Nano-scale viscoelastic properties of polymer materials

The AC force modulation technique in nano indentation has been extended to study the dynamic viscoelastic properties of polymer materials. The frequency and temperature dependent loss and storage modulus, the time-temperature superposition, the mechanical relaxation and the activation energy for the relaxation process can all be directly measured from nana scale contact. The results obtained for PMMA and Polyisoprene are in good agreement with the reported literature results obtained from conventional dynamic testing. The technique is likely to be of particular value for polymer thin films.