Li-doping-modulated gelatin electrolyte for biodegradable electric-double-layer synaptic transistors

Recent advances in the fabrication of neuromorphic electronic devices using biomaterials have received increasing attention for their prospect in biologically compatible and “green” electronic devices. Here, we proposed a novel electric-double-layer (EDL) synaptic transistor gated with Li-doped natural gelatin membranes, demonstrating larger capacitance at low frequency and extremely strong electrostatic modulation behavior. Experimental results have shown that a concentration of 2 wt. % Li-doping can obtain better electrical performance of EDL synaptic transistor. Ion/Ioff of 4.86 × 105 and threshold voltage of 0.68 V were obtained. Meanwhile, some important synaptic functions such as excitatory postsynaptic current, paired-pulse facilitation, and high-pass filtering characteristic have been successfully implemented. As a result, it can be inferred that the proposed gelatin-based natural polymer EDL electrolyte has demonstrated potential applications in “green” neuromorphic platforms.