
Ions in a multiphasic gel can exhibit complex cross-interface dynamics that can be used for neuromorphic processing.
Neuromorphic nanofluidics rely on nanoconfinement to regulate the ionic temporal dynamics. However, the inherent scales of the spatial interactions at nanoconfined interfaces limits the scalability and flexibility of such ionic neuromorphic devices. Here we report a multiphasic-gel-based ion transporter system with cascaded-heterointerfacial ion traps for soft-matter multistate ionic neuromorphic processing. The approach relies on interionic hierarchical cross-interface retardation and dissipation to induce heterointerface-trap dynamics. The resulting system offers ionic bipolar rectification with ratios exceeding 103 and spike-strength-dependent and timing-dependent dual-order plasticity. By integrating temporal short- and long-term memory effects, we show that the system can implement complex ion-based synaptic adaptability and learning rules, and offers multistate ionic neuromorphic processing with an energy consumption as low as 0.61 pJ per spike. We also develop a biohybrid neural circuit by interfacing an in vivo neuro-iontronic processor with the transected sciatic nerve of a rat, achieving bioneuron-driven ionic neuromorphic processing for interneural signal reconfiguration. A multiphasic-gel-based ion transporter system with cascaded-heterointerface ion traps can offer multistate ionic neuromorphic processing with energy consumption as low as 0.61 pJ per spike.