For the last decade, most applications of microfluidics for "Lab-On-a-Chip" (LOC) technology have focused on the successful transfer of established technologies from conventional lab bench methodologies to a miniaturized chip-based format. The Lab on Chip Applications Development (LOCAD) team at NASA's Marshall Space Flight Center is utilizing LOC to support technology developments specifically for space exploration. In this study the microfluidic filling processes in a microwell/microarray integrated system, protein trap, and an optic well with an entrapped bubble are investigated by utilizing the Volume of Fluids methodology. Bubble removal strategies are developed for using pressure gradients across the well in order to remove entrapped bubbles. Numerical simulations indicate that the filling processes are a competition between inertia, adhesion, and surface tension. The results show that the Volume of Fluid methodology provides a successful and systematic approach to studying two phase flow phenomena in the microfluidic realm. |