title: Nonlinear current-voltage characteristics of nanochannels.
abstract: Like ion channels, nanochannels are known to exhibit curious non-Ohmic current-voltage (I-V) characteristics with an approximate piece-wise constant differential resistance. Using a nanoslot model and a nonequilibrium ion transport theory, we attribute the nonlinear resistance to overlapping double layers inside and an extended polarized layer of space charge outside the nanochannel. The overlimiting current beyond a critical voltage is shown to develop when the polarized layer is destabilized by a microvortex instability at one entrance. By extending earlier nanochannel and polarized layer models to include this instability, nonideal ion permselectivity and field-focusing effect, quantitative predictions-together with explicit differential resistance expressions-are offered for the nonlinear I-V features of a nanochannel surrounded by microreservoirs from a simple pseudo-one-dimensional model.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Center for Microfluidics and Medical Diagnostics, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Gilad
authors.initials: G
authors.lastname: Yossifon
authors.forename: Peter
authors.initials: P
authors.lastname: Mushenheim
authors.forename: Yu-Chen
authors.initials: YC
authors.lastname: Chang
authors.forename: Hsueh-Chia
authors.initials: HC
authors.lastname: Chang