Electrical Circuit Modelling of Nanofluidic Systems*

In this talk, we will address one of the central challenges faced by the nanofluidics community: scaling the electrical properties of a single nanochannel to that of a nanoporous membrane. We demonstrate that the electrical circuit of an array of nanochannels and microchannels is equivalent to a parallel circuit of mutually independent single-channel systems [1], comprised of three serially connected resistance contributions: the microchannel and nanochannel resistances and the field-focusing resistance. Field-focusing resistances are a generalization to the classical access resistance solution (limited to highly isolated circular pores) and hold for interacting pores of any geometry. Notably, the total resistance of the array is shown to scale inversely with the number of channels. Our approach provides an invaluable tool for analyzing and interpreting experimental measurements, characterizing surface charge properties of newly developed materials, and a method for the design and development of function-specific nanofluidic devices.

[1] Sebastian and Green, Electrical circuit modelling of nanofluidic systems, https://arxiv.org/abs/2205.09437