Electrical Impedance Spectroscopy of Colloid-Nanoslot Interactions

Electrical Impedance Spectroscopy has been used extensively for the experimental study and characterization of a wide variety of electrochemical systems including ion-exchange membranes, micro-nanochannel devices, and colloidal suspensions.  The interplay of electrokinetic transport mechanisms with colloid dynamics in the vicinity of micro-nanochannel interfaces is of both fundamental and applied interest. We present recent results concerning the characterization of colloid dynamics in the vicinity of a micro-nanochannel interface using electrical impedance spectroscopy. Frequency-dependent response of colloids in bulk solution and colloidal aggregation and accumulation at the nanochannel entrance under DC bias are compared and analyzed to determine the utility of impedance methods in the study of colloid dynamics and trapping.