Comment on 'Temperature dependence of the energy dissipation in dynamic force microscopy'

A recent article in this journal by Roll et al (2008 Nanotechnology 19 045703) presents experimental results of the temperature dependence of dissipation in dynamic force microscopy which they use to elucidate the mechanisms of such a dissipation signal in the PTCDA on KBr system. We argue here that dissipation results are often highly dependent upon the tip structure, and urge caution in the interpretation of single sets of experimental data.