Fundamental considerations in the manipulation of a single C-60 molecule on a surface with an STM

We discuss the conditions needed to perform mechanics on the nanoscale. Various modes for adsorbates manipulation using a scanning tunnelling microscope (STM) are presented. Amongst those, which include sliding, pulling and pushing, we find that molecules such as fullerene C-60 are repositionable by pushing. This mechanism is modelled using molecular mechanics calculations, which provide the threshold STM tunnel junction resistance necessary to translate C-60 parallel and perpendicular to a step edge on a Cu(100) surface. Perpendicular translation provides the opportunity for more complex mechanics on the nanoscale such as the control of the kinetic energy of a single adsorbate. (C) 1997 Elsevier Science B.V.