Integrated DEP architectures for microfluidic actuation and manipulation of liquids and particles

The Development of miniaturized (micro) total analysis systems (microTAS) is of increasing interest among the research community. Often referred to as 'Laboratory-on-a-chip' (LOC), this technology offers new prospects for health care, biomedical research and environmental analysis. Manipulation of biological cells and microscopic particles are in high demand in such applications. Dielectrophoresis (DEP), a non-uniform electric field effect on neutral, but polarizable particles is utilized successfully for manipulating biological cells and particles.; Microfabrication of low cost microfluidic devices has been made possible by the recent developments in soft lithography techniques. Fabrication of microfluidic devices in Poly(dimethylsiloxane) [PDMS] is rapid and cost effective, compared to conventional methods. The utilization of this soft lithography technique for the fabrication of a microfluidic system and the implementation of DEP in such system is demonstrated in this thesis.; Furthermore, this thesis presents an innovative sample handling technique for transporting and manipulating microscopic particles on a planar substrate surface. This technique integrates a two-stage dielectrophoretic droplet dispensing and distribution system with particulate DEP to create a novel LOC platform capable of manipulating biological cells based on the varied dielectrophoretic signatures that distinguish cells in a population, for example, viable from non-viable cells. This offers a simple, robust, and flexible architecture for sensitive, massively parallel diagnosis of cell disease, such as, early-stage cancerous "fingerprints".