Detachable and Reusable: Reinforced π-Ion Film for Modular Synaptic Reservoir Computing

Abstract

Organic electrochemical transistors (OECTs) show significant promise for bioelectronics and neuromorphic computing applications due to their low operating voltage, biocompatibility, and ion-mediated charge transport. However, conventional OECTs with permanently fixed organic semiconductor (OSC) layers lack modularity and reusability for sustainable electronics with e-waste reduction. Here, a novel reinforced pi-ion film OECT featuring a detachable and reusable OSC layer that creates a unified composite with dielectric and gate components, establishing a new paradigm for modular device architectures is proposed. Through solvent exchange and mesh-supported gelation, pi-ion film exhibits enhanced mechanical stability, detachability, and superior electrical performance. The OECTs demonstrate remarkable 35-day air stability, 50-day storage lifetime, and over 80% performance retention after 600 electrical cycles. Furthermore, the pi-ion film OECTs exhibit synaptic behavior with paired-pulse facilitation of 167% and long-term memory retention of 34% maintained synaptic current after 250 s. These characteristics enable reservoir computing applications with a 4-bit encoding scheme for image recognition, processing 16 x 16 pixelated input patterns, demonstrating reliable state differentiation and stable signal retention. Even at lab-scale development, reinforced pi-ion film OECTs represent a promising eco-friendly platform for modular, reusable components in next-generation neuromorphic computing systems, aligning with electronic waste reduction policies by enabling component reuse.