Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
738328 | Sensors and Actuators A: Physical | 2007 | 6 Pages |
Magnetically actuated micromirrors have been developed for high sensitivity magnetic field measurement. Computer modelling was carried out to determine the micromirror structure at low field actuation. A novel SOI wafer process was established for micromirror fabrication. The process offers stress-free micromechanical structures without the stiction problem encountered in conventional surface micromachining process. By using two-step etching, the thickness of suspension beams of a micromirror can be independently defined. The new process also made it possible to electroplate a permalloy layer on one side of a micromirror and to maintain a mirror like reflection surface on the other side. The magnetically actuated micromirrors have been characterised using a simple laser beam reflection and CCD camera recording system. The measurement results have confirmed the computer modelling. Magnetic field detection sensitivity of about 1° of mirror deflection per 10−4 T of field intensity has been achieved.