Ion current rectification in a fluidic bipolar nanochannel with smooth junction

We have simulated bipolar nanochannel based fluidic diode for different values of junction sharpness. We can obtain significant ion current rectification even for a smooth junction between oppositely charged zones. The rectification increases with junction sharpness due to increase in unipolar character of electrolyte but a sharp junction is not a necessary condition for rectification. The ion current rectification increases with surface charge density due to increase in unipolar character of electrolyte and decrease in reverse ion current. The fluid enters (exits) the nanochannel through the centre from (to) the opposite directions for reverse (forward) bias due to fluid pressure. (C) 2011 American Institute of Physics. [doi:10.1063/1.3627181]