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In this research effort, we developed MEMS micromirrors which are suitable for large angle deflections for optical scanning applications using the PolyMUMPs™ foundry fabrication process. This foundry process uses polysilicon and gold as the structural layers to form the bimorph beam structures which make up our actuation assembly. From both modeling and experimental testing, current micromirror designs fabricated in the PolyMUMPs™ process do not meet the deflection requirements to enable large angle scanning. As a result, we developed several post processing deposition techniques, using the PolyMUMPs™ structural layers as the baseline structure, to enable the necessary upward deflections to permit large angle scanning. In this research, we design, model, post fabricate, and test high out-of-plane MEMS actuators intended for integration with SOI micromirror arrays to enable the broadband, high fill-factor scanning applications. These arrays are designed to scan in multiple directions due to the segmented actuation design. The upward deflection is accomplished through material selection and design control (i.e., structure length, material thickness, material coefficient of thermal expansion (CTE), deposition temperature, and material layer composition) of bimorph structures. Following the post processed fabrication and sacrificial release; the initial deflection profiles are measured and compared against COMSOL™ models.

MEMS micromirrors for large angle beamsteering are needed for numerous broadband steering and imaging applications. However, current scanning micromirrors generally exhibit scanning angles (

This research effort is focused on the development of a micro-electro-mechanical system (MEMS) energy harvesting device using large, out-of-plane bimorph MEMS structures fabricated in the PolyMUMPs™ foundry process. In general, MEMS designers have limited options for commercial device fabrication, each bringing the advantage of quick prototyping, and repeatable results but also unique limitations. The design rules limit the designers to specific materials, structural layers, and fabrication processes to those of the fabrication facility. In previous work we have shown that the PolyMUMPs™ process will provide an adequate foundational structure for the device, meeting the initial out-of-plane deflection and flexibility requirements. However, it will require some post-processing to add the required mass and piezoelectric material layers to the structures. COMSOL™ finite element modeling software is used to evaluate various mass sizes, orientations, and materials as well as to explore different piezoelectric materials and configurations to produce optimal results from the in-house post-processing of these designs. Initial modeling of the structures illustrates unique design flexibility such that the operational frequency can be tailored to meet specific resonances enabling these devices to be adapted for a multitude of applications. Lastly, since the device provides the added benefit and flexibility, they can easily be integrated into an array for increased output voltage making them a prime candidate for micro power generation circuits.