NANOSCALE INDENTATION OF POLYMER SYSTEMS USING THE ATOMIC-FORCE MICROSCOPE

The use of the atomic force microscope (AFM) to measure surface forces has been developed to optimize its operation as a surface imaging too l. This capability can potentially be extended to evaluate nanoscale m aterial response to indentation and would be ideal for the evaluation of multi-component polymer systems, such as adhesives and composites. In this paper, previous work related to the development of the AFM as a nanoindentation device is reviewed, and a technique is proposed whic h allows the AFM to be used to probe local stiffness changes in polyme r systems. Cantilever probes with spring constants ranging from 0.4-15 0 N/m were used to investigate a number of polymer systems, including an elastomer, several polyurethane systems, thermally cured epoxies, a thermoplastic polymer-thermosetting polymer adhesive system, and a th ermoplastic matrix composite.