Nanoscale wiring by controlled chain polymerization

Chain polymerization of amphiphilic diacetylene compounds in a monomolecular layer on a graphite substrate can be observed and controlled at a nanometer scale using a scanning tunneling microscope (STM). The wavelength dependence of photoreactivity suggests that the graphite substrate sensitizes the photoreaction. The chain polymerization can be initiated not only by irradiating light, but also by applying stimulation using an STM tip. We can also control the termination of chain polymerization by an artificial defect, so that we can create a polydiacetylene nanowire of designated length at any designated position.