Implementation of nanoporous anodic aluminum oxide layer with different porosities for interferometric RGB color pixels as handheld display application

This study presents the approach to implement the interferometric modulation color pixels application by using nanoporous anodic aluminum oxide (np-AAO) layer as the key suspended micro structure. In this work, the presented bi-stable color pixels have averaged reflectivity of 60%, and the central wavelengths are 651 nm, 554 nm and 452 for red, green and blue, respectively. Advantages of the presented np-AAO color-pixel are as follows, (1) porosity of np-AAO layer can be easily adjusted by low temperature fabrication process to modulate the refractive index of proposed device, (2) color-pixels of different porosities (refractive indices) can be implemented and integrated on single np-AAO layer by process for different colors modulation, and (3) anti-stiction coating is not required since contact adhesion force significantly reduced by porous surface. The study reports the design, fabrication, and experimental results of the color pixels to demonstrate the advantages of the presented device.