While the details of the photolithographic approach to large-scale synthesis of Affymetrix are not publicly known, it requires complex infrastructure similar to that needed for I-line integrated semiconductor manufacturing: steppers and wafer processing systems, and chrome photomask production and handling capabilities. This complexity inspired a much simpler approach based on the then newly introduced digital micromirror device (DMD) technology from Texas Instruments . DMDs are large arrays of microscale mirrors, each of which can be tilted into one of two angles, "ON" and "OFF".