忆阻器的温度效应改进模型及其仿生神经突触传递  

AN IMPROVED TEMPERATURE-BASED MEMRISTOR MODEL AND ITS BIONIC SYNAPTIC TRANSMISSION

作　　者：张蒙 成宇 张艺 朱庆花 韩芳[1] Zhang Meng;Cheng Yu;Zhang Yi;Zhu Qinghua;Han Fang(Donghua University,Academy of Information Science and Technology,Shanghai 201620,China;Donghua University,Academy of Materials Science and Engineering,Shanghai 201620,China)

机构地区：[1]东华大学信息科学与技术学院,上海201620 [2]东华大学材料科学与工程学院,上海201620

出　　处：《动力学与控制学报》2021年第6期67-75,共9页Journal of Dynamics and Control

基　　金：国家自然科学基金资助项目(11572084,11972115)。

摘　　要：突触传递是温度敏感的,由于缺乏温度依赖性的突触电导分析模型,无法在神经系统建模时包括温度效应.忆阻器因其阻值连续可变和纳米尺寸的优势,被广泛认为可以模拟生物突触.本文通过改进忆阻保留值和考虑温度对离子迁移和扩散的影响,提出一种新的氧化钨忆阻器模型,此模型更加符合忆阻器的实际行为特性.首先,改进的数学模型不仅具有原模型的功能,同时可以拟合忆阻器的实际遗忘规律.另外,将此忆阻器作为生物突触耦合两个相同的HH神经元,能够体现温度对突触传递的影响,即温度上升引起氧空位迁移和扩散速率发生变化,导致忆阻器电导变化速率加快,进一步影响兴奋性突触后膜电位幅值和放电次数,而相关仿真结果与神经生理实验现象相符.本文的工作表明,改进的氧化钨忆阻器模型更适合作为仿生突触应用到神经形态系统中,将为指导忆阻器的设计制造工艺以提高其仿生突触性能提供参考,也为研究温度对突触传递的影响提供了一种新思路.Synaptic transmission is temperature-sensitive.However,due to lack of a temperature-dependent synaptic conductance model,it is difficult to study the temperature effects when modeling nervous systems.The memristor is widely considered to be ideal bionic synapse due to its continuously variable resistance and nanometer size.This paper proposes a new tungsten oxide memristor model by improving the memristive retention value and taking into account the effect of temperature on ion migration and diffusion,which theoretically captures the actual behaviors of the memristor.In addition,this memristor is used as a bionic synapse to couple two identical HH neurons,and this system can reflect the influence of temperature on synaptic transmission.Simulation studies demonstrate that,as the temperature rises,the rate of oxygen vacancy migration and diffusion increases,and hence accelerates the memristor conductance change rate,and further affects the amplitude of excitatory postsynaptic membrane potential and the number of postsynaptic neural firings,all of which accords well with biological experimental findings.This paper shows that the improved tungsten oxide memristor model is more suitable for simulating neural synapse in neuromorphic systems,and hence could guide design and manufacturing of memristor to improve its bionic performance,and this model also provides a new idea for studying the effect of temperature on synaptic transmission.

关 键 词：忆阻器 神经突触 温度 离子迁移和扩散 

分 类 号：TN60[电子电信—电路与系统]