A Sub‐10 nm Vertical Organic/Inorganic Hybrid Transistor for Pain‐Perceptual and Sensitization‐Regulated Nociceptor Emulation

Abstract

Pain‐perceptual nociceptors (PPN) are essential sensory neurons that recognize harmful stimuli and can empower the human body to react appropriately and perceive precisely unusual or dangerous conditions in the real world. Furthermore, the sensitization‐regulated nociceptors (SRN) can greatly assist pain‐sensitive human to reduce pain sensation by normalizing hyperexcitable central neural activity. Therefore, the implementation of PPNs and SRNs in hardware using emerging nanoscale devices can greatly improve the efficiency of bionic medical machines by giving them different sensitivities to external stimuli according to different purposes. However, current most‐normal organic/oxide transistors face a great challenge due to channel scaling, especially in the sub‐10 nm channel technology. Here, a sub‐10 nm indium‐tin‐oxide transistor with an ultrashort vertical channel as low as ≈3 nm, using sodium alginate bio‐polymer electrolyte as gate dielectric, is demonstrated. This device can emulate important characteristics of PPN such as pain threshold, memory of prior injury, and pain sensitization/desensitization. Furthermore, the most intriguing character of SRN can be achieved by tuning the channel thickness. The proposed device can open new avenues for the fascinating applications of next‐generation neuromorphic brain‐like systems, such as bio‐inspired electronic skins and humanoid robots.

Ion‐Gated Transistor: An Enabler for Sensing and Computing Integration

“…IGTs based on electrostatic doping mechanism, that is, EDLTs, have been first used to emulate artificial synapses. [154][155][156][157][158] Based on a proton-conductor solid electrolyte and an indium zinc oxide channel, Zhu et al constructed a laterally coupled IGT with co-plane structure. [158] The volatility of EDLTs in the transistors is used to comprehensively emulate the short-term plasticity of synapses, including pair pulse facilitation, dynamic filtering, and spatiotemporal information processing.…”

“…[65,66] By using a comb-like source electrode and constructing the channel at its edge, Wan et al achieved sub-10 nm length channels. [155] Regardless of their forms, the purpose is to achieve larger on-state current and high switching frequency by shorting the channel length of IGTs. [66] When adopting vertical structures, the change in working mechanism may occur due to the significant reduction in device size, and some side effects such as short-channel effect found in vFETs may also appear in IGTs.…”

Defect Engineering in Ambipolar Layered Materials for Mode‐Regulable Nociceptor

“…In the W‐mode, three EPSC weights extracted from two consecutive laser stimuli show a declining trend as the time interval increasing from 0.05 to 4.8 s, indicating the relaxing behavior of biological systems. The spike‐rate dependent plasticity shows that the synaptic weight can be determined using the stimulus frequency, [ 58 ] and this can also be emulated vividly using the PdSe 2 device. All EPSCs were excited by each light‐spike train at different rates (Figure S12, Supporting Information).…”

Artificial nociceptor based on TiO2 nanosheet memristor

“…Besides achieving some basic synaptic plasticity, the devices exhibit nociceptorlike responses that depend on the intensity, duration, and frequency of the external stimuli [17]. In previous reports of memristor-based artificial nociceptors, verification was performed using a complex and cumbersome process [18]. Here, we verify the nociceptor behavior using a new and facile principle.…”