Authors: T.M.F. Amin, M.Q. Huda, J. Tulip, W. Jäger
Affilation: University of Alberta, Canada
Pages: 17 - 20
Keywords: MEMS, optical MEMS, actuator, external cavity laser
The design, fabrication, and characterization of a virtual pivot MEMS actuator with externally mounted mirror is presented. The provision for an externally mounted mirror can be useful for many optical applications which require large and high quality reflecting surfaces. The point of rotation of the actuator movable arm is distant from the physical actuator which is a requirement for many applications, such as an external cavity laser. The device has a maximum radius of 5 mm and a physical clearance of 3 mm from the pivot point. The dynamic characterization of the device with finite element analysis simulations shows that the resonance frequency of the in-plane rotational mode is well separated from that of the out-of-plane bending mode, confirming high in-plane stability. A rotation angle of about ±1.1 degree was achieved with an applied voltage of 190 V. The devices were fabricated on a SOI wafer with device layer thickness of 100 µm using bulk micromachining on both sides of the wafer using two level masking. Thin mirrors, fabricated by dicing of a 100 µm thick silicon wafer followed by gold sputtering, were mounted onto the MEMS device using a developed mounting process that utilizes a die bonder, vacuum tip and Silver epoxy.