Micro-fluidic flow control using the electroosmosis

Abstract

The objective of the proposed thesis is the introduction and development of micro-scale particle image velocimetry ([u]-PIV) to study the micro-scale flow field in the electroosmotic flow, which is the flow produced by the action of an electric field on a fluid with a net charge, called Zeta potential, which is confined in the Debye layer. This basic phenomenon in the electro-kinetic transports plays an important role on the micro-fluidic systems being explored today because it shows potential application to a variety of MEMS devices. A noble micro-scale particle image velocimetry ([u]-PIV) system has been developed for the velocity measurements using an Ar-ion laser, microscope, CCD camera and optical filters. By tracking the fluorescence images of sub-micron seeding particles, the full-field velocity distributions have been measured in the Eulerian viewpoint. Also, the experiment has focused on finding the effects of electroosmotic forces on the micro-scale flow fields, and flow control of electroosmotic flow in micro-geometries. Using the micro-PIV techniques, electroosmotically driven flows in various microchannel configurations have been measured to examine their feasibility to use for micro-pumping and micro-valve applications.