Nanoscale characterization of mechanical properties (stiffness, dissipation, etc.) is essential for development of advanced polymer-based materials. Towards this end, we describe atomic force microscopy (AFM) techniques that operate in contact mode with dynamic excitation at or near the cantilever resonance. Modulus measurements using contact resonance (CR) frequency instead of cantilever amplitude offer greater sensitivity than ones made by quasistatic methods. Use of higher-order CR modes facilitates operation at lower tip-sample forces and ensures accurate data analysis. Practical methods and instrumentation for rapid, quantitative imaging with CR techniques are discussed, as well as progress in mapping viscoelastic properties. Recent innovations that combine CR and pulsed AFM methods are also presented. Simultaneous mapping of CR peaks and tip-sample adhesion forces will enable more accurate nanomechanical measurements. These advances move us closer to the goal of fast, accurate, damage-free nanomechanical mapping of soft materials.

When "contrast" is not enough: Contact resonance methods for quantitative AFM nanomechanics

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.