Transmembrane Potential across Single Conical Nanopores and Resulting Memristive and Memcapacitive Ion Transport

Memristive and memcapacitive behaviors are observed from ion transport through single conical nanopores in SiO2 substrate. In i-V measurements, current is found to depend on not just the applied bias potential but also previous conditions in the transport-limiting region inside the nanopore (history-dependent, or memory effect). At different scan rates, a constant cross-point potential separates normal and negative hysteresis loops at low and high conductivity states, respectively. Memory effects are attributed to the finite mobility of ions as they redistribute within the negatively charged nanopore under applied potentials. A quantative correlation between the cross-point potential and electrolyte concentration is established.