AVS 46th International Symposium
    Nanometer-scale Science and Technology Division Tuesday Sessions
       Session NS1-TuM

Paper NS1-TuM10
Measuring and Imaging Contact Stiffness Quantitatively at the Nanoscale using Force Modulation

Tuesday, October 26, 1999, 11:20 am, Room 612

Session: Nanomechanics
Presenter: S.A. Syed Asif, University of Florida
Authors: S.A. Syed Asif, University of Florida
K.J. Wahl, Naval Research Laboratory
R.J. Colton, Naval Research Laboratory
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Depth-sensing nanoindentation has been widely used to measure the nanomechanical properties of materials. However, measuring quantitative mechanical properties of surfaces and thin films on a scale below 10 nm is still a problem. In this presentation we show that combining force modulation with depth-sensing nanoindentation allows measurement of the mechanical properties of materials on the sub-nanometer scale. The stiffness sensitivity of the technique is ~0.1 N/m, which is sufficient to detect long-range surface forces and locate the surface of compliant materials. The tip-surface interaction during approach to contact, asperity deformation during contact and time-dependent deformation at the atomic scale can all be studied. We also present a novel quantitative stiffness imaging technique, which can be used directly to map the mechanical properties of materials with sub-micron lateral resolution. Quantitative stiffness imaging is particularly valuable for polymers, thin films, and other nanostructured materials.