Electrical impedance spectroscopy of microchannel-nanochannel interface devices
Jarrod Schiffbauer, Sinwook Park, and Gilad Yossifon
Accepted
We report experimental verification of the depression of the slope in the Warburg branch of the electrochemical impedance spectrum using a fabricated microchannel-nanochannel device. This was previously theoretically predicted to occur with increasing DC bias voltage as a result of nanochannel EOF, and provides an example of the influence of net fluid flow on electrokinetic transport. The dominant influence of nanochannel polarization in the kHz-range of the impedance response is also demonstrated experimentally. This latter effect may be significant in both fundamental electrokinetics of micro-nanochannel devices as well as in practical molecular sensing applications.