Title |
Design of an Electromagnetically-driven Micromirror Through the Coupled Physics Analyses |
Authors |
한승오(Han, Seung-Oh) ; 김병민(Kim, Byoung-Min) ; 박정호(Pak, Jung-Ho) |
Keywords |
MEMS ; Micromirror ; Electromagnetic force ; Coupled physics |
Abstract |
A micromirror for a laser display system actuated by the electromagnetic force induced by the surface coil and the permanent magnet was designed and analyzed through the coupled physics analyses incorporating the electromagnetics, mechanics, and electrothermal analysis because the mechanical rotation of the micromirror is driven by the electromagnetic driving force. The proposed micromirror has two torsion beams to sustain the mirror plate which has surface coils on the top and the two permanent magnets exists on both sides of the micromirror for an external magnetic field source. The designed micromirror has the resonant frequency of 3.82kHz. When the magnetic field of the permanent magnet is 0.4T, the coil has 4 turns, and the current density of coil is 3.6A/mm^2, the estimated z axis displacement of the mirror plate edge is 0.23mm which corresponds to the rotation angle of 14.2°. When considering the joule heating in the current-carrying coil, the maximum temperature of the mirror plate is obtained as 300.045K, which induces the negligible changes in the rotation angle and the resistance of the coil. |