Field-effect control of ion transport of power-law fluids in a pH-regulated nanochannel

Abstract

Precise control of ion transport of fluids in nanochannels is a key challenge. In this study, two control methods, field effect transistor (FET) and solution pH, were used to regulate the ion transport of power-law fluids in a nanochannel. The velocity field, potential distribution, and ion distribution were calculated by numerical simulation, and the effects of power-law index (n) and bulk pH (pH_b) on fluid flow and ion transport were investigated. The results show that FET and charge modulation can effectively manipulate the ion transport of the power-law fluids in the nanochannel. The power-law index and gate voltage have a greater effect on ion transport at high pH_b compared to low pH_b. At pH_b = 8 and V_g = 50 V, the average fluid velocity and ionic current of the power-law fluid with n = 0.8 are 10 times and 1.1 times that of the Newtonian fluid, respectively.