<p> In recent years, deformable micromirror arrays have become the focus of several attempts to create cost efficient adaptive optics systems for vision science. Conversely, the Digital Micromirror Device™ (DMD™) has been overlooked by several applications, including adaptive optics, due to its inherent bistability. As a means of addressing this limitation, this thesis suggests multiple methods to demonstrate the feasibility of analog operation of the DMD™. The first step in this process involves the characterization of the DMD™ by means of an automated, optical measurement system. This system was developed to actively monitor the angular deflection of individual micromirrors in the MEMS array. Two key mechanical properties of the microstructure - the natural frequency and the quality factor - are determined through analysis of the micromirrors' recorded dynamic behaviour. Further, through automation of the characterization setup, an investigation of device uniformity is
presented exposing a clear trend in the measured micromirror properties over 160 tested mirrors in the DMD™ array. This linear trend is attributed to the variation in thickness of the torsional hinges as a result of the sputtering deposition process. Using the DMD™ characteristics discovered through experimentation, a computationally inexpensive, one-dimensional model based on the fourth order Runge-Kutta numerical method is constructed to simulate the response of the DMD™ micromirrors to user defined input voltage waveforms. Simulations are initially used to exhibit the validity of the model for existing DMD™ voltage patterns through a comparison with measured micromirror responses, and subsequently used to demonstrate two proposed methods of analog operation. The first method creates a limited form of analog control by varying the amplitude of 16 analog bias voltage lines, whereas the second method provides complete analog operation of the DMD™ using high frequency pulse width modulation of the underlying address circuitry.</p> / Thesis / Master of Applied Science (MASc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/21752 |
| Date | January 2006 |
| Creators | Lockhart, Robert A. |
| Contributors | Kleiman, R. N., Engineering Physics |
| Source Sets | McMaster University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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