Modification of a Commercial Atomic Force Microscope for Nanorheological Experiments: Adsorbed Polymer Layers
Shannon M. Notley a1, Vincent S. J. Craig a2andSimon Biggs a1c1 a1 Department of Chemistry, University of Newcastle, Callaghan, New South Wales, Australia a2 Department of Applied Mathematics, Research School of Physical Sciences and Engineering, Australian National University, Canberra c1 Department of Chemistry, University of Newcastle, Callaghan, New South Wales 2308, Australia
Abstract
The atomic force microscope (AFM) has previously been applied to the measurement of surface
forces (including adhesion and friction) and to the investigation of material properties, such as hardness. Here
we describe the modification of a commercial AFM that enables the stiffness of interaction between surfaces
to be measured concurrently with the surface forces. The stiffness is described by the rheological phase
difference between the response of the AFM tip to a driving oscillation of the substrate. We present the
interaction between silica surfaces bearing adsorbed polymer, however, the principles could be applied to a wide
variety of materials including biological samples.
