Fast nonlinear ion transport via field-induced hydrodynamic slip in sub-20-nm hydrophilic nanofluidic transistors

Abstract

Electrolyte transport through an array of 20 nm wide, 20 μm long SiO_2 nanofluidic transistors is described. At sufficiently low ionic strength, the Debye screening length exceeds the channel width, and ion transport is limited by the negatively charged channel surfaces. At source−drain biases >5 V, the current exhibits a sharp, nonlinear increase, with a 20−50-fold conductance enhancement. This behavior is attributed to a breakdown of the zero-slip condition. Implications for energy conversion devices are discussed.