AVS 49th International Symposium
    Nanometer Structures Monday Sessions
       Session NS-MoM

Invited Paper NS-MoM5
Dynamics and Mechanics of Nanoscale Adhesive Contacts

Monday, November 4, 2002, 9:40 am, Room C-207

Session: Nanomechanics
Presenter: K.J. Wahl, U.S. Naval Research Laboratory
Authors: K.J. Wahl, U.S. Naval Research Laboratory
S.A.S. Asif, Hysitron, Inc.
Correspondent: Click to Email
Recent advances in atomic force microscopy (AFM) and nanoindentation enable examination of surface mechanical properties of ultrathin films and compliant materials with far greater resolution and accuracy than ever before. In our laboratory, we have implemented dynamic mechanical analyses of nanoscale adhesive contacts using a 'hybrid' nanoindenter, coupling depth-sensing nanoindentation with AFM positioning capabilities. This combination allows surface sensitive, quantitative mechanical properties measurements of nanostructures and thin films, at a single point as well as while scanning. We illustrate these expanded capabilities with several examples: 1) a dynamic nanoscale Johnson-Kendall-Roberts (nano-JKR) adhesion test, and 2) scanning nanomechanics. The nano-JKR test allows study of processes that occur during the formation and breaking of adhesive contacts with diameters smaller than the optical limit, and can be used to measure dynamic visco-elastic properties including loss and storage moduli, adhesion energy, and strain energy release rate. Scanning nanomechanics provides a means of directly imaging mechanical response and properties with sub-micron spatial resolution. We will discuss how these new capabilities can be used to test the models and limits of continuum contact mechanics.