Probing viscoelastic properties of a thin polymer film shearedbetween a beads layer and an ultrasonic resonator

International audienceWe report a study of viscoelastic properties of thin polymer films of 10−250nm at the MHz range. These thin films are confined between a quartz crystal resonator and a millimetric bead layer, producing an increase of both resonance frequency and dissipation of the quartz resonator. For the elastic film, both shear modulus and dynamic viscosity are extracted from these ultrasonic measurements. For the liquid film, the ageing effects are observed on both elastic and dissipative responses and the loss angle of the film is determined. This modified quartz resonator thus provides an effective tool for probing the rheological properties of viscoelastic thin films at ambient environment