Automated Nanomanipulation with Atomic Force Microscopes

Abstract

Automation has long been recognized as an important goal in AFM (atomic force microscope) nanomanipulation research. For the precise manipulation of small particles with sizes on the order of 10 nm, however, automation has remained an elusive goal, primarily because of the spatial uncertainties associated with the positioning mechanisms of the AFM and with the manipulation process itself. Extensive user intervention has been necessary for the construction of desired nanostructures with the AFM, resulting in very low throughput, and severely limiting the complexity of structures that could be built with a reasonable amount of time and labor. This paper describes a fully automatic system for building arbitrary planar patterns of nanoparticles by AFM manipulation. Given an initial, random distribution of particles on a substrate surface and a desired pattern to be formed with them, a planner determines the paths required to perform the manipulation operations. The output of the planner is a sequence of primitive commands for positioning and pushing operations involving motion along line segments. The primitive commands are executed through software that compensates for thermal drift, creep and hysteresis. Experimental results presented here show that the system can build in minutes a pattern that normally would take an experienced user a whole day to construct interactively.