Polarizable Thiol-Ene Cross-Linked Nitrile Dielectrics for Stretchable Low-Voltage Neuromorphic Transistors with...

Area of Science:

• Materials Science
• Electronics Engineering
• Neuroscience

Background:

• Developing advanced dielectric materials is crucial for next-generation electronic devices, particularly for neuromorphic computing.
• Stretchable electronics require materials that maintain performance under mechanical strain.
• Synaptic transistors need materials with specific electrical properties to mimic biological synapses.

Purpose of the Study:

• To demonstrate a stretchable, high-k dielectric material based on thiol-ene-cross-linked nitrile-butadiene rubber (NBR) for synaptic transistors.
• To investigate the effect of different thiol cross-linkers on the dielectric properties and transistor performance.
• To evaluate the synaptic functions and neuromorphic capabilities of the developed NBR-based transistors.

Main Methods:

• Formulating and cross-linking nitrile-butadiene rubber (NBR) using three different thiol cross-linkers via thiol-ene chemistry.
• Fabricating and characterizing synaptic transistors using the thiol-ene-cross-linked NBR dielectrics.
• Evaluating transistor electrical properties (mobility, ON/OFF ratio, threshold voltage) and synaptic behaviors (short-term plasticity, long-term potentiation/depression).
• Testing device performance under mechanical strain (up to 60%) and for acoustic classification tasks.

Main Results:

• The thiol-ene-cross-linked NBR dielectrics achieved a high dielectric constant (k=14.6), enabling low-voltage operation (<5 V).
• Increased thiol groups enhanced charge mobility and hysteresis, with transistors exhibiting high mobility (0.42 cm^2 V^-1 s^-1), high ON/OFF ratio (10^4), and small threshold voltage (0.2 ± 0.4 V).
• The devices effectively mimicked synaptic functions, displaying robust short-term and long-term plasticity, and maintained performance under 60% strain.
• Acoustic classification accuracy close to 99% was achieved, even under mechanical deformation.

Conclusions:

• Thiol-ene-cross-linked NBR is a highly promising material for stretchable, low-voltage neuromorphic devices.
• The material's properties can be tuned by varying thiol cross-linkers, impacting charge mobility and hysteresis.
• The developed NBR-based synaptic transistors demonstrate significant potential for applications in flexible and wearable neuromorphic systems.