Ultrasonic Atomic Force Microscopy

Abstract

For the development of advanced electronic and mechanical devices on the micro- and nanoscale, there is an increasing need for the characterization of elasticity and subsurface defects. As a useful method, principle, implementation, and applications of ultrasonic atomic force microscopy (UAFM) and related methods for elastic materials characterization are described. It measures the contact stiffness from the resonance frequency of cantilever with the tip in contact with the sample surface. We focus on the concept of effective enhancement of the cantilever stiffness caused by the inertia of a soft cantilever at or above the contact resonance frequency. By virtue of this effect, new findings on elasticity of materials were achieved by many groups so far. Relation between UAFM and ordinary atomic force microscopy (AFM) is explained in detail. Also, lateral modulation atomic force microscopy (LM-AFM) with application to nanotribology is explained. Keywords: atomic force microscopy; nanotechnology; elasticity; ultrasonics; defects; contact resonance; contact stiffness; graphene; delamination