Novel digital memory devices were fabricated with a thermally and dimensionally stable polyimide containing carbazole moieties in its side groups by using a simple and conventional solution coating process. The devices exhibit excellent unipolar ON and OFF switching behavior. With very low power consumption, the devices can be repeatedly written, read, and erased in air. The ON/OFF current ratio of the devices is high up to 1011. The high ON/OFF switching ratio and stability of the devices, as well as their repeatable writing, reading, and erasing capability with low power consumption, open up the possibility of the mass production of high performance non-volatile memory devices at low cost.