Solution based methods for the fabrication of carbon nanotube modified atomic force microscopy probes

Abstract

High aspect ratio carbon nanotubes are ideal candidates to improve the resolution and lifetime of atomic force microscopy (AFM) probes. Here, we present simple methods for the preparation of carbon nanotube modified AFM probes utilising solvent evaporation or dielectrophoresis. Scanning electron microscopy (SEM) of the modified probes shows that the carbon nanotubes attach to the probe apex as fibres and display a high aspect ratio. Many of the probes made in this manner were initially found to exhibit anomalous feedback characteristics during scanning, which rendered them unsuitable for imaging. However, we further developed and demonstrated a simple method to stabilise the carbon nanotube fibres by scanning with high force in tapping mode, which either shortens or straightens the carbon fibre, resulting in stable and high quality imaging AFM imaging.