Nanoscale materials patterning and engineering by atomic force microscopy nanolithography

This review article aims to provide an updated and comprehensive description on the development of atomic force microscopy (AFM) nanolithography for structuring and fabrication at the nanometer scale. The many AFM nanolithographic techniques are classified into two general groups of force-assisted and bias-assisted nanolithography on the basis of their mechanistic and operational principles. Force-assisted AFM nanolithography includes mechanical indentation and plowing, thermomechanical writing, manipulation and dip-pen nanolithography. Bias-assisted AFM nanolithography encompasses probe anodic oxidation, field evaporation, electrochemical deposition and modification, electrical cutting and nicking, electrostatic deformation and electrohydrodynamic nanofluidic motion, nanoexplosion and shock wave generation, and charge deposition and manipulation. The experimental procedures, pattern formation mechanisms, characteristics, and functionality of nanostructures and nanodevices fabricated by AFM nanolithography are reviewed. The capabilities of AFM nanolithography in patterning a large family of materials ranging from single atoms and molecules to large biological networks are presented. Emphasis is given to AFM nanolithographic techniques such as dip-pen nanolithography, probe anodic oxidation, etc. due to the rapid progress and wide applications of these techniques.