MXene-Based Antifreeze Inhibitory Artificial Synapses

Abstract

Artificial synaptic devices, which successfully mimic the excitation transmission between neurons, have rapidly developed in recent years. However, inhibitory artificial synapses require further research, especially in terms of their performance at low temperature. Herein, an antifreeze inhibitory artificial synapse based on lithium–poly(ethylene oxide), i.e., (Li–PEO)/Ti₃C₂ MXene, is proposed. The function of inhibitory biological synapses was simulated by using a combination of Ti₃C₂ MXene with a Li–PEO solid-state electrolyte layer. An inhibitory artificial synaptic device fabricated with a Cu/SiO₂/Li–PEO/Ti₃C₂MXene/Cu structure simulates the potential transmission function of inhibitory neural synapses and can generate an inhibitory postsynaptic potential. The Li⁺ ions provided by the PEO solid electrolyte layer migrate within the PEO and Ti₃C₂ MXene layers under an electric field and are eventually captured by Ti₃C₂ MXene. The captured ions no longer participate in potential transmission, causing a decrease in the postsynaptic membrane response as the number of free ions decreases. Importantly, the device demonstrates excellent antifreezing performance for practical applications, still maintaining about 80% of its performance at a low temperature of 220 K. This work offers insights into the MXene-based architecture design toward the development of inhibitory artificial synapses and high-performance artificial nervous systems for low-temperature operation.