Probing space charge and resolving overlimiting current mechanisms at the microchannel-nanochannel interface

Jarrod Schiffbauer, Uri Liel, Neta Leibowitz, Sinwook Park, Gilad Yossifon

Research output: Contribution to journalArticlepeer-review

Abstract

We present results demonstrating the space charge-mediated transition between classical, diffusion-limited current and surface-conduction dominant over-limiting current in a shallow microchannel-nanochannel device. The extended space charge layer develops at the depleted microchannel-nanochannel entrance at high current and is correlated with a distinctive maximum in the dc resistance. Experimental results for a shallow surface-conduction dominated system are compared with theoretical models, allowing estimates of the effective surface charge at high voltage to be obtained. In comparison to an equilibrium estimate of the surface charge obtained from electrochemical impedance spectroscopy, it is further observed that the effective surface charge appears to change under applied voltage.

Original languageEnglish
Article number013001
JournalPhysical Review E - Statistical, Nonlinear, and Soft Matter Physics
Volume92
Issue number1
DOIs
StatePublished - 2 Jul 2015
Externally publishedYes

Funding

FundersFunder number
Israel Science Foundation2015240

    Fingerprint

    Dive into the research topics of 'Probing space charge and resolving overlimiting current mechanisms at the microchannel-nanochannel interface'. Together they form a unique fingerprint.

    Cite this