Flexible Carbon Nanotube Synaptic Transistor for Neurological Electronic Skin Applications

Abstract

There is an increasing interest in the development of memristive or artificial synaptic devices that emulate the neuronal activities for neuromorphic computing applications. While there have already been many reports on artificial synaptic transistors implemented on rigid substrates, the use of flexible devices could potentially enable an even broader range of applications. In this paper, we report artificial synaptic thinfilm transistors built on an ultrathin flexible substrate using high carrier mobility semiconducting single-wall carbon nanotubes. The synaptic characteristics of the flexible synaptic transistor including long-term/short-term plasticity, spikeamplitude-dependent plasticity, spike-width-dependent plasticity, paired-pulse facilitation, and spike-time-dependent plasticity have all been systematically characterized. Furthermore, we have demonstrated a flexible neurological electronic skin and its peripheral nerve with a flexible ferroelectret nanogenerator (FENG) serving as the sensory mechanoreceptor that generates action potentials to be processed and transmitted by the artificial synapse. In such neurological electronic skin, the flexible FENG sensor converts the tactile input (magnitude and frequency of force) into presynaptic action potential pulses, which are then passed to the gate of the synaptic transistor to induce change in its postsynaptic current, mimicking the modulation of synaptic weight in a biological synapse. Our neurological electronic skin closely imitates the behavior of actual human skin, and it allows for instantaneous detection of force stimuli and offers biological synapse-like behavior to relay the stimulus signals to the next stage. The flexible sensory skin could potentially be used to interface with skeletal muscle fibers for applications in neuroprosthetic devices.

<p>Flexible and Transparent Artificial Synapse Devices Based on Thin-Film Transistors with Nanometer Thickness</p>

“…4 In biological synapses, action potentials reach the pre-synapse, promote the release of the neurotransmitter, and cause excitatory postsynaptic potential (EPSP). 5 In the artificial synaptic device mentioned in the manuscript, a voltage is applied to the gate electrode to simulate the action potential, and the change of the channel current is to simulate the excitatory postsynaptic current. Therefore, the presynaptic stimulation is the pulse applied to the gate electrode.…”

High-performance hysteresis-free perovskite transistors through anion engineering

“…In addition to higher mobilities than those of I-pristine, I/Br, and I/Cl devices, the TFTs based on I/Br/Cl perovskite channels also exhibited signi cantly reduced, even negligible, current-voltage hysteresis. To quantitatively analyse the hysteresis for the I-pristine, I/Br, I/Cl, and I/Br/Cl TFTs, we calculated the difference in V GS (ΔV GS ) at |I DS |=10 −7 A, halfway between the on and off states 30 , and presented the data in Fig. 1c.…”

Advances in Triboelectric Nanogenerators for Self‐Powered Regenerative Medicine

“…[229,230] This characteristic opens up the possibility for artificial intelligence to imitate the human brain through an extensive artificial synapse devices with low power consumption. [231,232] Therefore, Liu et al [229] fabricated a self-powered artificial synapse system with usage of an electric double-layer transistor and a TENG that was constructed via spin-coating PDMS on a PET/Cu layer, and the use of an Ion-gel on a Si wafer layer followed by deposition of the PDVT-10 (Figure 9D). Touching the TENG (as a presynapsis spike) resulted in the excitatory postsynaptic current (EPSC) generation via a transistor, and simultaneously depicted tactile synapse functionality of the self-powered system.…”