Electrical modification of a conductive polymer using a scanning probe microscope

We have demonstrated the electrical modification of a conductive polymer for data storage using a scanning probe microscope (SPM). A blend of polyaniline and polymethyl-methacrylate as the conductive polymer was spun on a silicon substrate to make a test specimen. The tip of a conductive SPM probe was placed in contact with the conductive polymer and electrical modification was carried out by applying a voltage between the SPM probe and the conductive polymer. The conductance image and a simultaneous topographic image were taken with the SPM. It was found that the electrical conductivity was decreased more than 20 times by this modification. Measurement of the topographic image shows no obvious change to the surface topography in the modified area. Measurement of the I–V characteristics suggests that a chemical reaction occurred at an applied voltage of about 3.2 V.