Microscopy and Microanalysis



Scanning Probe Microscopy

Modification of a Commercial Atomic Force Microscope for Nanorheological Experiments: Adsorbed Polymer Layers


Shannon M. Notley a1, Vincent S. J. Craig a2 and Simon 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.