Extraction of inner layer from multiwall carbon nanotubes for scanning probe microscope tip

Carbon nanotube tips and tweezers, for scanning probe microscopes (SPM) open out the possibility of processing and manipulating in the nanometer-scale region. The tip radius of the nanotube is crucial to taking a high resolution image in the SPM measurement, but it is difficult to control the tip shape. In this study, we have discovered a process to prepare a capped thin nanotube tip by extracting an inner nanotube from multiwall nanotubes. We demonstrate the extraction of the inner layer of multiwall nanotubes for providing a capped sharp probe for SPM using electrical breakdown and the SEM manipulation.