Synaptic Emulation with Chitosan‐Gated Organic Electrochemical Transistors

The human brain performs remarkable feats of computation with minimal energy, an efficiency that modern artificial intelligence struggles to replicate using conventional, power-hungry hardware. This work explores a sustainable path toward brain-inspired computing by combining organic electrochemical transistors (OECTs) for synaptic emulation with a novel electrolyte derived from chitosan, an abundant and biodegradable biopolymer sourced from seafood waste. We first established a performance benchmark by rigorously characterizing OECTs, demonstrating their ability to replicate key synaptic functions like paired-pulse facilitation and extracting the fundamental ionic and electronic time constants that govern short-term plasticity. In parallel, we engineered and evaluated multiple chitosan formulations, culminating in an optimized eutectic gel that achieved a notable ionic conductivity of 3 mS/cm. Critically, this sustainable electrolyte successfully enabled fundamental synaptic learning rules in functional OECT devices. This work demonstrates that high-performance neuromorphic hardware need not rely on synthetic materials, effectively bridging the gap between computational efficiency and ecological responsibility for a new generation of green and bio-integrated electronics.