Single-crystal nanowires of the organic semiconductor tetracyanoquinodi-methane-Cu (TCNQ-Cu) are directly integrated into prefabricated micro-electrode structures by growing the wires from an intermediate copper layer on the electrodes, as shown in the figure. This technique allows the nanowire growth to be integrated with device fabrication on a wide variety of substrates, eliminating the need for further assembly. The nanowire devices show bistable electrical switching behavior, which may be useful for high-density data storage.