Application of an all-polymer flexural plate wave sensor to polymer/solvent material characterization

An all-polymer, polyvinylidene fluoride (PVDF) flexural plate wave (FPW) acoustic sensor is used to determine the humidity-dependent material parameters of a polyvinyl alcohol (PVA) affinity layer as a sample analyte-affinity layer system. The Young´s modulus, volumetric swelling, mass change, and vapour/solid partition coefficient of drop cast PVA are determined through a set of vapour absorption experiments and numerical regression fitting. The low stiffness of the substrate and the high sensitivity of the antisymmetric flexural plate wave modes to stiffness effects allow for contributions of stiffness and mass changes to the sensor response. These experimental results are compared with reference measurements to examine the effectiveness of this method.