Effect of field-focusing and ion selectivity on the extended space charge developed at the microchannel–nanochannel interface. (21st June 2016)

• Record Type: Journal Article
• Authors: Liel, Uri; Leibowitz, Neta; Schiffbauer, Jarrod; Park, Sinwook; Yossifon, Gilad
• Is Part Of: Journal of physics. Volume 28:Number 32(2016)
• Publication Date: 2016-06-21
• Subjects: extended space charge -- microchannel–nanochannel interface device -- concentration polarization; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/28/32/324002
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: We present results demonstrating the effect of varying microchannel depth and bulk conductivity on the space charge-mediated transition between classical, diffusion-limited current and over-limiting current in microchannel–nanochannel devices. The extended space charge layer develops at the depleted microchannel–nanochannel entrance when the limiting current is exceeded and is correlated with a distinctive maximum in the dc resistance. This maximum is shown to be affected by the microchannel depth, via field-focusing, and solution conductivity. In particular, we observe that upon their increase, the maximum becomes flatter and shifts to higher voltages.