Measuring dynamic mechanical properties of thin polymer films

Polymer dynamics under confinement on nanoscale exhibits substantial deviation from the bulk and has received a great deal of research interests in the past two decades. To date, some representative physical properties of confined polymers such as glass transition temperature and structural relaxation, have been studied extensively. Despite milestone progress in measuring Young’s modulus, creep, and stress-strain curves of thin polymers, mechanical properties of confined polymers are still far from well understood, and remain to be elucidated in many other aspects. Here we demonstrate an experimental apparatus for direct measurement of dynamic mechanical response of thin polymer films. We utilize a sinusoidal pressure wave on a polymer film to induce vibration, and the response of the material is record by a high-speed digital camera. By analyzing the data on stress, stain, and the phase difference in between, we obtained dynamic mechanical properties of polymer films with various thickness.