WS 2 nanotubes as tips in scanning probe microscopy

${\mathrm{WS}}_{\mathrm{2}}$ nanotubes a few microns long were attached to microfabricated Si tips and tested afterwards in an atomic force microscope by imaging a “replica” of high aspect ratio, i.e., deep and narrow grooves. These ${\mathrm{WS}}_{\mathrm{2}}$ nanotube tips provide a considerable improvement in image quality for such structures when compared with commercial ultrasharp Si tips. The nanotube tip apex shape was extracted by blind reconstruction from an image of Ti spikes, showing a smooth cylindrical profile up to the end.