Simulation of pulse responses of lithium salt‐doped poly ethyleneoxide

Abstract

Ionic migration in organic electrolytes resembles that in neural system involving signal transportation. Here, ionic dynamic simulations are applied to explore pulse responses of lithium‐doped polyethyleneoxide complexes. Two main interactions were considered: diffusion of ions and directional movement guided by an applied electric field. Frequency responses are simulated using arbitrary wave shape. It is found that redistribution of ions results in accumulation of charge and establishes a reverse inbuilt electric field controlling the discharging process and the frequency response. The charging current's wave shape is controlled mainly by contribution from the diffusion process, which strengthens the charging current in the first millisecond before weakening it. For stimulation with higher energy density (higher frequency), activation of ion channels should be considered and an active ion number is introduced to describe the process. The weights of calculated discharging current agree well with the experimental results. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 831–837

Sliding threshold of spike‐rate dependent plasticity of a semiconducting polymer/electrolyte cell

“…The latter then resulted in variation of the absolute values of synaptic weight and the threshold frequency of transition from depression to potentiation . Besides, we have demonstrated the ionic kinetic origin of the simple potentiation microscopically, and also suggested that the ionic migration during the period of an input pulse might contribute to the bidirectional signal transferring …”

“…We suppose that these modifications might be the physical mechanisms to select signal strength and routine adaptively under the multidomains system. We have adopted a microscopic model to well simulate pulse responses of Li‐PEO . The activation of more domains at HFS might involve in mechanical modifications of electrolyte molecules.…”

“…It has been reported that ion migrations in macromolecular systems take on the ability of signal generation, encoding, and information handling similar to that in a neural system . Spikes resembling action potentials can be generated by using polyelectrolyte membranes containing no lipids, followed by electrical injection .…”

“…Lipid membranes have been discussed as neuronal models for signal propagation in a long term . Recent year, we have mimicked several synaptic plasticity protocols using the responses to pulse stimulations of salt‐doped electrolyte/semiconducting polymer systems, which are very attractive because of plenty of artificial materials available in large scale.…”

Spatial summation of the short-term plasticity of a pair of organic heterogeneous junctions

“…Recent studies have found that ionic migrations in organic semiconductor and/or electrolyte heterogeneous junctions possess features in common with those in the macromolecules of biological neural networks, particularly in the aspect of responses to electrical stimulations. [1][2][3][4][5][6][7][8] Frequency selectivity was found in an organic semiconducting polymer/electrolyte heterojunction device, i.e., the semiconducting polymer/electrolyte device responded to low-frequency pulses in depression and to high-frequency pulses in potentiation. 9,10 A modulation of the semiconducting layer could realize long-term plasticity (memory) from short-term plasticity, 6,11 i.e., conventional spikerate-dependent plasticity (SRDP), a widely discussed learning protocol in neuroscience.…”