Design, fabrication, and evaluation of vacuum testing of a novel electromagnetic microactuator

A novel electromagnetic microactuator with lateral magneto-static force was developed in this study. A simple fabrication process with low cost was proposed to realize the device for optical applications. The actuation performances in different vacuum degrees were also examined for the verification of following packaging efficacy. The present method assembled a tiny permanent magnet on a supporting beam to couple with a fixed solenoid coil for driving a suspension plate in vibration by applying an alternating current. Actuation modes with torsion and bending beams can be designed to satisfy the different optical applications, such as barcode reader, optical switch, and laser display. The typical experiment results for higher and lower actuation frequencies under the first resonant mode are 4.43 kHz and 179 Hz, respectively. In an ambient environment, the corresponding mechanical tilt angle to the case of higher frequency is 11.2 deg at the supply voltage +/- 2.5 V. The maximum tilt angle at the vacuum degree of 76 mTorr is increased by 31% compared with that of 760 Torr. The thermal effect induced by the coil is minimized to actuation performance, even at high vacuum environments. Thus, based on the results of this study, high reliability with high vacuum packaging can be expected. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI:10.1117/1.3641412]