Two-dimensional clay channels for tunable nanofluidic memristor

Abstract Dynamic reconfiguration of charge carriers in confined ion channels under electrical stimulation produces memory effects, where the internal resistance depends on the history of the electric field. Vermiculite nanofluidic devices harness this effect to store and process information within a single component. We report switching between distinct memory loops by tuning ion transport pathways, governed by asymmetrical device architecture and intrinsic surface charge. Polarity-dependent memory switching between crossing-1 and crossing-2 loops is achieved solely by altering electrode configurations, without modifying electrolyte, channel surface chemistry or device structure, providing mechanistic insights into ionic memristors through a straightforward, experimental strategy. The memristive characteristics are demonstrated in both in-plane and out-of-plane channel configurations with channel lengths spanning from centimetres to micrometres using re-stacked vermiculite membranes and further investigated for miniaturization with devices of nanometre-scale channel lengths, fabricated via the ultramicrotomy method. Furthermore, we demonstrate neuromorphic functionalities, including synaptic potentiation-depression and programmable memory retention, highlighting potential for bio-inspired computing systems. Cost-effective and scalable fabrication of solution-processed vermiculite membrane memristors is attractive for sustainable integration of nanofluidic memristors for neuromorphic computing applications.