Title :
Tilting Micromirror With a Liquid-Metal Pivot
Author :
Zeng, Hongjun ; Wan, Zhiliang ; Feinerman, Alan D.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Illinois, Chicago, IL
Abstract :
In this paper, we have developed a new micromirror with a compact footprint which can be rapidly tilted to large angles. The micromirror is supported by a liquid-metal drop (LMD) with low vapor pressure and is rotated by an electrostatic torque. A torsional spring model is proposed to predict the equivalent torsional constant of the LMD and the resonant frequency of the mirror. Micromirrors (1 mmtimes1 mmtimes25 mum) and actuating electrodes are microfabricated with a centralized wetting area surrounded by a nonwetting parylene area to confine the LMD. Our measurements of the mirror show the average snap-down voltage of ~ 79 V and the resonant frequency of 165 Hz. A single mirror is actuated to steer a laser beam with a maximum deflected angle of 23.6deg. A 1times3 mirror array is demonstrated for light switching, and has greater than 1 : 64 idle/deflection contrast. We also test the stability of the mirror to mechanical shake up to 56 g (g = 9.807 m/s2). The prototype mirror has 3.6 million cycles of operation
Keywords :
beam steering; liquid metals; micro-optomechanical devices; microactuators; micromirrors; polymers; torque; 165 Hz; MEMS; centralized wetting area; compact footprint; electrostatic torque; laser beam steering; light switching; liquid-metal drop; liquid-metal pivot; microactuator; microelectromechanical systems; microoptoelectromechanical systems; nonwetting parylene area; tilting micromirror; torsional spring model; Electrodes; Electrostatic measurements; Frequency measurement; Micromirrors; Mirrors; Predictive models; Resonant frequency; Springs; Torque; Voltage; Liquid-metal pivot; microactuator; microelectromechanical systems (MEMS); micromirror; microoptoelectromechanical systems (MOEMS);
Journal_Title :
Microelectromechanical Systems, Journal of
DOI :
10.1109/JMEMS.2006.883531
