Optoelectronic Control of PPy Nanoparticle-Engineered Ionogel Synapses for Multimodal Reservoir Computing

Abstract

Biomimetic ionic synapses capable of multimodal fusion are highly desirable for advanced neuromorphic technologies. Herein, we report a dual-mode nanoscale polypyrrole nanoparticle (PPy-NP)-engineered ionogel heterojunction synapse exhibiting bidirectional synaptic plasticity, enabled by the synergistic coupling between the photothermoelectric effect and field-induced ionic dissipation. The incorporation of 120 nm PPy nanoparticles creates nanoscale photothermal conversion domains and interfacial ionic regulation sites, enabling dynamic control of ionic migration and producing both excitatory and inhibitory synaptic responses within a single device. Leveraging this nanoscale-engineered ionic synapse, we constructed an optoelectronic reservoir computing system capable of multimodal signal fusion. The coupling of photonic and electrical inputs enhances the nonlinear projection within the reservoir, significantly improving classification accuracy to 99.3%. This work provides a bioinspired strategy for nanoscale soft ionic neuromorphic devices and advances the development of mixed-signal reservoir computing hardware.