Liquid‐Metal‐Induced Memristor Behavior in Polymer Insulators

Abstract

Resistive switching devices are enabling neuromorphic functionalities, which are exceptionally appealing in electronic gates and memories as active components. Polymer materials have been proven to be promising for resistive memory devices due to low cost, easy processability, mechanical flexibility, and smooth electronic performance tuning through innovative molecular design. However, conventional rigid metals utilized for such devices are not easy to induce resistive memory behavior. In addition, only some specific materials as active layers have been used to date. Herein, it is demonstrated that liquid metals (LMs) can be destined for memristors with various insulators including poly dimethyl siloxane (PDMS), poly (vinylidene fluoride) (PVDF), and poly methyl methacrylate (PMMA). In contrast to other metals that show memristor behaviors only for specific active materials or device architectures, LMs are found to easily form switchable conductive filaments in all the organic materials. All devices show uniform and bipolar resistive memory behavior with a low switching voltage, high ON/OFF ratio, longer endurance, and retention characteristics, possessing capability for next‐generation wearable and soft brain‐like neuromorphic resistive memory devices.

Advancement in Soft Iontronic Resistive Memory Devices and Their Application for Neuromorphic Computing

“…The resistive memory devices based on aqueous electrolytes required improvement in terms of material handling, device scalability and stability, high R OFF /R ON ratio, and large-area integration in a crossbar array for the hardware implementation of the neural network. [75,107] In this review paper, we present a timely and comprehensive study of the liquid resistive memory devices using different soft electrodes materials, [79,91] aqueous electrolytes as modulators, [97,98] different ionic liquid materials as an active materials for resistive switching, [77,84,146] different devices structures, [84,90] and ionic mechanism study based on ion concentration polarization, [99,107,140,147] which results in filament formation during SET and deformation during RESET process and its potential application as a neuromorphic device to perform electronic synapses, [76,85,101] as shown in Figure 1. The liquid resistive memory devices open a gate to produce artificial brain-mimicking systems.…”

“…[ 90 ] Copyright 2011, John Wiley and Sons. d) ITO/insulator (PVDF‐TrFE)/EGaln device I–V characteristics with voltage sweep of ±2.5 V, [ 91 ] e) device endurance for more than 20 000 s, [ 91 ] and f) schematic representation of device conduction mechanism during SET and RESET process. Reproduced with permission.…”

Recent Advances in Deformable Circuit Components with Liquid Metal

“…Additionally, Zaheer et al. [ 145 ] proposed fabricating soft liquid metal electrodes on top of an organic insulating polymer to induce memristor behavior for resistive switching. The memristor devices were able to maintain electrical stability for at least 800 cycles and achieve a low switching voltage in the −2.5 to 2.5 V range, which were found to have longer retention times up to 2 × 10 4 s for both OFF, high resistance at negative voltage bias, and ON, low resistance, states with an ON/OFF current ratio of roughly 3.4.…”

All Solution-Processed Inorganic, Multilevel Memristors Utilizing Liquid Metals Electrodes Suitable for Analog Computing

“…Our recent work based on EGaIn liquid metal (LM) based memristors demonstrated memory behavior independent of intermediate insulator material type. However, the effects of individual components of LM in the switching behavior were not studied, nor was the behavior at elevated temperature and synaptic behavior . The study of such effects could possibly provide the key to realize the high performance of GLM memristor devices for use in a plethora of applications.…”

“…However, the effects of individual components of LM in the switching behavior were not studied, nor was the behavior at elevated temperature and synaptic behavior. 39 The study of such effects could possibly provide the key to realize the high performance of GLM memristor devices for use in a plethora of applications. Herein, we report on a solution-processed memristor based on inorganic materials—BiVO 4 and TiO 2 —loaded with LMs (EGaIn and GaInSn 68.5% gallium, 21.5% indium, and 10% tin) with a droplet as the top electrode.…”