Influence of streaming potential on the elastic response of a compliant microfluidic substrate subjected to dynamic loading

In the present study, we investigate the effect of streaming potential on the elastic response of a compliant surface subjected to dynamic loading conditions. For illustrating the pertinent physical phenomena, we analyze in particular the dynamical characteristics of the system on squeezing out of a liquid layer through a narrow gap formed between an elastic fluidic surface and an incipient rigid oscillating sphere. We reveal that the streaming potential effects may amplify the elastic force response of the substrate to a considerable extent. Interestingly and nontrivially, this increment turns out not only to be a function of the pertinent electrokinetic parameters dictating the establishment of the streaming potential, but also a combined consequence of the oscillation frequency and the stiffness of the substrate, consistent with a dynamical interaction between interfacial electrochemical-hydrodynamics and structural responsive characteristics that has hitherto not been emphatically explored. (C) 2010 American Institute of Physics. [doi:10.1063/1.3524530]