Microfluidic Concentration Gradient Generation and Integrated Magnetic Sorting of Microparticles

Microfluidic systems, with their feature size similar to that of biological cells, have great potential for cell manipulation and interrogation. On the other hand, the process of drug discovery involves vast amount of tests of candidate drug molecules with cells, and hence requires intensive manipulation and interrogation of cells. Therefore, it is conceivable that microfluidics can be and should be sufficiently exploited to facilitate drug discovery process. This dissertation investigates two of the most frequently performed cell operations in drug discovery, which are often performed in series, i.e., chemical stimulation of cells (cell treatment and chemotaxis) and cell sorting. For chemical stimulation of cells, rapid and novel designs of concentration gradient generation (CGG) devices are presented; for cell sorting, a magnetically The most prevalent type of CGG devices, i.e., complete mixing-based laminar-flow CGG devices, involves massive channel networks. The design of alternative laminar-flow CGG devices suffers lack of efficient and systematic design framework, and is currently implemented through time-consuming numerical simulations. Therefore, we first propose passive mi