Algorithms and Software for Nanomanipulation with Atomic Force Microscopes

Interactive manipulation of nanoparticles by mechanically pushing them with the tip of an Atomic Force Microscope (AFM) is now performed routinely at many laboratories around the world. However, a human in the loop introduces significant inaccuracies and results in a very slow process, mostly because of the need to locate the particles before and after the manipulation operations in the presence of large spatial uncertainties, which are often comparable to the size of the particles. In this paper we describe the nanomanipulation systems developed at USC's Laboratory for Molecular Robotics during the last decade, culminating in a fully automatic system that is capable of accurately positioning small nanoparticles, with diameters of around 10 nm. This system uses software compensators for the non-linearities inherent in the piezoelectric actuators used in most AFMs. The planner and execution systems are described, as well as the software architecture of the systems. Experimental results are presented that validate the approach and show that nanoparticle patterns that would take hours to build interactively can now be built in minutes. Automatic operation makes it possible to use manipulation to construct much more complex nanostructures than those built in the past.