Control and Characterization of Line-Addressable Micromirror Arrays

This research involved the design and implementation of a complete line addressable control system for a 32x32 electrostatic piston-actuated micromirror array device. Line addressing reduces the number of control lines from N2 to 2N making it possible to design larger arrays and arrays with smaller element sizes. The system utilizes the electromechanical bi-stability of individual elements to hold arbitrary bistable phase patterns, a technique previously used on tilt arrays. The control system applies pulse width modulated (PWM) signals to the rows and columns of the device to generate a static phase pattern across the array. Three modes of operation were considered and built into the system. The first was the traditional signal scheme which requires the array to be reset before a new pattern can be applied. The second is an original scheme that allows dynamic switching between bi-stable patterns. The third and final mode applies an effective voltage ramp across the device by operating above mechanical cutoff. Device characterization and control system testing were conducted on samples from two different foundry processes.