scholarly journals Ion transport across solid-state ion channels perturbed by directed strain

Nanoscale ◽  
2020 ◽  
Vol 12 (18) ◽  
pp. 10328-10334 ◽  
Author(s):  
A. Smolyanitsky ◽  
A. Fang ◽  
A. F. Kazakov ◽  
E. Paulechka

Using computer simulations, we demonstrate ion permeation measurements across strained membranes that may potentially be used to obtain directional profiles of ion-pore energetics as contributed by the pore edge atoms.

The Analyst ◽  
2021 ◽  
Author(s):  
Yuan-Ju Tang ◽  
Shui Jie Zhang ◽  
Zi-Tao Zhong ◽  
Wenming Su ◽  
Yuan-Di Zhao

Solid-state nanochannels have attracted much attention for their similar ion transport properties to biological ion channels. The construction of porous ion channels with good stability at submicro/micrometer scale is very...


Author(s):  
Joseph S. Najem ◽  
Graham J. Taylor ◽  
Charles P. Collier ◽  
Stephen A. Sarles

Memristors are solid-state devices that exhibit voltage-controlled conductance. This tunable functionality enables the implementation of biologically-inspired synaptic functions in solid-state neuromorphic computing systems. However, while memristors are meant to emulate an intricate signal transduction process performed by soft biomolecular structures, they are commonly constructed from silicon- or polymer-based materials. As a result, the volatility, intricate design, and high-energy resistance switching in memristive devices, usually, leads to energy consumption in memristors that is several orders of magnitude higher than in natural synapses. Additionally, solid-state memristors fail to achieve the coupled dynamics and selectivity of synaptic ion exchange that are believed to be necessary for initiating both short- and long-term potentiation (STP and LTP) in neural synapses, as well as paired-pulse facilitation (PPF) in the presynaptic terminal. LTP is a phenomenon mostly responsible for driving synaptic learning and memory, features that enable signal transduction between neurons to be history-dependent and adaptable. In contrast, current memristive devices rely on engineered external programming parameters to imitate LTP. Because of these fundamental differences, we believe a biomolecular approach offers untapped potential for constructing synapse-like systems. Here, we report on a synthetic biomembrane system with biomolecule-regulated (alamethicin) variable ion conductance that emulates vital operational principals of biological synapse. The proposed system consists of a synthetic droplet interface bilayer (DIB) assembled at the conjoining interface of two monolayer-encased aqueous droplets in oil. The droplets contain voltage-activated alamethicin (Alm) peptides, capable of creating conductive pathways for ion transport through the impermeable lipid membrane. The insertion of the peptides and formation of transmembrane ion channels is achieved at externally applied potentials higher than ∼70 m V. Just like in biological synapses, where the incorporation of additional receptors is responsible for changing the synaptic weight (i.e. conductance), we demonstrate that the weight of our synaptic mimic may be changed by controlling the number of alamethicin ion channels created in a synthetic lipid membrane. More alamethicin peptides are incorporated by increasing the post-threshold external potential, thus leading to higher conductance levels for ion transport. The current-voltage responses of the alamethicin-based synapse also exhibit significant “pinched” hysteresis — a characteristic of memristors that is fundamental to mimicking synapse plasticity. We demonstrate the system’s capability of exhibiting STP/PPF behaviors in response to high-frequency 50 ms, 150 mV voltage pulses. We also present and discuss an analytical model for an alamethicin-based memristor, classifying that later as a “generic memristor”.


2021 ◽  
pp. 2003250
Author(s):  
Zhenjiang Yu ◽  
Xueyan Zhang ◽  
Chuankai Fu ◽  
Han Wang ◽  
Ming Chen ◽  
...  

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuaifeng Lou ◽  
Qianwen Liu ◽  
Fang Zhang ◽  
Qingsong Liu ◽  
Zhenjiang Yu ◽  
...  

Abstract Interfacial issues commonly exist in solid-state batteries, and the microstructural complexity combines with the chemical heterogeneity to govern the local interfacial chemistry. The conventional wisdom suggests that “point-to-point” ion diffusion at the interface determines the ion transport kinetics. Here, we show that solid-solid ion transport kinetics are not only impacted by the physical interfacial contact but are also closely associated with the interior local environments within polycrystalline particles. In spite of the initial discrete interfacial contact, solid-state batteries may still display homogeneous lithium-ion transportation owing to the chemical potential force to achieve an ionic-electronic equilibrium. Nevertheless, once the interior local environment within secondary particle is disrupted upon cycling, it triggers charge distribution from homogeneity to heterogeneity and leads to fast capacity fading. Our work highlights the importance of interior local environment within polycrystalline particles for electrochemical reactions in solid-state batteries and provides crucial insights into underlying mechanism in interfacial transport.


Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1012
Author(s):  
Takuya Mabuchi ◽  
Koki Nakajima ◽  
Takashi Tokumasu

Atomistic analysis of the ion transport in polymer electrolytes for all-solid-state Li-ion batteries was performed using molecular dynamics simulations to investigate the relationship between Li-ion transport and polymer morphology. Polyethylene oxide (PEO) and poly(diethylene oxide-alt-oxymethylene), P(2EO-MO), were used as the electrolyte materials, and the effects of salt concentrations and polymer types on the ion transport properties were explored. The size and number of LiTFSI clusters were found to increase with increasing salt concentrations, leading to a decrease in ion diffusivity at high salt concentrations. The Li-ion transport mechanisms were further analyzed by calculating the inter/intra-hopping rate and distance at various ion concentrations in PEO and P(2EO-MO) polymers. While the balance between the rate and distance of inter-hopping was comparable for both PEO and P(2EO-MO), the intra-hopping rate and distance were found to be higher in PEO than in P(2EO-MO), leading to a higher diffusivity in PEO. The results of this study provide insights into the correlation between the nanoscopic structures of ion solvation and the dynamics of Li-ion transport in polymer electrolytes.


Author(s):  
Shi Wang ◽  
Xiang-Chun Li ◽  
Tao Cheng ◽  
Yuan-Yuan Liu ◽  
Qiange Li ◽  
...  

Covalent organic frameworks (COFs) with well-tailored channels have the potential to efficiently transport ions yet remain to be explored. The ion transport capability is generally limited due to the lack...


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