A Micro-Fluidic Real-Time Monitoring of the Dynamics of Polymeric Liquids

Manipulating liquid fluids within networks of micro-channels is crucial in the fabrication of micro-fluidic devices for electronic and for medical applications, as well as for the fundamental understanding of the fluid dynamics properties in geometrical confined systems, in which localization phenomena and surface effects can strongly affect the fluid behaviour. A detailed analysis of the fluid dynamics properties is particularly important for glass-forming liquids, polymeric solutions or bio-fluids, which do not behave as Newtonian fluids, due to the the elasticity of the molecules. For these materials the determination of the structural dynamical parameters is not trivial, requiring the solution of a complex many body problem and the introduction of non-linear mechanical parameters. In this work we have provided a micro-fluidic approach to assess the structural rheological parameters of a glass-forming liquid under real operation conditions. The method was applied to a viscoelastic polymeric liquid, polyurethane (PU) adhesive, during its driving flow in a micro-capillary network.