric, the electrostatic mechanism has advantages of major fabrication technology, mass production with high reliability and low power consumption. However, the limitation of the micro-mirror driven electrostatically is the high operation voltage (∼100 V) required for a large rotation angle at the high scan frequency (∼15 kHz). This is due to the large stiffness of torsion hinge for the high scan frequency. The requirements for laser scanning .
