The memristive device is a fourth fundamental circuit element with inherent memory, nonlinearity, and passivity properties. Herein, we report on a cost-effective and rapidly produced ZnO thin film memristive device using the doctor blade method. The active layer of the developed device (ZnO) was composed of compact microrods. Furthermore, ZnO microrods were well spread horizontally and covered the entire surface of the fluorine-doped tin oxide substrate. X-ray diffraction (XRD) results confirmed that the synthesized ZnO was oriented along the c-axis and possessed a hexagonal crystal structure. The device showed bipolar resistive switching characteristics and required a very low resistive switching voltage (±0.8 V) for its operation. Two distinct and well-resolved resistance states with a remarkable 103 memory window were achieved at 0.2-V read voltage. The developed device switched successfully in consecutive 102 switching cycles and was stable over 102 seconds without any observable degradation in the resistive switching states. In addition to this, the charge–magnetic flux curve was observed to be a single-valued function at a higher magnitude of the flux and became double valued at a lower magnitude of the flux. The conduction mechanism of the ZnO thin film memristive device followed the space charge limited current, and resistive switching was due to the filamentary resistive switching effect.
Brain‐inspired computation is a promising field toward the next generation of intelligent computing systems. To mimic the brain functions, this field requires devices that can support the goal of computing efficiency, size, and cost. Therefore, researchers are trying to fabricate soft and flexible devices using synthetically organic and inorganic materials like solid‐state or ionic liquids. Herein, a soft and flexible bioinspired neuromorphic computing device based on organic silk fibroin gel, which is robust under external forces, is proposed. Silk fibroin protein is composed of essential and nonessential amino acids. with special amount of positively charged glycine, alanine, which plays an essential role during ionic movement to perform neuromorphic computing. Detailed electrical characterization of the proposed (Cu/silk fibroin gel/Cu) discrete device confirms the synaptic behavior by applying different pulse amplitudes, pulse widths, and frequencies. In addition, the proposed device delivers stable performance during mechanical deformations. The analysis of the present results defines that the proposed device is a potential candidate for environmentally friendly wearable intelligent electronics.
The aqueous electrolyte can be a deformable and stretchable liquid material for iontronic resistive memory devices. An aqueous medium makes a device closer to the brain‐like system with the movement of ions. This review paper proposes advances in liquid resistive memories and neuromorphic computing behavior to emulate electronic synapses. Primarily, the aqueous iontronic resistive memories can be used to study electrode and active layer materials and different device structures. Hence, herein, a timely and comprehensive study of these devices using ionic liquids, hydrogels, salt solutions, and soft electrodes to classify the device mechanism is presented. The filament formation is discussed in detail based on ion concentration polarization, electrode metallization, and movements of ions and charged molecules, which result in the formation of the metal dendrite. To manufacture a higher‐performance memory, device parameters should be optimized based on aqueous electrolytes, electrode materials, and other device design parameters. Aqueous electrolytes have smooth neurotransmission ability to fabricate brain‐inspired resistive memories with stable performance and device repeatability with smooth ion transmission. Aqueous electrode materials can be reliable for neural interface activities to compute electronic synapsis with electrical and chemical properties to ensure device reliability for a longer time period.
Many thin film-based devices with solid electrolytes have been studied for memristive applications. Herein, we report a simple and facile way to fabricate solution-based, low-cost, and discrete two-terminal memristive devices using the KMnO4 solution. The water and methanol were used as a solvent to prepare different concentrations of KMnO4 to carry out the optimization study. Furthermore, the effect of KMnO4 concentration with aqueous and methanol solvents was studied with the help of current-voltage, device charge, charge-flux, and cyclic endurance properties. Interestingly, all developed devices show the asymmetric time-domain charge and double valued charge-flux properties, suggesting that aqueous KMnO4 and methanol-KMnO4 based devices are non-ideal memristors or memristive devices. The statistical measures such as cumulative probability and coefficient of variation are reported for the memristive devices. The possible switching mechanism of the discrete memristive was tried to explain with the UV-visible spectrum and theoretical framework. The optimized device was further studied using the cyclic voltammogram, Bode plot, and Nyquist plot. An equivalent circuit was derived for the optimized discrete memristive device using electrochemical impendence spectroscopy results. The results of the present investigation are beneficial to develop programmable analog circuits, volatile memory, and synaptic devices using discrete memristive devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.