Point of care microfluidic tool development for resource limited settings

Abstract: The development of point of care diagnostics using recent advances in microfluidics have the potential to transform health care in several ways, especially in resource limited settings with limited access to advanced health care infrastructure. However, translating a point of care device to reality is often a challenging task because of the complexities involved in integrating a number of diverse engineering concepts into an easy to use, accurate and portable device. This thesis focuses on miniaturization of crucial diagnostic laboratory tools, that can be used in a portable point of care format without compromising on the accuracy or performance. The first part of the thesis (Paper I-III) focuses on understanding and applying elasto-inertial microfluidics, which is a label-free and passive bio-particle sorting and separation method. A basic understanding of particle trajectories in both inertial (Paper I) and visco-elastic flows (Paper II) is established, followed by an investigation on the combined effects of inertia and elasticity (Paper III). The second part of the thesis (Paper IV-VI) focuses on developing integrated microfluidic platforms, each of which addresses different aspects of point of care diagnostic applications. The applications include neonatal diagnostics using a hand-driven Slipdisc technique (Paper IV), rapid nucleic acid quantification using a novel precipitate-based detection on a centrifugal microfluidics platform (Paper V), and hematocrit level measurement in blood using a portable lab-on- Disc platform operated by a mobile phone (Paper VI). The proof of concept microfluidic tools presented in the scope of this thesis have the potential to replace a number of functions of standard laboratory equipment, at a fraction of the price and without compromising performance. Hence, the different methods developed should contribute towards decentralization of medical testing laboratories, making healthcare accessible to one and all.