Visualization and analysis of nano-manipulation in liquid environment with atomic force microscopy

This paper focuses on theoretical analysis of AFM based nano-manipulation in a liquid environment. To achieve this goal, major forces in the liquid environment were reviewed and the manipulation processes were modelled by introducing the eect of intermolecular and hydrodynamic forces. The dynamic behaviour of pushing a gold nanoparticle of 50-nm radius on a silicon substrate at a velocity of 100 nm/s was investigated. A virtual reality user interface was also implemented and evaluated in a liquid environment, so users can get a sense of the forces. The results show that, in comparison to air, the required forces and time are increased by 2 and 6.5% for sliding and 2 and 4.3% for rolling in a liquid environment. Furthermore, for various submerged lengths of the cantilever in water, forces and time values are varied at 8 and 10.5%, respectively. Based on simulation results, sliding occurs at nominal values and critical forces and manipulation times in the liquid environment increase over the values. For biological manipulation purposes, the liquid environment is superior in comparison to air and the obtained results are veried by existing experiments.