Rapid and Reproducible Fabrication of Carbon Nanotube AFM Probes by Dielectrophoresis

Atomic force microscopes (AFM) are commonly used to map the surface structure and topography of different objects and devices.1 The resolution, sensitivity, and probing depth of an AFM depend on the structure of the probe. AFM probes are commonly made by lithography and have a pyramidal shape. Prior publications have demonstrated that the spatial resolution, wear resistance, and especially the probing depth of an AFM can be significantly increased by utilizing carbon nanotubes (CNTs).2,3 Several methods have been developed to either mount or directly grow CNTs on the apex of a commercial AFM probe. Techniques such as “gluing”2 or “spot-welding”4 a CNT protruding from a nanotube source with the aid of an optical microscope, transferring CNTs from a support surface inside a scanning electron microscope,5 and picking up a vertically aligned CNT from the substrate