Bioinspired Ion Doping for Threshold Control in Green Chitosan-Based Flexible Transistor Neuromorphic Devices

Area of Science:

• Materials Science
• Electronics Engineering
• Neuroscience

Background:

• Electrolyte-gated transistors (EGTs) offer low-voltage operation for flexible neuromorphic electronics.
• Precise threshold voltage control in EGTs is challenging due to electric double layer (EDL) dynamics.

Purpose of the Study:

• To develop a facile doping strategy for modulating the EDL in chitosan-based EGTs.
• To achieve continuous threshold voltage tuning and enhance device performance for neuromorphic applications.

Main Methods:

• Incorporation of sodium (Na+) cations via NaCl doping into chitosan-based EGTs.
• Modulation of the EDL by varying NaCl doping concentrations.
• Characterization of device performance, stability, and synaptic emulation capabilities.

Main Results:

• Continuous threshold voltage tuning achieved by controlling NaCl doping concentrations.
• A transition from depletion to enhancement mode observed at 0.5 wt% NaCl doping with significant reduction in drain current.
• Energy consumption for synaptic functions reduced by approximately 200 times.
• High on/off ratios (>10^3), operational stability (>100 days), and mechanical durability (>1000 bending cycles).

Conclusions:

• The Na+-doped EGTs provide a scalable, biocompatible, and energy-efficient platform for threshold-controllable green bioelectronics.
• The developed EGTs successfully emulate synaptic behaviors, enabling high-accuracy neuromorphic computing for image recognition (>95%).
• This work paves the way for next-generation flexible neuromorphic devices with enhanced control and efficiency.