Ionic current transport and nanopores go hand in hand. Ionic current has been used to investigate properties of nanopores and vice versa for many years. Nanopores are simply
holes which contain dimensions on the nanoscale and ionic current is produced through
them by placing the pores in a solvent containing an electrolyte. Ionic transport is
investigated typically using current-voltage or current-time measurements. In this thesis
ionic transport is studied and manipulated through three separate projects. We begin using
cylindrical polymer pores ~700 nm in diameter and 11 μm in length to investigate the effect
of organic solvents on ionic transport and thus electrochemical properties of polymer/liquid
interfaces. Current-voltage measurements were taken in solutions with varying solvent type
and varying concentration of LiClO4. These measurements probed electroosmotic flow and
allowed us to deduce surface charge properties of the pores. It was found that the
carboxlyated surface of PET can flip charge polarity dependent on solvent type and
concentration of LiClO4. This work helped overall understanding of the origin of the effective xii
surface charge in organic solvents and its impact on ionic transport. Another method of ionic
transport manipulation which was investigated utilized an ionic bipolar junction transistor.
Nanopores in silicon nitride were sandwiched together with a thin film of Nafion which also
contained a gate electrode. Current-voltage measurements were taken across the device
while varying voltage at the gate. It was successfully demonstrated through this system that
an ionic transistor with fully ionic inputs and outputs can easily be rearranged into
amplifying units providing amplifications up to 300 times. Finally, this document goes on to
investigate interpore effects by using arrays of nanopores with a gate electrode placed near
one of the pores within the array. Ionic transport is investigated through modeling currentvoltage characteristics both with and without application of voltage at the gate electrode. In
this system complex interactions were revealed which allow for different pores to exhibit
different ionic transport properties though subject to the same bulk solution concentration
and voltage configuration. Findings from these projects could be useful in a variety of
applications including preparation of artificial biocircuits or spatially controllable drug
delivery devices.