Ultralow-power Flexible Transparent Carbon Nanotube Synaptic Transistors for Emotional Memory

Emulating biological behavior of the human brain with artificial neuromorphic device is essential for the future development of human-machine interactive system, bionic sensing system and intelligent robot. In this paper, the artificial flexible transparent carbon nanotube synaptic transistors (F-CNT-STs) with signal transmission and emotional learning function are realized by adopting the poly(vinyl alcohol) (PVA)/SiO2 proton-conducting electrolyte. Synaptic functions of the biological synapses including excitatory and inhibitory behavior are successfully emulated in the F-CNT-STs. Besides, synaptic plasticity such as spike-duration-dependent plasticity, spike-number-dependent plasticity, spike-amplitude-dependent plasticity, paired-pulse facilitation, short-term plasticity, and long-term plasticity have all been systematically characterized. Moreover, the F-CNT-STs also closely imitate the behavior of human brain learning and emotional memory functions. After 1000 bending cycles at the radius of 3 mm, both the transistor characteristics and the synaptic functions can still be implemented correctly, showing outstanding mechanical capability. The realized F-CNT-STs possess low operating voltage, quick response, and ultra-low power consumption, indicating their high potential to work in the low-power biological systems and artificial intelligence systems. The flexible artificial synapse transistor enables its potential to be generally applicable to various flexible wearable biological and intelligent applications.