MEMS Fabricated Structures with Large, Out-of-Plane Deflections

LaVern Starman, David Torres-Reyes, Robert Lake, and John Walton
Air Force Research Laboratory, Ohio, United States

Keywords: MEMS, micromirror, beamsteering, electrothermal, electrostatic

This research effort is focused on the development of large angle, out-of-plane bimorph MEMS micromirror devices fabricated in the PolyMUMPs foundry process. Based on design constraints, current designs fabricated in the surface micromachining PolyMUMPs process do not meet the upward requirements to enable large angle optical steering. Thus, several post-processing techniques are being pursued using the PolyMUMPs foundry fabricated device as the foundation of the final design. Currently, we have been evaluating these post-processing techniques using Comsol finite element modelling software. From preliminary modelling results, our actuation assembly designs can be uniquely tailored through the addition of select material layers during post processing to exhibit over 300 ┬Ám of upward deflection, meeting design goals. Several different PolyMUMPs fabricated actuation assemblies are currently being post-processed to validate our modelling results. The actuation assemblies are the primary baseline component to develop arrays of high-deflection micromirrors having a fill factor greater than 90%.