Characterization of non-Newtonian fluids at small length scales

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Fluids show highly viscous behaviour at length scales of millimetres and below, while the flow of these materials can be highly complex due to their complex properties. Flows at such small length scales exist with many examples in nature, living organisms, manufacturing, and environmental and biomedical devices. My research program aims at increasing our understanding of this complex flow behaviour at small length scales in order to develop new production methods, as well as to design effective device concepts with important applications in life sciences, natural resources, and printing. This grant supports research on several projects within this research program involving two types of flow problems: (1) the flow of thermally responsive fluids that can solidify reversibly at elevated temperatures and (2) solvent casting of polymers. Research in both areas will benefit from the advanced imaging and flow characterization methods developed in my lab.***We will demonstrate several concepts of smart valves based on these thermally responsive fluids for applications in biomedical and environmental monitoring devices. We will also deposit thermally responsive fluids onto transparent heated surfaces to elucidate the solidification mechanics of drops on surfaces, which is difficult to observe in relevant opaque fluids such as molten food stuff (i.e. chocolate) and molten metal. Further, we will measure how the presence of salts can affect the solidification of thermally responsive fluids, as well as investigate the flow of these fluids in small channels comparable to the pores of rock in oil reservoirs. We will assess whether these biocompatible fluids are suitable for enhanced oil recovery and also develop methods to remove these fluids after use.***In solvent casting of polymer solutions, the solvent evaporates leaving a polymer coating on the mould. This process allows the fabrication of microstructured devices such as microneedles for biomedical applications. We will characterize the flow within these polymer solutions as the solvent evaporates to predict the polymer deposition profile on the moulds, as well as design adequate materials and optimize process conditions. We will apply our understanding of the flow phenomena during solvent casting to the integration of electronic chips during the solvent casting process. This will eventually lead to inexpensive high-performance biomedical and environmental devices and systems for the rapid detection of compounds.***The characterization of non-Newtonian fluids at small length scales throughout this research program will lead to significant breakthroughs in our understanding of small-scale fluid mechanics enabling new technologies to improve the lives of Canadians and the environment with a positive impact on Canada's economy.*****