Redox-Regulated Nonvolatility Switching in Single-Nanopipette Memory Diodes

Nanofluidic memory devices featuring brain-mimicking functions could mitigate von Neumann architecture limitations, but long-term memory and controllable volatility-nonvolatility state switching remain challenging to establish, which are foundational for higher-order complexity functions. By integrating the redox polymer PEDOT:PSS into single-nanopipette diodes with memristor properties, hysteretic ion transport is regulated by coupled electron transfers, which switch nanotip conductivity hundredfold. Oxidation and reduction of PEDOT lock in different nanotip conductivity states, accompanied by stochastic current spikes and switching behavior. Reversible volatile and nonvolatile rectified memory effects are controlled by low electric potentials: redox-regulated conductivity state changes drive long-term memory and potential sweeping or pulse trains stimulate short-term ionic memory effects. Integrating gate controls in three-terminal transistors into two-terminal memristor diodes constitutes a generalizable design principle for advancing iontronics and neuromorphic computing capabilities.