Transverse Electrokinetic Effect: Experiments and Theory

We observe the transverse electrokinetic effect (TEK), namely, the generation of a transverse potential difference due to the flow of liquids over a surface on which self-assembled arrays of metallic nanoparticles are immobilized. This paper covers the recent experimental findings and improvements to the theoretical model described in ref 1 [Subramaniam, C.; Pradeep, T.; Chakrabarti, J. Phys. ReV. Lett. 2005, 95, 0164501], leading to a better understanding of the phenomenon. Issues critical for the comprehension and applicability of this effect as a potential flow sensor such as the need for a critical dipole moment, optimum surface coverage, nature of the flow rate dependence, and generalization of the phenomenon for several metallic nanostructures have been addressed in detail from both experimental and theoretical perspectives. This complete work stresses the uniqueness of this new phenomenon which could find applications in emerging areas of science, like microfluidics.