Electrokinetics
Chip-based microfluidic devices for micro total analytical systems (µTAS) have been studied extensively since the early 90's. These systems offer the potential of assays with increased sensitivity and resolution, reduction of sample volume, and integration of multiple laboratory processes and functions on a single platform. Comprehensive reviews of microfabrication, chip designs, sensors, new functionality, and applications for µTAS have been presented (see Vilkner, Janasek & Manz 2004). Some reviews have focused on engineering challenges or the mechanics of dispersion and mixing (see Ghosal 2004; Locascio 2004; Stone, Stroock & Ajdari 2004). Many of these devices use liquid-phase electrokinetic phenomena to pump, transport, separate, concentrate and mix samples. Electrokinetics is a branch of electrohydrodynamics (EHD) that describes the coupling of ion transport, fluid flow and electric fields and is distinguished from EHD by the relevance of interface charge at solid-liquid interfaces.
Here we describe some of our projects relate to electrokinetic phenomena.
Electrokinetic Instabilities
Electroosmotic Pumps
Electrokinetic Phenomena in Non-dilute Suspensions
Representative Publications:
1. J.D. POSNER AND J.G. SANTIAGO. 2006. Convective instability of electrokinetic flows
in a cross-shaped microchannel, Journal of Fluid Mechanics, V555, pp. 1-42.
2. S. YAO, A.M. MYERS, J.D. POSNER, K.A. ROSE, AND J.G. SANTIAGO. 2006. Electroosmotic Pumps Fabricated from Porous Silicon Membranes, Journal of Microelectromechanical
Systems, Journal of Microelectromechanical Systems, V15, No. 3
3. Kim, D., J.D. Posner, and J.G. Santiago. High Flow Rate per Power Pumping of Aqueous Solutions and Organic Solvents with Electroosmotic Pumps. in Electrochemical Society (ECS) Transactions, Annual Electrochemical Society Meeting 2005. October 16-21, Los Angeles, CA.
4. C.R. BUIE, J.D. POSNER, T. FABIAN, S-W. CHA, D. KIM, F.B. PRINZ, J.K.
EATON, AND J.G. SANTIAGO. 2006. Water Management in Proton Exchange Membrane
Fuel Cells using Integrated Electroosmotic Pumping, Journal of Power Sources,
V161, 191-202
5. P.M. Wheat, J.D. POSNER, AND J.G. SANTIAGO. Quantification Of Convective Electrokinetic Instability Micromixing using Ion Indicating Dyes. 15th U.S. National Congress on Theoretical and Applied Mechanics, Micromixing Symposium, Boulder CO June 2006.
