Manipulation of nanoscale components with the AFM: principles and applications

Bottom-up construction of nanostructures from molecular-sized components is a promising approach to nanofabrication. This paper discusses bottom-up techniques that involve positioning of nanoparticles or nanorods with an Atomic Force Microscope (AFM), and, for certain applications, chemical linking of such components. The physical principles of nanomanipulation with an AFM are described, with an emphasis on Dynamic Force Microscopy (DFM). Sources of spatial uncertainty are discussed. It is shown that nanoparticles and nanorods can be reliably positioned on a surface by pushing them with the tip of an AFM. Typical nanomanipulation operations are conducted at room temperature, in ambient air or in a liquid. For many applications nanostructures composed of nanoparticles or nanorods must be linked together. This can be done by using self-assembling linkers or by electroless deposition. The ability to immobilize the particles on a surface also is important in some applications. Again, self-assembly techniques can be used to imbed the particles in deposited layers.