PROJECT TITLE :

Design and Fabrication of a Long-Arm Comb-Drive Rotary Actuator With Externally Mounted Mirror for Optical Applications

ABSTRACT:

During this paper, we gift the planning, fabrication, and characterization of a protracted-arm comb-drive actuator with an externally mounted massive mirror for optical applications. The provision for an externally mounted mirror will be useful for several optical applications, that need massive and high-quality reflecting surfaces. The angular stretch of the comb fingers at the far end is kept smaller than those close to the anchor point. This structural feature permits the planning of actuator arm lengths of over 5 mm. The truss of the actuator is designed carefully to support the big movable arm. An analytical model for the electrostatic forces within the actuator was developed, and detailed analyses for facet instability and resonance frequency were performed. The whole fabrication method involving bulk micromachining of silicon-on-insulator (SOI) wafer using a 2-mask method is described. A procedure for efficient mounting of the mirror utilizing die bonder, vacuum tip, and silver epoxy is demonstrated. Static characterization measurements show that the actuator can achieve a rotational angle of three° with an applied voltage of 130 V. A resonance frequency of ~246 Hz for a mirror size of two mm × a hundred μm × 1 mm determined by optical characterization; this closely matches with the simulation results and therefore the analytical model.