Single crystalline nanoneedles of three families of most studied conductive organic polymers - polythiophene, polyaniline and polypyrrole - were synthesized for the first time using an interfacial polymerization process that takes place with simultaneous crystallization. As the crystal growth is concurrent with polymerization, more ordered crystal packing can be expected. Most of the bulk conducting-polymer systems studied previously contains regions that are inhomogeneous. Single nanocrystals of conducting polymers have not been reported, although needle-shaped bulk crystals of the quarterphenyl cation radical salt have previously been studied. The investigation of

processes in a nanodomain of a single crystal is critical in ascertaining the inherent electronic properties of polymer nanoelements.

The organic conductive nanoneedles were characterized using TEM, HRTEM, electron diffraction, EDS, and EPR to establish their crystal structure and composition. Scanning tunneling microscopy/spectroscopy (STM/STS) investigation was conducted to examine their electronic conduction behaviors, leading to the discovery a field-induced conductance switching with response times on or faster than the millisecond level. The switch voltages are in the range of 3 to 4 volts, consistent with the trend of the band gap of the polymers.