Electrochemically actuated capillary flow control for the development of integrated microfluidic devices

Identifier:  TDX:1183

Handle:  https://hdl.handle.net/20.500.11797/TDX1183

Authors:  Washe, Alemayehu Paulos

Abstract:
Capillary force-operated microfluidic devices are easy to use, low cost realization platforms for Lab-on-a-Chip (LOC) configurations. If such “simplistic” LOC applications are to have success, flow control is an important unit operation to develop. This is particularly true for ASSURED (a term introduced by A. Guiseppi-Elie: Affordable, Sensitive, Specific, User-friendly, Rapid and robust, Equipment-free and Deliverable) devices for bioanalytical applications where an analytical response depends on the dissolution of previously deposited reagents, the kinetics of biological affinity and enzymatic reactions, and mass transport of products to a transducer in the microchannels. In this thesis the design, fabrication and implementation of three different electrochemically actuated capillary flow control schemes have been developed through low voltage electrowetting/ electrochemical actuation of the flow using i) electrical stimuli responsive superhydrophobic surfaces based on intelligent polymers ii) superhydrophobic nanoporous carbonaceous surfaces, and iii) superhydrophobic electrodes coupled to other electrodes that facilitate the generation of gradients to propel the liquid. The thesis unravels the mechanism of response of such systems and demonstrates ways for reduction to practice of such devices for the “democratization” of theranostics.