Flexible TiO2 crossbar memory device arrays were fabricated on plastic substrates using amorphous titanium oxide thin films grown by the low-temperature plasma-enhanced atomic layer deposition method. Al/TiO2/Al memory cells on polyethersulfone (PES) showed an enhanced endurance property (up to 10(4) cycles) and low switching voltages compared to the cells on rigid substrates. The multi-stacked memory arrays were constructed by forming the additional Al/TiO2/Al layer on the first memory device layer. Memory cells on each layer exhibited stable switching characteristics and mechanical robustness without interlayer cell-to-cell interference.