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Background: Artificial synaptic behaviors are necessary to investigate and implement since they are considered to be a new computing mechanism for the analysis of complex brain information. However, flexible and transparent artificial synapse devices based on thin-film transistors (TFTs) still need further research. Purpose: To study the application of flexible and transparent thin-film transistors with nanometer thickness on artificial synapses. Materials and Methods: Here, we report the design and fabrication of flexible and transparent artificial synapse devices based on TFTs with polyethylene terephthalate (PET) as the flexible substrate, indium tin oxide (ITO) as the gate and a polyvinyl alcohol (PVA) grid insulating layer as the gate insulation layer at room temperature. Results: The charge and discharge of the carriers in the flexible and transparent thin-film transistors with nanometer thickness can be used for artificial synaptic behavior. Conclusion: In summary, flexible and transparent thin-film transistors with nanometer thickness can be used as pressure and temperature sensors. Besides, inherent charge transfer characteristics of indium gallium zinc oxide semiconductors have been employed to study the biological synapse-like behaviors, including synaptic plasticity, excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), and long-term memory (LTM). More precisely, the spike rate plasticity (SRDP), one representative synaptic plasticity, has been demonstrated. Such TFTs are interesting for building future neuromorphic systems and provide a possibility to act as fundamental blocks for neuromorphic system applications.

Background: As a key component in artificial intelligence computing, a transistor design is updated here as a potential alternative candidate for artificial synaptic behavior implementation. However, further updates are needed to better control artificial synaptic behavior. Here, an updated channel-electrode transistor design is proposed as an artificial synapse device; this structure is different from previously published designs by other groups. Methods: A semiconductor characterization system was used in order to simulate the artificial synaptic behavior and a scanning electron microscope was used to characterize the device structure. Results: It was found that the electrode added to the transistor channel had a strong impact on the representative transmission behavior of such artificial synaptic devices, such as excitatory postsynaptic current (EPSC) and the paired-pulse facilitation (PPF) index. Conclusion: These behaviors were tuned effectively and the impact of the channel electrode is explained by the combined effects of the joint channel electrode and conventional gate. The voltage dependence of such oxide devices suggests more capability to emulate various synaptic behaviors for numerous medical and non-medical applications. This is extremely helpful for future neuromorphic computational system implementation.

In-Ga-Zn-O (IGZO) nanometer thin-film transistors (TFTs) are promising candidates for liquid crystal display (LCD) drivers and human body sensors. It is critically important to study the temperature dependence of IGZO TFTs on electrical properties. However, the mechanism of the enhanced IGZO TFT function at different temperatures has not been fully determined. Here, a single transistor was used to act as a temperature sensor to save the space, and transfer curves shifting positively were found for the first time, different from conventional temperature-dependent behaviors. This behavior suggests at least two mechanisms that dominate and are responsible for the different shifts. According to the Arrhenius law, the formula between temperature (T) and threshold voltage (V TH ) was modified. Besides, two different values of activation energy (E a ) on different temperature ranges indicate that there are two main mechanisms. For further verification, different experimental approaches were conducted to study the temperature effects, including subgap density of states (DOS), X-ray photoelectron spectroscopy (XPS), and simulation experiments. This mechanism, shown here for the first time, might better the understanding of TFTs and, thus, further their applications in medicine and beyond.

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Uneven lithium (Li) electrodeposition hinders the wide application of high‐energy‐density Li metal batteries (LMBs). Current efforts mainly focus on the side‐reaction suppression between Li and electrolyte, neglecting the determinant factor of mass transport in affecting Li deposition. Herein, guided Li+ mass transport under the action of a local electric field near magnetic nanoparticles or structures at the Li metal interface, known as the magnetohydrodynamic (MHD) effect, are proposed to promote uniform Li deposition. The modified Li+ trajectories are revealed by COMSOL Multiphysics simulations, and verified by the compact and disc‐like Li depositions on a model Fe3O4 substrate. Furthermore, a patterned mesh with the magnetic Fe−Cr2O3 core‐shell skeleton is used as a facile and efficient protective structure for Li metal anodes, enabling Li metal batteries to achieve a Coulombic efficiency of 99.5 % over 300 cycles at a high cathode loading of 5.0 mAh cm−2. The Li protection strategy based on the MHD interface design might open a new opportunity to develop high‐energy‐density LMBs.

Figure 1 Thin-film transistor-based synapse device. (A) Three-dimensional structure of the single thin film transistor. (B) Cross-section structure of the single thin film transistor. (C) SEM top image of a single device and (D) Flexible transparent single device in an enlarged image.